The value of regeneration for insect fauna associated with leaf litter in the Brazilian savanna: A comparative study of biomass and trophic structure

Abstract The expansion of agricultural activities in the Brazilian Cerrado has led to the degradation of large areas, impacting biodiversity and soil ecosystem functions. This study investigated the impact of land use and natural regeneration on soil and litter insect communities. We tested the hypothesis that regenerating (R) and native (N) areas would present higher insect total biomass, taxon richness and a more complex trophic structure compared to pasture (P) areas. Total biomass, taxon richness and biomass by trophic groups (detritivores, phytophagous, mycetophagous, herbivores, omnivores, parasitoids and predators) were compared in three types of environments in the Cerrado: P, R area and N area. Two‐way ANOVA for total biomass and trophic group, and Analysis of Similarities, Detrended Correspondence Analysis and Discriminant Analysis were used to evaluate the differences in the composition of trophic groups and families between environments. Our results demonstrate that regeneration and N areas presented higher total biomass and taxon richness than P, with no statistically significant differences between these two environments. The absolute biomass of key trophic groups, such as detritivores, predators, and notably, omnivores, was substantially higher in regeneration and N areas. The composition of trophic groups and families differed between environments, with a clear recovery gradient, with the regeneration area positioned intermediately between P and N areas, and the trophic groups with the highest biomass acting as the main discriminators. The biomass and richness of soil insects in the Cerrado are severely impacted by conversion to P, but natural regeneration shows remarkable potential to restore the structure and function of these communities. Our findings highlight the importance of conservation and restoration policies for soil health and resilience of Cerrado ecosystems, with soil insects serving as excellent bioindicators of restoration success.