三峡库区消涨带维管植物区系的初步研究

A Preliminary Study on the Vascular Plant Flora of the Water-Level-Fluctuating Zone in the Three-Gorge Reservoir Area

三峡库区消涨带是指三峡库区范围内长江干流及其支流由于江 (河 )水水位季节性涨落 ,导致其沿江 (河 )两岸土地出现周期性淹没而自然形成的带状区域。该带维管植物区系具有以下特征 :植物种类比较丰富 ,计有维管植物 83科、2 4 0属、377种、2 6变种和 2变型 ;地理成分复杂 ,联系广泛 ,温带成分占优势 ;区系组成表现进化性 ,生活型组成以多年生草本、一年生草本和灌木为主 ;地方特有成分不多 ,但中国特有种类比较丰富 ;带内不同区段物种丰富度有差异 ,干流多于支流 ,奉节以东多于奉节以西 ,带上部多于带中部和带下部 ;优势现象明显 。

The water level fluctuating zone in the Three Gorge Reservoir Area is a belt zone of the bank beside Yangtze River and its branches in the Three Gorge Reservoir Area,which emerges and submerges periodically with the water level fluctuating seasonally.The vascular plant flora in this area shows many characteristics:the vascular plants are relatively abundant in species,and there are 377 species,26 varieties and 2 forms,which belong to 240 genera,83 families.It is complex in geographical elements,having an extensive connection with nearby floristic area,and has more temperate plants than tropical ones;the floristic composition shows an evolutionary trend,and the life form constitutes with many perennial herbs,annual herbs and shrubs;there are few endemic plants to this area,but many endemic species to China;species richness of the plants in different parts of this area are not even.Namely,those in main channel,east to Fengjie,and the upside are higher than in branches,west to Fengjie,and middle part and downside respectively;the vascular plant flora in this area is characterized by not only obvious dominance phenomena but also abundant characteric taxa.