Geographic space, relief, and soils predict plant community patterns of Asteraceae in rupestrian grasslands, Brazil

We investigated the effects of geographic distance and environmental heterogeneity on Asteraceae communities in the rupestrian grasslands of the Espinhaço Range, southeastern Brazil. Asteraceae species composition and relative abundance were sampled in 21-1 ha plots distributed across park conservation units, comprising an environmental gradient in soils and relief (elevation and slope). We found high levels of heterogeneity overall in assemblages of herbaceous and woody Asteraceae species at the intermediate spatial scale of this study (10–100 km). We found that both relief and soil properties (texture and total exchangeable bases) explained significant proportions of variation in community composition, suggesting that definitions or expansions of conservation units should span the highest possible variability in observed relief and soil values. We also found that Asteraceae distribution exhibited strong spatial structure independent of environmental variation, reinforcing the need to...