The Vegetation Reconstruction And Restoration In The Upper Reaches Of Minjiang River

The upper reaches of the Minjiang River,located between the Qinghai-Tibet plateau to the Sichuan Basin,is a fragile as well as an important large-scale and compound ecological transition zone,which is a typical case in terms of its complexity of natural environment,fragility of ecosystem, marginalizatioin of economical development and transitionality of social-culture in China,hence becoming one of the hot spots of world biodiversity conservation and key areas of domestic biodiversity conservation.A long history of anthropogenic influencesc ombined with severe natural environments has resulted in its regional degraded vegetations,bringing out a series of ecological problems such as loss of biodiversity and posing a serious threat to the whole drainage basin of the Minjiang River even the ecological security and regional sustainable development in the upper reaches of Yangtze River.The readiness of regressive succession in ecological environment after being damaged and the slim possibility ofr estoration caused by fragility of ecological environment,makes an urgent call for a fundamental theoretical research on biodiversity conservation and restoration.In order to conserve the biodiversity and reduce the natural disasters and increase the potentil of sustainability in theMinjiang Region,the restoration of the degraded vegetation is indispensible.The pattern of the vegetation and biodiversity in Minjiang was researched in this paper to manage to find the key factors which effect the distribution of the vegetation.It can be used to direct the restoration practice of vegetation in Minjiang Origion Area.Through collecting the vegetation and landform data of the upper reach of Minjiang River,this paper mainly applies ArcGIS(9.2) & RS technology to extracting elevation & aspect information from relief maps,RS images and so on.Based on the analysis of vegetation's present situation,with synthesizing the authoritative & actual data,it classifies the vegetation of the upper reach of Minjiang River into 8 types and 1 un-vegetation type,49 formations,451 patches.Under the support of an essential hypothesis & advanced spatial analysis technology,the therotical vegetation distribution is obtained.Then make a contrast between the present situation and therotical distribution of vegetation, namely,GAP analysis,and find the "gaps",which should be restored & reconstructed.Finally,try to analyze the reasons and bring forward some countermeasures for these "gaps".According to results of vegetation mapping and GAP analysis,people who make decisions for vegetation protection or management will have a clear knowledge of the vegetation's present situation,which will be helpful and necessary for laying the foundation of biodiversity assement to construct a safe,sustainable & healthy eco-system in the upper reach of Minjiang River.Finally,under the consideration of vegetation,landform data,the influence of human activities and consultion of vast number of literature synthetically,this paper classifies the upper reach of Minjiang River into 8 zones,and will take different vegetation restoration & reconstruction countermeasures for different ones to protect their vegetation and eco-environment.