滨海湿地生态系统位于海陆交汇地带，是世界上极富特色且极具生产力的生态系统之一，同时也是受胁最严重的生态系统之一。水鸟依赖于湿地环境生存，是湿地生态系统不可或缺的重要组成部分。水鸟对环境变化具有敏感性，其群落特征可以反映湿地生态系统的稳定性和功能性。近年来，人类对自然环境开发加剧，对湿地生态系统和湿地水鸟生存构成巨大威胁。环渤海区域位于鸟类的重要迁徙路线东亚-澳大利西亚迁徙路线上，每年会有超过200多种、大于5000万只水鸟利用此区域停歇和中转，特殊的地理位置使得该区域成为迁徙水鸟不可替代的中停地。然而，该区域同样是城市化和人为改造程度较高的区域之一。因此，在环渤海地区开展土地利用变化与水鸟群落分布格局之间的研究，对于水鸟及其栖息地保护具有重要意义。本研究结合1998-2021年遥感影像和水鸟调查数据，对环渤海地区水鸟栖息地变化及其对水鸟群落的影响进行研究。获得的主要结果如下：
1.1998-2021年环渤海地区土地利用类型的变化主要为陆地建筑面积的增加和海洋围填海面积的增加；土地利用类型间面积转换最大的为耕地转化为建设用地。环渤海地区的自然湿地主要分布于辽东湾北部沿海、渤海湾沿海、黄河三角洲地区以及莱州湾区域等；人工湿地主要分布于辽宁盘锦至丹东沿海、渤海湾沿海等。研究期间，沼泽面积波动变化，滩地面积呈减少趋势，而养殖池和盐池面积呈增加趋势。环渤海地区湿地资源呈现先减少后增加以及自然湿地减少、人工湿地增加等趋势，2021年湿地总面积与1998年基本保持不变。
2.在时间尺度上，不同地理位置的沿海湿地记录到的水鸟种群数量和鸻鹬类种群数量趋势存在较大差异；研究早期和后期鸻鹬类数量总体保持稳定，物种数减少。多数地点的水鸟种类数和鸻鹬类种类数呈现先减少后增加的趋势，少数地点呈现先增加后减少或减少的趋势。水鸟多样性波动变化；半数地点的鸻鹬类多样性呈现出先减少后增加的趋势，少数地点呈现减少趋势。在空间分布上，环渤海地区水鸟种类、种群数量及多样性较高的区域主要为鸭绿江口、辽河口、渤海湾沿海区域、黄河三角洲湿地、莱州湾湿地等河口湿地和淤泥质滩涂湿地。滩涂面积变化与鸻鹬类种群数量变化之间存在显著正相关。
3.2021年水鸟的潜在栖息地主要分布于渤海湾沿海区域、黄河三角洲湿地、盘锦辽河口区域、胶州湾湿地等区域。鸻鹬类的潜在栖息地主要沿海岸线分布；雁鸭及䴙䴘类、鸥类、鹭类的潜在栖息地分布于内陆水系和沿海区域。四类水鸟的潜在栖息地面积占比平均值为32%，雁鸭及䴙䴘类的潜在栖息地面积最高，而鸻鹬类最低；水鸟潜在适生区受保护面积占适生区整体面积的比例平均为6.7%。对水鸟潜在栖息地预测贡献程度最高的主要因素为距水面距离、距建筑面积距离；对雁鸭及䴙䴘类、鹭类分布预测贡献度高的因素还包括年平均气温。

Coastal wetland ecosystem is located at the intersection of land and sea. It is one of the most characteristic and productive ecosystems in the world, and also one of the most threatened ecosystems. Waterbirds depend on wetland environment for survival and are an indispensable part of wetland ecosystem. Waterbirds are sensitive to environmental changes and their community characteristics can reflect the stability and function of wetland ecosystem. In recent years, human exploitation of natural environment has intensified, which poses a great threat to wetland ecosystem and the survival of wetland waterbirds. The Bohai Rim region is located on EAAF, an important migration route for birds. Every year, over 50 million waterbirds of more than 200 kinds use this region to rest and transit. The special geographical location makes this region an irreplaceable stopover place for migratory waterbirds. However, this area is also one of the regions with high degree of urbanization and artificial transformation. Therefore, it is of great significance to study the relationship between habitat change and waterbirds community distribution pattern in the Bohai Rim. In this study, remote sensing images and waterfowl survey data from 1998 to 2021 were used to study the habitat changes of waterfowl and their impacts on waterfowl communities in the Bohai Rim. The main conclusions are as follows:
1. The changes of land use types in the Bohai Rim region from 1998 to 2021 mainly include the increase of the built-up area of land area and the increase of reclamation area of marine area. The largest area conversion among land use types is crops into built-up area. The natural wetland in the Bohai Rim are mainly distributed in the northern coastal areas of Liaodong Bay, Bohai Bay, Yellow River Delta and Laizhou Bay, etc. Artificial wetlands are mainly distributed in the coastal areas from Panjin to Dandong and the coastal areas of Bohai Bay. During the study period, the area of marsh fluctuated, the area of mudflats decreased, and the area of aquaculture ponds and salt ponds increased. The wetland resources in the Bohai Rim region show a trend of first decreasing and then increasing, as well as a decrease in natural wetlands and an increase in artificial wetlands. The total area of wetlands in 2021 remained basically unchanged from 1998.
2. On time scale, there are significant differences in the trend of recorded waterbirds populations and shorebirds populations in coastal wetlands of different geographical locations; The sum number of shorebirds remain stable in the early and late stages of the study, but the number of species decreased. The number of waterbirds species and shorebirds species in most locations showed a trend of first decreasing and then increasing, while a few locations showed a trend of first increasing and then decreasing or decreasing. It shows fluctuations in the diversity of waterbirds; The diversity of shorebirds in half of the locations showed a trend of first decreasing and then increasing, while a few locations showed a decreasing trend. In terms of spatial distribution, the areas with high species population number, and diversity of waterbirds around the Bohai Sea are mainly Yalu River Estuary, Liaohe estuary, Bohai Bay coastal area, Yellow River Delta wetland, Laizhou Bay wetland and other estuarine wetlands and mudflat wetlands. There is a significant positive correlation between the tidal flat area change and the population change of charover Sandpiper.
3. The potential habitat areas of waterbirds in 2021 are mainly distributed in Bohai Bay coastal area, Yellow River Delta wetland, Panjin Liaohe estuary area, Jiaozhou Bay wetland and other areas. The potential habitat of shorebirds is mainly distributed along the coastline; The potential habitats of ducks and grebes, gulls, and egrets are distributed in inland water systems and coastal areas. The average potential habitat area precent of the four types of waterbirds is 32%, with the highest potential habitat area for the ducks and grebes, while the lowest potential habitat area for the shorebirds. The protected area of potential suitable area of waterbirds accounts for 6.7% of the total area of suitable area on average. The main factors that contribute the most to the prediction of potential habitat for waterbirds are distance from water surface and distance from built-up area; The factors that contribute highly to the prediction of the distribution of ducks and grebes, and egrets also include the annual average temperature.