| ABSTRACT Mussununga, an oligotrophic sandy savanna ecosystem, comprises distinct physiognomies along fire, water and nutrient availability gradients. Grasslands and woodlands are constrained at the opposite poles of these gradients, with grasslands occurring in areas with poorer soils and higher levels of both water-stress and fire intensity. According to the stress-dominance hypothesis, one might expect the importance of competition for community assembly to increase from grasslands to woodlands. Assuming conservation of ecological niches within evolutionary lineages, this should increase phylogenetic overdispersion from grasslands towards woodlands. To test this, we calculated phylogenetic diversity and community structure using different null models as... |
