Researches on species extinction caused by the shrink or loss of habitat are one of the hottest points of biological study, in which numerous biological scientists have been involved. The Tianjin Qilihai Wetland was set to example to simulate the mechanism between habitat destruction and species richness. This research combined theoretical research with numeral simulation and set up the evolutional model of exponent upon the effect of human activities. 1) The exponent value of dis defined as the coefficient value of the interaction between species and environment and it can be applied to research the evolutional mechanism of different meta-population. When the condition of d<1 is met, the effect of environment on meta-population is beneficial to the development of species and habitat destruction will not lead to species extinction. While the condition of d>1 is met, the strongest species will be driven to extinguish owing to the decrease of content of habitat and the system will reach new state in a short time. The bigger the value of d is, the shorter of time system reach new state is. 2) The third mechanism of extinction of meta-population, the coordinate law of evolution and degradation of species in the restoration of destruction habitat are also found, which is the same evolutional trait of different species. The evolutional law between the restoration and destruction of habitat has same points and differences.

The model of Patch-dynamics was applied to simulate the land cover based on land change data. The results indicated that the percentage of arable land in total area will continue to descend while urban construction and forest land will ascend along time. The model of Patch-dynamics is better than traditional simple dynamics model in that it takes into a account the change process of simulation's object and interaction of different land use type. Compared with actual condition in 2001, the difference between the results of Patch-dynamics model and actual condition lies between 0 and 0.05 and has small difference for little percentage of land use type. The result makesclear that the model of Patch-dynamics can simulate the change condition of future scene. However, the model of Patch-dynamics can only apply to ten-year scale of land use change. The longer the simulation period, the more the simulation relative error. The conflict of land use should be harmonized, the urban green space should also be maintained, and some suggestions about land use and urban green space have been carried out.