Anthropogenic Wetland Transformation: Impacts of Floating Photovoltaic Systems on Waterbird Diversity in Subsidence Area

Solar photovoltaics provides an environment-friendly alternative to fossil fuels and has expanded rapidly across the world. Amid escalating demands for land utilization and growing concerns over terrestrial ecosystems, floating photovoltaic (FPV) systems have become a globally prioritized renewable energy solution in recent decades, exemplified by its large-scale implementation in North China Plain subsidence wetlands. However, it remains unclear how the taxonomic, functional, and phylogenetic diversity of waterbirds responds to the installation of FPV systems on subsidence wetlands. Here, we conducted a field survey on waterbird communities of 5 subsidence wetlands before and after the installation of FPV systems in the Huaibei mining area of the North China Plain during the wintering of 2017–2025. We found that the installation of FPV systems caused an overall decrease in waterbird taxonomic, functional, and phylogenetic diversity, and also altered waterbird community compositions. Moreover, FPV systems triggered a complete habitat abandonment by all threatened waterbird species residing in these wetlands. The presence of FPV systems resulted in a decrease in the proportion of the Anatidae but an increase in the proportion of the Rallidae. This may stem from adverse habitat conditions that forced numerous waterbirds to abandon these subsidence wetlands. Our findings highlight that FPV systems coverage has substantial impacts on the waterbird assembly. Given the anticipated growth of FPV installations, our results emphasize that strategic planning is critical for the sustainable development of FPV systems in subsidence wetlands and the protection of waterbirds.