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杨树人工林的快速扩张及其对湿地生态系统的影响是西洞庭湖生态系统管理亟待解决的关键问题.本研究基于遥感影像数据、西洞庭湖湖底高程数据以及西洞庭湖水文数据,分析2000—2014年杨树在西洞庭湖洲滩湿地的时空分布特征.结果表明:2000—2011年,杨树面积大幅增加,从3233.5 hm~2增加到10915.6 hm~2,增速为698.4 hm~2·a-1,其中,2004—2007年增长速度最快,达到1000.6 hm~2·a-1;2011年达到峰值后逐渐减少,2014年杨树人工林面积回落到10153.1 hm~2.芦苇、水域泥滩地和草滩地对杨树人工林扩张的贡献度依次为41.8%、37.0%和21.2%.错误的鼓励性政策、经济利益驱动等人为因素是导致西洞庭湖杨树迅速扩张的主要影响因子,泥沙淤积以及三峡大坝运行之后,洞庭湖水文节律的变化为加速杨树人工林的扩张提供了客观条件.2013年以后,西洞庭湖开展“退林还湿”工程是扭转杨树林扩张、并造成2014年杨树林面积下降的主要原因.
The rapid expansion of poplar plantations and its impact on wetland ecosystems are the key issues to be solved urgently in ecosystem management of West Dongting Lake.Based on the remote sensing image data, the elevation data of West Dongting Lake and hydrological data of West Dongting Lake, - The Spatial and Temporal Distribution of Poplar in Wetland in West Dongting Lake in 2014. The results showed that poplar area increased significantly from 3233.5 hm 2 to 10915.6 hm 2 in 2000-2011 with a growth rate of 698.4 hm 2 · A-1, of which, the fastest growth rate reached 1000.6 hm 2 · a-1 in 2004-2007, and then decreased gradually after peaked in 2011. The area of poplar plantation in 2014 dropped back to 10,153.1 hm 2, The contribution of mudflats and beach land to the expansion of poplar plantations in turn was 41.8%, 37.0% and 21.2%, respectively.The erroneous encouraging policies and the economic profit-driven human factors contributed to the rapid expansion of poplar in West Dongting Lake Factors, sedimentation and the operation of the Three Gorges Dam, Dongting Lake hydrological rhythm changes in order to accelerate the expansion of poplar plantation provides an objective condition after 2013, West Dongting Lake to carry out Poplar expansion, and made As the main reason for the decline of poplar area in 2014.