Study On Persistence And Periodic Solution For Autonomos Lotka-Volterrathe Three-population-competition Model In Mixed Grassland Of Cultivated Perennial Grass In Alpine Region Of Qinghai-Tibetan Plateau Of China And Computer Simulator Investigation

Based on specific and interspecific competition mechanism in Mixed Grassland of Cultivated Perennial Grass in Alpine Region of Qinghai-Tibetan Plateau of China,establishing, a class of Autonomos three populations Lotka-Volterrathe competition Model is established:It's shown that the system can be made persistence under some appropriate conditions.Moreover,sufficient conditions that guarantee the existence of a unque positive periodic solution which is globally asympototic are derived. In order to find the ideal ways to maintain Mixed Grassland of Cultivated Perennial Grass stability, from May, 1998 to Octobr of 2002, this study was conducted at the Jingqianghe Alpine Grassland Station of Gansu Agricultural University, which is located in Tianzhu County, 3000m ASL of altitude (with -0.1 癈 of annual temperature and 416mm of precipitin annually).According to the experiment data, computer simulation models were established. The results indicate: All the communities of grass hi this study can be assorted into 2 groups according to their compatible abilities, namely , the unstable communities, including Elymns nutans + Bromus inermis + Clinelumus nutans, Clinelumus nutans + Elymus nutans + Agropyron cristatum, and the transition community between stable and unstable communities, Bromus inermis + Elymus nutans + Agropyron cristatum.The study provides a new approach to deal with the further improvement of interspecies competition models of the Mixed Grassland of Cultivated Perennial Grass in Alpine Region of Qinghai-Tibetan Plateau and the Mixed Grassland competition-growth relationship ecological study.