We assessed the potential impacts of land-use changes resulting from a change in the current biof... more We assessed the potential impacts of land-use changes resulting from a change in the current biofuel policy on biodiversity in Europe. We evaluated the possible impact of both arable and woody biofuel crops on changes in distribution of 313 species pertaining to different ...
Functional diversity within communities may influence ecosystem functioning, but which factors dr... more Functional diversity within communities may influence ecosystem functioning, but which factors drive functional diversity? We hypothesize that communities assembled from many phylogenetic lineages show large functional diversity if assembly is random, but low functional diversity if assembly is controlled by interactions between species within lineages. We combined > 9000 descriptions of Dutch plant communities, a species-level phylogeny, and information on 16 functional traits (including eight dispersal traits). We found that all traits were conserved within lineages, but nevertheless communities assembled from many lineages showed a smaller variation in trait-states of most traits (including dispersal traits) than communities assembled from few lineages. Hence, within lineages, species are not randomly assembled into communities, contradicting Neutral Theory. In fact, we find evidence for evolutionary divergence in trait-states as well as present-day mutual exclusion among related, similar species, suggesting that functional diversity of communities increased due to past and present interactions between species within lineages.
Aim To estimate invasiveness of exotic plant species, many studies have used the frequency of oc... more Aim To estimate invasiveness of exotic plant species, many studies have used the frequency of occurrence within a defined region. This measure is informative on how widespread exotics are, however, it does not inform on their local dominance, which is crucial for conservation of biodiversity and ecosystem functioning. The aim of the present study is to determine if regional frequency
Long-distance seed dispersal is generally assumed to be important for the regional survival of pl... more Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by first relating plant species’ dispersal traits to seed dispersal kernels and then relating the kernels to regional survival of the species. We used a recently developed and tested mechanistic seed dispersal model to calculate dispersal kernels from dispersal traits. We used data on 190 plant species and calculated their regional survival in two ways, using species distribution data from 36,800 1 km2-grid cells and 10,754 small plots covering the Netherlands during the largest part of the 20th century. We carried out correlation and stepwise multiple regression analyses to quantify the importance of long-distance dispersal, expressed as the 99-percentile dispersal distance of the dispersal kernels, relative to the importance of median-distance dispersal and other plant traits that are likely to contribute to the explanation of regional survival: plant longevity (annual, biennial, perennial), seed longevity, and plant nutrient requirement. Results show that long-distance dispersal plays a role in determining regional survival, and is more important than median-distance dispersal and plant longevity. However, long-distance dispersal by wind explains only 1–3% of the variation in regional survival between species and is equally important as seed longevity and much less important than nutrient requirement. In changing landscapes such as in the Netherlands, where large-scale eutrophication and habitat destruction took place in the 20th century, plant traits indicating ability to grow under the changed, increasingly nutrient-rich conditions turn out to be much more important for regional survival than seed dispersal.
... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we pres... more ... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we present the expected beneficial/detrimental effects on a selected subset of biodiversity under this scenario ... support policy makers to assess their choices in order to sustain biodiversity in the ...
... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we pres... more ... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we present the expected beneficial/detrimental effects on a selected subset of biodiversity under this scenario ... support policy makers to assess their choices in order to sustain biodiversity in the ...
Almost a century ago, Josias Braun-Blanquet developed his phytosociological approach for vegetati... more Almost a century ago, Josias Braun-Blanquet developed his phytosociological approach for vegetation field study. At that time, nobody could foresee what the impact of this methodology would be for vegetation science as well as for its application in nature conservation. Hundreds of thousands of so-called relevés (vegetation plot records) have been made, collected in field books, and many of them have been published afterward. Some 20 years ago, the software package Turboveg was developed for the input, storage, and handling of vegetation data. Since then, many national and regional vegetation databases have been compiled, providing the basis for national and international classification overviews and other scientific studies. It is estimated that currently there have been more than 4.2 million relevés made throughout Europe, including 1.8 million relevés already available in electronic dabatases and about 45% of these available in Turboveg format. The computerized vegetation data have been shown to offer new possibilities for ecological research (a new branch of study, called eco-informatics), of which a number of examples will be discussed. Furthermore, the electronic data form a fundament for the compilation of ecological information systems. As an example of these, the information system SynBioSys will be discussed as a new tool for nature conservation and policy making, including Natura 2000.
The nature of the plant community has been a long-standing point of discussion in vegetation scie... more The nature of the plant community has been a long-standing point of discussion in vegetation science. Already in the early decades of the last century, debate focused on whether plant communities existed as discrete, intra-dependent entities or merelyas loose assemblages of species each responding individualistically to local environmental conditions. Despite the fundamental nature of this question, the issue is generally
We assessed the potential impacts of land-use changes resulting from a change in the current biof... more We assessed the potential impacts of land-use changes resulting from a change in the current biofuel policy on biodiversity in Europe. We evaluated the possible impact of both arable and woody biofuel crops on changes in distribution of 313 species pertaining to different taxonomic groups. Using species-specific information on habitat suitability as well as land use simulations for three different biofuel policy options, we downscaled available species distribution data from the original resolution of 50 to 1 km. The downscaled maps were then applied to analyse potential changes in habitat size and species composition at different spatial levels. Our results indicate that more species might suffer from habitat losses rather than benefit from a doubled biofuel target, while abolishing the biofuel target would mainly have positive effects. However, the possible impacts vary spatially and depend on the biofuel crop choice, with woody crops being less detrimental than arable crops. Our results give an indication for policy and decision makers of what might happen to biodiversity under a changed biofuel policy in the European Union. The presented approach is considered to be innovative as to date no comparable policy impact assessment has been applied to such a large set of key species at the European scale.
Aim Local communities are subject to spatiotemporal contingencies of landscape processes; commun... more Aim Local communities are subject to spatiotemporal contingencies of landscape processes; community assembly is thus often considered to be unpredictable and idiosyncratic. However, evolved trade-offs of species’ life histories may set distinct constraints on the assembly of species communities. In plants, the recruitment and invasion success of species into communities depend primarily on the number of propagules available and on their generative or vegetative character. Life-history trade-offs prevent individual plants from producing large numbers of both generative and vegetative propagules, but it is not clear whether this constrains their availability at the landscape scale. We thus tested whether: (1) the observed relationship between generative and vegetative propagules deviates from the null expectation stating that species contributing the bulk of generative propagules to the propagule rain should also contribute the bulk of vegetative propagules; and (2) whether vegetative and generative propagule pressures are negatively correlated once species abundance in the regional pool is accounted for.Location A large riparian landscape in the Netherlands.Methods Analyses were based on an extensive trapping of floating propagules (214,049 propagules of 47 species), and a rough proxy of species abundance across the entire pool. We used both species and phylogenetically independent contrasts as data points, and accounted for variation in size of generative propagules.Results Both hypotheses were confirmed. Numbers of generative and vegetative propagules trapped per species were significantly negatively correlated (r = −0.33; t45 = −2.61, P = 0.006) and thus strongly deviated from the null expectation. This was confirmed by analyses accounting for variation in species abundance across the species pool, and in the size of generative propagules.Main conclusions The results indicate that plant recruitment and community assembly across streams may be influenced by the way individual plants allocate their resources between competing life-history functions. Life-history evolution across angiosperms might thus have constrained the present-day assembly of local communities.
We assessed the potential impacts of land-use changes resulting from a change in the current biof... more We assessed the potential impacts of land-use changes resulting from a change in the current biofuel policy on biodiversity in Europe. We evaluated the possible impact of both arable and woody biofuel crops on changes in distribution of 313 species pertaining to different ...
Functional diversity within communities may influence ecosystem functioning, but which factors dr... more Functional diversity within communities may influence ecosystem functioning, but which factors drive functional diversity? We hypothesize that communities assembled from many phylogenetic lineages show large functional diversity if assembly is random, but low functional diversity if assembly is controlled by interactions between species within lineages. We combined > 9000 descriptions of Dutch plant communities, a species-level phylogeny, and information on 16 functional traits (including eight dispersal traits). We found that all traits were conserved within lineages, but nevertheless communities assembled from many lineages showed a smaller variation in trait-states of most traits (including dispersal traits) than communities assembled from few lineages. Hence, within lineages, species are not randomly assembled into communities, contradicting Neutral Theory. In fact, we find evidence for evolutionary divergence in trait-states as well as present-day mutual exclusion among related, similar species, suggesting that functional diversity of communities increased due to past and present interactions between species within lineages.
Aim To estimate invasiveness of exotic plant species, many studies have used the frequency of oc... more Aim To estimate invasiveness of exotic plant species, many studies have used the frequency of occurrence within a defined region. This measure is informative on how widespread exotics are, however, it does not inform on their local dominance, which is crucial for conservation of biodiversity and ecosystem functioning. The aim of the present study is to determine if regional frequency
Long-distance seed dispersal is generally assumed to be important for the regional survival of pl... more Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by first relating plant species’ dispersal traits to seed dispersal kernels and then relating the kernels to regional survival of the species. We used a recently developed and tested mechanistic seed dispersal model to calculate dispersal kernels from dispersal traits. We used data on 190 plant species and calculated their regional survival in two ways, using species distribution data from 36,800 1 km2-grid cells and 10,754 small plots covering the Netherlands during the largest part of the 20th century. We carried out correlation and stepwise multiple regression analyses to quantify the importance of long-distance dispersal, expressed as the 99-percentile dispersal distance of the dispersal kernels, relative to the importance of median-distance dispersal and other plant traits that are likely to contribute to the explanation of regional survival: plant longevity (annual, biennial, perennial), seed longevity, and plant nutrient requirement. Results show that long-distance dispersal plays a role in determining regional survival, and is more important than median-distance dispersal and plant longevity. However, long-distance dispersal by wind explains only 1–3% of the variation in regional survival between species and is equally important as seed longevity and much less important than nutrient requirement. In changing landscapes such as in the Netherlands, where large-scale eutrophication and habitat destruction took place in the 20th century, plant traits indicating ability to grow under the changed, increasingly nutrient-rich conditions turn out to be much more important for regional survival than seed dispersal.
... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we pres... more ... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we present the expected beneficial/detrimental effects on a selected subset of biodiversity under this scenario ... support policy makers to assess their choices in order to sustain biodiversity in the ...
... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we pres... more ... f Norwegian Institute for Nature Research, Gaustadalleen 21, N-0349 Oslo, Norway. ... we present the expected beneficial/detrimental effects on a selected subset of biodiversity under this scenario ... support policy makers to assess their choices in order to sustain biodiversity in the ...
Almost a century ago, Josias Braun-Blanquet developed his phytosociological approach for vegetati... more Almost a century ago, Josias Braun-Blanquet developed his phytosociological approach for vegetation field study. At that time, nobody could foresee what the impact of this methodology would be for vegetation science as well as for its application in nature conservation. Hundreds of thousands of so-called relevés (vegetation plot records) have been made, collected in field books, and many of them have been published afterward. Some 20 years ago, the software package Turboveg was developed for the input, storage, and handling of vegetation data. Since then, many national and regional vegetation databases have been compiled, providing the basis for national and international classification overviews and other scientific studies. It is estimated that currently there have been more than 4.2 million relevés made throughout Europe, including 1.8 million relevés already available in electronic dabatases and about 45% of these available in Turboveg format. The computerized vegetation data have been shown to offer new possibilities for ecological research (a new branch of study, called eco-informatics), of which a number of examples will be discussed. Furthermore, the electronic data form a fundament for the compilation of ecological information systems. As an example of these, the information system SynBioSys will be discussed as a new tool for nature conservation and policy making, including Natura 2000.
The nature of the plant community has been a long-standing point of discussion in vegetation scie... more The nature of the plant community has been a long-standing point of discussion in vegetation science. Already in the early decades of the last century, debate focused on whether plant communities existed as discrete, intra-dependent entities or merelyas loose assemblages of species each responding individualistically to local environmental conditions. Despite the fundamental nature of this question, the issue is generally
We assessed the potential impacts of land-use changes resulting from a change in the current biof... more We assessed the potential impacts of land-use changes resulting from a change in the current biofuel policy on biodiversity in Europe. We evaluated the possible impact of both arable and woody biofuel crops on changes in distribution of 313 species pertaining to different taxonomic groups. Using species-specific information on habitat suitability as well as land use simulations for three different biofuel policy options, we downscaled available species distribution data from the original resolution of 50 to 1 km. The downscaled maps were then applied to analyse potential changes in habitat size and species composition at different spatial levels. Our results indicate that more species might suffer from habitat losses rather than benefit from a doubled biofuel target, while abolishing the biofuel target would mainly have positive effects. However, the possible impacts vary spatially and depend on the biofuel crop choice, with woody crops being less detrimental than arable crops. Our results give an indication for policy and decision makers of what might happen to biodiversity under a changed biofuel policy in the European Union. The presented approach is considered to be innovative as to date no comparable policy impact assessment has been applied to such a large set of key species at the European scale.
Aim Local communities are subject to spatiotemporal contingencies of landscape processes; commun... more Aim Local communities are subject to spatiotemporal contingencies of landscape processes; community assembly is thus often considered to be unpredictable and idiosyncratic. However, evolved trade-offs of species’ life histories may set distinct constraints on the assembly of species communities. In plants, the recruitment and invasion success of species into communities depend primarily on the number of propagules available and on their generative or vegetative character. Life-history trade-offs prevent individual plants from producing large numbers of both generative and vegetative propagules, but it is not clear whether this constrains their availability at the landscape scale. We thus tested whether: (1) the observed relationship between generative and vegetative propagules deviates from the null expectation stating that species contributing the bulk of generative propagules to the propagule rain should also contribute the bulk of vegetative propagules; and (2) whether vegetative and generative propagule pressures are negatively correlated once species abundance in the regional pool is accounted for.Location A large riparian landscape in the Netherlands.Methods Analyses were based on an extensive trapping of floating propagules (214,049 propagules of 47 species), and a rough proxy of species abundance across the entire pool. We used both species and phylogenetically independent contrasts as data points, and accounted for variation in size of generative propagules.Results Both hypotheses were confirmed. Numbers of generative and vegetative propagules trapped per species were significantly negatively correlated (r = −0.33; t45 = −2.61, P = 0.006) and thus strongly deviated from the null expectation. This was confirmed by analyses accounting for variation in species abundance across the species pool, and in the size of generative propagules.Main conclusions The results indicate that plant recruitment and community assembly across streams may be influenced by the way individual plants allocate their resources between competing life-history functions. Life-history evolution across angiosperms might thus have constrained the present-day assembly of local communities.
Aim Many biologists explain the global richness of lineages and local co-occurrence of lineage me... more Aim Many biologists explain the global richness of lineages and local co-occurrence of lineage members by distinct processes: speciation/extinction versus ecological interactions. Moreover, allopatric distribution, rarity and local competition limit local co-occurrence of species even within species-rich lineages. However, whether and why the global richness of lineages relates to local co-occurrence of lineage members has not been tested. We study angiosperms, and hypothesize that in globally species-rich genera species frequently encounter con-geners locally, reflecting (1) random sampling of species pools into local communities and (2) processes of global species production and local survival such as hybridization, niche filling and a reduced risk of extinction. Location Netherlands, South Africa, worldwide. Methods Analysing more than 350,000 plots we quantify per species the observed number of co-occurring congeners as well as the null expectation based on random sampling from species pools. From the literature we quantify the global species richness of genera, and abiotic niche positions and breadths, hybrid status and regional species declines. Results In some genera species frequently encounter congeners locally, while in others congeners are rarely encountered. This is independent of the total number of species encountered, and is consistent between the Netherlands and South Africa. 'High-co-occurrence genera' are particularly species rich across the globe, consistently so in most families and even after controlling for niche positions, age and regional richness of genera. Species in high-co-occurrence genera tend to occupy niches that are large and close to congeners' niches. These species are more often hybrids and rarely decline. Relationships explain little variance (< 10%) but are stronger than expected from random sampling of species rich pools. Main conclusions Local co-occurrence and global species richness are largely independent, but not entirely so, reflecting random sampling of pools into communities , niche partitioning, hybridization and the reduced risk of regional extinction in high-co-occurrence genera. Increased extinction risk in low-co-occurrence genera implies a proportionately high loss of lineages and their evolutionary heritage from local communities.
Aim Biodiversity hot-spots are regions containing evolutionary heritage from ancient or recent ge... more Aim Biodiversity hot-spots are regions containing evolutionary heritage from ancient or recent geological epochs, i.e. evolutionary ʻmuseumsʼ or ʻcradlesʼ, respectively. We hypothesize (i) there are ʻmuseumsʼ and ʻcradlesʼ also within regions: some species pools of particular habitat types contain angiosperm (flowering plants) lineages from ancient geological epochs, others from recent epochs; (ii) habitat-specific abiotic factors control numbers of angiosperm lineages contained from a given epoch in a given habitat species pool. Location The flora of the Netherlands Methods We studied the world’s largest vegetation-plot database and a new, uniquely resolved dated angiosperm phylogeny available for the Netherlands. We characterized species pools of habitat types by a novel concept: epoch-specific lineage diversities. Results We found that species pools of most habitat types were characterized by over- or underrepresentation of lineages from at least one epoch, dating back until the origin of angiosperms. These patterns are not captured by mean lineage ages. Abiotic environments explained on average 56% and up to 75% of the variance in numbers of lineages per epoch, but with opposing effects of the same factor for different epochs. Specifically, warm and dry habitats tend to contain lineages dating back to warm and dry epochs. Identifying lineages from sets of random time intervals rather than from a set of geological epochs significantly reduced relationships with the environment. Main conclusions Within a region, habitat types differ significantly in the evolutionary heritage they contain from different geological epochs, and the environment controls these differences.
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Papers by Wim Ozinga
Location The flora of the Netherlands
Methods We studied the world’s largest vegetation-plot database and a new, uniquely resolved dated angiosperm phylogeny available for the Netherlands. We characterized species pools of habitat types by a novel concept: epoch-specific lineage diversities.
Results We found that species pools of most habitat types were characterized by over- or underrepresentation of lineages from at least one epoch, dating back until the origin of angiosperms. These patterns are not captured by mean lineage ages. Abiotic environments explained on average 56% and up to 75% of the variance in numbers of lineages per epoch, but with opposing effects of the same factor for different epochs. Specifically, warm and dry habitats tend to contain lineages dating back to warm and dry epochs. Identifying lineages from sets of random time intervals rather than from a set of geological epochs significantly reduced relationships with the environment.
Main conclusions Within a region, habitat types differ significantly in the evolutionary heritage they contain from different geological epochs, and the environment controls these differences.