库姆塔格沙漠植被特征分析

沿7条考察路线布设了91个样地,对库姆塔格沙漠植物组成、群落结构及植被分布等特征进行调查分析。结果表明:(1)库姆塔格沙漠植物相对稀少,有23科73属109种植物,物种组成趋向于集中在少数大科中和单种属中,优势科属组成较少,植物区系的温带性质明显,并与古地中海成分关系密切。(2)库姆塔格荒漠植被类型较为丰富,拥有4种植被型17个植被群系。受干旱气候及古水系变化的影响,植被群落物种组成稀少,结构单调,在一定程度上反映了荒漠生态环境的严酷性。(3)库姆塔格荒漠植被分布格局受气候、水分条件的影响较大。沙漠南缘降水条件相对较好,植被分布由东到西随降水的递减而呈现减弱趋势,北缘植被则表现为随古水系的萎缩而减小;植被随海拔高度的分布则表现为随海拔由南到北逐级降低,气候愈为干燥,地表径流减少,植被分布更为稀少。

Analysis of Vegetation Character in Kumtag Desert

The features about species composition,community structure and vegetation distribution are researched with 91 plots along 7 route of the study tour of Kumtag desert.The results indicated that:(1) the species are relatively poor in Kumtag desert,which consisted of 23 families,73 genera and 109 species.The composition of species trends towards preponderant families and monophyletic genera.The geological elements have obvious relation not only with temperate flora,but also with ancient Mediterranean Sea.(2) The type of vegetation was abundance.There are 4 vegetation types and 17 associations in Kumtag desert.Seldom species as well as simply structure was affected by dry climate and change of ancient water system,which reflected the severity of desert ecological environment in large degree.(3) It was drought climate and moisture that affected the plants distribution in Kumtag desert.At the southern fringe,vegetation distribution was gradually diminution with precipitation decreasing from east to west.On the other hand,the vegetation of northern fringe has diminished with ancient water system shrink.The changes of climate and hydrological condition affect the vegetation distribution.The altitude and rainfall are gradually decreased from south to north and the vegetation distribution becomes sparser.