Succession of potential vegetation in arid area of northwest China

Vegetation background research, especially the basic work of ecological environment construction in arid area of northwest China has become much more significantly gradually. Potential vegetation is the most stable and mature climax vegetation type which achieves the balance state finally without human interference, and it can also be used to rehabilitate and reconstruct of vegetation regionally. With the support of GIS technology, this paper analyzed the succession process of potential vegetation in arid area of northwest China based on the IOCSG model. The annual precipitation and above 0 °C annual cumulative temperature data in northwest China from 1961 to 2005 were provided by 119 and 115 meteorological stations respectively, The conclusion as follow: potential vegetation increased the complicated process of succession due to climate change in the study area. From the view of transformation characteristics and changes in quantity of potential vegetation types, the distribution area of potential vegetation shows there are three kinds of characteristics: reduced steady, increased steady and changed fluctuant. In the view of geographic distribution pattern change and the development direction of potential vegetation types, the main areas with significant succession include Turpan basin, northern Xilinguole plateau, Hulunbeier plateau, and Taipingling Region. The spatial change and succession direction of potential vegetation were different. With regard to the driving factors of potential vegetation succession, under conditions of climate changes, changes in hydrothermal conditions which affected the distribution of vegetation caused the changes of the decision relationship between climate and vegetation.