43 research outputs found
Native Tallgrass Prairie Remnants as "Living Museums": Landscape Context, Metacommunity Dynamics, and Private Management Practices of Native Prairie Hay Meadows
In fragmented tallgrass prairie remnants within eastern Kansas, smaller patch area, greater isolation, and poorer matrix quality are predicted to result in (1) decreased species richness, (2) decreased site `quality,' and (3) decreased presence of specialist species. Within five counties, 301 native tallgrass remnants were surveyed. Total site area, as well as habitat heterogeneity, contributed to richness and quality, but isolation and matrix quality did not. In fact, isolation and matrix quality appeared to contribute to decreasing richness and quality. These results can be explained by regional environmental variation and historic non-random process of human landscape changes at the time of settlement. This suggests that the hypothesis that dispersal plays a role in the community assembly of tallgrass prairie remnants is probably false. Although species-rich communities may persist for decades and possibly centuries after fragmentation, in the long term the effects of random local extinction have been underestimated for native tallgrass prairie communities
Data from: Processes of community assembly in an environmentally heterogeneous, high biodiversity region
Despite decades of study, the relative importance of niche-based versus neutral processes in community assembly remains largely ambiguous. Recent work suggests niche-based processes are more easily detectable at coarser spatial scales, while neutrality dominates at finer scales. Analyses of functional traits with multi-year multi-site biodiversity inventories may provide deeper insights into assembly processes and the effects of spatial scale. We examined associations between community composition, species functional traits, and environmental conditions for plant communities in the Kouga-Baviaanskloof region, an area within South Africa's Cape Floristic Region (CFR) containing high α and β diversity. This region contains strong climatic gradients and topographic heterogeneity, and is comprised of distinct vegetation classes with varying fire histories, making it an ideal location to assess the role of niche-based environmental filtering on community composition by examining how traits vary with environment. We combined functional trait measurements for over 300 species with observations from vegetation surveys carried out in 1991/1992 and repeated in 2011/2012. We applied redundancy analysis, quantile regression, and null model tests to examine trends in species turnover and functional traits along environmental gradients in space and through time. Functional trait values were weakly associated with most spatial environmental gradients and only showed trends with respect to vegetation class and time since fire. However, survey plots showed greater compositional and functional stability through time than expected based on null models. Taken together, we found clear evidence for functional distinctions between vegetation classes, suggesting strong environmental filtering at this scale, most likely driven by fire dynamics. In contrast, there was little evidence of filtering effects along environmental gradients within vegetation classes, suggesting that assembly processes are largely neutral at this scale, likely the result of very high functional redundancy among species in the regional species pool
Baviaanskloof percent cover, trait, and environment dataset
A dataset combining trait measurements for species observed in releve plots in the Baviaankloof region of South Africa. Environmental conditions at those plots also included
Processes of plant community assembly in the environmentally heterogeneous, high biodiversity Baviaanskloof Mega-reserve
<p>A talk about community assembly in the Baviaanskloof region of South Africa given at the symposium Plant Diversity in the GCFR: From Genomes to Biomes</p
Data from: Functional traits in parallel evolutionary radiations and trait-environment associations in the Cape Floristic region of South Africa
Evolutionary radiations with extreme levels of diversity present a unique opportunity to study the role of the environment in plant evolution. If environmental adaptation played an important role in such radiations, we expect to find associations between functional traits and key climatic variables. Similar trait-environment associations across clades may reflect common responses, while contradictory associations may suggest lineage-specific adaptations. Here, we explore trait-environment relationships in two evolutionary radiations in the fynbos biome of the highly biodiverse Cape Floristic Region (CFR) of South Africa. Protea and Pelargonium are morphologically and evolutionarily diverse genera that typify the CFR yet are substantially different in growth form and morphology. Our analytical approach employs a Bayesian multiple-response generalized linear mixed-effects model, taking into account covariation among traits and controlling for phylogenetic relationships. Of the pairwise trait-environment associations tested, 6 out of 24 were in the same direction and 2 out of 24 were in opposite directions, with the latter apparently reflecting alternative life-history strategies. These findings demonstrate that trait diversity within two plant lineages may reflect both parallel and idiosyncratic responses to the environment, rather than all taxa conforming to a global-scale pattern. Such insights are essential for understanding how trait-environment associations arise and how they influence species diversification
Data from: Functional traits in parallel evolutionary radiations and trait-environment associations in the Cape Floristic region of South Africa
Evolutionary radiations with extreme levels of diversity present a unique opportunity to study the role of the environment in plant evolution. If environmental adaptation played an important role in such radiations, we expect to find associations between functional traits and key climatic variables. Similar trait-environment associations across clades may reflect common responses, while contradictory associations may suggest lineage-specific adaptations. Here, we explore trait-environment relationships in two evolutionary radiations in the fynbos biome of the highly biodiverse Cape Floristic Region (CFR) of South Africa. Protea and Pelargonium are morphologically and evolutionarily diverse genera that typify the CFR, yet are substantially different in growth form and morphology. Our analytical approach employs a Bayesian multiple-response generalized linear mixed effects model, taking into account covariation among traits and controlling for phylogenetic relationships. Of the pairwise trait-environment associations tested, 6/24 were in the same direction and 2/24 were in opposite directions, with the latter apparently reflecting alternative life history strategies. These findings demonstrate that trait diversity within two plant lineages may reflect both parallel and idiosyncratic responses to the environment, rather than all taxa conforming to a global-scale pattern. Such insights are essential for understanding how trait-environment associations arise and how they influence species diversification