FSC 102 SILVICULTURAL PRACTICES AND SYSTEMS (2+1)

Theory

Forest regeneration – Natural regeneration under different silvicultural systems –

Regeneration survey – Artificial regeneration – Selection of site – Choice of species –
Kinds of sowing – Taungya – Pure and mixed crops – Works to be done in the tree
planting area – Season, methods and pattern of planting – Tending operations –
Thinning – Types and methods of thinning – Silvicultural systems – Classification – The
clean strip system – Shelterwood system – The group system – The selection system
and group selection system – Accessory systems – Coppice systems – Pollard system –
Conversions – Choice of silvicultural systems.

Practical

Regeneration survey – Estimation of plant per cent – Demonstration of different

mixtures – Different kind of sowing – Spacing of different tree species – Design for
different kinds of fence – Demonstration of different kinds of pits and trenches –
Demonstration of planting techniques and estimation of planting material –
Demonstration of pruning – Application of formulae used in mechanical thinning –
Demonstration of ordinary thinning, crown thinning and tending operation –
Demonstration of clear felling system – Selection system – Shelterwood systems and
coppice systems.

Lecture Schedule

1. Methods of regeneration - natural regeneration - factors governing natural

regeneration from seed.
2. Natural regeneration under clearfelling, shelterwood and selection systems
3. Techniques of obtaining natural regeneration of important species in various
types of forests
4. Natural regeneration from vegetative parts - Natural regeneration by coppice -
Factors affecting natural regeneration by coppice - Tending of stool coppice -
Natural regeneration by coppice under various silvicultural systems.
5. Natural regeneration by root suckers - other operations to promote vegetative
growth.
6. Cultural operations - Natural regeneration supplemented by artificial
regeneration
7. Artificial regeneration - definition and objectives - objects of reforestation -
choice between artificial and natural regeneration.
8. Essential preliminary consideration in reforestation - choice of species -
mixtures - merits and demerits.
9. Selection of site - choice of method of artificial regeneration
10. Arrangements of staff and labour for tree cultivation - Taungya cultivation -
Taungya types - Advantages and disadvantages of Taungya.
11. Pure and mixed crops - Nurse crops and cover crops - Fast and slow growing
species - W o r k s to be done before tree planting - indent of planting
material - estimation of quantity of seeds
12. Seed sources – quality seed and nursery stock production technology in brief.
13. Works to be done in the tree planting area - boundary demarcation - soil and
tree planting area map - Inspection path preparation - fencing - staking out
14. Season of planting - methods of planting - patterns of planting
15. Tending operations - difference between tending and cultural operations
Weeding - cleaning - pruning - climber cutting
16. Thinning - objectives - standard tree classification - Kinds of thinning -
mechanical thinning - ordinary thinning- Crown thinning - free thinning and
Advance thinning
17. Mid-semester examination
18. Factors affecting thinning practice - thinning cycle, intensity and regime -
Thinning in mixed plantation and coppice crops - thinning in irregular crops -
Selection thinning - improvement felling - girdling – pollarding.
19. Silvicultural systems - Introduction - s c o p e - c l assification - need for
classification - need for standardization of names
20. The clear felling system - definition - pattern of felling - method of obtaining
regeneration - method of artificial regeneration - methods of natural
regeneration - tending - character of crop produced - a d v a n t a g e s -
disadvantages – application - examples
21. The clear strip and Alternate strip systems
22. General description of shelterwood systems - The uniform system - definition -
kinds and pattern of felling - method of regeneration - character of the crop
produced - regeneration period and periodic blocks - fixed or permanent,
floating periodic blocks - advantages - disadvantages - application - examples.
23. The Group system - definition - pattern of felling - method of regeneration –
character of the crop produced - advantages - disadvantages - application
24. The shelter wood strip system and Wagner's Blender Saumschlag - The Strip
and Group system and the wedge system
25. The irregular shelter wood system - definition - difference with Bavarian
femelschlag and difference with selection system
26. The Indian Irregular shelter wood system - definition - pattern of felling -
character of the crop produced – application
27. The selection system - definition - pattern of felling - conduct of felling - mode
of regeneration - tending - character of the crop produced
28. The Group selection system - definition - advantages of selection system -
disadvantages - controversy - conditions of application - e x a m ples -
modifications in application
29. Accessory systems - Two storied high forest system- high forest with reserves
systems - Improvement fellings
30. The coppice systems - general description - The simple coppice system -
definition - pattern - s e ason - method of felling - mode of regeneration -
tending - character of the crop produced - advantages - disadvantages -
conditions for applicability – examples - The coppice of two rotations system
and the shelter wood coppice system.
31. The coppice with standards system - definition - difference with coppice of two
rotations system - difference with shelter wood coppice system - pattern of
felling - mode of regeneration – tending – character of crop produced –
advantages –disadvantages – conditions of applicability – examples.
32. The coppice with reserves system - history - definition - pattern of felling -
mode of regeneration - tending - character of the crop produced - difference
with C.W.S System - advantages – disadvantages- conditions of applicability -
examples
33. The coppice selection system and the pollard system - definition - pattern of
felling - method of regeneration - character of the crop produced - application
34. Conversions- definition - objectives - change in crop composition - change in
silvicultural system - techniques - speed of conversion – examples - Choice of
silvicultural system.

Practical Schedule

1. Exercise in regeneration survey and construction of regeneration stock map

2. Techniques of obtaining natural regeneration
3. Estimation of plant per cent
4. Demonstration of different mixtures – estimation of line and block mixtures.
5. Demonstrations of different kinds of sowing
6. Estimation of seed and planting material for teak, Acacia's, tamarind, neem
7. Design for different kinds of fence - cattle proof, game proof and special fences
8. Demonstration of different kinds of pits
9. Demonstration of different kinds of trenches - trenches with vertical sides -
Trench with slanting sides, double trench and trench ridges
10. Exercise in line, square, triangular and quincunx plantings and Estimation of
planting material per unit area under different methods of planting
11. Standard tree classification adopted in Indian Forestry. Demonstration of
pruning in trees
12. Application of formulae used in mechanical thinning.
13. Demonstration of different grades of ordinary thinning and crown thinning –
calculation of stand density index
14. Demonstration of tending operations-Weeding, Cleaning, Climber cutting
15. Demonstration of clear felling systems- Selection system.
16. Demonstration of shelterwood systems and coppice systems
17. Final Practical examination

Assignment

1) Natural regeneration in trees

2) Estimating stocking for different tree species
3) Planting stocks used in different tree species in India
4) Impact of thinning and pruning on timber quality
5) Study of silvicultural systems adopted for different tree species in India

Reference Books

Champion and Seth, 1968. General Silviculture of India. Government of India

Publication.
Champman, G.W. and Allan, T.G. 1978. Establishment Techniques for Forest Plantation
F.A.O Forestry Paper No.8. F.A.O Rome
Champion .H.G.,and Trevor.G. 1987 .Hand book of Silviculture.Ranikapur Cosmo
Publication .New Delhi.2. p.505.
David.M.Smith 1989. The Practice of Silviculture.EBD Educational Pvt.Ltd.Dehra
Dun.P.526
Dwivedi, A. P. 1992. Principles and Practice of Indian Silviculture, Surya Publication,
420p.
Dwivedi, A.P. 1993.A Text Book of Silviculture,International Book Distributers,Dehradun
Khanna, L. S. 1984. Principles and Practice of Silviculture ,Khanna Bhandu, Dehra Dun.
P. 476.
Luna, R. K. 1989. Plantation forestry in India, International Book distributors, Dehra
Dun. P. 476.
Luna, R. K. 1989. Plantation forestry in India, International Book distributors, Dehra
Dun. P. 476.
Ram Prakash and L.S. Khanna. 1991. Theory and Practice of Silvicultural systems.
International Book Distributors, Dehra dun. 298p.
Ralph D. Nyland. 1996. Silviculture concepts and applications. Mcgraw-Hill, New York,
P.633
 FSC 102 SILVICULTURAL PRACTICES AND SYSTEMS (2+1)

NATURAL REGENERATION

The trees and forest crops depreciate in value and die with age. But the forester
does not want the tree crops to grow to a size that their value may depreciate. He
therefore utilizes the trees when they have gained maximum value. Having utilized the
trees when they have gained maximum value. Having utilized the trees it is his duly to
see that the crop is regenerated with trees of the desired and economically valuable
species so that he gets maximum return on a sustained basis in perpetuity. As already
stated, to regenerate means to renew a forest crop by natural or artificial means. Thus,
regeneration is defined as the renewal of a forest crop by natural or artificial means. It
also refers to the crop so obtained. Reproduction is a synonym for regeneration but it is
more usually applied to a forest crop obtained by natural method, viz., self sown seed,
coppice or root suckers, etc.

Methods of Regeneration
From the above definition, it is apparent that there are two main methods of
regenerating forest crops but in practice, a combination of the two methods is also
sometimes adopted. Thus, the methods of regeneration of forest crops are
i) Natural regeneration
ii) Artificial regeneration and
iii) Natural regeneration supplemented by artificial regeneration

Natural Regeneration
Natural regeneration is defined as ‘the renewal of a forest crop by self-sown seed
or by coppice or root suckers. It also refers to the crop so obtained. Thus, the natural
regeneration may be obtained from the following two main sources:
i) From seed and
ii) From vegetative parts
When regeneration obtained from seed forms a crop, it is called a seedling crop
which is defined as ‘a crop consisting of seedlings neither planted nor of coppice or root
sucker origin but originating in situ from natural regeneration’. When this seedling crop
grows into a forest, it is called a high forest. When regeneration obtained by coppice
forms a crop, it is called coppice crop and when it develops into a forest, it is called
coppice forest to differentiate it from the high forest. Root suckers are, however, not
used for large scale regeneration operation.

Natural Regeneration from Seed

Natural regeneration from seed depends upon
1) Seed production 2) Seed dispersal
3) Germination and 4) Establishment

1) Seed Production
The most important prerequisite of natural regeneration from seed is the
production of adequate quantities of fertile seed by the trees of the area or immediate
neighbourhood. The production of seed depends upon species, age of trees, size of
crown, climate and other external factors. All species do not seed annually and
abundantly. For instance, while teak, babul, khair, shisham seed every year, deodar, fir,
spruce seed at an interval of years. The quantity of seed produced by annual seeders
also varies within wide limits and so seed years are described as good, moderate or poor
depending on whether the quantity of seed produced is abundant, moderate or less.
Interval between moderate and good seed years of a few important species is given
below
Interval in years between
Species
Moderate seed years Good seed years
Shorea robusta 2 3–5
Terminalis tomentosa 2 3–4
Pinus wallichiana 2 2–3
Pinus roxburghii 3 4–5
Cupressus torulosa 3 7–8
Cedrus deodara 3 4–5
Picea smithiana 3 5–6
Abies pindrow 6 10

The age of trees also affects the production of adequate quantities of fertile
seed. The seeds produced by immature trees as well as over mature trees are,
sometimes, infertile. Abundant quantities of fertile seeds are produced by the trees
after the height growth has culminated because during the period of height growth,
carbohydrate produced is utilized in it. Thus, abundant quantities of fertile seeds are
produced from middle-aged trees.
The size of the crown of trees also affects seed production. As a general rule,
the bigger the crown, the larger the production of seed. Therefore, while selecting seed
bearers for natural regeneration, middle-aged mature trees with well developed crowns
should be selected.
Climate also affects the seed production. As a general rule, warmer climate
favours larger seed production. Therefore, in the hills the trees growing towards the
lower limit of the altitudinal zone of their species produce more seeds than those
growing towards the upper limit. Hot dry years are generally followed by heavy seed
years on account of increase in photosynthesis. Heavy rain storms at the time of pollen
dissemination reduce chances of good seed production. Similarly, late frost adversely
followed affects seeding.
The other external factors which affect seed production are fire injury, insect
attack and girdling. Injury by fire and insect attack stimulate seed production.
Similarly, girdling is by heavy seeding.

2) Seed Dispersal
The seed produced by the trees is dispersed by the agency of wind, water,
gravity, birds and animals. Some examples of seed dispersal by various agencies are
given below:
By wind – Conifers, Acer, Betula, Rhododendron, Populus, Alnus, Salix, most
Dipterocarps, Terminalias, Dalbergia, Acacia catechu, Adina, Bombax, Holoptelia, most
Apocynacea a n d Asclepiadaceae, Casuarina, Cedrela, Chloroxylon, Pterocarpus
marsupium, etc.
By water – Trewia, most mangrove species, Dalbergia, teak, etc.
By gravity – Oaks, Juglans regia, Aesculus, etc.
By birds – Prunus, Mulberry, Broussonetia, Trema, Diospyros melanoxylon, etc.
By animals – Acacia Arabica, Prosopis juliflora, Ziziphus, Anthocephalus, etc.
As the seeds of all confiers in hills are dispersed by wind, special care has to be
taken to see that the seed bearers are retained on ridges and on the upper portion of
hill slopes so that they can cover maximum area.
3) Germination
After dispersal, a lot of seed is destroyed by insects, birds and rodents. The
others germinate provided they are deposited on suitable soil. Germination of seed
depends upon:
a) Internal factors b) External factors
a) Internal factors – The internal factors are the factors pertaining to the seed
itself. The following internal factors affect germination:
i) Permeability to water – Moisture is very essential for germination; if the
seed has a hard coat, it prevents moisture reaching the seed embryo and therefore
prevents germination. Such seeds germinate only when the hard coat weathers due to
exposure to sun and rain or when it has been partially eaten up by insects.
ii) Permeability to oxygen – Oxygen is necessary for germination. Factors
which inhibit moisture reaching the seed, also prevent oxygen reaching it.
iii) Development of embryo – The embryo should be fully developed at the
time of seedfall. If it is not developed, the seed lies dormant, till it is fully developed. A
typical example of this is seen in Fraxinus floribunda in which the seeds lie dormant on
the ground for the whole year.
iv) After ripening – Even if the embryo is fully developed, seeds, sometimes,
do not germinate because the embryo is not chemically ready for germination. Such
seeds germinate only when they have undergone a process of after-ripening. Delayed
germination of Juniperus macropoda is due to after-ripening.
v) Viability – Viability is defined as the potential capacity of a seed to
germinate. Some seeds lose their viability soon while others retain their viability for a
year or more. Thus, in case of seeds which lose their viability soon, if the environmental
conditions are not favourable for germination at the time of their fall, they die. For
example, under natural conditions sal seeds remain viable for about a week. If
monsoon is delayed, most of the seeds that fall on dry ground, die.
Conifers – Abies pindrow (17 seed/gm), Cedrus deodara (9 seeds/gm),
Cupressus torulosa (240 seeds/gm), Picea smithiana (63 seeds/gm), Pinus roxburghii (9
seeds/gm), Pinus wallichiana (16 seeds/gm).
Broad-leaved – Acacia arabica (8 seeds/gm), Acacia catechu (39 seeds/gm),
Acrocarpus fraxinifolius (32 seeds/gm), Adina cordifolia (11288 seeds/gm), Aesculus
indica (40 seeds/kg), Ailanthus excelsa (9.5 seeds/gm), Ailanthus grandis (1235
seeds/kg), Albizzia lebbek (7400 seeds/kg), Albizzia procera (23 seeds/gm), Bischofia
javanica (92 seeds/gm), Bombax ceiba (26 seeds/gm), Casuarina equisetifolia (758
seeds/gm), Dalbergia sissoo (53 seeds/gm), Dendrocalamus strictus ( 3 0 seeds/gm),
Eucalyptus hybrid (2700 seeds/gm), Fraxinus micrantha (7 seeds/gm), Gmelina arborea
(1764 seeds/kg), Hymenodictyon excelsum (170 seeds/gm), Juglans regia ( 1 1 0
seeds/kg), Kydia calycina (32 seeds/gm), Morus alba (455 seeds/gm), Pterocarpus
marsupium (1623 seeds/kg), Quercus incana (529 seeds/gm), Quercus semecarpifolia
(140 seeds/kg), Shorea robusta (529 seeds/kg), Tectona grandis (1760 fruits/kg),
Terminalia tomentosa (529 seeds/kg), Toona ciliata (247 seeds/gm).
The size of the seeds varies not only from tree to tree in the same species but
also on the same tree. Some seeds are thin and poorly developed while others are
thick. As a general rule, within the average size of the seed produced by the species,
the thicker the seed, the better the germination.
(vii) Germinative capacity and germinative energy-All the seeds that fall to
the ground do not germinate. As the percentage of seeds that germinate, affects
natural regeneration, it is important to know the germinative capacity and germinative
energy of the seeds of the species. Germinative capacity is defined as ‘the percentage,
by number, of seeds in a given sample that actually germinate, irrespective of time’.
This is the commonly accepted definition though some workers have defined it
differently as given in the footnote 1. Germinative energy is defined as ‘the percentage,
by number, of seeds in a given sample that have germinated upto the time when the
rate of germination (number of seeds germinating per day) reaches its peak (Holmes)’.
Some workers like to specify the period in which this it to be calculated as will be seen
by the definition given in footnote 2. The germinative capacity of some of the species is
given below:

Germinative Species
capacity
1-5 Alnus nitida, Anogeisssus latifolia;
5-10 Buxus wallichiana, Grewia tiliaefolia;
10-20 Abiespindrow, Anthocephalus cadamba, Kydia calycina;
20-30 Boswellia serrata, Cassia fistula, Duabanga sonneratiodes, Picea
smithiana;
 30-50 Bombax ceiba, Tectona grandis, Cupressus torulosa’
50-70 Acacia Arabica, Betula alnodies, Dendrocalamus strictus, Terminalia
tomentosa, Toona ciliate, Melia azedarach, Pinus wallichiana,
Cedrus deodara;
70-90 Acer campbellii, Butea monosperma, Ougeinia oojeinensis, Pinus
roxburghii, Acacia catechu, Albizzia procera, Juglans regia, Shorea
robusta;
90-100 Albizzia lebbek, Anacardium occidentale, rtocarpus chaplasha,
Bauhinia variegate, Cassia siamea, Dalbergia sissoo.

1. Germinative capacity – (a) The percentage, by number, of seeds in a given sample

that actually germinate within twice the energy period (Baldwin). (b) The total
number of seeds that germinate in a germinator, plus the number of sound seeds
remaining at the end of the test, expressed as a percentage of the total sample
(Holmes).
2. Germinative energy-The percentage, by number, of seeds germinating within a given
period, e.g., seven or fourteen days, under optimum conditions (Baldwin modif).
(viii) Plant percent - All the seedlings resulting from the germination of seeds
do not survive long as many of them succumb to the adverse environmental factors.
Therefore, the number of plants that survive till the end of the growing season is an
important factor affecting natural regeneration. This information is given by the term
plant percent which is defined as ‘percentage of the number of the seeds in a
sample that develop into seedlings at the end of the first growing season’.
The following table shows the germinative capacity and plant percentage of a few
species to give an idea of their relationship:
Species Germinative capacity Plant percent
Acacia Arabica 50 26
Shoea robusta 80 66
Tectona grandis 50 25
Terminalia tomentosa 70 29
Gmelina arborea 85 30
Dalbergia sissoo 90 78
Pinus roxburghii 80 37
Pinus wallichinana 66 63
Cedrus deodara 65 58
Abies pindrow 13 6

(b) External factors – External factors are the factors of environment which
affect germination. These are:
(i) Moisture – An adequate quantity of moisture is very essential for
germination. Moisture activates the dormant embryo and by softening the seed coat
helps it to come out. Moisture is also necessary for dissolving the food material
collected in the cotyledons and for translocating it in solution to the radicle and the
plumule. Diffusion of oxygen for respiration also takes place in aqueous solution.
(ii) Air – The germinating seeds require oxygen and this is supplied by air.
Seeds buried in the deeper layers of the soil often remain dormant for want of oxygen.
In the germinating seed, respiration is very rapid and therefore, a constant supply of
oxygen is very essential.
(iii) Temperature – Temperature is essential for germination but range of
temperature within which seeds of various species germinate varies with species.
Within this range, the higher the temperature the better the germination.
(iv) Light – Most species are indifferent to light conditions for their germination
but some, e.g., Cassia fistula, Albizzia procera, require light.
(v) Seed bed – It is necessary that the seed should be deposited on proper
seed bed for germination. If the seed falls on sheet rock, boulder deposit, a thick layer
of dry leaves or a dense ground cover, it will not germinate or even if it germinates, as
often happens in the case of seeds deposited on thatched roofs, it does not survive. A
light burning or shrub cutting is sometimes useful to provide a good seed bed in cases
where thick layer of dry leaves and/or dense ground cover are the inhibiting factors.
Even on a suitable seed bed, the depth of covering has a great influence on natural
regeneration. While the seeds buried very deep in the soil, do not germinate for want of
oxygen, and even if germinate, are not able to push the plumules through the soil, the
seeds which are not properly covered do not germinate and this is so mostly with thick
or large seeds like acorns. Seeds which are covered with soil equal to about half their
diameter germinate best, provided other factors are favourable.
 Seedling year – Seedling year is defined as a year ‘in which a given
species produces abundant first year seedlings.’ It is ‘also used to designate
a year, in terms of the amount of natural seedling regeneraton produced by a
particular species, as good, fair, poor or very poor.’
As the is usually a considerable seedling mortality as a result of adverse climatic
and soil factors as well as weed growth, a good seed year is not necessarily a good
seedling year and therefore it is necessary to differentiate between the two. A good
seedling year requires a rare coincidence of good flowering, good seeding, favourable
climatic and edaphic factors and absence of adverse weed competition.
(4) Seedling establishment – Even if the germination is good it does not
mean that the natural regeneration would be good because a large number of seedlings
die at the end of rains or as a result of frost during winter or drought during summer.
In addition, there may be other factors such as weeds, grazing, burning, which may kill
them. These adverse factors pose a threat to seedlings not only in the first year but
also for several years depending upon their rate of growth. Thus, good natural
regeneration can be achieved only when the seedlings are established. Establishment
is defined as the ‘development of a new crop, naturally or assisted, to a stage
when the young regeneration, natural or artificial, is considered safe from
normal adverse influences such as frost, drought or weeds and no longer
needs special protection or tending operations other than cleaning, thinning
and pruning.’ The following factors affect establishment of seedlings:
(i) Development of roots – For some time after germination, the seedlings
depend upon the food reserves of the cotyledons but soon they have to depend on their
own resources. For this, it is essential that the seedling may develop a long tap root
soon so that it reaches a depth where there is permanent moisture in the soil. If the
development of roots does not reach that depth in the first growing season, the seedling
may be killed by drought after the rains or in the summer season. Thus, in the species
in which the development of root is fast, the seedling mortality is less.
(ii) Soil Conditions – As the tiny seedling has to depend upon the soil for its
food, moisture and air, its establishment depends upon favourable soil conditions. The
soil should have adequate moisture. Excess of moisture or its deficiency are both
injurious for plant growth. Deficiency of nutrients has adverse effect on the
development of seedlings. The presence of a thick layer of undecomposed organic
matter inhibits establishment because while, on the one hand, its presence is an
indication of deficiency of nutrients in the soil, on the other hand, it presents physical
obstruction to the roots in reaching the mineral soil. The seedlings whose roots do not
reach the mineral soil and remain only in the undecomposed organic matter, die after
the rains due to moisture deficiency. Soil aeration also plays an important role in
seedling establishment. Soil aeration affects seedling establishment in two ways, viz.,
(i) due to deficiency of air as a result of water-logging as is seen in case of teak whose
seedlings die as a result of poor aeration resulting from waterlogging, and (ii) as a result
of imbalance in the constituents of the soil air as is seen in case of sal whose seedlings
start dying as soon as carbon dioxide/oxygen ratio reaches 2.8.
(iii) Light - Light is a very important factor in seedling establishment but its
requirement varies from species to species and even in the same species according to
climatic conditions and age. For example, in moister localities teak seedlings must have
sufficient light from the very beginning but in dry hot localitites, a sudden influx of light
on young seedlings may cause their death. In fact, in such localities, teak seedlings, in
their infancy, actually require protection against sun. The requirement of light increases
with age. The younger seedlings require comparatively lesser light b ut as they grow in
age, the require more light.
(iv) Other climatic factors - Extremely high or extremely low temperature are
both harmful for seedling establishment. In extremely high temperature, seedlings are
killed due to insolation while in extremely low temperature they are killed by frost. For
seedling establishment, only adequate rainfall is not essential but its proper seasonal
distribution is also essential. Otherwise, the long dry season after the monsoonic rains,
kills most of the seedlings.
(v) Condition of grass, and other competing weed growth-The effect of
grass and other competing weed growth depends upon the nature of weed growth and
the climatic conditions. The competing weed growth may be grass alone, a mixture of
grass and shrubs or shrubs alone. The density of the weed growth has a great influence
on establishment. A dense growth of grass is very harmful particularly when it forms
dense mat-like roots and causes water logging. For instance, very few species,
including teak can survive in the dense growth of Imperata. Similarly, dense growth of
shrubs, particularly low shrubs, is very harmful as they cut off light. For example, dense
g r o w t h o f Strobilanthes a n d Petalidium is very harmful for teak regeneration,
Clerodendron for sal regeneration and Parrotia for deodar regeneration. A light growth
of grass and shrubs generally present good conditions for seedling establishment. In
the dry and arid areas, a certain amount of weed growth is helpful in conserving
moisture and affording a certain amount of shade to the seedlings but in moister
localities, weeds, particularly dense weeds, are very harmful. The effect of grasses,
shrubs and other weed growth on seedling establishment also varies with their species.
While some species of grasses and shrubs are not harmful, others are. Thus, the
species of grasses, shrubs, etc., indicate conditions favourable and unfavourable for
natural regeneration of a particular tree species. For example, while Viola canescens is
an indicator for favourable conditions for natural regeneration of deodar and kail,
Impatiens, Strobilanthes, Spirea sorbifolia, Dipsacus, Parrotia (inKashmir) are indicators
of unfavourable conditions. Similarly, while Flemingia spp. and Narenga porphyrocoma
indicate favourable conditions for sal natural regeneration, Imperata arundinacea,
Saccharum procerum indicate unfavourable conditions for it.
(iv) Grazing, browsing and burning – Light grazing and browsing is not harmful
to seedling establishment but uncontrolled grazing and browsing completely destroy
regeneration. Similarly, light or controlled burning is not harmful. On the other hand, it
reduces the density of shrub growth and destroys the undecomposed organic matter,
and thus favours rapid growth in seedlings. Uncontrolled burning is, however, very
injurious. The resistance to and the power of recovery from grazing the fire injuries
vary with species and with age.
(vii) Drip – Drip from the large leaves of species such as sal, teak is very harmful
for seedling establishment because it removes soil from the roots of the tiny seedlings in
splash erosion thereby exposing the roots resulting in the death of plants. The splashed
soil covers the shoot of the tiny seedling and besides preventing it to perform
photosynthesis, also kills it by rotting of shoot.
(viii) Composition of the crop – The composition of the crop affects soil
conditions and therefore affects the establishment. A mixed crop is believed to create
more favourable condition for seedling establishment than pure crops.

DYING BACK OF SEEDLINGS

In some species, the shoot portion of seedlings keeps on dying year after year
while the root remains alive. This phenomenon, which is known as dying back, results
in keeping back the progress of the seedlings to towards establishment because every
year the shoot dies back to produce whippy new shoots little or no bigger than the last
year’s shoot from the ground level. This continues for as many as 20 years or more
with the result that the seedling does not develop a permanent shoot. As the root stock
keeps on developing, it produces in some year with rare coincidence of absence of all
adverse factors, a shoot that does not die and thereafter the shoot makes steady
progress. This phenomenon is seen in sal, Pterocarpus santalinus, Terminalia
tomentosa, Bombax ceiba and Boswellia serrata. It is caused by adverse climatic and
edaphic factors as well as adverse weed competition.

DYING BACK OF SAL SEEDLINGS

After a good seed year and with the timely commencement of rains, sal seed
germinate readily and thousands of seedlings are seen covering the forest floor. But
soon after they start dying back. Some die during the rainy season, some towards the
end of rainy season, some in the ensuing dry season, some during the winter and yet
some others during the summer. Te dying back starts with the formation of blotches
on the leaves followed by their drying and the drying of the shoot. The dying back may
result in the death of the whole shoot generally but some times only a part of the shoot
dies. Next year, one or two new small whippy shoots are produced. These shoots meet
the same fate and the root stock sends forth new shoots again. Thus, while the root
stock keeps on developing, the shoot remains small, thought it increases slowly in
height. The process comes to an end when in a chance year as a result of absence of
all adverse factors, the root stock sends a shoot whose height is about 50 cm and leaves
relatively larger. After this the seedling does not die regularly and gradually makes
progress. In this way, it, sometimes, takes about 40 years to establish.

CAUSBS OF DYING BACK OF SAL SEEDLINGS

The factors responsible for dying back of sal seedlings are:
(i) Dense overhead canopy and inadequate light reaching the forest floor. Even
though sal does not require complete overhead light, yet it does require diffused light
which is not possible under a dense overhead canopy. Under inadequate light
conditions, leaves become small and develop blotches; photosynthesis is retarded and it
has an adverse effect on root development.
 (ii) Dense weed growth – Dense weed growth not only affects light but also
causes root competition and both these have adverse effect on the growth of the
seedlings and their establishment. Even if the shrubs are replaced by dense growth of
grass, it is injurious for the seedlings. For sal seedlings, the ideal undergrowth is a fifty
fifty mixture of light grass and shrubs.
(iii) Undecomposed lef litter – The leaves of sal are coarse and they do not
decompose easily with the result that there is often a thick layer of undecomposed
leaves which presents physical obstruction to the roots in reaching the mineral soil.
(iv) Accumulation of carbon dioxide – Towards the end of rains, there is an
accumulation of carbon dioxide in the soils of sal forests as a result of respiration by
roots and decomposition of organic matter. When the carbon dioxide/oxygen ratio
reaches 2.8, the sal seedlings start dying back.
(v) Frost – A fairly large number of seedlings die during winter as a result of
frost.
(vi) Drip – As a result of destruction of the middle storey, drip from the leaves of
the top canopy causes splash resulting in the death of seedlings by exposure of roots,
retardation of photosynthesis by leaves covered with splashed mud or rooting of tender
shoot.
(vii) Drought – Sal seedlings require adequate moisture but between two
consecutive rainy seasons, it has to face a long dry period. Though winter rains relieve
the hardship, yet large number of seedlings die as a result of post monsoon as well as a
summer drought.
(vii) Grazing and browsing – In places where there is heavy grazing, some
seedlings die as a result of trampling as well as due to their being eaten up with grass.
An excess population of cheetal and sambhar has also a serious adverse effect on the
growth of seedlings. During the summer when all other vegetation is leafless or has dry
hard leaves, sal seedlings produce attractive, coloured and juicy leaves and therefore
they are heavily browsed.

SEEDLING ESTABLISHMENT PERIOD

The seedling establishment period is defined as the period which elapses
between the initiation of natural regeneration and the time when it is considered safe
from adverse influences such as frost, drought or weeds. This would naturally vary with
species and in the same species with locality.
After the seedlings have established, the seedling or sapling crop has to be
protected against all kinds of damages and it has to be tended so that the plants of the
desired species may be protected against adverse competition from not only the
unwanted species but also the inferior individuals of the desired species. In short, the
development of a forest of the desired species from seed under natural conditions
depends upon the following conditions:
(i) Adequate and well distributed seed supply, i.e., there should be not only
adequate seed but that seed should be well disseminated over the whole
regeneration area.
(ii) Favourable conditions for the germination of seeds.
(iii) Favourable conditions for the development and establishment of seedlings.
(iv) Favourable conditions of under growth, ground cover and overhead canopies so
that the seedlings receive not only adequate light but are also free from root
competition.
(v) Protection against all kinds of injuries.
(vi) Tending during most part of the life span of crop.
(vii) Control over mixture.
All these conditions have to be attended to in different ways while developing a
new crop of desired species under various silvicultural system. The method of obtaining
natural regeneration and developing it into a high forest under various silvicultural
systems will be discussed separately later. But it is important to note here that in order
to achieve successful natural regeneration of any species, the knowledge of the
conditions in which it regenerates freely and bundantly in nature and in which it does
not regenerate is an essential prerequisite. The branch of science which gives this
knowledge is called ecology which is defined as ‘the study of plants and/or
animals in relation to their environment, i.e., all the biotic and abiotic factors
of a site.’ Therefore in order to achieve successful natural regeneration of any species,
it is necessary to create those conditions in the various silvicultural systems in which,
according to ecology, it regenerates freely in nature. The importance of the knowledge
of ecology is abundantly clear from the following two examples:
 (1) In the riverain areas, the first tree species to come are khair and sissu but
they do not regenerate under their own canopy.
(ii) Sal and chir regenerate freely in nature but once they form pure crops, under
certain conditions, their regeration becomes a problem.
If the causes of failure of regeneration in both these cases are analysed it would
be seen that the regeneration of these species require relatively drier condition than that
which exists under their canopies. Khair and sissu come up in infertile sandy soil with
complete overhead light and great diurnal range of temperature. But once these
species form a forest crop, the conditions of the forest floor are changed considerably.
The moisture retentivity and the fertility of the soil improves, complete overhead light is
no longer available on the forest floor and the diurnal range of temperature is also not
as wide as before. It means that if khair and sissu have to be regenerated naturally, the
conditions of site have to be reversed to the first stage of succession. Chir regenerates
in nature in areas where grazing is common and fire occurs regularly periodically or
annually. Similarly, in very moist areas, sal regenerates in crops with broken canopy
and subjected to periodic or annual fire. But once these species form extensive pure
crops, scientific management exercises a check on both these factors with the result
that the conditions in these forests become too moist for these species to regenerate
freely and abundantly. Evergreen shrubs come up in large numbers to make conditions
still more difficult for the regeneration to come. Thus, the generation of these species
becomes a victim of the conditions created by vigorous protection against fire and
grazing. If natural regeneration is to be achieved, retrogression in the site conditions
has to be brought about, which is, sometimes, not possible.

NATURAL REGENERATION UNDER VARIOUS SILVICULTURAL SYSTEMS

The following are three main high forest systems which are used in the
regeneration and management of forests:
1.Clear-felling system;
2. Shelterwood system; and
3. Selection system.
The methods of obtaining natural regeneration vary with silvicultural systems
used and the species. These are being described separately.
NATURAL REGENERATION UNDER CLEAR-FELLING SYSTEM
Clear-felling system is defined as the system in which the mature crop is
removed in one operation. In other words, the area having a mature crop is clear-
felled. This area is then regenerated either naturally or artificially. The natural
regeneration of the area depends for seed or seedlings from one of the following
sources:
(i) From the adjacent standing mature forest;
(ii) Seed already lying dormant in the clear-felled area;
(iii) Ripe seed on the mature trees before they were clear-felled;
(iv) Advance growth already present in the clear-felled area.
As the area has been clear-felled there is generally a lot of felling refuse in the
area. It has to be disposed of and the shrubs cut and burnt down so that the area may
provide a clean ground for natural regeneration to come up. If the regeneration has to
be ontained from seed already lying dormant on the ground or dispersed from the trees
felled or from the advance growth which does not coppice, the disposal of the felling
refuse scattered all over the area by burning has to be ruled out and it has to be
collected in the nalas or selected places of limited extent, so that the seed or the
advance growth is not destroyed. In these isolated places, sowing or planting is done
after burning. In case the advance growth possesses power of coppicing, and it is
sufficient to restock the area, burning of slash may be done even in the area.
If the regeneration is to be obtained from seed from adjacent unfilled areas, the
regeneration area should be in the form of a strip, i.e., it should be of such width that
the seed from the adjacent area can reach the whole width. In such a case the
direction of the prevailing wind at the time of seed fall has to be kept in view and annual
felling areas so arranged that unfilled area is followed by felled in the direction of the
wind, so that wind disseminates seeds in the regeneration area.
Once the regeneration comes up, it has to be weeded and cleaned and when it
reaches pole stage, it has to be thinned. As the coppice shoots of the weeds grow much
faster than the natural regeneration, they have to be kept under control by regular
cutting back every second or third year. By this process a new crop is obtained.
Instances of clear-felling followed by natural regeneration from seed are not
common in this country. In the dry teak forests, regeneration comes up after felling and
light burning, from seed lying on the ground but even in this case, most of the
regeneration is the result of seedling coppice. This is an example of clear-felled blocks.
Clear-felling (except for retention of 3 to 5 trees per hectare) followed by natural
regeneration from seedling coppice is extensively used in Singhbhum sal forests of
Bihar, though local officers call it as conversion to uniform system. This method is also
adopted in parts of sal forests of M.P. (South Raipur and Bastar) and Orissa. Clear-
felling by strips has, however, been tried in case of sal and Pinus kesiya in Assam but is
has been given up in favour of taungya or departmental plantations. It was tried on an
experimental basis in case of sal in U.P. but had to be given up as success was not
achieved.

NATURAL REGENERATION UNDER SHELTEWOOD SYSTEMS

Shelterwood systems are defined as the systems in which the mature crop is
removed in a series of operations, the first of which is the seeding felling and the last is
the final felling. Other fellings, if any, are called secondary fellings. The regeneration is
obtained under a shelterwood which is removed in final felling only when the natural
regeneration is established. The interval between the seedling felling and final felling on
a particular area such as a compartment, is called regeneration interval and it
determines the degree of uniformity of the resulting crop.
The form and nature of the new crop depends upon the method in w3hich the
mature crop is removed or felled and on the nature of the new crop depends the name
of the shelterwood system. For example, if the seeding felling is done in such a way as
to make well-distributed small gaps over the whole compartment, the generation comes
up in those opening over the whole are uniformly. This system is there fore called
Shelterwood Uniform System. But if the seeding felling is done in groups, the
regeneration also comes in groups and the system is called Shelterwood Group System.
If advance growth in the form of sapling and poles is retained either to minimize the
sacrifice of immature poles, etc., or to make up likely deficiency of natural regeneration,
the resulting crop is irregular and so the system is called Irregular Shelterwood System.
The basic principle of all these shelterwood systems is that some trees of the
mature overwood may be retained to supply seed while other may be felled to admit
light on the forest floor so that regneratin may come in the openings. The regeneration
is then tended to grow up under the shelter of the seed trees. As the regeneration
grows up, the rest of the overwood is removed in one or two operations. Keeping these
basic principles in view, natural regeneration is obtained in shelterwood system by
carrying out various operations as described below:

(1) SEED SUPPLY

The most important operation in obtaining natural regeneration is the
arrangement of seed supply. This can be achieved only when there are sufficient middle
aged trees of well-developed crowns uniformly distributed over the whole area. The
number of such trees required to supply the seed, depends upon the species. For
example, while 1 or 2 Adina cordifolia trees per hectare are sufficient to meet the seed
requirement, 30 to 40 trees per hectare are required in case of sal. In fvourable
localitites, even 8 chir trees per hectare are sufficient to meet the requirement of seed
but 12 to 15 are generally retained as an insurance against unforeseen accidents. The
number of trees retained for seed also varies with aspects. Generally larger number of
trees is retained on hotter aspect than on the cooler aspect. But this is with the object
of minimizing the desiccating effect of the hotter aspects as well as to make up the loss
resulting from heavy seedling mortality in such places. If middle-aged trees with well
developed crowns are not available uniformly distributed over the area, their deficiency
is made up by leaving some more trees of slightly younger or higher age classes. The
number of trees to be retained for seed supply is also affected by the presence of
advance growth. If in any area adequate established advance growth is present, there
is no need to retain any seed trees in that area and generally all overwood is removed,
unless required for some other function, e.g., protection against frost of for fire
insurance, etc.

(2) LIGHT REQUIREMENT AND CANOPY MANIPULATION

(a) Overwood - The trees retained in the overwood not only meet the seed
requirement but also determine the light reaching the forest floor. Light affects the soil
conditions, undergrowth, germination, etc., and therefore adequate quantity of light
must reach the forest floor. This is achieved by manipulation of canopy, i.e., by removal
of certain trees from the canopy, which are not required for seed. The removal of trees
creates gaps in the canopy and admits light on the forest floor. The manipulation of the
canopy varies with the system being followed. For example, in the uniform system, the
gaps are made uniformly over the whole area while in case of group system, the
seedling felling is done in bigger patches at selected places in the compartment. When
the regeneration comes in these patches, seeding felling is done round these patches.
Thus, the area of patches is gradually extended and a time comes when they merge
with each other.
For the same species and the same silvicultural system, the opening of the
canopy is lighter in drier areas than in moister areas to prevent the area becoming still
drier due to excessive evaporation and to protect the seedlings from desiccation. Weed
growth also affects the size of openings. If there is a danger of weeds and grasses
invading the openings, they are made cautiously.
Requirement of light varies with the size of the regeneration. The young
generation requires less light but as it grows in size, its requirement of light increases.
Thus, some more trees have to be removed. This felling is called secondary felling and
is done to admit more light for the growing regeneration. But this felling results in
damage to the regeneration also and therefore, in practice, secondary fellings are
avoided.
When the requirement of seed is met by a fewer number of trees but the
requirement of light necessitates the retention of a larger number of trees, extra trees
retained may, sometimes, be of the associate species. The regeneration of some of the
important species like sal, deodar and silver fir, etc., often comes profusely under the
canopies of such associate species. Thus, in sal forests, retention of extra trees of light-
crowned thin-leaved species su c h a s Lagerstroemia parviflora, Emblica officinalis,
Anogeissus latifolia, Lannea coromandelica, etc., is sometimes recommended. If such
trees are not available in sufficient quantities, trees of Terminalia tomentosa, Terminalia
belerica, Pterocapus marsupium, etc., may be retained. Ncrease in demand of these
secondary species, which, till recently, had extremely low value, has made retention of
such species a viable proposition.
(b) Middle storey – As middle storey also obstructs light, it has to be
manipulated to admit sufficient light on the forest floor according to the requirement of
species. The middle storey normally consists of species other than the main species of
the over wood. In coniferous forests, it usually not dense. In sal forests, it consists of
miscellaneous species such as Mallotus, Cassia, Lagerstroemia, Anogeissus, etc., and is
some times very dense. Therefore, in these forests where the middle storey is dense, it
is thinned retaining trees having straight bole and light crown with thin leaves, and
removing branchy, thick-leaved trees of low height. For example, in sal forests, the
trees retained in the middle storey generally are of Lagerstroemia parviflora, Anogeissus
latifolia, Emblica officinalis, Ougenia oojeinensis, Cassia fistula, etc. Mallotus, which is an
evergreen species, is not retained because it often forms thickets and casts dense shade
on the forest floor. In the drier areas, however, manipulation of the middle storey is
done cautiously to prevent the area form becoming drier due to excessive evaporation.
(c) Undergrowth – Undergrowth also obstructs the light, admitted in the forest
by manipulation of the overwood and middle storey, from reaching the ground. The
density and nature of undergrowth varies with the type of the forest. In the subtropical
pine forest, it is the least, while in the tropical wet evergreen forest, it is very heavy.
The undergrowth consists of grass and shrubs which may be tall and/or low. Tall
undergrowth generally consists of coppice shoots arising from the stools of felled middle
storey miscellaneous trees. For example, in sal forests coppice shoots of Mallotus and
Lagerstroemia form heavy thickets. The tall undergrowth does not cast so much shade
as the low spreading shrubs such as, Clerodendron, Pogostemon, Eupatorium, and
locally Ardisia in sal forests, Strobilanthes and Petalidium in teak forests, Parrotia,
Indigofera in deodar forests, Strobilanthes, Dipsacus, Senecio, Polygonum, Impatients,
etc., in high level fir and spruce forests and Lantana in the tropical dry deciduous
forests. They may, some times, be so dense as to inhibit natural regeneration of the
main species. The following methods are used to reduce their density:
(i) Regular cutting back – Cutting down of shrubs is the most usual method of
controlling their density. The season of cutting, which has a marked influence on the
result, depends upon the growth of shrubs, the nature of regeneration and availability of
labour. The best time to cut the shrubs is the time when their growth period is over and
the reserves of food material are at the lowest ebb. But the season in which the
regeneration is likely to suffer most from suppression or exposure, depending upon the
nature of the regeneration, has also to be kept in view. For example, rains shrub
cuttings have been found to be very beneficial for sal regeneration. Study of growth
pattern of sal seedlings shows that out of 3 peak growth periods in the year one is in
early and the other in late rainy season. At that time there should be the least
competition from weeds. At that time there should be the least competition from
weeds. But in certain places labour is not available during the rains. Therefore, shrub
cutting has to be done during winter and summer. In the fir and spruce forests of
Himachal Pradesh, shrub cutting before the snow fall is considered very beneficial
because if it is not doe then, shrubs which are flattended over the regeneration as a
result of snow fall, smother it.
(ii) Controlled burning – In areas where the young regeneration possesses
coppicing power, the shrubs are cut or, sometimes, only pressed down and control-
burnt annually or periodically to reduce their density.
(iii) Uprooting – Uprooting of shrubs, particularly shallow-rooted, is one of the
most effective methods of eradicating them and if this is done during the rains when the
ground is soft, it is not very costly too. For example, in the teak forests Petalidium is,
sometimes, uprooted and burnt on a five year cycle. It is claimed that only 2 operations
are sufficient.
(iv) Use of weedicides – Weedicides are, sometimes, used to keep the density
of the shrubs under control. The weedicides are, however, selective in action and their
effect varies with season and mode of application. If spraying is done, it has to be done
cautiously so that it may not affect the natural regeneration. Generally, spraying of the
new shoots arising from cut back portion, and the basal portion gives good results.
Control of grass – In certain areas undergrowth consists of thick grass. Dense
grass is generally very harmful to natural regeneration and in order to reduce its harmful
effect, it has to be cut regularly. But in order to have permanent effect, shrubs should
be allowed to grow so that they can suppress grass. Light grass is, however, not
harmful and sal and chir regenerate well under light grass undergrowth.
Control of bamboos – In certain sal forests of Assam and Orissa and teak forests
of M.P., and Maharashtra, bamboo forms a thick undergrowth and therefore presents
great difficulty in obtaining natural regeneration. They are, therefore, cut and, after
extraction of the commercial sizes, burnt. This operation has to be repeated on a 5 year
cycle to reduce their density.

(3) SOIL CONDITION

Soil condition exercises a profound influence on natural regeneration. If soil
condition is not favourable, natural regeneration does not come and even if it comes, it
does not survive. For success of natural regeneration, the soil should be such that the
seedling can develop a long taproot which may reach permanent soil moisture in the
first growing season so that post-monsoon or summer drought may not be able to kill it.
This is only possible when the soil is permeable. If the soil has become very compacted
as result of grazing by heavier animals, it has to be dug up. The digging up may be
done manually in strips to reduce cost. If a small tractor is available, the whole area can
be ploughed but this is only possible when there are no stumps in the area. Presence of
stumps and thick roots close to the surface makes tractor ploughing difficult. In
experiments carried out in the bhabar sal forests of U.P., soil working in good seed year
has been found to be very beneficial for sal natural regeneration and has been
recommended as an essential part of the technique of obtaining sal natural regeneration
in such areas, in conjunction with other measures.
The presence of undecomposed organic matter also presents a serious difficulty
in obtaining natural regeneration. For example, a thick layer of acid humus in the dense
fir forests of Himachal Pradesh inhibits natural regeneration completely while a thick
layer of partly decomposed sal leaves creates toxic conditions toxic conditions for the
natural regeneration. In the case of fir forests, the decomposition of the acid humus
has to be accelerated either by exposure, raking, etc., or by permitting grazing so that
the needles may break down under the hoofs of the goats so that the needles may
break down under the hoofs of the goats and sheep and mineral soil exposed at places.
In the case of sal forests, however, burning can destroy the leaf litter.
Excess or shortage of moisture also affect natural regeneration. Excess of
moisture results in water logging and this kills the natural regeneration. If excess of
moisture is due to poor drainage caused by local topography, or due to the presence of
any impervious pan in the soil, very little can be done to improve the conditions. In
other cases, however, excess of soil moisture can, sometimes, be rectified by burning or
canopy opening. On the other hand, deficiency of moisture also has adverse effect on
the natural regeneration. But in this case, conditions can be slightly improved by
making contour bunds, etc.

(4) BURNING
Beneficial effects of burning on natural regeneration as well as on soil conditions
have already been described in chapter 3. Because of these beneficial effects,
controlled burning is used as a tool to obtain natural regeneration in certain types of sal,
chir and teak forests.
 Sal Forests – In the very moist and moist sal forests, annual or periodic burning
is used to reduce the density of the shrubs and soil moisture and to burn leaf litter to
provide clean seed bed for natural regeneration. But this is done after careful inspection
of the area so that is does not do any harm. For instance, in grassy areas, continued
burning makes the area drier and the growth of grass thicker and denser. Similarly,
burning is not done fore one or two years after a good seedling year so that the young
seedlings may not be killed out by fire. Burning is harmful in dry types of sal forests.
Chir forests – Controlled-burning is done in chir forests before carrying out
seeding felling and it may be continued even after slash disposal for a year or two till a
good seed year comes. This burning destroys the needles and the shrubs and provides
clean bed for seeds to germinate. After a good seed year burning is not done because
chir does not coppice and over most of the area, natural regeneration comes after a
good seed year. The controlled use of fire is resorted to again when the natural
regeneration has reached a size that the area is to be put outside the regeneration area.
As the regeneration ares are carefully fir protected, the fires that are a regular feature of
the chir forests. Therefore, before taking out any compartment outside the
regeneration area or before carrying out final felling, the natural regeneration is control-
burnt for three years. This burning is done down the hill in 2 or 3 chain wide strips. It
is started from a ridge or a foot path and to keep it in predetermined width, burning is
done along the edges of the strip and is not allowed to go beyond the edge on the
unburnt side. If the fire is extremely slow in moving down hill, some fire is set at about
8 to 10m below and is allowed to move up. The burning cones rolling down the hill
slope can convert this controlled-burning into an uncontrolled fire by starting a fire at
the bottom of the hill slope and therefore 2 or 3 men are engaged for extinguishing the
burning cones. The areas having unestablished regeneration and so unable to
withstand even the controlled-burning, are excluded from such burning by making a fire
trace round them. Controlled-burning should be done during November and December
but in no case, should be delayed beyond February because after that it is difficult to
control the fire.
Teak forests – In the moister teak forests, indiscriminate fire protection has an
adverse effect on natural regeneration of teak by encouraging dense weed growth.
Controlled-burning in such forests induces natural regeneration. On the basis of an
experiment in Tharawady (Burma) in two adjacent and initially comparable plots, Troup
showed in 1905 that the unprotected plot had about 10 times more seedlings than the
fire protected plot. But in dry teak forest, fire is harmful and may kill the natural
regeneration altogether, though for inducing natural regeneration light burning is
considered to be advantageous.

(5) SLASH DISPOSAL

The felling of trees for canopy manipulation results in leaving large quantities of
slash in the regeneration area. This has to be disposed off to make the area clean for
germination of seed as well as to reduce fire hazard. This operation is called slash
disposal which is defined as ‘the treatment or handling of slash for reducing harzards
from fire, insects or fungi and for providing the seeds with access to the soil’. In the
inflammable coniferous forests, after taking out all saleable material, the remaining slash
is cut in spices, stacked away from the seed trees and burnt. The work is done as soon
after felling as possible without running the risk of starting accidental fire. Thus, in chir
forests this is done during winter while in deodar and fir and spruce forests, it is done
after the rains but before the snowfall. Slash disposal is, generally, not necessary in the
sal and teak forests (except very remote ones, e.g., Bastar in M.P.) as practically every
thing is sold out or removed by the neighbouring villagers.

(6) WEEDING
Inspite of burning, weeds appear in the area long before the natural
regeneration comes in and therefore, as soon as germination of the desired species is
complete, weedlings should be done to protect the young regeneration against weed
which compete with it for light as well as moisture. Generally weedings should be done
before the weeds have suppressed the regeneration or the latter has stopped growing.
Actually no weeding should be done from October onwards as the dormant seedlings
then require protection against frost or animal damage. In case of sal, rains weedings
have been found to be most effective but another weeding very late in winter or on the
onset of summer is also beneficial as it cuts down transpirational losses at a time when
the moisture in the soil is very little.
The number of weedings to be done in a year has a great influence on the
success of natural regeneration because excess of weedings as well as insufficiency of
weedings are both harmful. While excess of weeding exposes the seedlings to the
dangers of insolation, frost and animal damage, insufficiency of weedings results in
killing them from suppression. The number of weedings to be done in a year and the
number of year for which weeding should be done varies with species being naturally
regenerated as well as the rate of growth of the weeds. For example, in case of tropical
wet evergreen forests, three weedings may be necessary in the first year, two in the
second year and one or more later but with fast growing species only one weeding may
be enough. In the fir and spruce forests of Himachal Pradesh, weeds are a serious
menace and effective method of controlling them is yet to be evolved. Howsoever
necessary the weedings in the natural regeneration areas, particularly in the coniferous
forests, are generally neglected. In this connection, the use of weedicides gives great
promise because the trials made have given encouraging results, though the cost is
considered to be high and environmental effects are to be watched. A lot more
experimental work will have to be done to find out the best weedcide for the particular
weeds in the type of forest, concentration, method and season of application, side-
effects, etc., before large scale application can be made. Along with weedings, the
herbaceous climbers. e.g., Dioscorea, Mikania should also be uprootead instead of
cutting them.

(7) CLEANING
When regeneration grows up into sapling, cleanings are done. Cleaning is
defined as ‘a tending operation done in a sapling crop, involving the removal
or topping of inferior growth including individuals of the favoured species,
climbers, etc., when they are interfering with the better grown individuals of
the favoured species’. Cleanings are done periodically, say at an interval of 3 to 5
years, and should be restricted to removal of only those shrubs which are interfering or
are likely to interfere in the next two or three years. Like weedings, excess of cleanings
may result in adversely affecting the regeneration in the sapling stage, by exposure,
frost and animal damage. It, sometimes, results in invasion of obnoxious weeds. For
example, cold weather shrub cutting in eastern sal forest is liable to encourage
Eupatorium which seeds in February, while continued shrub cutting in the evergreen
forests is reported to encourage invasion of climbers like Mikania cordata.

(8) PROTECTION AGAINST DAMAGE BY ANIMALS

 The effect of unrestricted grazing and browsing has already been described in
the chapter on locality factors. Therefore the natural regeneration has to be protected
against animal damage right from the beginning. There are two types of animals from
which the regeneration has to be protected, viz., the domestic cattle and the wild
animals. Where the incidence of animal damage is great, he regeneration area has to
be fenced before the germination starts or at the latest before weedings are started so
that the exposed seedlings in the weeded area do not become an easy food of the cattle
and wild animals. The damage by domestic cattle can be prevented by erecting a cattle-
proof fence or a stone wall fence but the damage by wild animals, particularly cheetal
and sambhar, can be prevented only by erecting a game-proof fence. If the damage by
porcupines and pigs is also appreciable, he game-proof fence is modified to have special
porcupine-proof woven wire at the bottom instead of ordinary woven wire so that pigs
and porcupines can not enter the regeneration area. No fence can keep out wild
elephants who can be kept out only by digging a ditch all-round the regeneration area.
Brief description of these fences is given in the next chapter.
The period for which the regeneration area should be closed to grazing and
fenced against damage by wild animals is an important consideration on which the
success of natural regeneration depends. The period should neither be too long nor too
short. Too long a closure results in increasing the cost of its maintenance and
consequently the cost of natural regeneration besides antagonizing the local public who
have grazing rights or concessions in the area. Too short a period would defeat the
object with which the fence was put up. The period for which the regeneration areas
are closed to grazing and fenced against wild animal damage, depends upon the rate of
growth of natural regeneration and incidence of cattle or animal damage. The main
consideration is that the regeneration should attain that size in which it could not be
damaged by the animals. Thus, the period varies from 10 to 30 years.
NATURAL REGENERATION UNDER SELECTION SYSTEM
The systems described so far are based on concentrated fellings and produce a
new crop which is regular. In the selection system, on the other hand, the mature crop
is removed either as single trees or in small groups over the whole of the felling series
and consequently the resultant crop is always irregular. This system actually follows
nature in which mature and over mature trees keep on dying out and their places are
taken up by the regeneration. Thus, in this system, mature trees above a certain
exploitable diameter are felled so that regeneration comes in the voids created. Often,
they are felled only in places where saplings and poles of the main species are present
to take the place of the mature trees being removed. In the year after the main felling,
cultural operations are carried out. If climbers are heavy, climber cutting is done on a
regular cycle or once in a while.
Though theoretically, the fellings should be carried out over the whole felling
series, it is neither feasible nor practicable to cover the whole area except when it is
very small. Therefore in extensive areas, fellings are done in parts of the felling series
at a certain interval of years. In other words, the area of the felling series is divided into
as many parts as there are years in the interval and they are felled in a sequence taking
one part each year so that all of them are felled during the period and after completing
one cycle, the felling comes back to the first part. Thus, interval is called felling cycle
which is defined as ‘the time that elapses between successive main fellings
on the same area.’ Felling cycle is generally, though not always, of 10 to 20 years.
In India, typical selection system is not used any where. Mostly it is selection
felling and often it is only selective felling. In parts of the tropical wet evergreen
forests, selective fellings on fairly long felling cycles are carried out. Similarly, selective
fellings are carried out in parts of tropical moist deciduous forest where canopy is
gradually being opened up and chances of obtaining natural regeneration are becoming
remote.
The hill sal forests of U.P. and some high level sal forests of M.P., are worked
under a system of selection fellings mostly on a 10-15 year felling cycle. The chief aim
is to obtain maximum sustained yield of timber from trees of exploitable diameter as far
as silvicultural conditions permit. Thus, the following three operations are carried out:
(a) Removal of trees of and above the exploitable diameter – Trees of
and over the exploitable diameter are marked upto a fixed percentage of the
silivculturally available trees.
(b) Thinnings in trees below the exploitable diameter – In order to nurse
up all trees below the exploitable diameter class under best possible conditions of
growth, thinnings are carried out in them.
(c) Cultural Operations – In the year after the main felling, cultural operations
are carried out not only to minimize the after-effects of felling but also to help the
regeneration and the younger age class trees present in the area.
 The selection fellings are also carried out in parts of teak forest along the west
coast while in some other parts it is only selective felling as it consists, essentially, of
felling a prescribed number of teak and other valuable trees of the exploitable size over
a definite felling cycle without regard to natural regeneration.
Selection fellings are also, sometimes, carried out in the hilly and rugged portions
of deodar forest, where shelterwood system may be difficult to apply. It is also applied
to some fir and spruce forests.

REGENERATION SURVEY
The natural regeneration obtained in the forest under the various systems is
generally hidden in grass and shrubs covering the forest floor and therefore its ocular
estimate is generally inaccurate. In the absence of 100% enumeration, reasonably
accurate assessment of natural regeneration can be obtained by Regeneration survey
w h i c h i s defined as ‘a survey for the assessment of established and
unestablished regeneration generally by sample enumeration.’
The regeneration survey may be carried out at the time of revision of working
plans with the following objects:
(i) to compare natural regeneration in any regeneration area at the end of the
working plan with that in the beginning to evaluate the effects of operations carried out
during the working plan period; and
(ii) to prepare a stock map of any area proposed to be regenerated to prescribe
correct silvicultural treatment for various parts on the basis of the status of the
regeneration in them as well as to serve as a basis for comparison the end of the plan.
Sampling patterns and intensity – Regeneration survey can be done alongwith
the enumeration or independently. In the flat terrain, the regeneration survey may be
carried out in linear strips or line plot surveys while in the mountainous terrain, it can be
carried out by topographical units. At present, however, regeneration surveys are
carried out in flatter terrain found in forests managed under shelterwood system. The
intensity is generally 2 to 4%. For this purpose, a base line is drawn on the base of the
map and parallel survey lines are drawn at right angles to the base line 200m or 100 m
apart after selecting the position of the first line by random sample. Regeneration
survey is then done in 2m X 2m squares on either side of the survey line. In this
survey, it is sufficient to record the occurrence of the most promising category of
regeneration only. Thus, in sal forests f U.P., attention is concentrated on established
saplings and poles below the lowest diameter limit of tree enumeration, and on woody
shoots on way to establishment. It is only when these classes are absent that the lower
classes of regeneration are recorded. In the sal working plans of U.P. the following
categories of regeneration are recorded by the symbol shown against each:
Category of regeneration Symbol Explanation
(1) (2) (3)
1. Established regeneration whose e Symbol e indicates that at least one
height should be 2.5 m or more such plant is present, which is
and d. b. h. 10 cm sufficient to stock the quadrat.
2. Woody shoot, which is not w In the absence of e, w indicates that
established but which is large there is at least one woody shoot
and vigorous and so expected to which is sufficient to stock the
become established early quadrat.
3. Woody shoot which has been w+ -
browsed
4. Whippy unestablished seedling u+ In the absence of e and windicates
whose height is more than 50 that there are more than one
cm unestablished whippy seedlings more
than 50 cm height in the quadrat.
5. Whippy unestablished seedlings u In the absence of e, w and u+, u
whose height is more than 50 indicates that there is one
cm unestablished whippy seedling more
than 50 cm in height, in the quadrat.
6. Sub-w h i p p y u n e s t a b l i s h e d s+ In the absence of other symbols (i.e.,
seedling whose height is less e, w, u+, u), s+ indicates that there
than 50 cm are more than one sub-whippy
seedlings in the quadrat.
7. Sub-w h i p p y u n e s t a b l i s h e d s In the absence of other symbols, s
seedlings whose height is less indicates that there is one subwhippy
than 50 cm. seedling in the quadrat.
8. Recruit (Current year’s r In the absence of other symbols, r
seedling). indicates that there are only current
year’s seedlings in the quadrat.
9. Blank o o indicates that there is no
regeneration in the quadrat.

Classification of data for regeneration stock maps – Seth has suggested a

detailed classification as given below:
Description Class Proportion of various categories of regeneration
e e+w e+w+u
Unstocked 1 - - Below 10%
 2 Below 10% Upto 25% Upto 75%
3 Below 10% Upto 25% Over 75%
4 Below 10% Over 25-50% Upto 75%
deficient in e 5 Below 10% Over 25-50% Over 75%
6 Below 10% Over 50-75% Upto 75%
7 Below 10% Over 50-75% Over 75%
8 Below 10% Over 75% -
9 Over 10-25 % Upto 50% Upto 75%
10 Over 10-25 % Upto 50% Over 75%
Promising in e 11 Over 10-25 % Over 50-75% Upto 75%
12 Over 10-25 % Over 50-75% Over 75%
13 Over 10-25 % Over 75% -
14 Over 25-50 % Upto 75% Upto 75%
Fair in e 15 Over 25-50 % Upto 75% Over 75%
16 Over 25-50 % Over 75% -
17 Over 50-75 % Upto 75% Upto 75%
Good 18 Over 50-75 % Upto 75% Over 75%
19 Over 50-75 % Over 75% -
Excellent 20 Over 75% - -
The data so collected is conveniently plotted on the map by dividing the area
into a number of rectangles on squares in such a manner that the sampling unit is
centrally situated in them. Then, assuming the sampling unit to be representative of the
square, each square is given appropriate class colour and hatching as given below:
Regeneration Class Colour Hatching black lines 2 mm apart
1 Yellow -
2 Red Horizontal
3 Red Vertical
4 Red Left slant
5 Red Right slant
6 Red Upright cross
7 Red Slanting cross
8 Red -
 9 Green Horizontal
10 Green Vertical
11 Green Left slant
12 Green Right slant
13 Green -
14 Blue Horizontal
15 Blue Vertical
16 Blue -
17 Burnt sienna Horizontal
18 Burnt sienna Vertical
19 Burnt sienna -
20 Sepia -
But in U.P. working plans, following relatively simplified method is being followed
these days:
The regeneration categories are given the value shown against each in the table
below:
Regeneration category Symbol Value
Established e 5.00
Woody shoots w 4.00
Woody shoots browsed w+ 4.00
Whippy unestablished u+ 2.00
shoots
Whippy unestablished u 1.00
shoots
Subwhippy shoots s+ 0.50
Subwhippy shoots s 0.25
Recruit r 0.00

The values are then totaled for every hectare. For instance, in 4% sampling
intensity in which survey lines are 100 m apart, 20 m length in 5 contiguous lines and
half the width of the strips on either side of the end lines would make a rectangle 20m X
500 m which is equal to one hectare. These 20 m lengths in 5 survey lines will have
100 quadrats. The values of these 100 quadrats when totaled will give the condition of
the regeneration in that hectare. The values calculated for these rectangles are shown
on the regeneration stock map as follows:
Total value of regeneration Description of the Colour in the map
categories in the rectangle condition of
regeneration
81 to 100 Excellent Green
61 to 80 Good Blue
41 to 60 Moderate Yellow
21 to 40 Fair Red
0 to 20 Deficient Blank (no colour)

TECHNIQUE OF OBTAINING NATURAL REGENERATION OF IMPORTANT SPECIES IN

VARIOUS TYPES OF FORESTS
CONIFEROUS FORESTS
Chir pine – The number of seed bearers retained is usually 12-15 per hectare on
cooler aspects and 20 to 25 on dry and hot aspects. At certain places, all vigorously
growing and straight poles upto 20 cm in diameter are also retained. Thus, badly
shaped poles upto 20 cm diameter and all trees other than the seed bearers are
removed. From groups of poles upto 20 cm diameter all overwood is removed. The
seed bearers are retained on the ridges and on the upper portions of the slope so that
they can command maximum area. After felling is over, all slash left in the area is cut
and collected away from the seed bearers and the pole crop and burnt during winter.
The area is continued to be control-burnt and allowed to be grazed till a good seedling
crop is obtained from a good seed year. After this the area is protected against burning
and grazing. Weeding and shrub cutting is done as and when necessary subject to the
availability of funds. Protection is continued till the regeneration is 1 to 2 m high on
gently sloping ground and 2 ½ to 3 m on steeper ground after which controlled-burning
is started. The grazing is allowed as soon as this an be done without harm because this
reduces fire hazard. The seed bearers are removed from fully regenerated areas when
the regeneration is 6 to 7 m high on gentler slopes and 9 to 10 m high on steeper
slopes. In areas likely to be frequented with frequent and destructive fires, it is usual to
retain three to five trees per hectare to provide seed in case the young crop is destroyed
by fire. At times, it is not possible to enforce closure to grazing and burning and in such
places it is usual that the regeneration is not uniformly complete. Therefore the blank
areas are often planted with polythene bag plants.
In the upper portions of the chir zone which may be very cool for chir and where
kail may have come in, the seeding marking is done in such a way that 25 to 30 seed
bearers of kail are retained and attempts to convert such areas into chir crop should not
be made.
Deodar – The number of seed bearers retained per hectare is 45 to 70 in the
drier forests and upto 100 in the moister forests. All suitable patches of advance growth
as well as established poles upto half the rotation age are retained, with condition of
minimum area, as part of the future crop. After fellings are over, the slash is cut and
collected in heaps away from the seed bearers and advance growth and burnt. Grazing
is allowed till a good seedling year results from a good seed year. In areas where there
may still be heavy weed growth and thick layer of undecomposed or partially
decomposed needles, contour strips may be cleared when a good seed fall is expected.
After this the area is closed to grazing and strictly fire protected. Weeding and shrub
cutting is done as and when necessary subject to the availability of funds. Parrotia
forms dense undergrowth in Kashmir valley especially when the canopy has been
opened up very much and hinders natural regeneration. Grazing is again allowed when
the regeneration is established and is beyond the reach of goat and sheep or at least
safe against the animal damage. As the natural regeneration is not uniformly complete
all over the regeneration areas, it has to be supplemented with artificial regeneration in
areas deficient in natural regeneration or without it. The overwood is removed in 2 ro 3
stages as the regeneration is established.
Silver fir and spruce – The technique of obtaining natural regeneration of
silver fir and spruce is still not known. Good seed years in these species occur at long
intervals (e.g., 10 years for silver fir and 6 year for spruce). Their light requirements are
fairly different. While silver fir is a shade demander and more definitely a climax
species, spruce is a moderate shade bearer and more of a pioneer often associated with
blue pine. But the main inhibiting factors for natural regeneration of these species in
Himachal Pradesh are excessive raw humus and heavy weed growth both perennial,
e.g., Strobilanthes and annual, e.g., Impatiens. While excessive raw humus prevents
the seedlings from sending their roots to the mineral soil, weed growth smothers the
seedlings during the growing season as well as during winter when it flattens over them
due to snow. In Uttar Pradesh, the main inhibitig factor is excessive grazing. These
forests are heavily grazed by sheep, goats and buffaloes from spring to the end of rains.
Though it was believed in Himacha, Pradesh that in areas where Impatiens is not a
problem, cutting down Strobilanthes and exposing the mineral soil in strips in good seed
year would bring natural regeneration, the problem has been resolved by resorting to
artificial regeneration for the last seven or eight years and the success achieved in this
in some forests, e.g., Chhachpur indicates that these forests could be regenerated
artificially and one need not bother about natural regeneration. In U.P., however, the
problem still evades a solution. In the natural zone of these species there is a lot of
mortality in the nurseries due to damping off. This can, however, be controlled by
treatment of soil before sowing by fungicides like Thiram, etc. It appears that, in U.P.
also, artificial regeneration will have to be depended for regenerating these forests as
closure of grazing appears to be difficult and impracticable under the present conditions.

DECIDUOUS FORESTS
Sal – The natural zone of sal is very extensive and the conditions vary
considerably. Therefore, it is not possible to make a general statement about the
conditions of its natural regeneration as well as the technique to obtain it. The problem
of sal natural regeneration has to be tackled for each type and subtype or even variety
separately as the conditions and the factors responsible for them vary considerably.
Condition of natural regeneration in various types, subtypes and varieties is briefly
described below:

VERY MOIST SAL-BEARING FORESTS

3C/C1a(i) – Very moist eastern Himalayan sal – Natural regeneration is
satisfactory as it is present in all stages of establishment, though bamboo checks it
locally.
3C/C1a(ii) – Very moist Khasi hill sal – Regeneration of sal is inadequate but
not difficult to obtain with judicious use of fire.
3C/C1b(i) – Very moist eastern Himalayan upper bhabar sal – Natural
regeneration is definitely deficient. Regular burning brings some regeneration but very
slowly.
 3C/C1b(ii) – Very moist eastern Himalayan lower bhabar s a l – Natural
regeneration is practically absent on account of dense evergreen undergrowth resulting
from fire protection.
3C/C1c – Very moist eastern terai sal – Natural regeneration is practically
absent on account of dense evergreen undergrowth and it will be impossible to get it
with fire protection.
3C/C1d – Very moist peninsular (coastal) sal – Natural regeneration is very
deficient where evergreen and bamboo undergrowth is heavy.

MOIST SAL-BERING FORESTS

3C/C2 a – Moist siwalik sal – Regeneration is adequate.
3C/C2b(i) – Moist bhabar-dun sal – Regeneration is both deficient and difficult to
induce.
3C/C2b(ii) – Moist dammar sal – Regeneration deficient and difficult.
3C/C2c – Moist terai sal – Though seedling regeneration is deficient, there is fair
coppice regeneration.
3C/C2d(i) – Moist western light alluvium sal – Regeneration is not a problem as
young crops are adequate.
3C/C2d(ii) – Moist chandar sal – Natural regeneration is abundant but is annually or
periodically cut back by frost followed by fire.
3C/C2d(iii) – Moist eastern heavy alluvium plains sal – Natural regeneration is fair
in whippy shoots and usually plenty in sapling and pole stages which give good coppice.
3C/C2 d(iv) – Moist Kamrup sal – Regeneration is adequate in burnt grass lands but is
stopped when fire protected.
3C/C2e(i) – Moist peninsular high level sal – Regeneration is abundant throughout
this variety.
3C/C2e(ii) – Moist peninsular low level sal – Regeneration is satisfactory.
3C/C2e(iii) – Moist peninsular valley sal – Regeneration is excellent.

DRY SAL-BEARING FORESTS

5B/C1a – Dry siwalik sal – Sal regeneration is usually scarce except for
occasional patches and is frequently absent. Establishment is slow.
 5B/C1b – Dry plins sal – Natural regeneration in large whippy or woody stages
is entirely absent except for occasional moist pockets. Recruitment takes place in a
good seedling year but dies out soon.
5B/C1c – Dry peninsular sal – In M.P., whippy regeneration is present in fair
amount and smaller diameter classes are also fairly represented. In Bihar, natural
regeneration is invariably best in shade. Though seedling regeneration is adequate,
coppice is mostly relied upon.
Thus, amongst the important sal forests, moist bhabar sal (type 3C/C2b) has
regeneration not only deficient but also difficult to induce. As a result of experiments
carried out during the last 40 years or so, a technique of obtaining natural regeneration
giving following sequence of operations has been evolved:
(i) Top canopy – No seeding felling is required in a normally thinned mature
stand as enough gaps exist in the canopy.
(ii) Middle story – In the middle storey, the low branching and dense-foliaged
species, particularly Mallotus should be heavily thinned. Light-crowned species should
be retained. Only a thin middle storey is required.
(iii) Soil working – Thorough soil working preferably with a light chain-type
tractor should be done before seed fall in good seed years. This is an essential part of
the technique.
(iv) Seed – Deficiency in natural seed fall should be made up by collecting and
broad-casting seed and if necessary it may be repeated in the second year also.
(v) Burning – Burning should be done before a good seed year. It may be
repeated later when necessary to stimulate the growth of stagnating whippy
regeneration.
(vi) Fencing – The regeneration area should be fenced with game-proof fence
right from the beginning.
(vii) Weeding and shrub cutting – Through rains weeding should be done
annually atleast for the first three or four years. Thereafter, intensive shrub cutting
during the rains should be carried out as long as shrubs impede the regeneration.
(viii) Top canopy – When sufficient number of large-leaved whippy seedlings
have been obtained, the canopy may be gradually lightened in atleast two operations.
When enough number of seedlings reach the woody stage, the canopy may be opened
up further and the area control-burnt after felling. This would incidentally stimulate the
growth of stagnating woody regeneration.
The essence of this technique lies in its complete and not piecemeal
implementation. Though it has not been tried on a large scale, it is claimed by Seth that
the moist bhabar sal forests can be regenerated by this technique in 20 years, i.e., one
or two years in getting the seedlings, about 8 or 9 years in tending them to a height of 2
to 3 m and then another 10 years in removing the overwood. This technique, which
comes very close to artificial regeneration, has not taken the operational cost and
availability of man power into consideration.
In the very moist and moist sal forests of Assam [type 3C/C1b and 3C/C2b(iv)] the
technique of obtaining sal natural regeneration in Goalpara and Kamrup is as follows:
(i) Cutting and burning of evergreen under growth till it is converted into
Imperata.
(ii) Strips 20 ch X 3 ch are cleared with North-South orientation and burnt
annually till a good seed year occurs.
(iii) Strips about 2 m wide are cleared, weeded along with hoeing round plants,
alternating with equally wide unweeded strips in which the weeds of the weeded portion
are burnt.
The technique is followed for several years till the regeneration is established.
Recent observations, however, indicate that the technique is not successful.
In Singhbhum forests of Bihar, areas with adequate advance growth are
regenerated successfully by clear-felling all trees above 30 cm excepting 3 or 4 trees per
hectare and cutting back advance growth followed by cleaning and thinning at regular
intervals.
In M.P. where enough advance growth is usually present and frost is not a
problem, the following technique is followed:
(i) Clear-felling is done if adequate thumb-thick woody shoots are present. The
adequacy of the woody regeneration is assessed by regeneration survey with 5%
intensity of sample and quadrats 2.4 m X 2.4m along the survey line. If 60% of the
quadrats have one or more woody shoot, the advance growth is considered adequate.
(ii) Cleaning is done in 5th and 10th year and first thinning in 20th year.
Areas deficient in regeneration are thinned moderately heavily and inspected
annually till they are fit for clear-felling.
TEAK
As this species can be artificially regenerated with great ease, natural
regeneration of this species has not been given the attention it deserves. As very large
areas are to be regenerated and as the cost of artificial regeneration is high, it would be
worth while to develop the technique of natural regeneration of teak for each type or
subtype and without being dogmatic, the cheaper and the surer method of regeneration
of a particular type should be applied. The All India teak symposium has recommended
the classification of teak forests into five types, viz., (1) Very dry teak, (2) Dry teak, (3)
Semi-moist teak, (4) Moist teak and (5) Very moist teak. As far as the present position
is concerned, the dry and semi-moist teak areas, found in Betul, parts of Hoshangabad,
Seoni, Chindwara (M.P.) keep on getting profuse natural regeneration throughout the
life of the crop. This can be developed into young established crop without difficulty. In
others, the natural regeneration is deficient or absent. In the moist and very moist
types, indications are that artificial regeneration is sure and cheqp but in the very dry
teak artificial regeneration appears to be neither sure nor sheap and therefore it would
better to develop some technique of natural regeneration supplemented with artificial
regeneration where necessary.

EVERGREEN AND DECIDUOUS FORESTS OF ANDAMANS

The natural regeneration of the evergreen and deciduous forests in Andamans is
obtained under ‘Andamans’ canopy lifting shelterwood system. The technique of
obtaining natural regeneration in both types of forest in pracitically the same with the
main difference that in deciduous forests a general burning is carried out after
regeneration fellings in the month of March/April but it is not carried out in evergreen
forests. The following operations are carried out in the sequence given:
1. Extraction of all commercial timbers from the regeneration area – All
saleable trees above a prescribed g.b.h., which is 150 cm for hardwoods, 120 cm for
softwoods and 180 cm for others, are felled and their timber is expeditiously removed.
All the sound trees of commercial species below the prescribed g.b.h. mentioned above,
are left as advance growth.
2. Canopy lifting – Closely following the extraction of timber, canopy lifting is
done by (a) felling all poles of non-commercial species and under growth upto 10m
height; (b) girding trees of 10 to 20 m height not needed as seed bearers or as part of
the future crop. The area presents a picture of ‘sieve without blanks’ so that adequate
light is filtered through the canopy.
3. Burning – During March-April, after completion of the above two operations,
a general burning without heaping the material is carried out in deciduous forests except
in those portions where adequate advance growth is present but this is not done in
evergreen forests.
4. Broad-casting seed – Where the advance growth and/or the seed bearers
are considered insufficient to regenerate the area, seed of the commercial species is
broadcast during April.
5. Weedings – As the rains start, the forest floor is stocked with new seedlings.
To help them to grow, two to three weedings are done in first year, one weeding the
second and third years. Climber cutting is also dope along with weedings.
6. Cleaning – All unwanted growth is felled or girdled in the regeneration is
considered established.
7. Thinning – The first thinning is carried out in 6th year followed by thinning at
the age of 15, 30 and 50 years.

EVERGREEN FORESTS IN ARUNACHAL PRADESH

Natural regeneration in these forests is obtained by carrying out the following
operations:
1. All trees above 180 cm g.b.h. are removed in one operation from the top
canopy and trees below this g.b.h. are retained as part of the future crop.
2. The trees of the middle storey are not felled to control the weed growth and
Mikania climber.
3The regeneration of principal species Dipterocarpus macrocarpus and shorea
assamica present in seedling and sapling stage is tended and supplemented. For this
1.2 m wide strips, spaced 10 m apart, are cleared. The regeneration in these strips is
weeded and cleaned by removing all unwanted weed growth and miscellaneous species
and the gaps are filled up by sowing 6 to 8 Diupterocarpus seeds in thalies 1.8 m apart.
The strips are weeded once during the rains and blanks in thalies planted up with
wildings. These tending operations are carried out for 3 years successively and there
after in the 5th, 7 th and 10th year when the regeneration in the entire area gets
established.

NATURAL REGENERATION FROM VEGETATIVE PARTS

Normally trees species regenerate by seed but some species have the power to
regenerate themselves by vegetative parts, viz., root, stem, branch, etc. Reproduction
obtained from these parts is called vegetative reproduction which is defined as
‘asexual reproduction in plants from some part of the plant body, e.g., of
trees by coppice or root sucker or from root, stem or branch cuttings’.

ADVANTAGES OF VEGETATIVE REPRODUCTION

The power to produce new plants by vegetative reproduction gives the species
following advantages:
(i) One plant produces several plants;
(ii) This is also possible when the plant is not capable of producing seed;
(iii) The plants obtained from vegetative reproduction grow faster than the
seedlings and cost less;
(iv) The capacity can be used for genetical improvement of the species either by
layering a branch of a plus tree or using its bud for budding or its flowering shoot for
grafting on an inferior tree of the species. A plus tree is defined as a tree which is
genetically superior, i.e., a tree which is superior to other trees in its habitat
from the point of view of its size, length, shape, and cylindricalness of stem,
height, diameter and volume increment, timber quality, resistance to disease,
and other specific qualities, viz., high resin yielding capacity etc.

METHODS OF VEGETATIVE REPRODUCTION

Vegetative reproduction can be obtained by any of the following methods:
(i) Coppice – Coppice is that method of vegetative reproduction in which the
tree, plants or the seedlings of a species when cut from near the ground level, produce
coppice shoots. Coppice shoot is defined as ‘a shoot arising from an
adventitious bud at the base of a woody plant that has been cut near the
ground or burnt back’.
 (ii) Root sucker – Root sucker is that method of vegetative reproduction in which
a root of a plant is partially or wholly cut to produce a shoot called root sucker.
(iii) Cutting – Cutting is that method of vegetative reproduction in which a
portion of the stem, branch or root is placed in the soil or other medium, in order that it
may develop into a plant. Depending on the part of the plant used, cuttings may be
classified into stem cutting, branch cutting, root cutting and root and shoot cutting
which is defined as ‘a young plant with pruned tap-root and severed stem used
for planting’.
(iv) Layering – Inducing development of roots on branches while they are still
attached to the trees is called layering. Layering may be done in soil or in air and so
layering is of two kinds, viz., soil layering and air layering. Soil layering is that method
of vegetative reproduction in which an undetached branch with bark or after removing a
ring of bark 1 cm wide is partially buried in the soil to enable it to strike root, when it is
cut from the parent plant to be planted elsewhere. Air layering, on the other hand, is
that method of vegetative reproduction in which bark is removed from part of the
circumference of a thin branch, and the wound is covered with some soil and moss and
tightly wrapped round with polythene sheet. When the roots are formed the branch is
gradually severed from below the rooted portion and planted in pots to be planted in
field later.
(v) Grafting – Grafting is a method of vegetative reproduction in which a portion
called scion, of one plant is applied to stock, usually rooted, which is another plant, with
the object of securing vegetative union between the two, when the scion is detached
from the parent plant and the shoot of the other plant is severed, to produce a new
plant to be planted out. There are several methods of grafting but cleft grafting has
been found to be more useful for genetical improvement work in forestry.
For cleft grafting, flowering shoots of plus trees are cut and kept about 40 to 45
cm long. These are scions. If the scions are to be transported to long distances, their
cut ends are dipped in melted wax and then taken out. Thus, the cut end gets a coating
of wax and therefore it does not dry and is not liable to be attacked by insects or fungi.
Inspite of this precaution, attempt is made to transport the scions to the grafting place
latest within 24 hours. On reaching the grafting site, the scion is kept about 30 to 40
cm long and the rest is cut off. The cut end is then given the shape of a wedge 5 cm
long and then the scion is made to stand in a bucket with some water.
 The stock is selected from those 2 or 3 year old nursery plants whose girth at
about 20 to 25 cm height from the ground may be about 1 to 2 cm. At this height the
stock is cut and is cleft with a sharp knife for a distance equal to the wedge of the scion.
Then the scion whose girth at the top of the wedge is equal to the girth of the stock is
fitted upright in the clefted stock with the wedge inside it. Then this portion is tied
firmly with sutli in such a way that the bark is not damaged. The sutli is tied from the
lower side upwards in such a way that neither the cleft portion of the stock nor the
wedged portion of the scion should be visible and that the scion can not be pulled out.
Then a polythene strip is wrapped over the joint and tied with sutli again so that rain
water can not enter the joint. After about 1 ro 2 months, the joint is opened to see if
the scion and stock have joined. If not, it is tied again. The most important precaution
in this work is to see that the diameter of the scion above the wedge and that of stock
are equal so that the cambium layers of the two join well. Such cleft-grafted plants start
producing genetically superior seed in 3 or 4 years. On the basis of an experiment
conducted on teak in Dehradun, April and May have been found to be the best months
of cleft grafting.
(vi) Budding – Budding is that method of vegetative reproduction in which a bud
with some portion of the bark of a genetically superior plant is grafted on an inferior
plant so that it may produce shoot when the old shoot of the stock is cut off. Bud is
grafted on the stock in the form of a patch after removing the bark of the stock in that
portion or by making an incision in the bark of the stock in the form of T and then fixing
the scion inside it. The scion is tied on the stock keeping the bud uncovered. The scion
is first tied with sutli and then with polythene strip and sutli as in the case of cleft
grafting. April and May have been found to be the best months for budding on teak in
Dehradun.
Out of the methods described above, coppice, root sucker and cuttings are used
for regeneration work, while layering, grafting and budding are used for genetical
improvement work in forestry. Of the methods used in regeneration of forests, coppice
and root suckers are used for natural regeneration work while cuttings are used for
artificial regeneration work. Therefore, the methods of obtaining natural regeneration
by coppice and root sucker only have been described in this chapter.

NATURAL REGENERATION BY COPPICE

Natural regeneration by coppice can be obtained either by:
(1) Seedling coppice; or (2) Stool coppice.
(1) Seedling coppice is defined as the ‘coppice shoots arising from the base of
seedlings that have been cut r burnt back’. This method of obtaining natural
regeneration is used for cutting back woody shoots and established reproduction which
is not making any progress so that they may produce vigorous shoots and soon develop
into saplings and later into poles. It is generally used in case of sal and teak. The
advance growth of sal in the form of whipply shoots, woody shoots and, some-times,
even the established regeneration often does not progress due to adverse
environmental conditions and keep on stagnating for year. If this stagnating advance
growth is cut back and given proper light conditions, it progresses fast and soon
develops into a sapling and pole crop. This method of obtaining natural regeneration of
sal is used in several sal divisions in U.P. (e.g., Dehradun), M.P., Bihar and Orissa,
Similarly, this method is used for obtaining natural regeneration to teak in many division
of M.P.
(2) Stool coppice is the coppice arising from the stool or a living stump. In this
method, regeneration is obtained from the shoots arising from the adventitious buds of
the stump of felled tree. The coppice shoots generally arise either from near the base
of the stump or from its top. Of the two, those arising from near the base are better
because they get established easily. The shoots arising from near the top of the stump
are liable to be damaged by he rotting of the upper portion of the stump as well as by
wind, etc.

FACTORS AFFECTING NATURAL REGENERATION BY COPPICE

The following factors affect natural regeneration by coppice:
(1) Species – All species do not coppice and even in the species that coppice, the
power varies with species. On the basis of their power to coppice, species are classified
into following four categories, some examples of each being given against them:
(i) Coppice strongly – Acacia catechu, Albizzia spp., Anogeissus spp.,
Azadirachta indica, Broussonetia papyrifera, Butea monosperma, Casia fistula,
Cleistanthus collinus, Dalbergia spp., Diospyros tomentosa, Emblica officinalis,
Eucalyptus globules, Garuga pinnata, Melia azedarach, Morus alba, Ougeinia oojeinensis,
Prosopis juliflora, Robinia pseudacacia, Salix spp., sapium sebiferum, shorea robusta,
Syzygium cumini, Tectona grandis, etc.
(ii) Coppice firly – Aesculus indica, Chloroxylon swietinia, Hrdwickia binata,
Jglans regia, Pterocarpus marsupium, Quercus incana, Quercus lanuginose, Quercus
semecarpifolia, Terminalia belerica, Terminalia tomentosa, etc.
(iii) Coppice badly – Adina cordifolia, Bombax ceiba, Casuarina equisetifolia,
Madhuca latifolia, Populus ciliate, etc.
(iv) Do not coppice – Abies pindrow, Cedrus deodara, Picea smithiana, Pinus
roxburghii, Pinus wallichinana, etc.
In some species, e.g., Acacia Arabica, Boswellia serrata, Quercus dilatata, etc.,
coppicing power varies, sometimes, with locality to locality.
(2) Age of tree – The older the tree, the lesser is the coppicing power because
old bark prevents the emergence of dormant buds. Youngers saplings and poles, as a
rule, coppice readily and profusely.
(3) Season of coppicing – The best season for coppicing is a little before growth
starts in spring because delay results in reducing the growing period. This season has
another advantage that at this time there is large reserve of food material in the roots
and all of it is utilized in the growth of coppice shoots. The greater the delay after the
growth season has started, the more depleted will be the food reserves and
consequently the growth of the coppice shoot will be affected. But in places where
there may be danger of late frost in spring, coppicing should be done after the danger is
over. If the coppice coupe has to be burn after felling, burning should be done as early
as possible and definitely before coppice shoots have started sprouting, otherwise they
will be burnt.
(4) Height of stump and method of cutting it – The effect of height of stump
varies with species. For example, some bad or indifferent coppicers, e.g., Casuarina
equisetifolia, Hardwickia binata, Manilkara hexandra, produce better coppice shoots
when the stumps are higher.
Usually, lower the stump, the better it is for the coppice because they are not
liable to be damaged by wind or animals. Such coppice shoots also develop
independent roots and rooting of the stump does not affect them. On the other hand,
coppicing low is expensive and there is usually a danger of the stump splitting or drying
up from top and in such cases, coppice may be adversely affected. Low coppicing is
also, sometimes, inadivisable if the stump is affected by root rot as in case of dry sal
and teak coppice areas. If the stump is cut flush with the ground level, there is no place
for the buds to sprout. On the other hand, the higher the stump, the greater the
possibility of the shoots being damaged. Thus, the stumps should be neither too low
nor too high, a height of about 15 to 25 cm being very suitable.
The method of cutting or trimming the stump also affects the coppice. In the
past, it was insisted that the stump should be made conical with the highest point in the
centre so that the water drains off. In this method, besides expense, there the water
drains off. In this method, besides expense, there was always a danger of the stump
being damaged. Therefore, now the stump is given some slope in one direction. It
should be clean cut without damaging the bark or splitting the wood.
(5) Rotation – Since most of the trees coppice best during the early age, coppice
rotation should be short. Long rotation encourages seedling regeneration and for that
reason, coppice rotation is generally shorter than the age at which trees produce good
viable seeds.
(6) Silvicultural system – The coppice shoots are strong light demanders and
therefore they must be worked under systems involving clear-felling. At the most, some
standards may be kept. The silvicultural system under which coppice regeneration is
obtained depends upon the method of obtaining regeneration. When natural
regeneration is obtained form seedling coppice, the silvicultural system is a high forest
system because the essence of a coppice system lies in obtaining the new crop from
stool coppice under short rotations. Thus, seedling coppice is used to obtain natural
regeneration of sal and teak under clear-felling system in Bihar, M.P., and parts of
Maharashtra and under uniform or Indian irregular shelterwood system for sal in U.P.
When natural regeneration is obtained from stool coppice, the silvicultural system may
be either simple coppice system, coppice-with-standards system or coppice-with –
reserves system.
Stool mortality in coppice – Trees can not keep on coppicing indefinitely and
they die after sometime. Therefore in every coppice forest, some stools do not coppice
in each in every coppice forest, some stools do not coppice in each rotation. The
mortality of stools in coppicing varies with species and locality. For example, while in
dry fuel forests of Tamil Nadu the mortality in stools has been observed to be about 10
to 15%, the mortality in khair in Ramnagar division (U.P.), has been observed to be 20
to 75%. The mortality can be made up by encouraging seedling regeneration to come
up and develop into trees. If this does not take place, coppice reproduction may be
supplemented with sowing or planting.

TENDING OF STOOL COPPICE

Usually each stool produces several coppice shoots. In order to enable them to
develop into good poles, it is necessary that the number of shoots be reduced to 2 or 3
in the second or third year and on their developing further, the number be reduced to
one. This has favourable effect both on height and diameter increment.

NATURAL REGENERATION BY COPPICE UNDER VRIOUS SILVICULTURAL SYSTEMS

As already mentioned, natural regeneration by coppice is generally obtained by
simple coppice system, coppice-with-standards system and coppice-with-reserves
system.
The simple coppice system is that coppice system in which coupes are clear-
felled on short rotation to get new coppice crops. Naturally, this system is applicable to
species which coppice strongly. As younger trees coppice more vigorously, coppice
rotation is usually kept as 20 to 40 years. All trees of the coupe are clear-felled with no
reservation for shelter-wood. In the year following the clear-felling, the coppice species
where they may be interfering with that of better species and by climber cutting. If the
number of coppice shoots per stool is more than two, the most promising two shoots
are kept and the rest are cut back. After a year or two, only one shoot per stool is kept
by cutting down the other. As stumps can not coppice indefinitely, natural seedlings
appearing in the area are allowed to grow. The blanks in the coupes are regenerated by
sowing or planting.
The coppice-with-standards system is that coppice system in which part of the
crop is retained to form an uneven-aged overwood. Thus the resultant crop is two
storeyed, the upper storey being of standards standing over the lower storey of coppice
crop. The standards are generally of some wind-firm, valuable species and may be even
of species other than the coppice. The rotation of the standards is a multiple of that of
the coppice and when it is more than twice of the coppice rotation, the standards are
retained in such a way as to give proper representation to all age class multiples of
coppice rotation. The standards occupy about 1/3 to ½ of the area of the canopy and
this space is equally divided into standards of all age classes. After selecting standards
of coppice rotation and its multiples, the ret of the crop is clear-felled. The coppice
shoots are cleaned and thinned like the simple coppice system.
The coppice-with-reserves system is a coppice system in which well-grown
saplings and poles are retained in coupes to form part of the new crop and the rest is
felled. The reservation is done with the object of improving the condition of the crop,
providing protection against frost and erosion, supplying seed, protecting valuable
species as well as species with edible fruit, etc. In this system, felling is done keeping
the requirements of the crop in view and may range from clear-felling in certain portions
to practically no felling in others. Thus, the regeneration of the area is not only by
coppice but also by saplings and poles grown from seed. This system also provides for
artificial regeneration in clear-felled patches if coppice does not come up. The new crop
is tended regularly as in other systems.

NATURAL REGENERATION BY ROOT SUCKERS

Natural regeneration by root suckers is not being attempted on any large scale
any where in this country. This method used to be followed, sometimes, on the canal
bank plantations in U.P. and the chief species in which this was effected was sissoo.
Where this method was followed, it was usually to dig continuous or discontinuous
circular trenches with diameter of about 6 m round the isolated trees so that their roots
may be severed and root suckers produced, which, with tending, could be developed
into trees.
The trees produced in this way are liable to wind-throw and poor in growth and
therefore this method is not being favoured now. Diospyros root suckers are sometimes
encouraged because the root suckers produce best biri leaves.

OTHER OPERATIONS OF VEGETATIVE GROWTH

The following operations, though they are not methods of obtaining natural
regeneration, are, sometimes, carried out for obtaining new vegetative growth on trees
for various purposes:
1. Pollarding – Pollard is defined as ‘a tree whose stem has been cut off
in order to obtain a flush of shoots, usually above the height to which the
browsing animals can reach’. Thus pollarding is an operation in which the stem of a
tree is cut off at a height beyond the reach of browsing animals with the object of
producing a crown of new shoots from buds below the cut. The flush of new shoots is
cut down periodically so that the pollard may produce fresh shoots again.
Examples: (i) Salix is pollarded in the Kashmir valley to produce shoots for wicker
work.
(ii) Hardwickia binata is pollarded in Andhra Pradesh to produce shoots suitable
for fibre extraction.
(iii) Some species of mixed dry deciduous forests in North Coimbatore (Tamil
Nadu) are pollarded to provide fuel of preferred dimensions for boiling jaggery.
(iv) Grewia oppositifolia is pollarded in Kumaon and Garhwal hills (U.P.) to
provide shoots for fibre and fodder.
2. Lopping and pruning – Lopping means cutting of branches of a tree.
Incidentally the lopped trees produce new shoots which are annually or periodically
lopped for various purposes. Though pruning means cutting of branches from the bole
of trees for improvement of timber of trees, this term is, sometimes, used for cutting
branches to produce new shoots.
Examples: (i) Butea monosperma, Schleichera oleosa, Ziziphus mauritiana,
Ziziphus oxylopyra, Acacia Arabica, Acacia catechu, Albizzia lucida, etc., are regularly
pruned to produce succulent shoots with thin back not only to provide proper feeding
ground for the lac larvae but also to improve the general crown structure of the host
plant.
(ii) Diospyros is regularly lopped to produce new shoots with tender leaves
required for biri industry.
(iii) Quercus incana, Quercus dilatata, Quercus semecarpifolia, Acaia spp.,
Anogeissus spp., Grewia spp., Hardwickia binata, Melia zedarach, Moringa oleifera,
Morus spp., Ougeinia oojeinensis, Schleichera oleosa, STereospermum personatum,
Tamarindus indica, Terminalia tomentosa, Terminalia paniculata, Terminalia belerica,
Kydia calycina are annually lopped for leaf fodder for domestic and gujar’s cattle.
(iv) Quercus incana, Morus spp., are regularly lopped for rearing tussar and silk
worms.
CULTURAL OPERATIONS
In the year following the year of regeneration fellings, it is necessary to carry out
some operations, called cultural operations, in the regeneration area to remove the
after-effects of felling and to improve the conditions of growth for the regeneration.
Cultural operation is defined as ‘the operation, as a rule not directly
remunerative, undertaken to assist or complete existing regeneration, to
promote the proper development of the crop or to minimize the after-effects
of felling damage. It, therefore, includes subsidiary felling, weeding,
cleaning, unremunerative improvement fellings, and thinning in groups of
advance growth, girdling or poisoning of unwanted growth, climber cutting
and even pilling of felling debris, and controlled-burning but usually not other
ground operations nor pruning. It is generally associated with silvicultural
systems relying primarily on natural regeneration.’
In short, the cultural operations, done in the year following main or ny felling,
usually consist of:
(i) Removal of marked trees left unfilled provided their felling is still considered
necessary;
(ii) Removal of trees so badly damaged in felling that their retention is of no use;
(iii) Cutting back malformed and ill-developed advances growth if it can give a
good coppice shoot;
(iv) Removal of inferior species or weed growth where it is interfering with the
growth of the economically more important species and where advance growth has been
coppiced to admit light for the coppice to develop;
(v) Thinning of even-aged groups of poles if it has not been done with felling;
and
(vi) Climber cutting.

NATURAL REGENERATION SUPPLEMENTED BY

ARTIFICIAL REGENERATION
Often the natural regeneration is not complete during the regeneration period
and part of the regeneration area remains blank. Under such circumstances, there are
tow alternatives to deal with the situation, viz., (i) either increase the regeneration
period and allow the area to remain under regeneration for some more years, or (ii) fill
up the blank patches artificially and complete the work. As the first alternative creates
complication in management, the failed patches of the regeneration area are generally
filled up by artificial regeneration either by sowing or planting. The earlier his work is
done the better because delay results in the invasion of the failed patches by grass and
weeds making the artificial regeneration work difficult. In addition, delay also results in
the increase in the period of closure to grazing and protection against fire, both of which
cause annoyance in the local population.
This work is done in practically all types of forests, viz., - in sal, chir and deodar
forests managed under shelterwood system, in teak coppice coupes and natural
regeneration areas deficient in advance growth in Madhya Pradesh and Maharashtra, in
the teak-bearing deciduous forests, in the tropical moist deciduous and wet evergreen
forests and in bamboo forests where bamboo has flowered and died.
Supplementation work is done either by sowing seed, or by planting root-shoot
cutting or any other kind of cutting, naked root planting, or planting plants raised in
containers such as polythene bags, etc.
Examples of methods of supplementing natural regeneration of some
species:
Sal – Sowing of seeds or planting container plants raised in polythene bags, e.g.,
in Midnapur (West Bengal) and Dehradun (U.P.)
Teak – Stump (root and shoot cutting) planting.
Deodar – Naked root planting.
Chir – Sowing seed or planting 2 year old plants raised in polythene bags.
 ARTIFICIAL REGENERATION

Natural regeneration described in the last chapter, is a special feature of forestry,

which makes it fundamentally different from other branches of land use. Nobody thinks
of regenerating agricultural or horticultural crops by natural means. Sowing and
planting methods have been in use in these enterprises for hundreds of years but in
forestry they have been adopted relatively recently, and still more recently on a larger
scale. The ratio of artificial regeneration areas to natural regeneration areas varies from
state to state and even from division to division. While in some western countries, it
may be as high as 50% or more, in India it was only about 2% upto the end of the 4th
plan.

DEFINITION
Artificial regeneration is defined as ‘the renewal of a forest crop by
sowing, planting or other artificial methods. It also refers to the crop so
obtained.’ Normally such a crop is called by another term ‘plantation’ which is
defined as ‘a forest crop raised artificially, either by sowing or planting.’
Sowing refers to direct sowing which is defined as the ‘sowing of seed directly
on an area where a crop is to be raised as opposed to sowing in a nursery’
Planting refers to transferring of seedlings or plants in the area to be regenerated after
they have successfully passed the critical stages of germination and initial development.
The planting stock may be procured from some other forest, and in that case it is
referred to as wilding which is defined as ‘a natural seedling (in contrast to a
nursery grown seedling) used in forest planting.’ But it is usually more
economical to raise them, as in agricultural or horticultural crops, in controlled
conditions in an area called nursery which is defined as an area where plants are
raised for eventual planting out.’ Planting is a far more dependable method of
artificial regeneration, than direct sowing which can be done successfully only under
very favourable conditions.

OBJECTS OF ARTIFICIAL REGENERATION

Artificial regeneration is mainly carried out for the following two objects:
 (A) Reforestation (B) Afforestation.
Reforestation may be defined as the ‘restocking of a felled or otherwise cleared
woodland’ by artificial means. In other words, reforestation is the raising of a forest
artificially in an area which had forest vegetation before. On the other hand,
afforestation is the ‘establishment of a forest by artificial means on an area from which
forest vegetation has always or long been absent.’

REFORESTATION
OBJECTS OF REFORESTATION
Reforestation is carried out with the following objects:
(1) To supplement natural regeneration – This has already been described
in the last chapter.
(2) To give up natural regeneration in favour of artificial regeneration –
When natural regeneration of the desired species is very slow and uncertain, it is not
economical to regenerate areas by natural regeneration. In such cases, artificial
regeneration is adopted in place of natural regeneration, to ensure quicker, cheaper and
more certain stocking of the regeneration areas. Artificial regeneration of fir and spruce
forests in Chachpur (H.P.), sal forests in parts of U.P., Bengal and Assam and teak
forests in parts of M.P., Maharashtra, Kerala etc., are examples of this object.
Sometimes, artificial regeneration is adopted to improve the quality of timber, example
being artificial regeneration of twisted chir areas with seed from straight grained trees.
(3) To restock forests destroyed by fire and other biotic factors – Even in
case where natural regeneration can be ensured, artificial regeneration has to be
adopted if the forests are destroyed by fire and no seed bearers are left in the area to
supply seed for natural regeneration.
Similarly, the forests destroyed by excessive felling followed by unrestricted
grazing and lopping have to be regenerated artificially to cover the area with forest
vegetation soon. This type of work has been done in Hoshiarpur siwaliks (Punjab),
Panchayat forests of Tamil Nadu, and in the catchment areas of the rivers with hydro-
electric projects.
(4) To change the composition of the crop – Sometimes, the natural forests
are of low value as the proportion of the valuable species in the crop is low. Selective
fellings of valuable species reduces their percentage still further. Mixed deciduous
forests and wet evergreen forests are examples of such forests. Their work is being
done in most of the states in dry mixed deciduous forests. In the temperate forests, the
attempt to raise deodar in oak forests and in the lower zone of fir and spruce forests is
an example of this type of work.
(5) To introduce exotics – Sometimes, the indigenous species are so slow-
grown that they cannot satisfy the objects of management or the requirements of any
industry. In such circumstances, it becomes necessary to introduce some exotics which
can be raised successfully in the locality and yet fulfill the objects of management or the
requirements of any industry. Plantations of Eucalyptus, tropical pines, poplars, etc., are
examples of this object.
FACTORS AFFECTING THE CHOICE BETWEEN ARTIFICIAL AND NATURAL
REGENERATION
Before taking up artificial regeneration work on a large scale, it should be seen
as to which of the two methods of regeneration, viz., natural or artificial, satisfies the
objects of management more efficiently in the given set of conditions. The choice
between the two methods is governed by the following considerations:
(i) Risk of loss and deterioration of soil – While in the natural regeneration,
there is minimum exposure of the soil, the artificial regeneration involves its exposure
for a longer period. The exposure of the soil results in erosion by water on sloping
areas and by wind on sandy flatter areas and deterioration elsewhere. Thus, the fertility
of the soil is reduced. The situation is worsened if agriculture is also practiced prior to
and / or after the sowing or planting. But this does not happen in natural regeneration.
Therefore where deterioration of loss of soil is likely to be serious, natural regeneration
should be preferred to artificial regeneration.
(ii) Crop composition – In the renewal of the forest by natural regeneration the
composition of the original crop is more or less maintained. Therefore, if the original
crop consists of only few valuable trees, natural regeneration cannot improve the new
crop in terms of value. On the other hand, artificial regeneration can drastically change
the composition of the new crop either by raising mostly the valuable species occurring
on that site, or by introducing other valuable indigenous or exotic species suitable for
the locality, in pure crops or in desired mixtures. It also provides an opportunity of
raising a cover crop or a soil-improving crop along with the forest species. Thus, where
crop composition has to be changed to get a better return from the new crop, artificial
regeneration has to be adopted.
(iii) Genetical consideration – Even where the crop composition is not to be
changed, it is at least desired that the new crop should consist of trees of good quality.
In natural regeneration, the seed for the new crop is obtained from the trees occurring
on the site. Though it is expected that the selected seed bearers would be genetically
superior trees, the continued selection and felling of good trees, generally leaves the
area full of inferior or average trees. Under these circumstances, the new crop would
also be of inferior or average quality trees. If he quality of the trees forming the new
crop is to be improved, it is absolutely necessary that the natural regeneration should be
given up in favour of artificial regeneration in which seed from the genetically superior
trees is sown or plants raised from genetically superior seeds, are planted. In twisted
chir pine areas, there is no way of improving the quality of the trees of the new crop
except by artificial regeneration.
(iv) Risk of damage by pests – It is generally said that mixed crops resulting
from natural regeneration are far more resistant to attack by insect pests than the pure
and unmixed crops resulting from artificial regeneration. Concentration of food of a pest
at one place in pure plantations may result in building up population of that pest to
epidemic proportion causing serious, and sometimes irreparable, damage to the
plantation. On the other hand, physical separation of food plants in mixed natural
forests tends to inhibit the spread of the insect pests and also keeps their population
under control. Similarly, plant parasites and fungi are reported to spread rapidly in pure
plantations than in natural forest. Therefore where there may be danger of pure crops
being attacked by insects, parasites and fungi, natural regeneration should be preferred
to artificial regeneration as the former usually results in mixed crops.
(v) Flexibility of operation – In artificial regeneration, elaborate arrangements
have to be made well before time of sowing or planting. For instance, the area has to
be cleared and fenced and soil working completed by May. Having done all this, if the
seed is not available or the monsoon fails, all the expenditure incurred is wasted. On
the other hand, in natural regeneration, very little work is done before seedfall and
therefore the work can be postponed without any serious loss of money or effort. Thus,
in case of uncertain conditions, natural regeneration is to be preferred to artificial
regeneration.
 (vi) Density of stocking – In artificial regeneration, it is easier to obtain a
correct and uniform stock while in natural regeneration, it is too dense at some places
and too sparse at others because seed dispersal is governed by wind and the situation
of the seed bearers. Thus, if uniform stocking is aimed at, artificial regeneration should
be preferred.
(vii) Yield – The yield per hectare in terms of volume and its value is higher in
case of artificial regeneration because of the saving in time of establishment, greater
proportion of more valuable species, resultant full stocking of proper density and
concentration of work. Even the less valuable species can be sold at higher price along
with more valuable species because of concentration of work. Thus, for better volume
and financial yield, artificial regeneration should be preferred to natural regeneration.
(viii) Time factor – Time is the most important factor in deciding the choice
between natural or artificial regeneration. Natural regeneration is liable to considerable
delays, especially with species which seed at long intervals and have uncertain
establishment period. Delay results in increased cost of formation, loss of increment
and lengthening of rotation. On the other hand, artificial regeneration completes the
regeneration work quickly and therefore results in considerable economy in cost of
formation and in better financial return. In addition, time is important from another
point of view also. In our country, the local villagers have grazing rights or concessions
and the regeneration areas cannot be kept fenced and closed to grazing indefinitely for
obtaining natural regeneration. The greater is the time required for establishment of
young crop, the greater are the chances of its failure. Therefore, if regeneration area
can be stocked completely within reasonably short time by natural means, it should be
followed; otherwise artificial regeneration should be taken up.
(ix) Cost – Cost is another important consideration affecting choice of method of
reproduction. Naturally, cheaper of the two methods has to be selected. Natural
regeneration is supposed to be cheaper than artificial regeneration. Though there is
practically no initial cost of formation except slash disposal and fencing, where
necessary, in natural regeneration, the weedings and shrub cutting have to be repeated
for such a long time, that natural regeneration often becomes as costly as, and
sometimes costlier than, artificial regeneration. Unlike plantations, results of natural
regeneration are generally slower and, sometimes, even inconspicuous; whereas the
success or failure of a plantation is apparent by the end of the very second year.
 In short, natural regeneration should be preferred to artificial regeneration if it
can be obtained satisfactorily, within reasonable time and cost. Otherwise, artificial
regeneration should be preferred. Leaving the cases in which natural or artificial
regeneration have proved their efficiency cent per cent, the golden rule should be to
follow natural regeneration for a reasonably short period and then complete the
regeneration operation by supplementing natural regeneration with artificial
regeneration.
Inspite of these academic considerations, the recent trend is towards man-made
forests and, during the past few years, greater effort has been made to raise them with
the following objects:
1. Increase the yield from forests to meet the fast increasing demand of timber
for building construction, industries, defence and communications;
2. Shorten the rotation by raising fast-growing species;
3. Locating forests with relation to the location of industries;
4. Meeting the demand of agricultural implements, housing, fodder and firewood
of the rural population;
5. Improvement of agro-ecosystem, control of erosion, and beautification of
countryside;
6. Concentration of work resulting in easier supervision, easier mechanization of
operation, cheaper logging and extraction; and
7. Increasing employment potential.

ESSENTIAL PRELIMINARY CONSIDERATIONS

After deciding in favour of artificial regeneration, decision has to be taken on the
following essential preliminary considerations:
I. Choice of species;
II. Selection of site;
III. Choice of method of artificial regeneration viz., sowing or planting, and
choice between the various methods;
IV. Spacing; and
V. Arrangement of staff and labour.

I. CHOICE OF SPECIES
 The success of artificial regeneration depends upon correct choice of species.
Slightest error in this regard may result in failure of the plantation and consequently loss
and wastage of money and time. Choice of species depends on the following factors:
(1) Climate and micro-climate – The general climate of the region as well as
the micro-climate of the plantation site are very important factors governing he choice
of species. Only those species which can grow in the regional climate as well as the
micro-climate of the plantation site, should be selected. As far as the indigenous species
are concerned, the species growing in the locality give a good indication of the species
that can grow. But for exotics, a comparison between the climatic (particularly
bioclimatic) conditions prevailing under their homeland and those in the proposed
plantation areas, should be carefully made and only those species should be selected
which have, in their original home, conditions similar to those in the proposed plantation
site.
(2) Soil conditions – Suitability of the species to the soil and moisture
conditions of the proposed plantation area is the most important factor governing the
success or failure of plantation. Only the species which are suited to soil and moisture
conditions should be elected to avoid failure. As the species growing on the site give a
good indication of species that can be successfully raised, a stock map of the area
prepared before felling is very helpful. Occasional presence of a species, however,
should not be taken to be a guarantee for its suitability. For example, even though
scattered teak of good quality is found in parts of Malabar, these areas have not been
found suitable for teak plantations. In a large plantation, as the soil may vary in
different parts, it is advisable to examine soil of the different parts of the plantation,
before allotting species to them. Guidance may, however, be taken from indicator
plants or indicators. Indicator plant (syn. Soil indicator) is ‘any plant which by its
presence, increase or decrease, indicates the quality of the site.’ Indicators
are ‘species or communities which, with reference to site, indicate generally
the presence in it of certain conditions, processes and uses and sometimes
specifically the species that would grow in it.’ A few examples of indicator plants
are given below:
(i) Lime rich soil
(a) in the Himalayas – Cupressus torulosa
(b) in peninsular India – Cleistanthus collinus, Ixora parviflora.
 (ii) Stiff Kankar Clay
(a) in the Northern India – Acaia leucophloea, Prosopis spicigera, Balanites
aegyptica, Capparis spp.
(b) in Central India – Chloroxylon swietenia, Soymida febrifuga, Acacia
leucophloea.
(iii) Clayey soil
(a) liable to water logging – Vetiveria ziznioides,
(b) no liable to water logging – Desmostachya bipinata
(iv) Soils with high concentration of soluble salts
Prosopis juliflora, Acacia Arabica, Tamarix aphylla, Salvadora oleoides,
Salvadora persica, Sporolobus marginatus, etc.
Thus, the species to be sown or plated in different parts of a plantation should
be decided on the basis of stock map prepared before felling, examination of the soil
and study of indicator plants.
(3) Stage of succession – Along with the factor of locality, the stage of
succession which the soil has reached should also be noted to decide the species which
can grow in it. Neglect of this important factor often leads to failure. For example,
attempts to raise sal in soil in the second stage of riverain succession are bound to fail.
There is, however, some retrogression in site conditions on removal of vegetation and
therefore, the species found in a stage earlier to that of site should be raised. This can,
however, be avoided if the retrogression of site can be prevented by leaving a
shelterwood.
(4) Object of management – Choice of species is also affected by the object
of the plantation. For example, if a plantation is being raised for pulpwood, only the
species which can give required quality of pulp should be raised. In case the plantation
is being raised to meet the requirement of some industry, species suitable for it should
be selected and large scale plantations raised because no industry can be set up unless
raw material is available in sufficient quantities on sustained basis. While studying the
requirements of industry the future market conditions should also be kept in view. This
is still more important for species which have to face competition from cement and
steel. For example, sal is used as building timber as well as railway sleepers. In both
these uses, sal is gradually being replaced by cement and steel. Therefore, it would not
be advisable to increase its area. Teak, however, does not face such a danger and,
therefore, its area can be increased.
(5) Consumer’s requirement – There was a time when there was a craze for
solid wood but the use of solid wood is being given up gradually for various reasons,
e.g., natural growth defects, alternate swelling and shrinkage, lack of strength in
compression and sheer, short supplies, high prices, etc., and the demand for light,
decorative composite wood is increasing. This change in taste of consumer has to be
kept in view while selecting species.
(6) Growth rate – The choice of species is also affected by their rate of growth.
As the gap between the demand and supplies of timber is fast increasing, the present
rend is to raise fast-growing species. A fast-growing species is one which has a height
increment of 60 cm per annum in the earlier stages of its life and which gives a
minimum yield of 10ma per hectare per annum in a short rotation of 10 to 15 years.
The concept of fast growth is relative. Therefore, in order to select a fast-
growing species for large scale industrial plantations, it is very necessary to lay down
specifications of size and quality of material required by industry and the shortest
possible period in which it is to be produced. At the same time, on the basis of climatic
and edaphic conditions, productivity zones should be decided and then the species
which can give maximum out-turn of the required specification in various zones, should
be selected. In this selection, the indigenous species should be given equal attention as
the exotics, and the relative merits of the two should be carefully assessed and
compared before preferring one to the other.
The following are some indigenous and exotic fast-growing species:
Indigenous – Acrocarpus fraxinifolius, Ailanthus excelsa, Albizzia spp.,
Anthocephalus cadamba, Bomax ceiba, Casuarina equisetifolia, Evodia meliafolia,
Gmelina arborea, Kydia calycina, Michelia champaca, Populus ciliate, Sterculia alata,
Sterculia companulata, Terminalia myriocarpa, Toona ciliate, etc.
Exoic – Broussonetia papyrifera, Eucalyptus hybrid, Eucalyptus grandis,
Eucalyptus globules; Tropical pines, e.g., Pinus patula, Pinus caribaea, Pinus
pseudostrobulus, Pinus kesiya; Poplars, e.g., Populus deltodies, P. casale 488, Populus
yunnanensis, Populus robusta, Populus rubrapoiret.
(7) Availability of suitable exotic – If indigenous species cannot meet the
fast growing requirement of industrial timber, there should be no hitch in selecting an
exotic which, as a result of experiment, has proved its suitability to local conditions as
well as to the requirements of industry. As already explained, an exotic is a species
which is ‘not native to the area in question’. In other words, it is a species which is
raised outside its natural range of distribution. Exotics may be classified into two
categories, viz., Indian exotic and foreign exotic. Indian exotic is a species which occurs
naturally in some parts of India but is being raised outside its natural range of
distribution and so is an exotic there. For example, teak is an Indian exotic for U.P. and
West Bengal as it is indigenous to M.P., Maharashtra, Kerala, etc. A foreign exotic is a
species which is not native to India and is yet being raised in this country. Examples of
foreign exotics are Anacardium occidentale, Acacia mollisima, A. deccurrens, Acaia
auriculiformis, Eucalyptus s p p . , Populus spp., tropical pines, Prosopis juliflora. As
already stated, similarity in the climatic and edaphic conditions of the original home of
the exotic with those of the proposed plantation site is absolutely essential for raising
successful plantation of an exotic. Even then, preliminary trials should be carried out to
test whether it can be raised in the new place. When these trials are successful, slightly
larger scale trials should be made before finally selecting the species.
(8) Ease of establishment – The ease with which a species can be raised also
affects the choice of species. If a species is difficult to raise, it should not be chosen
(unless there is no other alternative) because most of the attempts to raise it would
result in failures causing loss of public money. Therefore, only those species which are
easy to raise and which meet the object of plantation, should be selected.
(9) Cost – The cost of raising a species also affects the choice. Normally, only
those species, which are inexpensive to raise, are selected. A species which can be
raised easily, and which grows fast during the early period of its life, generally costs less
to raise.
(10) Effect on site – If a species reduces productive capacity of site, it should
not be selected inspite of ease with which it can be raisd.

MIXTURES IN PLANTATION
While making a choice about species, it should also be decided whether they will
be raised pure or mixed. In order to decide this, merits and demerits of pure and mixed
crops may be assessed from the point of view of the following considerations:
 (1) Soil deterioration – It is generally believed that pure crops, particularly
when they are of light demanding species, deteriorate soil and decrease its productivity.
Experiments carried out on teak plantations in Nilambur (Kerala) have indicated that
while there is no decrease in yield in the second rotation in the first and second quality
areas, there is some reduction in the third quality areas. More experimental data will,
however, be necessary to indicate the effect of pure crops on soil.
(2) Resistance to diseases – It has been observed that pure crops are often
destroyed by insects, plant parasites or fungi. For example, pure crops of Michelia
champaca in West Bengal have been destroyed by Urostylis puntigera; those of Toona
ciliate in West Bengal and of Swietenia macrophylla in Tamil Nadu have been badly
damaged by Hypsipyla robusta. The damage to pure teak by teak defoliators and
skeletonizers has already been mentioned in Chapter 3. Tonica niviferana has wiped out
large scale monoculture of Bombax ceiba while Ailanthus plantations have been ruined
by Atteva fabriciella and Eligma narcissus. Pure Gmelina plantations have been badly
attacked by Loranthus and more or less pure sissu plantation have been destroyed by
Ganoderma lucidum. The damage is not confined to monocultures of indigenous species
only but is found in exotics also. For example, pure plantations of Eucalyptus in general
and Mysore hybrid in particular experience large scale mortality mainly due to pink
disease caused by Corticium salmonicolor. On the other hand, mixed crops are believed
to exhibit high degree of resistance to insect pets, parasites and fungi. As already
mentioned, concentration of food of a particular pest in monoculture facilitates
occasional outbreak of attack in epidemic form, while physical separation of food plants
by non-food plants in mixed crops prevents such an outbreak. It may, however, be
mentioned that control of epidemic outbreak is easier in pure crops than in mixed crops.
Though statistical data showing comparison between percentage of damage in mixed
and pure crops is wanting, observations reveal that mixed and pure crops is wanting,
observations reveal that mixed crops are not absolutely immune to insect of fungal
attack. When one of the species of mixed crop is a favourite food of a particular insect
pest, it is attacked and, more often, completely destroyed in spite of the mixture. And if
one of the species of the mixture is an alternative host of the insect pest which attacks
the main species, then damage becomes all the more serious. As the pure crops of sal,
chir and deodar, even though mostly natural, have not been wiped out, it is clear that
the resistance of any crop to diseases, insect pests, fungi, etc., depend upon the
susceptibility of its constituent species and not on the doctrinaire generalization about
the superiority of mixtures. Therefore, while deciding whether a crop should be raised
pure or mixed, susceptibility of the species to attack by insects or fungi in the locality
should be considered carefully.
(3) Damage by wild animals – Raising of pure plantation of a species which may
be a favourite food of any wild animal in a locality where it may be in plenty, often
results in failure. For example, bamboo plantations in areas full of wild elephants are
generally destroyed by them. Damage by wild animals is, however, not confined to pure
crops and is found in mixed crops also. For example, when teak is mixed with Gmelina
or Dalbergia latifolia, the wild animals which browse the latter, damage teak by rubbing
against them. Therefore, decision about raising the crops pure or mixed should be
taken after considering the susceptibility of the main as well as accessory species and
the incidence of animal population.
(4) Increment and total yield – When a valuable species is raised pure, its
increment is not affected by any other species, as often happens in mixed plantations.
For example, experiments conducted on teak plantations in Java have indicated that all
mixtures result in loss of increment in teak, which is not compensated by the value of
mixed species. In pure plantations, all available space is occupied by the valuable
species. Therefore, the total yield of that species in pure plantation is much higher than
that in the mixed plantations where part of the space is occupied by accessory species.
Therefore, before deciding about raising a valuable species in mixture, it should be
clearly seen if there would be no loss in increment or the total yield of the valuable
species, which would not be made good by the growth of the accessory species.
(5) Difficulty in execution of silvicultural operations as well as in management –
When species with different silvicultural requirements, rates of growth and exploitable
ages are mixed in a plantation, they present great difficulty in execution of silvicultural
works as well as in management. For example, if a fire tender species is mixed with a
species which has to be regularly control-burnt, the controlled-burning becomes difficult.
Similarly, if fast-growing species is mixed with slow-growing species, thinnings become
difficult, particularly when the slow-growing specie sis more valuable. In such a case,
inexperienced staff often cuts out the valuable slow-growing species to retain the fat-
growing species of low value. In addition, the less valuable fast-growing species of low
value. In addition, the less valuable fast-growing species often suppress the valuable
slow-growing species. If the mixed crop consists of species with different rotations, the
felling of the mature trees has to be done in more than one operation. The felling of
trees with lower rotations, creates gaps in the plantations in which grass and weeds
come up and increase fire hazard. For example, in some of the taungyas of Siwalik
division (U.P.) sissu, whose rotation is 60 years has been raised with Broussonetia
papyrifera whose rotation is about 15 years. Felling of paper mulberry results in
creation of big gaps in these taungyas. Thus, mixtures of species with different
silvicultural requirements, varying rates of growth and rotations should not be created.
From the above, it is clear that, according to the present knowledge, the pure
and mixed plantations have their merits and demerits. Therefore, unless there is
through knowledge about any mixture, it is better to raise pure plantations. Only the
mixtures which have proved to be beneficial, and which do not present any silvicultural
or management problem, may be raised for the present.

KINDS OF MIXTURES
If it is decided to raise mixed crop, it may, as well, be decided as to what kind of
mixture will be appropriate. Mixtures may be of two kinds, viz., temporary and
permanent.
(i) Temporary mixture is one in which secondary species is mixed with the
main species only for a part of the rotation. Temporary mixture is raised with the
following objects:
(a) Providing protection against adverse factors – When the main species
is likely to be adversely affected by browsing, frost or insolation, it is temporarily mixed
with some species to afford protection against these. For example, khair is often mixed
in U.P. taungyas with species that are browsed to protect them against animl damage.
Ricinus communis is mixed with sal to protect it against frost. Evergreen Dipterocarpus
turbinatus is, sometimes, grown under two or four year old Gmelina arborea as a
protection against sun.
(b) Providing competition in the early stages to obtain better bole form
– Sometimes, when the main species is likely to become branchy, it is mixed with other
species in order to help it to develop good bole form. Pterocarpus dalbergioides and
Dalbergia latifolia are reported to develop good bole form when they are forced to pass
through their associates.
 (c) Providing additional revenue – Sometimes, some valuable species is
mixed as a temporary measure to obtain additional revenue. For example, sowing of
castor (Ricinus communis) is often done in plantation lines to obtain additional reveue
from the sale of castor seeds.
(d) Providing cover to the ground and suppression of weeds – When the
main species is sown at wide spacing some other species is sown in between to afford
protection to the soil as well as for suppression of weeds. For example, Leucaena is,
sometimes, mixed with teak to afford protection to the soil. In West Bengal,
Lagerstroemia flosreginae is often mixed with Pterocarpus dalbergioides to provide
ground cover as well as to keep down weeds.
The species mixed in temporary mixtures are removed as soon as the purpose
with which they were mixed is achieved.
(ii) Permanent mixture is one in which the mixed species remains with the
main species through out he rotation of the crop. Such mixtures are generally made to
avoid risks to which pure crops are exposed. These are of two kinds:
(a) Horizontal or even-aged mixture; and
(b) Vertical or uneven-aged mixture or storeyed mixture.
(a) Horizontal or even-aged mixture is one in which the species mixed re in the
overwood and of the same height. Examples of such mixtures are khair sissu, sal
Terminalia tomentosa a n d Albizzia spp.,semal and Ailanthus, etc. These mixtures re
difficult to manage when the mixed species are of varying silvicultural requirements,
rates of growth, and exploitable ages.
(b) Vertical, uneven-aged or storeyed mixture is one in which the main species is
in the top canopy while the accessory species is in the middle canopy. This may be
either due to the varying rate of height growth or to late sowing or planting of the
accessory species. Examples of such mixtures are sissu and mulberry, teak and
bamboo, teak and Swietenia macrophylla, teak and Leucaena glauca, sal and jamun,
etc.

PATTERNS OF MIXTURES
The mixtures may be of the following patterns:
(i) Intimate mixture – Intimate mixture is one in which seeds of all the species
are mixed together and then sown.
 (ii) Line mixture – Line mixture is one in which one line is sown with the seeds
of one species and the other line with the seeds of other species. Thus, different
species occupy different lines as against intimate mixture in which all species occur in
every line.
(iii) Strip mixture – Strip mixture is one in which the mixed species are raised
in different strips. A strip is usually more than 30 cm wide and may be upto 120 cm. In
some cases its width is upto 2.5 m. The seeds may be sown in he strip either in lines or
scattered all over. With seeds sown in lines, the strip differs from the line sowings in
having more than one line.
(iv) Block mixture – Block mixture is one in which different species are raised
in different blocks of the plantation. The area of the block depends upon various
considerations, viz., area of the plantation, number of species to be raised,
proportionate area to be allotted to various species, etc.

II. SELECTION OF SITE

Sometimes, the species to be raised are already known and the sites in which
they are to be raised are to be selected. Such species are generally those which as a
result of experiments, have proved their usefulness for a particular purpose, e.g.,
meeting the requirement of industries and therefore, large scale plantations of those
species are to be raised. Out of sheer enthusiasm, often such species are raised in any
site without verifying its suitability for the species in question, and therefore, many such
attempts result in failure. This causes not only waste of public money but also
discouragement to staff. Therefore, selection of site is a very important essential
preliminary consideration.
If the species to be raised are indigenous and found locally, inspection of the
local flora and the soil helps in deciding whether the species can be raised in a particular
site or not; local vegetation is the best guide to show what species can grow there. If
the indigenous species are not found locally in the area, or if any exotic is to be raised, it
is better to get the soil tested to find out its suitability for the species in question before
taking up large scale plantation work. For this, a pit 2 m long, 1 m wide and 2 m deep
is dug. In the width of the pit on one side, three steps are provided to enable worker to
enter the pit. Then the opposite face is made vertical and soil from different horizons is
collected in different polythene bags with the help of a khurpi, labeled and sealed.
These samples are sent to Forest Research Institute, Dehra Dun or any other soil testing
laboratory. If the area is large, at least 4 or 5 pits, one in each of the different parts of
the plantation, should be made and each of them should be given a pit serial number
which should also be written on the labels of the sample. Plantation of the species in
question should be raised if soil has been found to be suitable for it.

III. CHOICE OF METHOD OF ARTIFICIAL REGENERATION

After selection of species or site, as the case may be, method of artificial
regeneration has to be decided. Artificial regeneration can be accomplished either by
sowing of seed directly in plantation area or by planting seedlings or cuttings obtained
from some nursery.
Advantages of sowing – Sowing costs less and the work is completed soon.
As the seed is sown directly on the site, the result seedlings grows without any
disturbance to its roots as happens in planting, consequently, there is no adverse effect
on the growth of plant.
Disadvantages of sowing – Sowing requires large quantities of seed, the birds
and animals may destroy or eat up the seed sown. The seedling mortality is heavy. As
weedings have to be done for relatively longer period, they become costly.
Advantages of planting – The quantity of seed required is much less; the
damage to seed by birds is completely eliminated while that of animals is reduced.
Success is relatively ensured and weedings are cheaper.
Disadvantages of planting – Planting is costlier than sowing; it requires more
labour, particularly skilled labour and a nursery.
The choice between the two methods of artificial regeneration depends upon the
species to be raised, conditions of site, availability of seed and cost.
The species to be raised – Though most of the species can be raised by both
the methods, some of them, e.g., sal, khair, chir and kail were, till recent past, raised by
sowing as their planting was considered difficult. But now even these species are raised
by planting in many states or their parts, e.g., dona planting of sal has been in vogue
for quite sometime in West Bengal except in taungyas. Khair and chir are also being
planted as polythene bag plants in parts of Haryana, U.P. and Himachal Pradesh. Kail
planting has also been attempted in Kashmir. As a general rule, slow-growing species
or the species having seed enclosed in a hard coat are raised by planting. Ailanthus,
Albizzia, etc., however, continue to be raised by sowing.
Condition of the site – In poorer and difficult sites, sowing is generally not
successful and therefore, planting should be done. Infertile barren soils, places infested
with grass and other weeds, places where long closure is not possible due to pressure of
grazing, eroded soils and failed portions of natural regeneration and plantation areas are
examples of places where planting is generally adopted.
Availability of seed – As already stated, sowing requires larger quantities or
seed as all the seeds sown do not develop into seedlings due to adverse climatic and
edaphic factors. Therefore, the species which do not produce large quantities of seed
every year have to be raised by planting.
Cost – As a general rule, the method of artificial regeneration, which gives
greater success at comparatively lesser cost, is preferred.

KINDS OF SOWINGS
Sowing may be done in any of the following ways:
i) Broad cast sowing – Broad cast sowing is defined as the scattering of seed
more or less evenly over the whole area, either that on which the crop is to be raised
directly or a nursery bed. The seed is scattered after ploughing or digging up soil over
the entire area and leveling it roughly, though sometimes, soil preparation may not be
done at all. In large plantations, no attempt is made to cover the seed but in small
areas, like that of a nursery, soil is turned over lightly with a khurpi. This kind of sowing
is used for stocking burnt areas, desert areas, abandoned cultivations, landslides and
grassy blanks. It is also used for improving the stocking in fuel felling coupes. In
Assam, it has been used to supplement natural regeneration of Terminalia myriocarpa
with artificial regeneration by scattering seeds on soil exposed by making an elephant
drag a log through the blank portions of regeneration area.
The only advantage of this sowing is that the area is covered soon but it has
many disadvantages. Soil preparation has to be done over the whole area, making the
operation costly. Large quantity of seed is required. Weedings are costly and difficult.
A number of unremunerative cleanings and thinnings have to be done. Chances of
damage by animals are greatly increased.
 ii) Line sowing – Line sowing is the sowing of seed in drills or a single lines.
The drills or lines are made at predetermined interval after digging the soil in those
places. Normally, trenches are dug and the dug out soil is filled back in them after
weathering for about a month or two. On this filled up earth, a drill, i.e., a shallow
depression, is made with a hoe or a wooden peg. When the drill is made from one end
of the plantation to the other end and sowing is done in it throughout without a break, it
is called continuous line sowing. But if the soil is dug in small stretches, alternating with
undug stretches, drill is made in dug up portion after filling the soil back and sowing
done in the drills, the area will have dug up and sown portions alternating with undug
and unsown portions. This is called interrupted line sowing. If the sown portion of a
line is opposite to the unsown portion of the adjacent lines, the sowing is called
interrupted and staggered line sowing.
This is the usual method of sowing in most plantations. As compared to broad
cast sowing, the cost of soil preparation and quantity of seed required is considerably
less. Weedings are easy and less costly and the damage by wild animals greatly
reduced. On the other hand, the disadvantages are that soil working requires skilled
staff and labour because before digging, the lines and the portions to be dug therein
have to be properly aligned, marked on ground and staked out, if necessary. The
canopy takes longer time to close as compared to broad cast sowing.
iii) Strip sowing – Strip sowing is defined as the sowing of seed in narrow
strips prepared for the purpose usually at definite intervals from one another. Strips are
usually 45 cm to 90 or even 120 cm wide. Occasionally, they are made even 30 cm
wide while in Assam, they are, sometimes, made as wide as 1.8 to 2.5 m. The soil is
dug up in strips and after allowing it to weather, it is made into a seed bed. The seeds
are sown in two or more rows or without rows all over the strip. Strip sowing differs
from line sowing in having more than one row of sowing or broad cast sowing in each
strip while line sowing has only one row of sowing in each line. Like line sowings, strip
sowing may be continuous, interrupted or interrupted and staggered.
As there are more than one row of seeds in each strip, chances of failure of any
part of the plantation are remote. This method is very suitable for areas infested with
grass and other weeds. But the cost of soil preparation, seed and weedings, though
less than that in broad cast sowing, is more than that in line sowing.
 Line and strip sowings are done either on ridges or in trenches, depending on
the rainfall. In moist soils, high rainfall areas or areas liable to temporary water logging,
sowing is not done at the ground level but on ridges and therefore it is called ridge
sowing. In ridge sowing, the dug up earth is filled back in the trench to form a ridge in
the centre about 10 to 15 cm higher than the general ground level. The advantage of
making a ridge is that even if the filled up earth subsides during the rains, it does not
form a trough below the ground level and so the seed does not rot due to excess of
moisture. On the other hand, in dry or low rainfall areas, where water conservation is of
paramount importance, dug up earth is filled upto about half the depth. Thus, the seed
is sown in a trench and sowing. Apart from offering for the development of root of
seedlings, this method, unless care is taken, may result in losing the top fertile soil by
leaving it outside. In areas with uncertain rainfall, another method of sowing, called
ridge ditch sowing is practiced. In this method, dug up earth is filled back in the trench
in a sloping manner leaving part of the trench unfilled and the balance soil is used to
make a ridge partly inside and partly outside the trench. The seed is sown in three rows
at places marked I, II and III in the figure, i.e., a little above the lowest portion of the
trench, at the ground level and on the ridge. The advantages is that in case of poor
rainfall, lowest row sowing will be successful, in case of moderate rainfall, the middle
row while in case of heavy rainfall, sowing on the ridge alone will be successful.
iv) Patch sowing – Patch sowing is defined as ‘sowing a number of seeds in
specially prepared patches’, either circular or rectangular, made at regular interval. The
size of patch varies from place to place depending on local conditions. In order to make
patches, soil is dug upto a depth of 15 to 25 cm and filled back after weathering.
Sufficient number of seeds are sown in each patch depending on its size though only
one plant is expected in each.
The greatest merit of this method is that the patches serve as small temporary
nurseries inside the plantation area, whose extra plants can be used for planting up
blank patches in it as well as adjoining plantations later. In addition, soil preparation
and weedings are relatively much cheaper. But if the patches are smaller in size, there
is a danger of grass and weeds suppressing the plants. Another disadvantage is that
unless the patches are properly staked and made at fixed regular interval, a lot of time
is wasted in locating them fro weeding and subsequent tending and even then many are
lost sight of resulting in the death of the plants.
 In high rainfall areas or in places liable to water logging patch sowing is done on
mounds and in that case it is called mound sowing. The mounds are usually 1.2 m x
1.2 m at the base and 60 cm x 60 cm at the top and their height is about 60 cm higher
than the usual submergence level. On the other hand, in dry and arid areas, sowing is
done in pits and so it is called pit sowing. The pits are usually 1.5 m long and 1.5 m
wide and 30 cm deep but the size may vary according to local practice,
v) Dibbing – Dibbing is defined as sowing of seeds in shallow holes made with
suitable instruments at definite intervals. For this sowing, soil is dug up with some iron
or wooden instrument in small patches, viz., 8 to 10 cm long, 8 to 10 cm wide and
equally deep at regular interval. It is used for species such as Juglans, Quercus, etc.,
which produce large seeds and in their case one or two seeds are sown in each of the
patch. Soil working and sowing is done simultaneously and a stake is fixed by dibbled
site to enable easy location in subsequent years. Though this method is meant for large
seeded species, it is, sometimes, used for small seeded species also, but in such cases,
a pinch of seed is sown instead of one or two seeds.
It is a very cheap and quick method of sowing. As the seeds are dibbled without
any elaborate soil preparation, dibbling sites remain inconspicuous and escape animal or
bird damage. But unless properly staked, their location for subsequent tending
operation becomes difficult.
This method is used, sometimes, for sowing chir and Quercus incana as well as
for supplementing natural regeneration with artificial regeneration.
IV. SPACING
In order to reduce cost of formation, plants are raised at some distance. This is
called spacing; it is defined as the distance between the plants put out in a plantation or
standing in a crop. It is also sometimes referred to as espacement. Spacing is
described by giving distance between the lines multiplied by the distance between plants
in the same line in metres. For example, 4 m x 2 m means that lines are 4 m aprt and
the plants are 2 m apart in the same line, or vice versa. When the distance between
plants is small, it is called close spacing but when the distance is large, it is termed as
wide spacing.
Advantages of wide spacing – Wider spacing results in a saving in seed and
plants. The cost of plantation is reduced and less labour is required to complete the
work.
 Disadvantages of wide spacing – T h e canopy takes a long time to close
resulting in the danger of soil deterioration. If one of the plants dies, there is a big gap
in the plantation and it is usually infested with grass and weeds. The trees tend to
become branchy, resulting in timber becoming knotty. As the number of plants is less,
thinnings become difficult. Wide spacing results in rapid diameter increment and wider
annual rings; this may affect the strength of wood.
Advantages of close spacing – With close spacing, canopy closes soon and
this keeps a check on growth of grass and weeds. As the number of plants is more,
thinning becomes easier and natural pruning makes the boles of trees cleaner.
Disadvantages of close spacing – Close spacing requires large quantities of
seeds or large number of plants. It increases the cost of plantation and requires more
labour to complete the work.
The spacing varies with species and in the same species with the local
conditions. The following factors govern the spacing:
i) Rate of growth of species – The most important objective in artificial
regeneration is that canopy should close soon so that the soil may not deteriorate due to
exposure. Therefore the fast growing species have wider spacing and slow growing
species have closer spacing.
ii) Habit of branching – Large number of branches arising from the stem, not
only reduce the timber volume but also decrease its value. Therefore, the species which
have the habit of producing large number of branches, should be raised at close spacing
so that due to deficient light, natural pruning may make the bole clean.
iii) Number of annual rings per centimeter – The wood required in some
industries, e.g., paper pulp, match, etc. should have lesser number of rings per
centimeter. As this requires rapid diameter increment, the plants have to be raised at
wider spacing. On the other hand, if it is desired to produce denser wood with larger
number of rings per centimeter, the plants should be raised at closer spacing.
iv) Height of planting material – If tall plants are to be used for planting, the
spacing should be wider but if small planting stock is to be planted, the spacing should
be closer.
v) Site factor - In dry areas, the spacing should be closer. Similarly, in places
where there is a danger of infestation of weeds, e.g., Eupatorium, Lantana, etc., closer
spacing should be adopted. For example, in West Bengal Eupatorium invades the
plantations and taungyas. Therefore, in order to keep it under control, sal is sown at
closer spacing, i.e., the taungya lines are 1.8 m apart.
vi) Inter-cultivation – Where it is proposed to raise agricultural crops in
between the plantation lines, relatively wider spacing has to be adopted to protect the
agricultural crop from the shade of the tree species. Similarly, where tractors are used
for ploughing the interspaces or to keep down the grass, the spacing between the lines
is a little more than the multiple of the width of the plough.
vii) Market for small-sized timbers – The crops raised at closer spacing have
to be thinned early. As the material thinned is a small sized, it can be sold only when
there is a nearby market with demand for small sized timber. Thus, closer spacing can
be adopted only when the small sized material will pose a fire hazard. If the material
cannot be sold, wider spacing should be adopted.
viii) Fruit production as objective – In case of species of which fruit is more
valuable and therefore the objective of the plantation is fruit production, the spacing has
to be wider, e.g., Anacardium occidentale.
ix) Cost – Closer spacing increases the cost of soil preparation, sowing and
planting and weedings resulting in higher cost of formation of plantation per hectare.
On the other hand, wider spacing reduces the cost per hectare. Therefore, availability
of funds has a great influence on the spacing to be adopted.
USUAL SPACING OF SOME IMPORTANT SPECIES
i) Teak – Teak is usually planted at 1.8 m x 1.8 m in lower quality class areas
and at 2.6 m x 2.6 m in higher quality class work.
ii) Sal – This species is raised usually by line or strip sowings. In the lines, the
seeds are spaced at 8 cm (West Bengal) to 10 cm (UP) apart. The lines or strips are
spaced 1.8 m in West Bengal to 3 or 3.6 m in UP.
iii) Semal – There is a no recognized spacing for semal. It is raised at a
spacing from about 4.6 m x 4.6 m to 11 m x 11 m.
iv) Eucalyptus – The usual spacing varies from 2.4 m x 2.4 m to 3.3 m x 3.3 m
but where Eucalyptus hybrid is raised as pulp wood, its spacing can even be 1.2 m x
1.2m. Where tractors are used for soil working and suppression of thick grass, its
spacing is 1.2 m to 1.8 m from plant to plant in the same line, while the lines are spaced
from 3.6 m to 4.5 m apart.
V. ARRANGEMENTS OF STAFF AND LABOUR
ARRANGEMENT OF STAFF
When artificial regeneration work is to be done over a small area say 10 to 20
hectares, the existing range staff can do it in addition to its other duties but when larger
areas 25 to 80 hectares are to be taken for artificial regeneration in one range,
additional staff has to be posted. If, however, the area to be taken up under artificial
regeneration in one division is as large as 600 to 800 hectares or more, it is better to
create a new plantation division with full complement of staff and do the work in two or
three centres for the sake of concentration of work. The staff to be posted in these new
division should be efficient, experienced and resourceful. It is no use posting new staff
which has no experience of such work.
Arrangement of labour – The success of artificial regeneration work depends
upon the timely arrangement of efficient, willing and hard working labour. Failure to
arrange for labour at proper time for various operations of artificial regeneration results
in failure and waste of public money; therefore great care should be given to this item.
Artificial regeneration work may be done entirely by human labour, or partly by
machines and partly by human labour, as in our country mechanization has not
advanced so much as to undertake all works by machines. Part mechanization of
artificial regeneration work is usually done in the plains where due to several
development projects in progress, it is difficult to arrange for all the human labour
required for it.
When the work is done totally by human labour, the labour can be arranged
either on daily wages departmentally or by giving the work on contract or by
compensating the labour by permitting them to raise agricultural crops in the
interspaces.
Labour on daily wages – Artificial regeneration work by labour on daily wages
is possible where labour is available in plenty. Even then the forest guards and other
plantation staff have to go from village to village to arrange for labour. If local labour is
not available, imported labour, such as Nepali labour, has to be arranged but in this
case, the mate of the gang has to be persuaded to stay and work and not the individual
Nepali mazdoors as they blindly obey their leader. Even when local labour is to be
arranged, it is better to appoint a few mates by paying them a little more than usual
labour rate for arranging for sufficient labour all the time. Though sufficient labour is
available for soil preparation, there is usually difficulty in arranging for labour for
weedings as the labour is usually busy weeding the agricultural crops in villages where
they get usually higher rates of wages along with food and/or food grains. In order to
attract labour to forest work, it is usual to give them some inducement, e.g., making
chappars for those who want to stay in the forests, arrangement of cheap controlled
ration for them in the forest, free medicine, etc. As the climate of the forest is usually
bad, the success of artificial regeneration work depends upon the maintenance of good
health of labour by supplying common medicine free. Similarly, arrangement of cheap
controlled ration at the site of artificial regeneration work helps the labour to stay their
and work to their capacity without wasting time in going to market for purchasing
rations.
Work through contractors – All operations of artificial regeneration work
cannot be got done by contracts. Only such operations as soil preparation, fencing, etc.,
can be got done through contractors as the measurement of these works as also the
quality of work can be checked even later. Works such as sowing, etc., should never be
got done through contractors as any mistake in quantity of seed sown and the depth of
sowing in the absence of proper supervision by forest staff, may result in failure of the
plantation. The advantages of getting certain operations of artificial regeneration done
on contract are that (i) less staff is required for supervision of the work and (ii)
arrangement of labour has not to be made. But when the work of soil preparation is
given on contract, the depth of trenches, pits, etc., should be checked carefully before
the contractor is allowed to fill them back as the contractor has a tendency to do less
work.
Labour having permission to raise agricultural crops in the plantation
area – Sometimes, it is not possible to get labour on daily wages. The labour wants
permission to raise agricultural crops for themselves in the interspaces in lieu of, or in
addition to, wages for the work done. The plantations in which forest crops are raised
along with agricultural crops are known as Taungyas.
Taungya (taung = hill; ya = cultivation) is a Burmese word which means
cultivation in the hills. This cultivation is shifting cultivation which is defined as a
‘method of cyclical cultivation, chiefly in vogue in the tropics, where cultivators cut the
tree crop, burn it and raise field crops for one or more years before moving on to
another site and repeating the process. It is locally called by different names, viz.,
Kumri (Tamil), Pongam (Malayalam), Podu (Tamil), Jhum (Assamese), etc. This
destructive method of cultivation has been changed by Indian foresters into a cheap and
productive method of raising forest crops in conjunction with agricultural crops. In this
method, the area to be regenerated is handed over to taungya cultivators after clear
felling. They burn the felling refuse and raise agricultural crops for themselves. Along
with cultivation of agricultural crops, they also raise forest plantation in lines and
continue to cultivate the area for 2 or 3 years, after which they move to be next area.
Thus, the term taungya is now applied to the method of raising forest plantations in
combination with field crops, otherwise known as agri-silvi method or agri-silviculture
and to the plantation themselves.
The taungyas can be of following three types:
i) Departmental taungyas – Departmental taungya is that plantation in which
the forest department gets agricultural crops also raised along with the forest plants in
the interspaces of their lines by mazdoors on daily wages, like any other artificial
regeneration operation. The main object of raising agricultural crops is to keep down
the weeds and get additional revenue. But such taungyas are usually unsuccessful
because the forest staff is not expert in raising agricultural crops and in order to get
better return from the agricultural crops, the entire attention is concentrated on them,
resulting in the neglect of forest crops. Therefore, departmental taungyas should be
raised only when there is no other way to keep down the weeds.
ii) Leased taungyas – Leased taungyas are those taungyas in which
agricultural crops are raised in the interspaces of the lines of the forest plants, by giving
the land on lease to the person who offers maximum lease money. In this method, the
interspaces of each regeneration area are leased out immediately after clear felling for
raising agricultural crops for 2 years or so. The advantages of this method are:
a) There is no excessive burden of work on forest staff and they can concentrate
their efforts on raising forest crops only.
b) The entire cost of raising forest crops is nearly realized from agriculture leases
and thus the new plantations are raised without any extra expenditure incurred on
raising forest crops.
c) The weeds and grasses are suppressed without any expenditure
 This method requires proper supervision at the time when the lease holders
harrow the soil for raising their crops because they often damage the forest plants in
this operation, particularly at the end of the lines.
iii) Village Taungyas – Village taungyas are those taungyas which are raised
by villagers who have settled down in a village inside the forest for the purpose. The
advantage of this method is that the work of raising forest crops is done cheaply and in
areas where there is a chronic shortage of labour, the taungya villagers do other forest
work on daily wages and thus the problem of labour shortage is solved to a large extent.
The technique of village taungyas – After clearance of the regeneration area
by forest contractors, the area is divided amongst the taungya cultivators. The area to
be given to each taungya cultivator depends upon the area of the annual coupe, the
number of cultivators and the policy of the forest department. Usually a family as 0.8
hectare to 1.6 hectares in all in various taungyas. In any one year in one taungya, a
family gets about 0.2 to 0.4 hectare of land. Thus it gets 0.8 to 1.6 hectares of land in
4 different taungyas. On getting land, the taungya cultivators collect the felling refuse
lying in their portion of the land and burn it. When the land is cleared, they plough the
land for raising their crops and dig trenches at regular intervals as directed by the range
officer or his representative. After the soil of the trenches has weathered, the
cultivators fill it back and sow seeds, or plant seedlings or cuttings, on them under the
direction of the range staff. In the interspaces, they sow their agricultural crops. In
certain areas, the taungya cultivators are allowed to raise agricultural crops for one or
two years before the year in which sowing or planting is to be done. In such cases,
clear felling is done one or two years in advance and the cultivators raise their crops
only during the period after which the forest crop is raised while the raising of the
agricultural crop is continued with it. The taungya cultivators look after the forest crops
and carry out tending operations. After sowing or planting, they weed the forest crop
while weeding their crop. They keep their crop a little away from the line of the forest
plants so that it may not suppress them. If they irrigate their crop by digging a small
well in the area, the forest plantation is also digging a small well in the area, the forest
plantation is also irrigated. The period for which the agricultural crops are raised in the
interspaces depends upon the spacing of lines and the rate of height growth of the
forest plants. Generally, this period is from 2 to 5 years. The forest department has
also control over the agricultural crops that can be raised in the taungyas. Usually the
agricultural crops which may suppress the forest plants or otherwise harm them, are not
allowed to be raised. While deciding the crops to be raised, the food and other
requirements of the taungya cultivators are kept in view and if some crop, essential for
them, can not be permitted in taungyas, the cultivators are given some land in their
village for raising this crop, but it all depends upon the local conditions.
The conditions on which the taungya cultivators are allowed to raise agricultural
crops in forest plantations are incorporated in an agreement deed. These conditions,
which vary from place to place, depend upon the local conditions. If there is acute land
hunger, the taungya cultivators agree to raise agricultural crops on the conditions
favourable to the department. If the land hunger is not acute, the forest department
has to draw up conditions in such a way that they may be favourable for cultivators who
may then be attracted to take up cultivation work in the forest. For example, in the
former case, the forest department charges 2.5 to 5 rupees per hectare as rent for land
given to cultivators for raising agricultural crops, but in the latter case, the cultivators
are allowed to raise agricultural crops for one or two years even before raising forest
plants. If the conditions are still not attractive, the forest department gives cleared
land. Similarly, the cultivators collect the seeds of the forest species to be raised free of
cost if there is great demand for land; otherwise the department has to supply the
seeds. As there is heavy animal damage in the forest, the cultivators protect their crops
and the forest plants are also automatically protected. This protection requires fencing
in addition to the watch and ward done by the cultivators. In areas where there is land
hunger, the cultivators erect their own fences but in other cases, the forest department
supplies fence posts and barbed wire and the cultivators erect the fence free of cost. In
some areas, it is sufficient to provide the cultivators with hutting material to make their
huts but in places, where the land is not in much demand, the forest department has to
construct houses for them. In addition, the forest department arranges for free medical
aid to cultivators and their families, free education for the children, water supply, etc.
Success of the taungya method depends largely upon the taungya rules, in
addition to land hunger. The rules should be sympathetic as well as convenient and
easy so that the cultivators may be attracted to raise agricultural crops in the forest but
they should not be so liberal that the cultivators may become idle and in course of time,
refuse to sow forest species or look after them. Honest and sympathetic staff should be
deputed to supervise the taungya work and the transfer of staff should not be made
very early as it takes time to gain the confidence of the cultivators, without which
success is difficult. Similarly, the taungya rules framed carefully in the beginning should
not be changed often because if a new rule is imposed without the concurrence of the
cultivators, or the taungya policy is changed, without their involvement, it is not possible
to get their cooperation, without which taungya can never be successful.

ADVANTAGES OF Taungyas
(i) Form the financial point of view, artificaial regeneration is obtainted cheaply
by taungya method as compared to departmental plantations.
(ii) It solves labour problem and provides work to the landless labour.
(iii) It utilizes the site fully and helps to augment food production of the country.

DISADVANTAGES OF Taungyas
(i) The cultivation of agricultural crops results in exposure of the interspaces for
some time and loss of fertility of the soil.
(ii) The ploughing or tillering of the interspaces in sloping country increases the
possibility of erosion.
(iii) The cultivation of agricultural crops increases the danger of epidemics.
(iv) Once the cultivators are settled, they start neglecting the plantation work.
On the other hand, it becomes difficult to evict them. Thus a legal problem is created.
(v) In the age of human freedom, taungya is a method of human exploitation.

MECHANIZATION
While the extent of artificial regeneration area is increasing every year, there is
an increasing shortage of labour for forest works due to increased labour oriented
development plan activity all round. The chronic shortage of labour has got accentuated
these days because when the labour gets work in villages and towns, it is not interested
in going to the forest areas for work. The labour problem could be solved by taungya
method but this method is getting into disfavour because the taungya cultivators do not
leave the land after occupying it once, and do not work in forest plantations. Therefore
taungya method is not to be expended further. Thus, the only alternative left is to
resort to meachanization in artificial regeneration work. So far, mechanization has been
achieved in the following operations:
 (1) Soil preparation, viz., ploughing, harrowing and ridging.
(2) Digging pits for fence posts
(3) Transport of fence posts, seeds, plants, diesel and petrol, staff and labour,
and other material from once place to another.
(4) Fire protection of plantation and irrigation work of nursery.
(1) Soil Preparation – In mechanized plantations, soil preparation involves
ploughing of land, harrowing and ridging. As the three operations are performed by
different tractors and implements, they are separately described below:
(1) Ploughing – For initial breaking up of the land of ploughing, tractors and
ploughs are required. The tractors may be wheeled tractors or crawlers. The wheeled
tractors involve less capital cost, are convenient to handle and maintain, work wit h
speed and do not damage the forest roads. On the other hand, the crawlers of chain
type tractors are expensive, difficult to handle and maintain, do not have easy mobility,
and also damage the forest roads. But they have the following advantages over the
wheeled tractors:
(i) They have better grip, can work in difficult areas in wet season in a far more
satisfactory manner than the wheeled tractors.
(ii) They possess more pulling power for the same horse power, require less
turning radius and are more suited to heavy duties such as initial breaking of forest
soils.
(iii) The chain in the crawler type is comparatively safer against accidental
damage by hidden obstructions while the rubber tyres in the wheeled tractors are more
subject to accidental cuts and damage under forest conditions resulting in avoidable loss
of working hours and increased cost on repairs.
Therefore crawler tractors are more economical and suitable for initial breaking
or ploughing of land in forest conditions. Experience in U.P. has shown that crawler
type D4 caterpillar tractor of 55 to 65 H.P., is very useful, though, sometimes, wheeled
type heavy tractors such as Fordson major, Zetor super are also used.
The tractor gives the motive power. The actual breaking of land and ploughing
is done by the use of following implements, either alone or in combination with some
other implement:
(i) Subsoiler – Where soil is hard and/or has a pan below, subsoiler is used to
break it. It digs soil upto a depth of 50 cm.
 (ii) Mould board plough – It cuts the soil into bigger clods and turns it over,
thereby ensuring elimination of rootstock of grasses; because of heave wear on shears,
it is not economical to use.
(iii) Disc plough – As the name suggests, this plough has circular discs to
plough the land. It works to a depth of 25 to 30 cm over a strip of 60 cm to 1.2 m
depending upon the size of the plough ad discs. Experience in U.P. indicates that the
disc ploughs are the best but they should be fully matched with the tractor not only in
regard to the number of discs but their weight also. As there are several makes and
models, they should be given thorough trial before adopting any of them. The plough
should be of robust construction so as to resist damage from obstructions, e.g., stones,
roots, stumps, etc., found in the forest areas. It should have adjustment for depth
control and disc angles. The disc should be of the heavy duty type made of toughest
carbon steel to bear shocks. The number f discs should be capable of reduction so that
maximum number of discs after trial could be used. Usually discs of 70 cm diameter
trial could be used. They give a cut 20 to 25 cm wide so that 4 discs give a cut over a
strip 80 to 100 cm wide. The discs should be changed when they get reduced to 62.5
cm diameter from 70 cm diameter due to wear, or even earlier if they are not working to
designed depth.
Depending on the power of the tractor, 1.2 to 2 hectares of land can be
ploughed in a day, the higher figure being for crawler tractor of 55 to 60 H.P.
(b) Harrowing – Harrowing is the operation in which bigger clods of soil, cut
out in ploughing, are broken down to smaller clods. It is also done for suppression of
tall grasses between the lines. This is done by harrows attached to tractors. For
harrowing, wheeled tractors of 40 to 50 H.P., are used. The harrow should be heavy,
robust and of the heavy duty type. In addition, the harrow should be compact and
manoeuvrable. Angle of the front and year gangs should be adjustable to meet varying
conditions of the soil. The discs should be tough with sharp and lasting cutting edges.
The front gang may have toothed discs. The largest size of harrow that can be matched
with the tractor should be used, but the width of interspaces between lines of plants
should also be kept in view. For example, with the lines 3.6m apart, harrows 2.5 to 2.7
m wide would be most effective for harrowing between the lines without damaging the
plants in them.
 (c) Ridging – After harrowing, he lines, where the seed is to be sown or plants
planted, raised to form ridges about 90 cm to 1.2 m wide at the base and about 30 cm
high. Though ridges can be made by several implements such as bush breaker, mould
board plough, Rome-Dyke harrow, etc., yet experience in U.P. indicates that the most
economical implement is tool bar with border discs. These implements are used by
attaching them behind a tractor. The heights of ridges can be increased or decreased
by adjusting the distance between the discs.
(2) Digging pits for fence posts – Pits for fence posts are dug by augers
worked by tractors.
(3) Transport – The transport of fence posts, seeds, plants, diesel and petrol,
etc., is done by attaching a trolly behind a wheeled tractor of 35 to 40 H.P.
(4) Fire protection – Harrows attached to tractors are used to clear grass from
the fire lines and interspaces of the plantations and when fire breaks out, they are used
to make a fire line round the fire for the purposes of counter-firing and preventing the
spread of fire,
The irrigation work of nurseries for the mechanized plantations is also often
mechanized.
Advantages of mechanization – Mechanization effects economy in labour and
results in speedy and cheaper execution of work.
Disadvantages of mechanization – Mechanization requires heavy capital cost. It
increases dependence on skilled staff considerably. In forest areas it is difficult to keep
the machines in working order and breakdowns stop the work. It is difficult to get
replacement of parts, and in case of non-availability of damaged parts the machines
remain idle. Partial mechanization, as at present, results in most machines and
implements remaining idle for long periods.

ORGANIZATION OF PLANTATION WORK

PLANTATION TIME TABLE
After deciding the preliminaries, it is very essential that plantation work is
properly organized. This is only possible when the various works connected with a
plantation are done according to a time table, prepared in advance. For a plantation to
be raised in a particular year, arrangements have to be made and some works started,
ordinarily, 2 to 3 years (and sometimes even 3 to 5 years) before the actual planting. If
any of the operations is lost sight of, or not done in time, the success of the whole
plantation is jeopardized. For example, if the plantation is to be fenced and if the
fencing material has not been indented for, one or two years in advance, the plantation
would remain without proper fencing resulting in enormous danger to it from biotic
factors. Similarly, if it has been decided to do entire planting of deodar or fir, the
sowing should be done in nursery about 2¾ years before for deodar and 4¾ to 5¾
years for fir, otherwise good plantable seedlings will not be available in the plantation
year. The seed for this sowing will have to be collected whenever it ripens before the
time of sowing in nursery. Therefore, it is absolutely essential to draw up a plantation
time table after careful thought and follow it rigidly. The plantain time table can be
divided in 2 distinct parts:
(i) Works to be done outside the plantation area; and
(ii) Works to be done in the plantation area.

WORK TO BE DONE OUTSIDE THE PLANTATION AREA

ESTIMATE AND INDENT OF MATERIAL
The first item in the time table for works to be done outside the plantation area
is preparation of estimates and submission of indent of material required. A year or two
before the plantation is to be raised, an estimate of the plantation should be prepared
giving details of all items of work, their schedule rate and cost. The estimate includes
the cost of site clearance, demarcation, soil preparation, fencing, seed collection,
nursery cost, sowing, planting, weedings, etc. In case of species such as deodar, fir and
spruce, for which nursery has to be raised 3 to 5 years in advance, the nursery cost is
added on the basis of expenditure incurred in those years and working out the cost per
plant. Though this expenditure is not to be incurred again, it enables the sanctioning
authority to see that the ceiling of expenditure per hectare is not exceeded. Along with
the estimates, yearwise breakup of the same is also furnished. The estimate is then
submitted to divisional forest officer who, after scrutinizing the estimate, either
sanctions it himself, if the same is within his power, or obtains the sanction of the
competent authority.
Along with the estimate, an indent for barbed wire, woven wire, staples, etc.,
should also be sent to Divisional Forest Officer so that the he may arrange for the
indented fencing material.
ARRANGEMETN OF SEED AND PLANTING ATERIAL
The next item in the time table is the arrangement of seed and planting material.
The success of artificial regeneration depends largely on the efficiency with which the
arrangement of seed and planting material is made. Any default in this work may very
adversely affect the success of plantation even though all other arrangements may have
been done very carefully. Therefore, this work should be given the most careful
attention. The first thing is to calculate the quantity of seed required for direct sowing
and /or raising planting stock. This requires a knowledge of seed weights of the species
in question, their germinative capacity, plant percent, etc. It is also affected by the area
of the plantation, method of sowing, spacing, etc. The quality of seed should be
calculated keeping all these in view, and about 50% more seed should be collected
because sowing has often, to be repeated in part of the plantation area as result f
destruction f seed due to certain adverse factors.

EXAMPLE
(1) Calculate the quantity of seed that would be required for raising a sal
plantation (including 331/3% for resowing) over 10 hectares in which direct sowing is to
be done in strips 3 m apart having 3 rows of sowings with seeds touching each other
(i.e., 10 cm apart).
Assuming the plantation of 10 hectares to be a rectangle 400m X 250m, there
will be about 82 strips 400 m long. Therefore the number of seeds required for sowing
will be
3 X 82 X 400 X 100
------------------------ = 9,84,000
10
529 sal seeds weigh = 1 kg.
984000
Therefore, 984000 sal seeds will weigh = ------------ kg
529

= 1860 kg approximately
= 18.6 Quintals
Adding 331/3% for resowing, the quantity of seed required will be 18.6 + 6.2 =
24.8 or say 25 quintals.
 (2) Calculate the quantity of seed required for raising 10 hectares deodar
plantation by naked root planting of 21/4 year old seedlings raised in nursery, at a
spacing of 2.5m X 2.5 m assuming that 250 gms of seed is required to raise 1000 plants
fit for planting.
10 X 10,000
Number of plants required =-----------------
2.5 X 2.5
= 160 X 100
= 16,000
Assuming 25% casualties in transporting or in planting, 16000 + 4000 = 20,000
plants will have be raised in nursery.
For 1000 plants seed required = 250 gms
20,000 X 250
Number of plants required =------------------- gms
1000
= 5000 gms
= 5 kg.
After assessing the quantity of seed, it has to be decided whether this quantity of
seed can be collected locally (i.e., in the range) or not. If not, an indent of seed should
also be sent to the Divisional Forest Officer to enable him to get seed collected from
other divisions. It is always advisable to get seed collected from neighbouring ranges,
or even divisions, by sending the staff responsible for raising the plantation to collect the
seed so that the best quality seed is collected. If the seed is required for direct sowing,
it should be collected when it ripens before the time of sowing. If the seed is required
for sowing in nursery, it should be collected when it ripens before the time of sowing in
nursery.

SOURCE OF SEED
So far, the seed in our country is usually collected by mazdoors under the
supposed supervision of forest guards. In village taungyas, even this is not done and
the seed is got collected by the taungya cultivators. Even where the seed is collected
through the agency of forest guards, it has to be collected at the schedule rates. This
rate is generally so low that the forest guard and his labour worry more about the cost
rather than the quality f collection. Very often, the forest guard does not go to the
forest with the mazdoors and only asks them to collect a particular quantity of seed at a
particular rate. The result is that the seed is collected either from the ground or from
branchy, crooked and short-boled trees outside the forest and is, therefore, inferior from
many points of view. Naturally such seed cannot be expected to produce tall, large-
sized trees with well-shaped cylindrical boles, rapid rate of growth and good quality
timber. If the plantation is expected to produce trees with high volume of non-defective
timber, it is very essential to pay attention to the source of seed. The collection of seed
costs about 8 to 10 rupees per hectare of the plantation area while the total cost of the
plantation is 400 to 500 rupees (and in some cases upto 800 to 900 rupees) per
hectare. Thus, the expenditure incurred on the seed is collected from genetically
superior trees, even though it may cost a little more.
A genetically superior tree is a tree which is superior to other trees in its habitat
from the point of view of its size, length, shape of stem, height, diameter and volume
increment, timber quality, resistance to disease and other specific qualities, viz., high
resin yielding capacity, etc. The selection of such trees is beyond the competence of
forest guards or foresters. Such trees are normally selected by gazetted officers. But
until it is done, the range officer should, to meet his small demand of seed, select
middle-aged good phenotypes in his range, i.e., he should select middle-aged trees with
cylindrical straight long boles and well developed crowns and ring them with white paint.
As these are the best trees in the locality and have been selected for the purposes of
seed collection, they are called ‘seed trees’. The range officer, while selecting seed
trees should also pay attention to provenance. Seed trees should not be selected in
those areas where the quality of the trees may be inferior or it may have other defects
such as twisted fibres in chir. The seed trees should be selected in areas which have
the reputation of producing best trees of that species, and have also trees endowed with
special quality, such as higher yield of resin in case of chir. Studies made on chir in U.P.
show that while trees raised from seed from East Almora Division yielded 3820 gms of
resin in 175 days, those raised from seed from Kangra yielded 1740 gams, from seed of
Naintial origin 1985 gms and from Chakrata 2610 gms only. Thus, provenance has a
great effect on the quality of the trees produced and therefore, seed should be collected
from seed trees selected from trees of reputed provenances, if available in the range.
Seed production areas or seed stands – The requirement of large scale
plantations cannot be met from seed trees selected by the range officer. To meet their
requirement of seed, ‘seed production areas’ or ‘seed stands’ should be established.
Seed production area or seed stand may be defined as a crop of vigorously
growing, middle aged to mature trees of good vigour and well developed
crowns, with clear boles and managed exclusively for seed collection. The
main objects of establishing seed production areas are:
(i) to produce seed of improved inherent quality from the bet phenotypes
available in the stand by selecting and favoring trees which are vigorous, straight-boled,
and healthy and produce wood of desired quality.
(ii) to concentrate seed collection in a few specially treated areas of the forest,
thus making the seed collection easier to organize and control.
Selection of seed production areas is made only on the basis of age, external
appearance of trees and general condition of the crop. The crop should be middle-aged.
Vigour, health, and growth habit of trees are also taken into consideration in selecting
such areas. In case of chir, freedom from twist is an important consideration.
Proportion of good and healthy trees to poor and mis-shapen trees is also an important
factor to be considered. Only those areas are selected as seed stands where the
proportion of desirable trees in high.
The number of such trees per hectare varies with species. For example, while 50
trees per hectare are considered sufficient for chir, 75 to 125 trees, depending on their
size and height, are considered essential for teak. The total area of the seed stands in a
division or state depends upon the annual target of plantations, spacing, periodicity of
good seed years, seed weight, etc. It is, however, estimated that generally one hectare
of seed stand of annually seeding species should be sufficient to meet the seed
requirement of 15 to 20 hectares of plantation target of that species. The extent of the
individual seed production areas should be neither too small nor too large to facilitate
their proper management. While effective isolation is not possible in very small areas, it
is difficult to maintain the uniformly high quality of selected trees in very large areas.
The seed production areas so far selected in the country vary in area from 4 hectares to
10 hectares, though they could be upto 25 to 30 hectares.
After the selection of a seed production area, the first step in its formation is to
select and mark seed trees which will be retained for seed production. After selecting
the best phenotypes, they are distinctly ringed with paint and the remaining inferior
trees are marked for removal. If there is any congestion even after the removal of
inferior trees, the selected trees are so thinned that the crowns of the retained tree are
free from competition of their neighbours and have sufficient space to develop into good
crowns to produce maximum quantity of seed. In order to increase seed production,
soil working and application of fertilizers are also, sometimes, resorted to. Relative
efficiency of various fertilizers and their dosages are still under study.
In order to prevent pollination of flowers of the trees of the seed production area
with the pollen of the inferior trees of the neighbourhood, it is necessary that there
should be no inferior tree upto the distance the pollen of the species can travel. Usually
an isolation strip of 100 to 150 m width is considered sufficient. All the inferior trees of
this strip are also removed to avoid contamination.
Seed production areas are under the exclusive control of the state silviculturists
and are maintained only for seed collection. Normal working plan operations such as
fellings, etc., are not permitted in them. Seep production areas have so far been
established for deodar, chir, teak, semal, Eucalyptus hybrid, Casuarina, etc.
Seed orchards – The seed production areas are established from the existing
crop of a species by removal of the inferior trees. Therefore, it is not necessary that
they may produce genetically superior trees. The establishment of such areas is actually
an interim measure designed to produce seed of the best possible quality until seed
orchards reach production stage. Seed orchard is defined as a plantation of
genetically superior trees isolated to reduce pollination from genetically
inferior ones, and intensively managed to produce frequent, abundant, and
easily harvested seed. It is established by setting out clones (as grafts or rooted
cuttings) or seedling progeny of plus trees and thus may be of the following two kinds:
(i) Clonal seed orchard; and
(ii) Seedling seed orchard
(i) Clonal seed orchard is a seed orchard which ahs been raised by grafting
clones in the form of scion or bud of plus trees on the stock of 2 or 3 year old seedlings,
raised at proper spacing in advance or by planting rooting cuttings of plus trees at
proper spacing.
(ii) Seedling seed orchard is a seed orchard which has been raised from the
seedlings obtained from seeds of plus trees.
Of the two kinds mentioned above, clonal seed orchards are preferred for most
species as against seedling seed orchards because the former start producing seed
earlier.
 The location of the seed orchard should be such that it is isolated to prevent
pollen contamination from inferior outside sources of the same species. Isolation can be
achieved either by keeping an appropriate distance around the seed orchard free from
any plantation, or self grown tree of the same species or by screening off the seed
orchard by planting a belt of some other suitable species which does not intercross with
that within the seed orchard. As a rule, seed orchards of wind-pollinated species such
as pines and other conifers, in which pollen can travel long distances, should be given
greater isolation distances or wider and more effective barriers than those of insect-
pollinated species such as teak.
The site of the seed orchard should be such that will support a vigorous crop. It
should be flat or gently sloping, well-drained and easily accessible. The area should be
at least 4 hectares so that it is economical to operate the orchard. Though the number
of clones that should be in seed orchard varies with species, the genetic base should be
kept as wide as possible. Even 1 to 25 clone are regarded as a good number to use
provided these have been selected under high selection intensity from as many different
stands as possible within a major zone defined by edaphic and climatic conditions. The
clones or the seedlings of the various plus trees are raised in a seed orchard according
to a randomized design to ensure cross-pollination and avoid self-pollination.
Clover or other suitable leguminous crop may be cultivated in the interspaces
between the plants in a seed orchard. A seed orchard may be irrigated, preferably by
sprinkler system, and even fertilized to get maximum output of seed. Fertilizer
applications should be so planned that the existing deficiencies in the soil are corrected
and major elements are suitably supplemented. Time and frequency of application will
have to be worked out to ensure maximum seed production. Pruning of plants in seed
orchard is recommended to facilitate and collection and keep down the cost of
collection.
The seed orchards offer following advantages:
(i) Seed orchards produce genetically improved and hence superior seed;
(ii) They concentrate seed supplies, thus making seed collection easy and control
of seed origin practicable;
(iii) They can be used as breeding orchards, i.e., for carrying out controlled
crossing programmes between selected parent clones to achieve further improvement of
the species; and
 (iv) The size and germinative capacity of seed produced in seed orchards are
reported to be better than those produced under normal forest conditions.
Establishment of the seed orchards is the responsibility of the state silviculturist.
So far, seed orchards have been established in this country for semal and teak only.

TIME OF SEED COLLECTION

Collection of seed from seed production areas and seed orchards is arranged by
the state silviculturist. The range officers have to collect seed for their requirement
from the seed trees selected by them. Therefore, knowledge of the time of seed
collection is essential for them.
Seed should be collected on ripening before dispersal. Seed collected before
ripening or maturity may either give poor germination or may not germinate at all as it
may be quite ifatnerile. It is particularly with very minute seeds (e.g., Adin and
Anthocephalus cadamba) resulting in failure of plantations.
Though slightest error in judging the ripeness of the seed at the time of
collection may result in failure of plantation, yet no hard and fast rules can be laid down
to help in making correct judgement which comes only by experience based on constant
observation, though change in colour and softening of the tissues of fruit may give some
indication that the seed is approaching maturity. Most fruits turn reddish brown when
ripe. In case of pulpy fruits, the pulp soften and the skin starts getting wrinkles. The
hardening of seed also gives indication of approaching maturity. Though the seeds have
to be collected when perfectly ripe, care should be taken to see that there is no undue
delay resulting in dispersal of seed, thereby making collection difficult and, at times,
practically impossible. Most of the species have a fairly definite period in which their
seeds ripen and can therefore be collected. Time of seed collection of some common
species given below is indicated in brackets after their names:
Acacia Arabica (May), Acacia catechu (Jan.-Feb.), Ailanthus excelsa (April-May),
Ailanthus grandis (March-April), Abies pindrow (October-Nov.), Adina cordifolia (April-
June), Albizzia procera (Feb-March), Albizzia lebbek (Jan.-Feb.), Acrocarpus fraxinifolius
(April-May), Acer caesium (Sept.-Oct.), Azadirachta indica (June-July), Bombax ceiba
(April-May), Boswellia serrata ( M a y -June), Broussonetia papyrifera ( J u n e -Sept.),
Casuarina equisetifolia (June & Dec.), Cedrus deodara (Oct.-Nov.), Cupressus torulosa
(Oct.-Nov.), Dalbergia sissoo (December-Feb.), Dendrocalamus strictus ( M a y -June),
Eucalyptus hybrid (May-July, Nov.-Dec.), Eucalyptus citriodora (May-June), Jaglans regia
(Sept.-Nov.), Kydia calycina (Jan-Feb.), Morus alba (April – May), Picea smithiana (Oct.-
Nov.), Pinus roxburghii (March-April), Pinus wallichinan (Sept. – Oct.), Prosopis juliflora
(May-June), Pterocarpus marsupium (Dec.-April), Quercus incana (Dec.-Jan.), Shorea
robusta (June-July), Tectona grandis (Nov.-Jan.), Toona ciliate (May-June).
Though these are he normal periods when the seeds of the species mentioned
should be colleted yet the exact time changes from locality to locality, and within the
same locality from year to year due to cliamatic variations. Therefore, the exact time of
seed collection should be decided after inspection of the fruits each year.
During the period of seed collection, the seeds which ripen very early or very late
are generally poor and often infertile. For example, Terminalia tomontosa seeds start
falling from January but these seeds do not germinate. Exception to this general rule is
chir which, though ripens in March-April, can be collected in the felling areas after
December provided the length of the cone is not less than 10 cm.

METHODS OF SEED COLLECTION

The seed is usually collected by one of the following methods:
(i) Collection from the ground of seed which has fallen either naturally or by
shaking of the tree;
(ii) Collection of seed by lopping the braches of trees of from freshly felled trees;
and
(iii) Collection of seed from standing trees.
(i) Collection of fallen seed from the ground – This method is applied to
species which have large seeds or fruits which fall unbroken below the parent tree.
When seeds are collected from the ground, care should be taken to seed that only
freshly fallen seed is collected. This is ensured by clearing and sweeping the ground
below the selected trees and then by collecting the seed from the cleared places daily.
It should also be seen that the seed is of proper quality, is fully ripe, and is not insect-
attacked.
Examples – Sal, teak, Acrocarpus fraxinifolius, Trewia nudiflora, Gmelina arbrea,
Oaks, Artocarpus chaplasha, Anthocephalus cadamba.
(ii) Collection of seed by lopping the branches or from freshly felled
trees – This method is applied to species whose seed or fruit is either too small to be
economically picked from the ground after falling as in case of Terminalia myriocarpa,
Betula, etc., or likely to be widely dispersed by wind as in case of Dalbergia sissoo,
Acacia catechu, etc.
The cheapest and easiest method is to collect seed from the branches of the
freshly felled trees. This is only possible when the felling coupe has good seed trees
and when the time of felling corresponds with the time of seed collection (except in case
of chir). When it is not so, mazdoors are engaged to climb the trees and lop the
branches of good seed trees. In such a case, the ground below the tree is first cleared
and swept clean to prevent seed from being lost. But care must be taken to avoid, or at
lest minimize, damage to the trees in the process. The boles of the trees should not be
spoilt by hacking out foot-holds and lopping should be confined to smaller twigs and thin
branches.
Examples – Acacia catechu, Dalbergia sissoo, Albizzia s p p . , Holoptelia,
Hymenodictyon excelsum, Ailanthus, conifers, etc.
(iii) Collection of seed from standing trees – seeds which are likely to get
damaged in falling with branches, or get dispersed, are collected by hand from standing
trees. Sometimes, a sickle tied to a bamboo with a small bag attached to it, is also used
to collect seed or fruit from thin slender branches.
Examples – Acer, Morus, etc.

SEED EXTRACTION
Many seeds or fruits can be sown or stored as they are collected. But in other
cases, the seeds have to be separated from the fruit. The method of seed extraction
varies with the kind of fruit.
(i) Pulpy and fleshy fruits – As a general rule, the pulpy portion should be
removed as soon as possible. Even when seed is to be sown immediately, as in case of
Artocarpus, Michelia, etc., it is necessary to remove fruit pulp before sowing. Failure to
do so often results in serious fall in germinative capacity, e.g., Azadirachta indica.
The method of removing pulp varies with the kind of fruit. In some cases, it may
be done by treading or beating, e.g., Gmelina. But the usual method is to remove it by
hand after keeping the fruit in water in some container for some time after which it is
kneeded, pounded, and squeezed while still in water until the seeds are freed and can
be washed out. The soft pulp floats on water and the freed seed sinks to the bootom
and the two can be separated by decantation. Fleshy fruits with very small seeds (e.g.,
Morus, Anthocephalus, Broussonetia, etc.) need special treatment. After depulping
them in water, the water containing the pulp and seeds is put in a fine muslin cloth
through which the water and the soft pulp can be squeezed out, leaving the seed
behind.
Dry fruits – From the point of view of seed extraction, the dry fruits my be
classified into the following categories:
(i) Those in which the entire fruit is sown with seed contained in it, e.g., teak,
walnut, oak, ash, etc.;
(ii) Those in which part of the fruit is sown with the seed contained in it, e.g.,
Dalbergia sissoo; and
(iii) Those in which clean seed is sown, e.g., conifers.
The first category of dry fruits does not require any extraction. The second
category requires only beating to break the fruit. For this purpose, the fruit is generally
put in a gunny bag and given sufficient beating to break the fruit in as many parts as
contain a seed or two. The third category of fruits require complete extraction of seed.
The usual method of extraction consists in spreading the ripe fruit in the sun on clean
hard floor or in trays until they open up. They can, then, be shaken or beaten to
separate the seed. In some cases (e.g., Bombax ceiba) the opened fruits are kept in a
gunny bag of bamboo basket, and churned with a wooden stick till the seed is separated
and collected from the bottom of the bag or the basket.

DRYING, CLEANING AND GRADING

Drying – Though some seeds (e.g., oaks, and many Lauraceae) lose their
viability, or have their viability seriously weakened, by drying, most of the seeds, after
extraction, require drying to maintain their viability. The drying can be done either in
sun or in shade. The seeds of many species can be either in sun or in shade. The
seeds of many species can be spread out in the sun but in some case this is harmful. In
the absence of knowledge of the specific method of drying, the best rule is to follow
nature. Thus, the seeds of the open deciduous forests may be dried in the sun while
those of the damp shady or evergreen forests may be dried in shade.
Cleaning – After drying, the seed should be cleaned to remove all foreign
material such as twigs, small stones, fragments of fruit capsules or cones, husk, etc.
Empty, infertile or insect-attacked seeds should also be removed. Cleaning methods
vary with species. The usual methods of cleaning adopted are as follows:
(i) Hand picking – The larger-sized foreign material such as twigs, stones, etc.,
can be removed by hand picking. This method is also used for removing under-sized
and defective seeds in species which have larger fruits or seeds.
(ii) Separation by water – The light particles of capsules and most of the bad
seed can be removed by putting the seed in water. The good seed will sink to the
bottom, and the foreign matter and light infertile and will float. The two can be
separated by decantation. When this method is applied, the good seeds have to be
thoroughly dried again.
(iii) Winnowing – In order to remove light husk and dust, seeds can also be
winnowed.
(iv) Sieving – Foreign matter, which is larger in size than the seed, can be
separated by sieving the mix in a sieve with holes which may just permit the seeds to
pass through. On the other hand, foreign matter, which is smaller in size than the seed,
can be separated by using a sieve which does not allow the seeds to pass through.
Grading – After cleaning, the seeds should be graded to separate good and
poor seeds. In case of single seeds of single-seeded fruits, the larger seeds/fruits are
always good, and should be preferred. The seeds of the medium size may also be good
and can be accepted but the seeds of the smallest size may be eliminated as they are
likely to produce, if they germinate, poor seedlings. In case of multi-seeded fruits, he
size does not give any indication of he quality of the seed. For example, a single seed in
a small teak fruit often gives a better seedling than the seeds in a multi-seeded larger
fruit.
In some cases, colour of seed gives an indication about the quality of the seed.
For example, in Dalbergia latifolia brown seeds have been reported to have double the
germinative capacity than the black seeds.

SEED STORAGE
Excepting the seeds which ripen just at the time of sowing, all other seeds have
to be stored till the time of sowing. Even otherwise, as most of the species do not seed
every year, it becomes necessary to collect and store the seed in good seed years
without impairing their quality for use in the lean seed year.
 As a general rule, the ideal storage conditions are those in which respiration and
transpiration is reduced to a minimum without damaging the inherent vitality and
strength of seed embryo. Normally, the best method of storage suited to a species is
one in which the seed is stored in nature. The method of storage, thus, varies with
species and for this purpose the species may be classified as under:
(i) Species with seed of transient viability – The seed of those species,
which remain viable for a short time should, normally, be sown immediately after
collection, but sometimes due to unfavourable weather conditions or labour difficulty,
they have to be stored for a few days. This is best done by spreading them in shade,
on hard floor, if possible, to prevent injury by desiccation and giving them a sprinkling of
water from time to time. In this way they can be stored for 2 to3 weeks. Sal, most
Dipterocarps, many Myrtaceae and Lauraceae seeds are stored in this way.
(ii) Species whose seeds ripen in autumn and germinate in spring – The
species of the temperate region usually seed in autumn and their seeds keep on lying
either under snow or in very low temperature the winter. They germinate in spring
when snow melts. Naturally, the seeds of these species should be stored under low
temperature. Cold storage has been found to be very effective for pines, conifers and
other broad-leaved species of that region. Cold storage may be dry or wet. Generally
conifers require dry cold storage but the broad-leaved species of that region. Cold
storage may be dry or wet. Generally conifers require dry cold storage but the broad-
leaved trees require wet cold storage, i.e., they have to be kept moist and at low
temperature. Seeds of Quercus, Machilus and Juglans have been stored in Darjeeling
district (West Bengal) by putting them in pits dug in the soil so as to keep the top of the
seeds about 45 to 60 cm below the ground level and covering them with soil. The seeds
are dug out and sown early in spring so that germination does not start in the pit and
make handling of the seeds difficult.
(iii) Species whose seeds ripen in winter or summer and germinate in
following rainy season – Most species in the plains produce seeds in winter or
summer and these seeds germinate in nature in the following rainy season. Thus, they
bear the varying temperatures and moisture conditions before germinating in rains.
Such seeds can be stored in dry conditions.
If the quantity of the seed to be stored is small, it can be stored in a thatched
hut or a room of the forest guard quarter, but when large quantities of seed have to be
stored, a seed store has to be constructed. Seed store is normally a well-ventilated two
roomed house with a closed verandah. One of the rooms is very much longer than the
other and is fitted with shelves in tiers where seed packed in tins, bottles or sacks is
kept. The windows of this room should be fitted with fine wire netting so that insects,
rats, squirrels, etc., cannot get in. The floors of the rooms should be made of damp-
proof cement concrete. The small room is used for simple tests, weighments and
treatments. The closed verandah is used for drying, cleaning, etc. It is advisable to
have a low concrete platform outside for drying in sun and extraction of seed. The
whole area should be kept absolutely clean. All foreign matter removed in cleaning the
seeds and all rejected seeds should be burnt outside the compound. Water and
electricity should be provided in the seed store.
The seeds are stored in the seed store: (a) in heaps on dry floor; (B) in
gunny bags; (c) in sealed tins or drums; or (d) in stoppered bottles. If the quantity of
the seed to be stored is large, the seeds are stored in heaps on dry floor; other wise,
they are packed in gunny bags which are either hung from the rafters, or placed on the
ground or on the shelves of the seed store. In both these methods, the seeds are
subject to fluctuations to temperature and humidity of the room. If the quantity is still
smaller, the seeds can be stored in sealed tins or drums. This is a better method of
storing seeds and tests carried out in Java have indicated that the seeds stored in this
way registered higher germinative capacity than those kept in open baskets. Very small
seeds like those of Eucalyptus can be stored in stoppered bottles.
Protection of seed against insects during storage – Inspite of all
precautions taken at the time of cleaning the seed to remove insect-attacked seeds,
there are chances that some such seeds may escape detection and may thus go in the
seed store. Such seeds become foci of attack on other seeds. Besides this, some seeds
are liable to be insect-attacked during storage. Therefore, it is very essential to protect
the seeds during storage from insect attack by the use of insecticides such as D.D.T.
and B.H.C.