玛纳斯河流域近50年植被格局变化

以玛纳斯河流域47个残遗荒漠植被样方数据为基础，发现研究区植被与土壤理化性状存在着非常明显的分异规律，白梭梭群落、梭梭群落、琵琶柴-梭梭群落、梭梭-柽柳群落、柽柳群落、盐化灌木群落对应土壤的总盐含量、总有机碳含量依次递增，而土壤中砂含量却依次递减，这充分说明荒漠植被类型和对应的土壤类型之间有较好的指示关系。基于上述分析，利用玛纳斯河流域的土壤图复原研究区大规模开垦前植被格局，并将复原的植被图和基于TM影像解译的研究区现状植被图比较分析，发现近50年来玛纳斯河流域大约有20.37万hm²的荒漠被开垦为农田，主要分布在灰漠土上。利用荒漠植被和土壤之间较好的指示关系复原玛纳斯河流域未开垦前的原生植被有助于指导干旱区绿洲土地利用。

Changes of Vegetation Pattern in Manas River Basin over the Last 50 Years

It is found that there are evident differentiations of vegetation types and physical and chemical properties of soil in the study area based on data collected from 47 quadrats of remnant desert vegetation in Manas River Basin.The total salt and organic carbon contents increase in sequence in soils of communities of Haloxylon persicum community, Haloxylon ammodendron community, Reaumuria soongorica-Haloxylon ammodendron community, Haloxylon ammodendron-Tamarix ramosissima community, Tamarix ramosissima community, salt shrubs community and a converse tendency was detected for sand percentages.This indicates that there is a good indicative relationship between the desert vegetation types and soil types.The vegetation of 50 years ago in Manas River Basin derived from the soil map is compared with the current vegetation map interpreted from TM imagery.The result shows that 203 700 hm² area of desert has been cultivated to cropland during the past 50 years, mainly on grey desert soil.Vegetation reconstruction based on indicative relationships between desert vegetation will be beneficial to optimal land use in the arid region.