玉环市漩门三期围垦工程对围区内生态系统及鸟类群落的影响研究

Impact of the Xuanmen Phase III Reclamation Project on the Ecological System and Bird Community in the Reclamation Area

围垦工程截断滩涂区域与海域水体的生态关联,引起滩涂湿地生态系统结构和功能的急剧变化。漩门三期围垦工程于2006年开工、2010年合龙,圈围滩涂面积45.3 km^2,基于工程前和工程后围区内水体盐度、营养盐、生态调查数据和围区鸟类群落调查,分析漩门三期围区生态系统结构的变化,评估围垦工程对围区的生态影响。结果表明,围区建成之后,围区水体和滩涂不再受潮汐作用影响,围区水体呈现淡化,盐度在1.2‰~1.8‰;围区内原有的海洋生物均转变成适应淡水的物种,围区水体生态系统已形成新的淡水生态系统;从鸟类的调查结果看,工程后的围区记录到的水鸟多于历史记录,区域鸟类种类和数量集中分布在围区,究其原因可能是围涂区域由原来的潮间带湿地和海洋水体变成了养殖鱼塘、裸露高滩和静止水面,增加了鸟类栖息地类型,在现阶段增加了区域栖息的水鸟种类。后续围区开发和生态修复应遵循生态系统的转变,以淡水生态系统结构和功能为修复目标,以最大化围区生态系统服务功能。

The reclamation project cuts off the ecological relationship between the beach area and the marine waters,resulting in dramatic changes in the structure and function of the beach wetland ecosystem. Xuanmen Phase III Reclamation Project started in 2006 and closed in 2010,enclosing 45.3 square kilometers of beach area. Based on the water salinity,nutritive salt and ecological survey data before and after the project and the bird community survey,this paper analyses the changes of the ecosystem structure in this area,and evaluates the ecological impact of the reclamation project on this area. Results show that after the completion of the reclamation area,the water body and beach are no longer affected by tidal actions. As a result,the water in the enclosure is desalinated with a salinity ranging from 1.2‰ to 1.8‰. The original marine organisms in the enclosed area have been transformed into species adapted to freshwater,and the aquatic ecosystem in the enclosed area has formed a new freshwater ecosystem. The results of the bird survey show that more waterbirds were recorded in the enclosure after the project than in the historical records,and the species and quantity of birds were concentrated in the enclosure. The reasons could be that the reclamation area changes from the original intertidal zone wetland and marine waters to the present farmed fish ponds,bare high beach and static water,which to some extent increase the types of bird habitat,thus increasing the waterfowl types in the area. The further development and ecological restoration show follow the variation of ecosystem,aiming to restore the structure and functions of the freshwater ecosystem,so as to maximize the service function of the ecosystem in the enclosed areas.