额济纳绿洲生态环境变化及其恢复

黑河下游额济纳绿洲是我国西部干旱区具有重要生态防护功能的绿洲,近年来,在人类活动和气候变化的双重作用下,绿洲生态环境发生了一系列变化:1)由于黑河上中游用水量的增加,导致下游额济纳绿洲的入境水量逐年减少,并且地下水位不断下降,水质恶化。2)以胡杨林、柽柳、梭梭林为主的天然林大面积减少;草地生态系统呈现以草场面积减少,牧草产量下降,草地荒漠化和载畜能力降低等为特征的持续退化趋势。3)土地沙漠化和盐碱化现象在该区表现明显。为了使额济纳绿洲的生态环境向着良性循环方向发展,本文从水资源、植被及土地生态系统等方面对额济纳绿洲提出了生态恢复对策。

Eco-environmental Changes and Ecological Restoration on Ejina Oasis

Ejin Oasis,located in the lower reaches of Heihe River,has important ecological protective function in the arid district of western China.In recent years,under the joint influencesof human activitiesand climatic changes,a series of changes have taken place in the ecological environment of the oasis: 1)Because of the increase of the water consumption inupper and middle reaches of Heihe River,the water amount reaching Ejina Oasis at the low reaches reduced year by year,the water table dropedconstantly,and water quality was worsened.2)The wildwood,composedmainly of Populus diversifolia,TamarixSpp,Haloxylonammodendron,reduced by a large scalein area;Meadow ecosystem presented atrend of continuous degradation,which was characterizedthebygrass reduces,outputsof herb droped,decrease meadow decortication and load ability declinet.3)Land desertification and salinizationhappenedobviously in this district.In order to make the ecological environment of Ejin Oasis develop in the benign cycle direction,the papercountermeasures forecology resumes from in terms of water resource,the vegetation and land ecosystem of the oasis,etc were put forward.