Responses of soil-plant systems to anthropogenic disturbance in alpine-cold wetlands on the southeastern Tibetan plateau

Alpine-cold wetland ecosystems are highly sensitive to human disturbance, yet the responses and relationships of soil–plant systems to anthropogenic disturbance remain poorly understood. Taking the Napahai alpine-cold wetland in north-western Yunnan as the study area, this research assessed the responses of soil and plant systems to different disturbance types and explored the potential relationships among soil properties, microbial indicators, and vegetation characteristics. By combining vegetation surveys with laboratory analyses, we measured vegetation traits, plant total C, N and P contents, soil physicochemical properties, soil enzyme activities, and microbial biomass. Results showed that human disturbance significantly altered soil properties ( P < 0.05). Grazing, trampling and agricultural management markedly affected soil bulk density and total porosity, while agricultural management also influenced soil moisture. Under mowing, soil moisture and porosity were higher, and bulk density was lower. Vegetation cover, height, above-ground biomass and diversity were also strongly affected, with trampling causing the greatest structural damage and the lowest biomass, whereas agricultural management sites exhibited the highest plant diversity. Plant total C, N and P contents showed no significant differences across disturbance types. Soil microbial indicators responded markedly: cultivated sites showed higher soil enzyme activity and microbial biomass C, N and P, while grazing sites exhibited lower microbial biomass N. These findings indicate that human disturbance is associated with vegetation changes, and that soil structure, microbial activity, and nutrient cycling may represent potential pathways linking disturbance to vegetation responses. Soil–microbe coupling may serve as a potential mediator in wetland responses. The study provides new insights into the responses of alpine-cold wetland ecosystems to human disturbance and offers a scientific basis for ecological restoration in alpine-cold wetlands.