Spatiotemporal patterns of aboveground vegetation and soil seed banks in desert steppe under photovoltaic disturbance

The unique microenvironment created by photovoltaic (PV) power stations may progressively reshape ecosystem species composition through sustained effects on aboveground vegetation and soil seed banks. However, the long-term ecological impacts, particularly those on soil seed banks, remain poorly understood. We investigated aboveground vegetation and soil seed banks across three PV power stations with different operational durations (5, 10, and 15 years) in desert steppe ecosystems to assess how PV-induced microhabitats filter vegetation and seed bank assemblages. Our results show that with increasing operational duration, the density of soil seed bank outside the PV stations remained stable, whereas it increased progressively between panels, from 1657 seeds·m - ² at 5 years to 2279 seeds·m - ² at 10 years and 2880 seeds·m - ² at 15 years, and declined significantly beneath panels. Across all operational durations, seed bank density consistently followed the spatial gradient: between panels > outside the PV stations > beneath panels. The spatial distribution of aboveground vegetation mirrored that of the seed bank and patterns of α-diversity exhibited similar trends. Significant differences in community species composition were observed among locations within each operational duration, and community differentiation intensified over time. Early-stage divergence was primarily driven by a few dominant species but gradually shifted toward regulation by multiple species. In addition, the functional composition of both the aboveground community and soil seed banks changed: the proportion of perennial prostrate taproot clonal plants increased beneath panels with operational duration, whereas annual prostrate taproot non-clonal plants increased significantly between panels. Overall, PV stations progressively restructure plant communities and soil seed banks by creating spatially heterogeneous microenvironments, with ecological effects intensifying over time. These findings provide valuable insights for the ecological management and sustainable land-use planning of PV installations in arid and semi-arid regions.