Adaptive Characteristics of Paulownia fortunei to Rocky Desertification Habitats and Its Effects on Soil Properties
Rocky desertification poses a severe threat to ecosystem function in karst regions of southern China. This study, conducted in Jianghua Yao Autonomous County, Hunan Province, investigated the adaptive responses of Paulownia fortunei to rocky desertification habitats and its subsequent effects on soil properties. Leaf structural and physiological parameters were measured, alongside soil physicochemical properties. Results demonstrated that P. fortunei enhanced its adaptability through increased leaf thickness (upper epidermis +50%, total +27.38%), palisade tissue thickness (+22.45%), elevated chlorophyll a (+3.55 mg·g−1) and chlorophyll b (+1.39 mg·g−1) contents, and upregulated activities of superoxide dismutase, catalase, and peroxidase. Planting P. fortunei significantly improved soil structure and fertility: soil bulk density decreased by 0.57 g·cm−3, total porosity increased by 2.41% (0–5 cm) and 3.35% (5–10 cm), field water capacity rose by 18.63% and 18.87%, capillary porosity increased by 11.45% and 14.19%, and soil organic matter content improved from Grade IV to Grade II. These findings indicate a synergistic 'plant adaptation–soil improvement' feedback mechanism, highlighting the potential of P. fortunei for ecological restoration of rocky desertification areas.