Soil fauna, litter quality and land use as decomposition factors in the Brazilian semi-arid region

Abstract

Soil fauna mediate litter decomposition in many terrestrial ecosystems, and thus understanding how land use impacts the process has important implications. This study was conducted under semi-arid conditions in Minas Gerais, Brazil, using litterbags arranged in a randomized block design with four replications. The treatments included three land use systems (native forest, maize, and cocoa) and two mesh sizes (0.297 mm for mesofauna access and 4 mm for total soil fauna access), with decomposition assessed at seven-time intervals: 0, 30, 90, 150, 210, 270, and 330 days. Litter decomposition rates and the role of soil fauna were evaluated. Decomposition in natural vegetation was slower than in agricultural systems, despite its higher species richness and Shannon (H′) and Simpson (Es) diversity indices. Agroecosystems exhibited faster decomposition, with perennial crops outperforming conventional crops under unrestricted fauna access (4 mm mesh) and showing similar rates under macrofauna-restricted conditions (0.297 mm mesh). These findings contribute to understanding the interplay between soil fauna, litter decomposition, and land use systems in semi-arid regions.