Elevation Gradient

 Campanula spatulata is represented on Mt Olympos (2917 m) by two subspecies: the lowland spruneriana, from 400 to 1100 m, and the upland spatulata, from 1700 m to 2500 m. Spatulata populations significantly differed from those of spruneriana in the following features: (i) they consisted of shorter individuals with smaller flowers and lower flower production, (ii) they allocated more energy and resources below ground, (iii) they flowered much later in the year, had longer duration of flowering, and longer flower life span, (iv) they produced smaller fruits with fewer but heavier seeds, (v) they received lower numbers of insect visits for fewer hours per day, and (iv) they were pollinated by smaller insects. Between and within subspecies comparisons showed that in most cases the patterns of character change were neither gradual nor monotonous all along the elevation gradient. The differences in phenological characters are in agreement with patterns associated so far with elevation change. The taxonomic and biometric differences of the insect pollinators as well as the temporal separation of the flowering periods provide substantial evidence of reproductive isolation of the two C. spatulata subspecies on Mt Olympos.

In this review I will describe the importance of seed banks and thepopulation dynamics of seeds on the distribution of species in salinehabitats. The main questions being examined in this review include: 1.Does the seed bank represent the flora of the entire salinity gradient or isit restricted to the species in each zonal community? 2. Is the size andspecies composition of the persistent seed bank regulated by the degree ofsalt stress in habitats along an environmental gradient? 3. Does thepopulation dynamics of seeds influence the temporal and spatial distributionof plant species in saline habitats? Seed banks may be transient orpersistent depending upon the physiological responses of species and thesoil environment in which the seeds are found. The formation of zonalcommunities in salt marsh environments is affected by changes in soilsalinity and flooding along an elevational gradient. Population dynamics ofseeds have been found to determine the spatial and temporal distributionof species along salinity gradients. The flora and relative density of speciesof zonal communities are significantly dependent upon the stress toleranceof species at different stages of development and the presence of transientor persistent seed banks. The occurrence of a seed bank is related to thesalinity tolerance of species at the germination stage of development, aseeds ability to tolerate hypersaline conditions and flooding, and whetheror not species are able to maintain a persistent seed bank until hypersalineconditions are alleviated.

Linear variable differential transformers (LVDTs) and inclinometers are widely used in many industrial establishments, particularly in the metrology area. These sensors are used by many engineering disciplines because of their high-precision characteristics. In addition, Global Navigation Satellite System (GNSS) receivers and total stations are widely used in geodesy. Using GNSS receivers is very popular, particularly for navigational purposes. In this paper, a new railway track geometry surveying system, which is designed by integrating the LVDT, inclinometer, GNSS receiver, and total station, is introduced. This new surveying system is an alternative to classical geodetic measurement methods that are often used for controlling the railway track geometry. Track gauge, super-elevation, gradient, and track axis coordinates, which are railway geometrical parameters, can be instantly determined while making measurements by using the new surveying system.

In this preliminary elevation gradient (3000-4000 m) study of high ranges forest of Sikkim (eastern Himalayas), we have analyzed the (i) species composition, (ii) tree species richness, density, basal area and distribution range, and (iii) forest structure by diameter at breast height (DBH) classes. The main purpose was to identify the role of elevation in tree dominance, and species richness in the subalpine forests of eastern Himalaya. The study was conducted in the Yuksam-Dzongri transect nested within the Khangchendzonga National Park, west district of Sikkim state. The quadrat method was used to sample vegetation and sampling was done at every 100 m steps between 3000 m and 4000 m elevations, eventually ending up in the timberline ecotone. A total of 109 species belonging to 80 genera and 46 families were recorded. The species richness and total tree basal area (TBA) declined monotonically along the elevation gradient. Tree density in present elevation transect was significantly higher than its western Himalayan counter parts of Indian Himalayan region. The presence of 23 tree species in the highest 1000 m forested zone highlights the high tree species richness of the eastern Himalaya. It was largely because of the speciation of Rhododendron spp. Further investigation is required to develop a holistic understating of these vegetation patterns across the Indian Himalayan region.

We examined the patterns of tree species richness, density and basal area in the Eastern Himalayan elevation gradient, and evaluated the roles of geometric constraints and environmental factors for the observed pattern. We followed the quadrat sampling method for this study at 23 different locations along a 300–4700 m elevation gradient in Sikkim. We used regression analysis to establish elevational pattern of trees (species richness, density and basal area) and to relate environmental factors with tree species and density. We also tested geometric constraints on species distribution by comparing empirical species richness with null model predictions generated by a Monte Carlo Simulation Programme (McCain, 2004). We observed a total of 3874 individual trees belonging to 171 species and 58 families. Tree species richness depicted unimodal pattern with a peak at 1500 m, whereas basal area peaked at 1900 m. Although density did not follow a uniform pattern, maximum value was observed at 3050 m. Climatic and energy related factors–rainfall, temperature, moisture index (MI) and actual evapotranspiration (AET)-correlated positively with tree species richness. The Mid-domain effect null model showed significant deviation of empirical richness from simulated species richness. Stepwise regression revealed that combined effects of energy (surrogated by temperature), productivity (surrogated by AET) and precipitation (reflected by MI) influenced observed tree species patterns in the Eastern Himalayan elevation gradient although historical and spatial factors might interplay.

A faunal survey conducted along an elevational gradient in Balbalasang-Balbalan National Park in northern Luzon Island, Philippines, revealed 15 species of non-flying small mammals. Thirteen, including 1 shrew and 12 murid rodents, are native species endemic to the Philippines, 7 of which are endemic to northern Luzon.  Two species are non-native murid rodents that were restricted to disturbed habitats.  As seen elsewhere in the
Philippines, species richness was greatest in montane and mossy forest habitats at mid to high elevations.  Although species-rich, the Balbalasang gradient does not include the full diversity of species known from the Central Cordillera region. Comparative data fromsites elsewhere on Luzon reveal that total species richness is a function of local elevation, with more species present in areas with higher mountain peaks. These patterns reflect the fact that diversity of non-flying small mammals is concentrated in highland areas where local assemblages include species that differ in diel activity, spatial habitat use, and diet. Numerically dominant species are members of a single murid clade, and several of these are specialized predators of earthworms.  Similarly structured communities in the highlands of Mindanao include species that are only distantly related to those of Luzon. Community convergence is thought to reflect the influence of similar habitat structure, food resource availability, and trophic partitioning in shaping small mammal assemblages.

A two dimensional implicit finite volume scheme for solving the shallow-water equations is developed. The effects of the Coriolis force, surface wind stress, and waves are included. A non-uniform rectilinear forward staggered grid is used with Cartesian coordinates. The time integration is performed using the Euler implicit technique. The convective flux is treated using the deferred correction method. The viscous