不同放牧管理方式对天山北坡山地草原植物种群变化的影响机制OA

[Objective]This study aimed to explore the impacts of three grazing management practices,namely,grazing exclusion(M0),controlled grazing(M1),and free grazing(M2),on plant community structure,diversity,biomass allocation,carbon sequestration,and soil environment in mountain grasslands on the northern slope of the Tianshan Mountains,so as to provide a scientific basis for sustainable management and ecological conservation in the region.[Methods]A combination of field survey and laboratory analysis was conducted to determine plant community composition,diversity indices,biomass,carbon storage,and soil nutrient content under different grazing management practices.The relationship between such practices and plant functional group distribution was analyzed.[Results]Grazing management practices significantly influenced plant community composition and structure:M1 best maintained the dominance and community stability of grasses,with an importance value of 1.034 and a biomass proportion of 85.9%.In contrast,M2 led to a decline in grasses(importance value dropping to 0.411),while the importance value of Asteraceae species such as Seriphidium increased to 0.353,making them the dominant species.M0 facilitated the accumulation of biomass and carbon storage,with total biomass reaching 2 361.7 g/m² and carbon storage of 1 062.8 g C/m².In terms of diversity,M2 had the highest Shannon-Wiener(2.253)and Simpson(0.867)indices,whereas M0 exhibited the highest Pielou evenness index(0.893).Soil analysis indicated that grazing practices altered soil nutrient levels,thereby influencing the distribution of plant functional groups.[Conclusion]M1 helped maintain community stability,M2 enhanced species diversity but led to grass degradation,and M0 facilitated biomass accumulation and carbon storage.Important basis was offered by this study for scientifically management of grassland ecosystems in the region.