Karst hillslope rehabilitation and soil carbon recovery in Guizhou Province

¹ Huazhong Agricultural University, Wuhan, Hubei province, China
² Bukhara State Medical Institute, Bukhara, Uzbekistan

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Karst landscapes in Southwest China are highly susceptible to soil degradation due to thin soils, high rock outcrops, and episodic rainfall, yet they also present significant opportunities for ecological restoration that enhances soil organic carbon. This study evaluates how distinct rehabilitation pathways on Guizhou Province hillslopes influence soil organic carbon recovery and hydropedological stability. Using open remote sensing products, global soil databases, and national inventories, we compiled a panel of hillslope units representing passive natural regeneration, engineered revegetation, and agroforestry terraces. For each pathway, we compared baseline conditions during 2001-2005 with follow-up conditions during 2020-2024, harmonizing indicators in standardized units. We calculated soil organic carbon stocks to thirty centimeters depth, aggregate stability, canopy cover, and modeled soil loss. A before-after design with cross-sectional replication supported internal comparability. Results show consistent gains in soil organic carbon stocks and aggregate stability, with the largest increases observed under agroforestry terraces. Reductions in modeled soil loss and increases in canopy cover indicate broader co-benefits for erosion control and vegetation structure. The findings clarify trajectories of soil carbon recovery on karst hillslopes and provide practical benchmarks for provincial restoration programs focused on climate mitigation and nature-based solutions.