盐城保护区是全球野生丹顶鹤（Grus japonensis）迁徙种群主要的越冬栖息地之一。近年来，丹顶鹤越冬生境变化显著。应用MAXENT模型，结合丹顶鹤野外调查数据和主要环境特征变量，对2000—2013年盐城保护区丹顶鹤越冬生境变化和主要原因进行分析。模型分析结果表明，到道路距离、到养殖塘距离和到米草滩距离，以及到芦苇滩距离和到碱蓬滩距离分别是2000和2013年影响丹顶鹤分布的主要环境因子。2000—2013年期间，盐城保护区内丹顶鹤适宜生境面积持续减少，由94571 hm2减少为22365 hm2；适宜生境破碎化程度不断加剧，分布格局由连续分布变为集中分布在核心区周围区域。丹顶鹤适宜生境丧失与保护区内碱蓬滩、泥滩、盐田面积大幅减少，养殖塘面积大幅增加有关。建议保护区在丹顶鹤越冬生境保护中做好以下工作：（1）加强核心区湿地生境保护和恢复；（2）加强实验区和缓冲区人工湿地管护；（3）加强对保护区内人为干扰活动的监督和管理。
The Yancheng Nature Reserve ( YNR) is an important wintering ground for wild red?crowned crane ( Grus japo?nensis) in the world on their migration route. Recently, the wintering ground of YNR has undergone significant changes. An analysis was done of changes in the wintering habitat of red?crowned cranes in YNR during the period of 2000-2013 and their major causes, using the MAXENT Model, data of field surveys, and environmental characteristic variables ex?tracted from Landsat 5 TM and Landsat 8 images of 2000 and 2013. The analysis reveals that the distance to roads, fish?ponds and smooth cordgrass ( Spartina alterniflora) , and the distance to reed shoals and seepweed shoals, as well, were the main factors that influenced selection of wintering habitat by red?crowned cranes in 2000 and 2013, respectively. Dur?ing the period of 2000-2013, suitable habitats for red?crowned cranes decreased from 94 571 to 22 365 hm2 in area, and were getting more and more fragmented. The distribution of red crowned crane habitats changed in pattern, from a continu?ous one to one concentrated around the core area of YNR. The loss of suitable habitats may be related to drastic reduction of seepweed tidal flats, mudflats and salt pans in area, and rapid expansion of fish ponds. It is, therefore, recommended that more efforts be devoted to the following aspects of work in protecting red?crowned crane habitats in YNR:( 1) strengthen protection and restoration of the wetland habitats in the core area;( 2) intensify management and conserva?tion of the artificial wetlands in the buffer area and the experimental area;and ( 3) enforce supervision and management of human disturbance activities in YNR.