Abstract:In order to understand the adaptation of Gahnia tristis in the red soil erosion zone of southern China, the functional traits of leaves and roots of G. tristis, and the physicochemical properties of soil were determined and their correlations and the responses of leaves and roots of G. tristis to soil factors were analyzed by using mathematical statistics method. The results showed that there were significant differences in phenotypic traits of Gahnia tristis leaves between winter and summer, leaf length, leaf width, leaf tissue density and chlorophyll content were significantly higher in summer than those in winter, while the root phenotypic traits were more stable. The nutrient content of roots in winter was higher than that in summer, and the nutrient allocation in leaves was higher than that of roots. Leaf tissue density had positive correlation with chlorophyll content and negative with specific leaf area. There was significant negative correlation between root tissue density and specific root length and specific root area, and significant positive correlation between leaf and root nutrients. Soil carbon, nitrogen, and phosphorus contents were the main factors affecting the functional properties of G. tristis. Therefore, it was suggested that G. tristis could adapt to environmental changes by adjusting its functional traits, which could be used as a zonal plant for vegetation restoration and soil erosion control in the red soil erosion areas of south China.