The Ecological Environmental Change And Apocalypse On The Site Of Xanadu

This paper uses the history of literature research and field survey methods, which begins with the relationship between human activities and natural geographical environment, to research the ecological change process of Xanadu. The aim is to reveal the effects of human activities on the ecological environment, to understand the relationship between human activities and nature correctly, and to provide relevant historical reference and theoretical basis for Xanadu ecological environment and sustainable development. The main findings are as follows:(1) From the beginning of fifteenth Century to the end of nineteenth Century, under the control of the gradual cooling and drying climate, the vegetation growth of yuan Xanadu has been affected or even degeneration, and the ecological environment has deteriorated gradually. From twentieth Century to more than a hundred years, the overall climate showed a warming and drying trend in this area. These caused grassland degradation, desertification of arable land, marshes, wetlands to saline, bare land conversion and other consequences. During the process of evolution of woodland to grassland landscape typical steppe landscape in Yuan Xanadu, climate change is a major factor leading to its ecological landscape change.(2) As the human activity, the history war not only burned the city but also did the ecological environment of yuan Xanadu destroy. Policies and systems have an important impact on the ecological environment, from the Qing Dynasty in the late "wasteland keep people "and" the Migration", to ROC government developing a "wasteland Monte", then a series of policies that after the founding of New China’s "food for the program", "focus grazing", "settlement" lead to the region of Xanadu from the prairie landscape changes to the dominant factor in farming-pastoral landscape. Now tourism development, reservoir development, mining and industrial development and other human activities continues to affect the ecological environment of Xanadu site.(3) The plants of Xanadu site grow very well. There are 344 species of wild seed plants, belonging to 179 genera,53 families. Vegetation in good condition can prevent soil erosion and land desertification in the site, and enhance the stability of the ecological environment. Meanwhile, the site’s wall also covered by the plant. It has double effects on site’s wall. Roots of trees and shrubs are easy to cause the wall cracks, and it has a destructive effect; while the interaction of low herbage’s shallow root fixing soil reduces the erosion of rain on the site, and it has a certain protective effect on site up.(4) The traditional nomadic culture is a kind of power which can make the ecological environment of Xanadu site to maintain the stability. Changes of ecological environment also includes the change of traditional culture. The loss of traditional culture has the inevitable relation with the ecological environment change.