库姆塔格沙漠梭梭群落特征研究

 在对库姆塔格沙漠植被调查的基础上，以天然梭梭为研究对象，从群落结构、分布和生长特性等方面研究了梭梭群落的结构特征及其自然生存规律。结果表明：沙漠南缘地带为梭梭群落的分布定居区。由于生境及地貌类型的不同，群落结构差异性较大。随着植被类型由东部山前荒漠草原向西部典型荒漠植被类型过渡，梭梭群落相对数量及相对盖度增大，由伴生种转化为建群种。水分是影响梭梭种群自然生长及更新的主导因素，成龄梭梭的生长差异性表现为河床梭梭优于滩地梭梭，沙地梭梭好于戈壁梭梭;小龄级梭梭幼苗主要分布在河床冲沟边缘附近，形成垂直河床的条带状定居格局;深居沙漠腹地的老龄梭梭已基本上衰败死亡，测定年代距公元1950年为(314±54)a。风沙作用使沙漠南移，梭梭出现衰败死亡与自然更新的演替过程。

Study on Characteristics of Haloxylon ammoderon Community in Kumtag Desert

Based on investigation into desert vegetation in Kumtag desert,the structure features and natural survival rule of Haloxylon ammoderon community were studied.The results showed that the south margin is one of the main distributing regions of Haloxylon ammoderon community in Kumtag Desert area.The Haloxylon ammoderon community structure shows a great difference due to the changes of habitats and landforms.From desert steppe in the east to typical desert vegetation in the west of Kumtag Desert,the quantity and the coverage of Haloxylon ammoderon community increase,and the community changes from as companion species to as constructive species.Moisture is the main factor of affecting the community growth and renovation.Being in different habitats,the mature individual shows a great difference in growth status,growing better on riverside than on stony bottomland,better on sandy land than on Gobi.Young seedlings mostly distribute near the border of river bed,appearing in a belt distributing pattern.The Haloxylon ammoderon community in the hinterland of the desert was almost died,but their survival age reached 400 years.With the desert moves toward the south,the Haloxylon ammoderon community experienced the succession process of declining in the hinterland and regenerating in the outer desert.