Effects of different enclosure methods on early community vegetation structure and stability of alpine meadows in northwest Sichuan

This research explores suitable management measures for alpine meadows in northwestern Sichuan. In this study, grazing prohibition and grazing restrictions (grazing prohibition in growing season + grazing in non-growing season) and typical alpine meadow plots under the management of forage and animal husbandry were used as the research object for this research. Degraded grassland vegetation outside the fence was used to create a control group. Using a combination of field surveys and lab-based analyses, species diversity and stability of the alpine meadow plant community in Northwest Sichuan was examined. This research explored the relationship between species diversity and plant community stability immediately following enclosure of research plots to determine preliminary recommendations for an appropriate grassland management model. The results showed the following: 1) In the initial stage of implementation of the three enclosure management methods, grasses such as Elymus nutans are the dominant species in the plant community, with important values of 9.14, 13.52, and 8.17, respectively. No absolute dominant species were recorded in the degraded grassland community, with Potentilla anserina, Anemone rivularis, and Anaphalis flavescens being the main plant species observed. 2) Provision of fencing increased community species diversity. Sites where prohibition of grazing had been implemented had the highest species diversity. The lowest species diversity was recorded for the forage-livestock balance plant community. Simpson’s diversity index and Pielou evenness index of were slightly higher in the degraded grassland communities in comparison to grasslands where grazing was restricted. 3) The stability of the community in each plot is expressed as grazing restriction > forage-livestock balance > grazing prohibition > degeneration. Reasonable grazing can therefore improve grassland stability. 4) The relationship between community species diversity and stability was found to be negative. Species diversity is mainly affected by the type and quantity distribution of species, while community stability is closely related to the stability of dominant species. Therefore, taking into account the structure and stability of the plant community, grazing prohibition and grazing restriction management are effective measures for the ecological restoration of alpine meadow vegetation in northwest Sichuan.