乡土物种补播对青藏高原高寒草甸群落稳定性的影响

为了探究高寒草甸天然草地补播乡土物种对草地群落稳定性的影响，本试验以垂穗披碱草（Elymus nutans）、异针茅（Stipa aliena）、中华羊茅（Festuca sinensis）、溚草（Koeleria cristata）、星星草（Puccinellia tenuiflora）、扁蓿豆（Melissitus rutenica）、冷地早熟禾（Poa crymophila）为试验材料，设置5种混播组合，于2017年在青海省贵南县天然草地上进行补播。试验采用方差比率法（Variance ratio，VR）、M.Godron贡献定率法（Contribution law）以及生物量稳定性分析方法，结果表明：5种组合补播后使得群落联结性降低、生物量稳定性增大，群落整体稳定性增强，正向着稳定方向发展；5种组合中，组合D （扁蓿豆+星星草+垂穗披碱草+异针茅+溚草）的生物量稳定性最大，是对草地恢复最有效的物种组合。本试验筛选出了对草地生态修复最有效的物种组合，为草地保护及利用提供了科学依据。

Effects of Native Species Reseeding on the Community Stability of Alpine Meadow in the Tibet Plateau

For the past few years, the environment of the Tibet Plateau has been seriously disrupted because of the climate change and the irrational utilization of human beings. In order to study the Effects of reseeding native species on the community stability of alpine meadow in the Tibet Plateau, we selected seven kinds of native plants, including Elymus nutans, Stipa aliena, Festuca sinensis, Koeleria cristata, Puccinellia tenuiflora, Melissitus rutenica and Poa crymophila, and divided them into five combinations, which were reseeded on the natural grassland of alpine meadow in Guinan County, Qinghai Province in 2017. The inter-specific associativity among native species, community stability and biomass stability were analyzed using X²test, W test and M.Godron's Contribution law. The results showed that the inter-specific associativity among native species reduced and the biomass stability of community lifted and the community involved in a positive succession. What's more, the results indicated that among 5 combinations, the Combination D (Elymus nutans, Stipa aliena, Koeleria cristata, Puccinellia tenuiflora and Melissitus rutenica) had the biggest biomass and played the most effective role in the process of ecological restoration. To conclude, we selected out the best combination of native species that could restore the poor condition and these results could provide a scientific basis for the protection and utilization of grassland community in the future.