Assessment Of Ecosystem Services In Leymus Chinensis Typical Steppe Under Different Grazing Intensities

Rangeland ecosystem is one of the important components of globe land ecosystem. It has important ecosystem services value. On the basis of field research, the value on rangeland ecosystem services in Leymus chinensis steppe under different grazing intensities were primarily assessed. According to the classification method of rangeland degeneration series by LiBo, four grazing intensities,normal(CK), light degraded(LG), moderate degraded(MG), and heavy degraded(HG) were determined. Vegetation characteristics, soil physical and chemical characteristics of different degraded series of rangeland in the site were investigated. Rangeland ecosystem services were assessed. The results show as follows: with the increase of grazing intensity, 1) Above-ground biomass, vegetation coverage and net biomass of rangeland indicated an obviously decreased trend, but plant species of rangeland increased first, then decreased; 2) Soil bulk density of 0~20cm layer was increased, soil total N and 0~20cm layer organic matter have an obvious trend off decreasing along grazing gradients (from CK to HG). Total P and total K decreased at first then increased. 3) According to the economic evaluation methods on rangeland , the total value on rangeland ecosystem services in Leymus chinensis steppe under different grazing intensities ( from CK to HG) were 3.04×104 yuan/hm2·a, 2.92×104 yuan/hm2·a, 2.88×104 yuan/hm2·a, and 2.64×104 yuan/hm2·a, respectively. That is to say, with the increase of grazing intensity,the total value on rangeland ecosystem services in Leymus chinensis steppe decreased.