WANG Gen-xu, CHENG Guo-dong, LIU Guang-xiu, XU Zhong-min
In the periglacial regions, owing to the varied spatial environment and biological type zones the special landscape structure and pattern is formed under the high-cold environment. With the law of three orientation type zones, landscape heterogeneity exhibits gradual change and sudden change in landscape types at different orientation. In the Tibetan plateau. the landscape varies in space as the following model from southeast to northwest: forest→high-cold bush→high-cold meadow→high-cold steppe→high-cold desert. Besides the horizontal variation of landscape. the vertical variation of landsca pe is also marked with the following model: the high-cold steppe (or high-cold meadow, desert) high-cold bush (or high-cold steppe) hig mountain meadowglacier→snow, bore rock. The forest matrix with high-cold bush and meadow mosaics, high-cold meadow matrix with high-cold bush. cold-warm forest and bare rock patches and river corridor mosaics, high-cold steppe matrix with high-cold meadow, swamp, lakes, bare rock and desert patches and river corridor mosaics, high-cold desert matrix with high-cold steppe, meadow, desert and bare rock patches are the four main types of landscape. There are mainly environmental patch and disturbance patches as land scape mosaics, with simple landscape structure and coarse grain. The landscape pattern change is fast in time and large in space. Climate change. all types of periglacial activities, specially the change of freeze-thaw condition of frozen soil are the main driving forces of landscape ecological processes, forming a special freeze-thaw ecological process. It is important to understand the landscape ecology on the periglacial regions for protection and improvement of the ecological environment.