How does the transformation of Cerrado vegetation into exotic pastures affect insect communities? A meta‐analysis

Abstract

Cerrado is the largest and most biodiverse savannah worldwide. However, only a reduced amount of this ecosystem is conserved, and in the last decades, the vast agricultural expansion resulted in the substitution of native vegetation for exotic pasturelands. Insects are key components for both native and exotic ecosystems in Cerrado, performing critical functions for ecosystem maintenance. Our goal was to evaluate how the transformation of natural Cerrado into cattle pastures (exotic pastures) affects the insect communities in this biome. We conducted a meta‐analysis using data on species richness and abundance data of insect assemblages from conserved Cerrado and exotic pastures. The analysis was based on a set of 23 scientific articles. Fourteen studies focused on Coleoptera and nine on Hymenoptera. Conserved Cerrado encompassed a higher species richness of insects than exotic pastures, but their abundance did not differ between these two habitats. However, dung beetle abundance increases significantly in disturbed Cerrado over time. Synanthropic species that thrive in altered environments could be masking the actual decline in abundance of species sensitive to environmental disturbances provoked by exotic pastures. Our results highlight the consequences of the structural homogenisation of the Cerrado into cattle pastures. That is, despite having a similar open‐canopy vegetation structure, this land‐use change leads to a significant loss of insect species, resulting in a drastic simplification of insect communities. This study reinforces the importance of maintaining native Cerrado patches in order to maintain diverse and functional ecosystems in this region.