Soil Carbon Sequestration by Biological Crusts in Photovoltaic Power Stations: Southern Tengger Desert and Artemisia ordosica Shrubland Restoration

This study investigates the effects of different photovoltaic (PV) panel types on soil and biological soil crusts (BSCs) under vegetation restoration in sandy areas. A 150 MW PV power plant in Huanghuatan, located in the Tengger Desert, was selected as the research site. Soil and BSC properties, as well as carbon sequestration, were evaluated under three PV panel types: fixed-axis (FA); horizontal single-axis (HSA); and tilted single-axis (TSA). The objective was to clarify how these panel types influence soil quality and carbon storage during Artemisia ordosica Krasch. restoration in sandy environments and to explore the underlying mechanisms. The results showed that, compared with the surrounding pristine desert (PD), PV development significantly altered soil water content (WC), saturated water content (SWC), soil organic matter (SOM), and carbonate levels in soil and BSCs. Specifically: (1) FA and HSA panels increased WC in the BSCs and sub-crust soil, although water-holding capacity decreased in the HSA area; (2) SOM in the BSCs was notably lower under HSA and TSA panels; (3) HSA and TSA panels enhanced carbonate accumulation in non-crusted soil, while the lowest carbonate content in BSCs occurred under FA panels. The sub-crust soil in all PV areas had lower carbonate content than PD; and (4) Estimated carbon storage effectiveness was ranked as follows: HSA > TSA > PD > FA. This study provides theoretical support for ecological restoration in desert PV power plants.