Effects of partial shading by photovoltaic panels on grassland community structure in Karst area

The spatial differentiation of plant community structure reflects the adaptability of plants to the heterogeneous micro-habitat formed by photovoltaic panels shading. Based on field investigations of photovoltaic stations in Dongchuan, Yunnan Province, China, this study explored the variances in plant community structure among the full sunlight area, the front eaves, the rear eaves, and the underside of the panel with increasing shading. The results showed that: 1) the important value of Heteropon contortus decreased from 94.21 to 6.85 (P < 0.05), whereas the important value of Euphorbia heterophylla increased from 3.35 to 39.60 (P < 0.05) along with increased shading, indicating that the dominant species in the community were replaced. 2) The plant density and dominance index decreased significantly with increased shading, while the species diversity index increased significantly. The higher the shading degree, the lower the species similarity between the shading area and the full sunlight area. 3) The diversity of plant functional groups increased after shading. Annual bunch grasses or annual forbs appeared in the shading area, and the dominant functional groups changed from perennial bunch grasses to perennial forbs. The results indicated that the dominant native grassland plant species were replaced, the diversity and functional group species were increased, and the plant community structure presented a complex change trend along with increased shading of photovoltaic panels in Dongchuan, Yunnan Province.