Vegetation and soil characteristics of degraded grassland and their relationship

This study conducted a vegetation quadrat survey of typical degraded subalpine grassland in Huize county, Yunnan Province, and performed multidimensional scale (NMDS) measurement analysis to examine areas at different stages of degradation, grassland plant community species composition and diversity, and trends in the variation of soil physical and chemical properties, and assessed the implications of degradation. The results revealed that although the species diversity index, coverage, and evenness of grassland plants increased with an intensification of degradation, the species diversity and proportion of forage plants in the plant community all showed a decreasing trend, whereas the species diversity and proportion of noxious weeds showed an increasing trend. Overall, the soil nutrient contents of moderately and severely degraded grasslands were significantly lower than those of minimally degraded grasslands. In grassland communities at different stages of degradation, the plant species diversity index was significantly related to pH in the 0 – 20 cm soil layer (P < 0.05), whereas a combination of edaphic factors were found to influence variation in diversity of plant species in degraded grasslands, for which the explanatory rates were inconsistent. Our preliminary findings in this study, with respect to characteristics of the plant community and soil physical and chemical properties of subalpine grassland in southern China at different stages of degradation. and their inter-relationships, will provide a scientific basis for further examination of the mechanisms of grassland degradation, and also contribute to measures for the restoration of degraded grassland in this region.