Local and regional processes drive high plant taxonomic turnover in rocky outcrops of Serra do Cipó, MG

Potential interactive effects and trade-offs between drivers can regulate species diversity, affecting distributions by several orders of magnitude and distribution. The decomposition of β-diversity into turnover and nestedness could disentangle community assembly rules and offer the opportunity to encompass the processes that structure the communities and maintain the β-diversity on the campo rupestre. We evaluated α- and β-diversity and species conservation status of rocky outcrop communities in the Parque Nacional da Serra do Cipó, as well as the decomposed component of the β-diversity index. Due to the isolation characteristics of rocky outcrops, we expect to find high taxonomic turnover among the communities. The study was performed on five quartzitic rocky outcrops divided into two sampling stations. We used field expeditions and plant inventory data of shrubs and herbaceous layers. We recorded 286 angiosperms taxa among rocky outcrops of campo rupestre of Serra do Cipó. The structure and α-diversity showed significant differences among rocky outcrops and an evident oligarchic structure in the plant communities analyzed. Taxonomic β-diversity showed high turnover with a significant contribution of the turnover component to this index. This pattern reflects the interplay between regional and local scale processes. Therefore, we believe this approach becomes a unified framework, which allows the comparison of diversity patterns and ecological processes in rocky outcrops ecosystems. We highlight the high percentage of not evaluated species for threats and the need to fill this lack.