| Simplified Dynamic Models of Grass Field Ecosystem |
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| 作者姓名： | Zeng Qingcun Zeng Xiaodong Lu Peisheng |
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| 作者单位： | Institute of Atmospheric Physics，Chinese Academy of Sciences，Beijing 100080，Institute of Biophysics，Chinese Academy of Sciencese，Beijing 100101，Institute of Atmospheric Physics，Chinese Academy of Sciences，Beijing 100080 |
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| 摘 要： | Some simplified dynamic models of grass field ecosystem are developed and investigated. The maximum simpli-fied one consists of two variables, living grass biomass and soil wetness. The analyses of such models show that there exists only desert regime without grasses if the precipitation p is less than a critical value pc; the grass biomass continuously depends on p if the interaction between grass biomass and the soil wetness is weak, but the strong interaction results in the bifurcation of grass biomass in the vicinity of pc; the grass biomass is rich as p > pc, but it becomes desertification as p < pc. Periodic solutions also exist in the model, if the seasonal cycle of model’s parameters is introduced. An improved model consists of three variables, i.e. the living grass biomass x, the nonliving grass biomass accumulated on the ground surface y and the soil wetness z. The behaviours of such three variables model are more complicated. The initial values of y and z play a very important role.
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| 收稿时间： | 25 April 1994 |
Simplified dynamic models of grass field ecosystem |
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| Zeng Qingcun,Zeng Xiaodong,Lu Peisheng.Simplified Dynamic Models of Grass Field Ecosystem[J].Advances in Atmospheric Sciences,1994,11(4):385-390. |
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| Authors: | Zeng Qingcun Zeng Xiaodong Lu Peisheng |
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| Institution: | Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100080,Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101,Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100080 |
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| Abstract: | Some simplified dynamic models of grass field ecosystem are developed and investigated. The maximum simplified one consists of two variables, living grass biomass and soil wetness. The analyses of such models show that there exists only desert regime without grasses if the precipitation p is less than a critical value pc; the grass biomass continuously depends on p if the interaction between grass biomass and the soil wetness is weak, but the strong interaction results in the bifurcation of grass biomass in the vicinity of pc: the grass biomass is rich as p > pc, but it becomes desertification as p
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| Keywords: | Dynamic model Grass field ecosystem Bifurcation |
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