THE BASIC FEATURES OF VEGETATION OF FOPING NATURE CONSERVATION IN SHAANXI PROVINCE

Foping Nature Conservation (FNC) is the northernmost and easternmost distribution area of giant panda in China.The geographical elements of FNC vegetation are very complex because this region is a convergent and transitional zone of many floristic compositions.The genera of seed plant of tempe rate distribution patterns take a predominated position, and the tropical elements are also comparatively rich.The vegetation of FNC could be divided into three vertical zones:(1) deciduous broad leaved oak forest zone (below 2000 m),mainly including Quercus variabilis forest, Q.aliena var. acuteserrata forest and Q.serrata var. brevipetiolata forest;(2) deciduous broad-leaved birch forest zone (2000～2500 m),in which Betula albo sinensis forest and B.albo-sinensis var. septentrionalis forest are the symbol;(3) subalpine coniferous forest zone (above 2500 m),where almost all the space are occupied by Abies fargesii forest.There are also many communities in or among these vertical zones.Pine forest can not be recognized as the typical symbol of vegetation vertical zone in this area since they are in the risk of replacement by oak forest.