Atlantic Forest restoration recovers physical and biological properties in the short term, but not the general soil quality

Abstract

Ecological restoration has the potential to improve and recover soil quality, helping to mitigate soil degradation worldwide. However, soil monitoring is often overlooked in restoration, preventing a comprehensive understanding of how restoration interventions affect soil quality and the time required for recovering different soil properties. Herein, we tested if MAR areas (moderately assisted recovery—tree plantings) in the early restoration stage have better soil quality (and ecosystem services) than UNR areas (unassisted natural recovery—abandoned pastures) and pastures in continuous use (PCU). We collected 72 soil samples in three 5‐year‐old MAR areas and three 5‐year‐old UNR areas, one PCU, and one reference ecosystem (RE) in the Brazilian Atlantic Forest (Mata Atlantica). A total of 45 variables representing macrofauna, fertility, structure, and aggregation were measured and then submitted to multivariate analyses to compute sub‐indicators and a general indicator of soil quality (GISQ). The richness of orders and classes, cationic exchange capacity, total porosity, and biogenic aggregates contributed the most to the sub‐indicators. MAR and UNR areas had similar values to the RE for macrofauna, structure, and aggregation sub‐indicators, but they were far below the RE for fertility. In addition, all areas had lower GISQ values than the RE. Soils were classified as high quality in RE and medium quality in other areas. Our study evidences that some soils' physical and biological properties can be rapidly recovered through forest restoration, but 5 years is not enough time to change the general soil quality and make restoration areas have better conditions than the previous land use. If the restoration goal is to have high soil quality in the short term, corrective actions should be taken to improve soil fertility and help the area along the desired trajectory.