黑河下游河岸绿洲区包气带土壤水分与植被生长状况的研究

黑河下游荒漠平原区近年来由于河水流入量的持续减小，致使依赖河水补给来源的地下水呈减少趋势，造成区域性地下水位下降，从而引起一系列生态环境问题。通过研究黑河下游河岸绿洲区非饱和带的含水量、地下潜水埋深、土壤类型结构等与河岸绿洲植被生长状况之间的关系，发现土壤结构、地下水位埋深和土壤盐分是决定研究区植被生长状况的3个主要因素，而土壤结构是不可改变的，土壤盐分又与地下水关系密切，因此，地下水是极端干旱区植被生长状况的决定因素。

Research of relation about soil water contain in zone of acration and vegetation growth status at oasis of riverside in lower reaches of Heihe River

In recent years,due to the runoff which influx to the lower reaches plain of Heihe River persisting subduction and as a result of the regional table of groundwater decline,consequently product a series of problems about eco-environment.By research the relations of water contain in the zone of acration,depth of the water table,soil structure and vegetation growth status,it find that the vegetation growth at oasis in the extreme arid regions rely on the water in the zone of acration,the water contain of zone of acration decided by depth of the groundwater table and soil structure,different soil structure types have different capacity of capillary power and specific retention,when the vegetation roots reached the top of fringe,the vegetation growth status is good,otherwise,there are decline or death,following instead by other vegetation community.Soil salinity restrain the growth of vegetation,when its exceed suitable,the vegetation will decline or death or instead by other vegetation community.So the soil structure,the depth of the groundwater table and soil salinity are three primary factors for deciding the vegetation growth status at oasis of riverside in the lower reaches of Heihe River,but soil structure is crude and cannot been changed,soil structure and soil salinity have connection with the depth of groundwater table,so the depth of groundwater level is determinant factor for vegetation growth in the extreme arid regions.