Short-term effects of restoration measures on vegetation community and soil characteristics of an Achnatherum inebrians-type degraded alpine grassland in the Eastern Qilian Mountains

The Qilian Mountains constitute an important ecological security barrier in the northwest of China, with a wealth of habitat types and biological species. They have a profound impact on the surrounding area and even the world. However, due to both natural and anthropogenic influences, Achnatherum inebrians is widely distributed in this region, seriously threatening the balance of the grass-soil-livestock ecosystem. To explore appropriate restoration measures of alpine grassland of the Eastern Qilian Mountains degraded by the presence of A. inebrians, we studied the effects of restoration measures on the A. inebrians population, the grassland vegetation community, and soil characteristics following sward ripping (SR) and swarding ripping plus reseeding excellent forage (SREF) in Tianzhu County, Gansu Province; adjacent A. inebrians-type degraded alpine grassland without any measures was the control (CK). The SR and SREF inhibited A. inebrians growth and reproduction, increased the proportion of edible forage and the community species diversity, (especially aboveground biomass and sum of sub-coverage of edible forage by as much as two and three times), and improved soil nutrients and soil quality. The radar analysis showed that SREF had the best effect on the A. inebrians-type degraded alpine grassland. Correlation analysis showed that edible forage community, plant diversity, soil moisture, and available nutrient content were the main factors driving the restoration of this degraded alpine grassland. Implementing measures tailored to local conditions could effectively inhibit the spread of A. inebrians, stimulate edible forage growth, and improve the grassland plant community and soil environment. The results indicated a reasonable method of restoration for this poisonous weed-type degraded grassland and protection of the ecological environment.