Ecological impacts of single-axis photovoltaic solar energy with periodic mowing on microclimate and vegetation

Li, Yudi and Armstrong, Alona and Simmons, Christopher and Krasner, Noah Z. and Hernandez, Rebecca R. (2025) Ecological impacts of single-axis photovoltaic solar energy with periodic mowing on microclimate and vegetation. Frontiers in Sustainability, 6: 1497256. ISSN 2673-4524

Abstract

Large, ground-mounted photovoltaic solar projects (GPVs) are expanding rapidly worldwide, driven by their essential role in climate change mitigation and the transition to a low-carbon economy. With the global market for tracking systems projected to increase annually by 32% in capacity by 2050, understanding their ecological impacts, including those from their operation and management (O&M), is critical but understudied. This study presents the first comprehensive evaluation of microclimate and vegetation mosaics within a conventional, single-axis GPV managed through regular mowing. In the state of California’s Great Central Valley (United States), we developed a novel experimental framework to characterize five distinct “micro-patches” that capture the full spectrum of microclimate and vegetation zones modulated by the tracking PV system and O&M. Over a 12-month period, we monitored nine above- and belowground microclimate variables and 16 plant ecology metrics across these micro-patches. Beneath PV panels, photosynthetically active radiation decreased by 89%, and wind speed slowed by 46%, while open spaces within the GPV footprint exhibited greater soil surface temperatures (+2.4°C) and accelerated moisture loss (+8.5%) during drought periods. Furthermore, PV panel rotation influenced shading patterns throughout the day, creating temporal variability in air temperature and vapor pressure deficit. Plant surveys identified 37 species, 86% of which were non-native. Marked differences in vegetation across micro-patches indicated that GPVs drive changes in plant community composition, structure, and productivity. Compared to open spaces, vegetation near and within the PV array footprint displayed greater species richness (+8.4%), taller maximum height (+21%), reduced coverage of sun-loving plants (−71%), and less dead biomass accumulation (−26%), from shade-driven effects. These findings suggest the consideration of micro-patch-specific maintenance strategies and nature-based solutions to control invasive, exotic plant species, conferring opportunities to enhance operational, ecological, and socioeconomic sustainability while redressing the twin crises of climate change and biodiversity loss simultaneously.