Effect of two restorations on the grassland coverage after remediation of take-abandon soil field on the Qinghai-Tibet Plateau

Human activities and climate change have important impacts on the alpine grassland ecosystem of the Qinghai-Tibet Plateau. Human activities represented by highway construction affect the function of alpine grassland ecosystem. In order to explore the recovery effects of different restoration methods on the alpine grassland ecosystem, we selected six grassland sites after two restorations (seeding method and turf method) along the elevational gradient. The coverage of the low (3 012 and 3 335 m), medium (4 229 and 4 302 m) and high (4 433 and 4 577 m) elevation sites after two restorations was measured by VegCover. We found that the coverage of turf treatment (42.3%) is significantly higher than that of the grass in the field of seeding (16.8%). The grass coverage of seeding treatment decreased significantly with the increase of elevation, but no statistic difference of the coverage of turf treatment was detected along the elevational gradient. As a result, the natural logarithm response ratio of the degree of grassland coverage under the two restorations increased significantly with the increase of elevation (r = 0.37, P < 0.05). These results suggest that turf is a better way to repair the gauntlet of the alpine meadow and the seeding method is not to be used for the temporary grassland repair in the high-altitude area.