Photovoltaic Coverage Alters Soil Ecosystem Multifunctionality: Contrasting Effects and Underlying Mechanisms

The rapid expansion of photovoltaic (PV) infrastructure is crucial for climate mitigation, yet its ecological consequences─particularly on soil ecosystems─remain poorly understood. Here, we investigate the effects of PV coverage on soil microbial communities and ecosystem multifunctionality (EMF) across three land-use types (arable land, forest land, and tailings). PV coverage was associated with significant changes in soil microbiomes, suppressing phototrophic taxa while promoting heterotrophic and parasitic lineages in tailings soils. Critically, PV was associated with a severe decline (relative change: -1.02) in EMF within tailings, while EMF was higher in arable land by 2.21-fold. Structural equation modeling suggested soil moisture as the likely primary factor associated with EMF degradation in tailings. Microbial network complexity emerged as a positive correlate of EMF in arable land. These results underscore the context-dependent ecological impacts of PV installations and highlight the potential to modulate these effects through adjustable engineering designs, informing sustainable land-use planning for solar energy development.