Short-term effects of restoration on soil biological properties in degraded lands of the Brazilian semiarid region

Soil biological properties are sensitive indicators of land use changes. In particular, they have been widely used to assess the effects of land degradation and restoration. In this study, we evaluated soil biological properties in degraded and short-term (<5 years) restored lands in the Brazilian semiarid region to determine whether restoration efforts can enhance these properties. This study assessed three scenarios: native vegetation, degraded land, and restored land. Land degradation resulted from deforestation, which exposed the soil to erosion, while restoration efforts involved constructing successive stone dams to prevent erosion, increase soil moisture, and reintroduce native species. Soil biological properties were assessed during the dry and rainy seasons in 2022 and 2023. We evaluated soil microbial biomass C, soil respiration, respiratory and microbial quotients, and enzymatic activity as key indicators of soil biological properties. Soil microbial biomass C, respiration, and enzymatic activity were generally higher in the rainy season than in the dry season. Microbial biomass C was highest in native vegetation, with no significant differences between degraded and restored lands in 2022. However, land under restoration showed an increase in 2023. Soil enzymatic activity was also higher in areas with native vegetation, with acid phosphatase activity peaking during the rainy season. Temporal stability varied for soil respiration, beta-glucosidase, and urease activities, with native vegetation showing greater stability in respiration and beta-glucosidase. This study demonstrates that short-term restoration (<5 years) had a limited impact on improving the biological properties of degraded lands.