Vegetation and soil properties of typical steppe under different land use in Inner Mongolia, northern China
Unreasonable uses of land such as overgrazing and cultivation are the main causes of the degradation of typical steppe in the semi-arid area of Inner Mongolia. Exclosure was considered as the main approach of restoring the degraded grassland in this area, but there is a lack of systematic studies on the effect of different types of land use on grassland vegetation and soil property in this area. In this study, four adjacent sites were selected as follows: a site that has been enclosed for 24 years (E24), a site that has been enclosed for 11 years (E11), a site that has been continuously grazed (G), and a site that has been cultivated for 30 years (C). The mechanism of vegetation-soil degradation and restoration under different land uses was discussed. Obvious converse succession was observed in grassland community under continuous overgrazing, with Artemisia frigida and Cleistogenes squarrosa, indicator species for degradation, dominating the community. The height, coverage and biomass of the community were reduced dramatically, and at the same time, root density declined and soil degenerated. Compared with land surface coverage, root mass is correspondingly steady under disturbances, and serious soil degradation is usually accompanied by the decline of root density. Cultivation caused more damage than grazing did, since cultivation completely destroyed the original vegetation and soil. Both overgrazing and cultivation lead to soil degradation by allowing erosion. Overgrazing and cultivation increased sand particle content in the soil by 48.93 and 34.53 percent, respectively, which directly affected the organic substances content in soil. When 1 percent of clay and silt particle content is blown away by wind, organic carbon content in soil will reduce by 0.34945 g·Kg-1. Exclosure can prevent wind erosion by improving land surface status, which is important to soil restoration. Although exclosure can considerably restore the vegetation and soil of the degraded grassland, it should not be kept for too long, because long time exclosure would hinder the improvement of grassland productivity and the accumulation of soil nutrient.
Yuchun Yan TingtingYang Haiping Tang Xiaoping Xin Xu Wang Guixia Yang
Key Lab of Resources Remote Sensing and Digital Agriculture, Ministry of Agriculture, P.R.China, Hul Grassland Research Institute of Chinese Academy Agricultural Sciences, Hohhot, 010010, China State Key Laboratory of Earth Surface Processes and Resource Ecology Institute of Resources Science
国际会议
The Workshop of Sustainable Grassland Management in China and Australia(中国--澳大利亚可持续性草地管理研讨会)
乌鲁木齐
英文
4
2011-08-01（万方平台首次上网日期，不代表论文的发表时间）