中文摘要：

淡水湿地水文过程控制着湿地植被景观的形成与演变.基于Landsat TM/ETM＋遥感影像数据,利用决策树分类法提取鄱阳湖湿地1992、1999、2006、2012年4期景观信息,通过景观格局指数、转移矩阵和质心迁移法对苔草景观的空间变化及其与水文过程关系进行分析.结果表明：研究期间,鄱阳湖湿地秋、冬季苔草景观分布面积受到水位和退水过程的影响,低水位年的中滩位缓慢退水与低滩位快速出露更有利于苔草景观的扩张;苔草景观的空间格局与水位关系密切,在低水位年份,低位洲滩提前出露,苔草景观分布高程较低,部分低位光滩被苔草所侵占,原苔草分布的部分洲滩转变为芦荻景观,景观的破碎化程度较重,在高水位年份,低位洲滩长期被水体淹没,苔草景观分布高程相对较高,部分芦荻分布区被苔草所侵占,而原苔草景观的部分区域转变为水体和光滩,由于该期间苔草主要集中分布在湖周和入湖河口地带的高位洲滩上,其景观破碎化程度较轻;水位年际间的升降变化会影响苔草景观质心位置,年均水位上升引起景观质心发生向湖岸方向推进,而年均水位下降则会导致苔草景观质心向湖心方向转移.

英文摘要：

The formation and evolution of vegetation landscape are controlled by the hydrological processes in freshwater wetlands. Based on the Landsat TM/ETM＋ remote sensing images, the landscape information on Lake Poyang Wetland in 1992, 1999, 2006 and 2012 was extracted by using decision tree classification. The spatial variation of Carex landscape was analyzed by means of landscape pattern index, transfer matrix and centriod shifting methods. Meanwhile, the relationship between Carex landscape and hydrological processes was also preliminarily discussed. Results showed that the distribution and area of Carex landscape in autumn were influenced by the water level and recession process of Lake Poyang Wetland during the study period, the slow recession of in- termediate- elevation（ 14-16 m） areas and fast emersion of low- elevation（ 12-14 m） areas play a more important role in the forma-tion and expansion of Carex landscape than the water level. The spatial pattern Carex landscape in Lake Poyang Wetland was close-ly related to the annual mean water level. In the year of low annual mean water level, the distribution elevation of Carex landscape is relatively low, some exposed mudflats were occupied by Carex landscape, and the original distribution areas of Carex landscape were partly replaced by Phragmites and Triarrhena landscape, the fragmentation degree of Carex landscape was relatively heavy. While in the year with high annual mean water level, many low bottomlands were submerged, the elevation of Carex distributed was relatively high. Many regions of Phragmites and Triarrhena landscape were occupied by Carex, while the original distribution areas of Carex landscape became partly mudflat or water landscape types. Affected by the rising water level, Carex landscape mainly shif-ted and centered on the high zones of estuaiy