Abstract

Soil aggregate stability is a fundamental indicator of soil health and ecosystem functionality, influencing water infiltration, erosion resistance, and carbon sequestration. This study investigated the effects of different revegetation strategies on soil aggregate stability across degraded landscapes, examining the temporal dynamics and underlying mechanisms of soil structure recovery. A comprehensive field experiment was conducted over five years (2018-2023) across three distinct ecosystems: Abandoned agricultural land in temperate regions, post-mining sites in semi-arid environments, and degraded grasslands in subtropical zones. Six revegetation treatments were evaluated: natural succession (control), grass monoculture (Festuca arundinacea), legume monoculture (Trifolium repens), mixed grass-legume combination, shrub plantation (Atriplex canescens), and diverse native species mixture. Soil aggregate stability was assessed using wet sieving technique, measuring mean weight diameter (MWD), geometric mean diameter (GMD), and aggregate stability index (ASI) at 0-10, 10-20, and 20-30 cm depths. Results demonstrated significant improvements in aggregate stability following revegetation, with the diverse native species mixture achieving the highest MWD values (4.8 mm) compared to bare soil controls (1.2 mm) after five years. Mixed grass-legume treatments showed rapid initial improvements, reaching MWD of 3.9 mm within three years, while shrub plantations demonstrated superior performance in arid conditions (MWD = 4.2 mm). Aggregate stability strongly correlated with root biomass (r = 0.87), soil organic carbon content (r = 0.82), and microbial biomass carbon (r = 0.79). Fungal hyphal length increased from 2.1 m g⁻¹ soil in controls to 15.8 m g⁻¹ in diverse vegetation treatments, contributing significantly to aggregate binding. The >2 mm aggregate fraction increased from 18% in degraded soils to 68% following successful revegetation. Water-stable aggregates showed parallel improvements, with stability increasing from 22% to 79% across treatments. Economic analysis revealed cost-effectiveness of revegetation investments, with benefit-cost ratios ranging from 2.1 to 4.6 depending on treatment type and site conditions. The study concludes that strategic revegetation significantly enhances soil aggregate stability through multiple mechanisms including root network development, organic matter accumulation, and microbial community enhancement, providing a foundation for sustainable ecosystem restoration.