Environmental impacts of pastoral-integrated photovoltaic power plant in an alpine meadow on the eastern Tibetan Plateau

Abstract. Rising global energy demand and the transition to low-carbon sources have driven the rapid expansion of photovoltaic (PV) power plants, introducing significant land-use changes with largely unexplored ecological consequences. This study examined the microclimatic and soil hydrothermal impacts of a pastoral-integrated PV power plant in an alpine meadow ecosystem on the eastern Tibetan Plateau. Year-round observations from two 10 m towers, located inside and outside the PV power plant, revealed that PV installations increased annual net radiation by 28.9 %, while reducing albedo and wind speed by 31.6 % and 36.2 %, respectively. Air temperature responses were highly asymmetrical, with daytime and summer warming but nighttime and winter cooling. The PV power plant induced strong spatial heterogeneity in soil temperature and moisture: At 5 cm depth, PV array gaps exhibited cold and moist conditions, whereas areas beneath the panels were cold and dry. These changes extended the soil frozen period by approximately 50 d and reduced the soil moisture depletion rate by 1.3 to 3.5 times compared to the reference site. These findings indicate that the PV power plant can alter local energy and water balances in ways that may buffer ecosystem responses to climate warming. However, further multi-year studies are needed to evaluate their long-term impacts on vegetation dynamics, carbon fluxes, and permafrost processes.