Diversity and structural changes in Cerrado Rupestre under effects of disturbances

Abstract

Vegetation formations are undergoing constant floristic and structural change over time and space. Assessing these changes represents an important step to understand the effects of disturbances and propose ecosystem conservation and management strategies. We still lack, however, information on the dynamics of the woody vegetation in Cerrado Rupestre (rupestrian Cerrado—RC) formations over time, which comprise important refuge of the vegetation of the Brazilian Savanna and occur on rocky outcrops, which are considered restrictive environments. In this context, we describe the changes in floristic composition, richness, species diversity and structure of vegetation in RC over 12-year and link patterns to the disturbances that occur in the area—wildfire and cattle presence. We gathered data from three surveys conducted in RC in the Pireneus State Park (PSP), Goias, Brazil. We also registered hot pixels inside the study area and in the PSP neighboring area indicating presence of bovine and equine cattle in the Park. Disturbances, occurrence of wildfires, and presence of cattle promoted changes in vegetation structure, with a decrease in the number of small individuals, but not in diversity parameters. The increase in richness, evenness and diversity, even under the effect of disturbances, demonstrates the resilience of the RC. However, if these disturbances keep occurring, resilience will be compromised, with clearer changes in floristic composition and vegetation structure, according to what we proposed in a theoretical model describing the synergistic influence of cattle presence, exotic grass and wildfires on the dynamics of the Cerrado Rupestre.