| In this paper, a new model correction method, i.e. Fuzzy Amendment Act, which can evaluate the impact of season and environment on the breeding of certain species in biological system, is proposed. Compared with simple linear function, membership function in fuzzy mathematics, which resolves the uncertainty of reproduction number caused by season and environment, is more reliable in revealing the reproduction laws of certain species. By using qualitative theory of ordinary differential equations, the equilibrium points of the revised system are analyzed, and sufficient conditions of the existence and non-existence of limit cycle are obtained; further, examples of simulation and explanation of its ecological significance are provided.In the model which is based on fuzzy amendment and which contains one predator, i.e. lion, and two kinds of prey, i.e. wildebeest and zebra, the reproduction of wildebeest, which is denoted by the membership function, is greatly influenced by season and environment. We use three different membership functions to represent three situations, i.e. early breeding season, normal breeding season and delayed breeding season; and the simulation results testify to the rationality of the method. Meanwhile, diagrams reflecting the relationship between the number of wildebeest and the time and the relationship between equilibrium points and the time are provided. Through the contrastive study with H. Fay. Temple and Johanna. C. Greef and our simulation, it can be concluded that our amended model is more in line with the actual investigation data. Our simulation testifies that the Fuzzy Amendment Act is valid and rational. And this article gives the method of choosing membership function.
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