Characteristics of grassland and ecological change of vegetations in Baiyin Region of Gansu Province

The constitution and degrading character of natural grassland are of very important ecological significance for exploiting the natural grassland rationally and for restoration of the degrading grassland ecosystem. In this paper, we have researched into and analyzed the constitution of resources, types and structures on the degraded grassland in Baiyin Region. We have also studied the varying regularity of ecological types and output of vegetation in different degrading periods on natural grassland. With the severity of degeneration of grassland, from the initial stage to a latter period, the plant in perch-bud first disappeared, the plant amount of vegetation community and the density of predominant plant declined sharply. The convergence, biomass and the proportion of the production of fresh grass to edible grass have also declined rapidly. We have also put forward some countermeasures, which can help ensure the grassland and its stockbreeding in a sustainable way.