Landscape structure and local variables affect plant community diversity and structure in a Brazilian agricultural landscape

Abstract

The biodiversity in agricultural landscapes depends on land-use types, natural elements, and farming intensity. The Brazilian Cerrado is a biodiversity hotspot, however, the native vegetation loss rates have increased in the last years, leading several plant species to extinction risk. Here, we analyze the effects of local (soil fertility and litter amount) and landscape variables (patch shape, habitat amount, compositional heterogeneity, matrix dominance and connectivity) on alpha species richness and diversity, and basal area of different Cerrado vegetation types (savanna, forested savanna, and forest) using linear models and Akaike information criterion. We calculated landscape metrics at different spatial scales for 49 sampling sites in intensive farming landscapes. Woody plant diversity and richness were positively related to soil fertility and landscape compositional heterogeneity at 1500 m spatial scale. Plant richness was negatively related to the patch shape of remnants at 1000 m spatial scale. The effects of litter amount to explain the basal area varied between vegetation types. We found a positive effect in savanna and forested savanna and a negative effect in forest areas. Our findings suggest that the increase of monocultures lead to a decline on plant diversity in the studied landscapes. Also, local variables and the diversity of vegetation types need to be considered to design restoration actions in Cerrado. Sustainable intensification and biodiversity-friendly production systems may be alternatives to increase compositional heterogeneity, thus favoring plant diversity in Cerrado farming landscapes. Abstract in Portuguese is available with online material.