Effect of Light Heterogeneity Caused by Photovoltaic Panels on the Plant–Soil–Microbial System in Solar Park

The large-scale construction of photovoltaic (PV) panels causes heterogeneity in environmental factors, such as light, precipitation, and wind speed, which may lead to microhabitat climate changes that may affect ecosystems. In this study, plant–soil–microbial systems in shady and non-shady gaps of PV panels in a solar park in Northern China were investigated. The shading caused by the PV panels significantly affected the alpha diversity of plant and fungal communities (p < 0.05). The compositions of plant and soil microbial (bacteria, fungi, and protists) communities were significantly different between shady and non-shady areas (p < 0.05), and the beta diversity of the plant community was significantly correlated with that of the soil microbial community (p < 0.05). Shading enhanced the complexity of microbial communities by strengthening the associations among soil microbes. Photosynthetically active radiation was the main driving factor in the assembly of aboveground and belowground communities on a small scale, and it indirectly shaped the microbial community through its effects on the plant community. This study highlights the important effects of light on microbial community formation and on the relationships among communities in plant–soil–microbial systems. Thus, the effects of solar park establishment on degraded ecosystems should be considered.