Effects of anthropogenic disturbances on biodiversity and biomass stock of Cerrado, the Brazilian savanna

Abstract

Maintaining plant biodiversity and important ecosystem services depend on the species' ability to survive and disperse after anthropogenic disturbance, loss of natural habitat, and fragmentation. The Cerrado, one of the main biodiversity conservation hotspots in the world, loses natural habitat at a very high rate and suffers from disturbances generated by land use and advancement of the agricultural frontier. Given the need to generate knowledge about land use in Cerrado biome, this study aimed to evaluate if the anthropogenic disturbance alters biodiversity indexes and the capacity to store biomass of these savanna. We installed a permanent plot (20 m × 50 m) inside each study fragment and assessed the intensity of local disturbances such as cattle grazing, earthworm extraction, Caryocar fruit harvesting, and fire. To measure habitat loss and fragmentation, we used configuration and composition metrics in local and landscapes scales. Cattle grazing caused a loss of taxonomic and phylogenetic diversity, while fragment size and Cerrado cover in landscape increased phylogenetic diversity. The patch density, shape complexity and edge density in the landscapes also had a negative influence on phylogenetic diversity. Landscapes with more Eucalyptus sp. plantation area had lower phylogenetic diversity. In addition, the percentage of Cerrado in the landscape had a negative influence on biomass while the number of patches had a positive influence. Thus, we conclude that anthropogenic disturbances in the Cerrado generates loss of taxonomic, phylogenetic diversity and alters biomass stock patterns.