The Succession of the Vegetation on the loess District Northward to Qinling
Since the quanternary occured, the vegetations of this district have appeared several serious variations. They sheav that the mold and cold asi- culisilvae and bush-wood meadow, tundra vegetation theropeucedrymion, forest steppe and dry steppe have occurred simultaneously. All of these variations are generally belonged to the succession of climatogenic exadynamies. Rece- ntly, through the occurrence of anthropogenic influences, the north parts of this district are developing to the deriction of the steppe.