盐沼湿地大规模恢复的概念生态模型——以盐城为例

大规模湿地生态恢复是一项耗资巨大、复杂的系统工程,需要以整个区域湿地结构和功能恢复作为基本目标,将时间和空间上分散的研究成果进行系统梳理,形成对区域湿地生态变化及其驱动因素的规律性认识。本研究以盐城盐沼湿地为案例,以1987年作为未干扰或干扰较少的状态,从结构-过程-功能耦合作用角度,确定区域湿地恢复的关键生态特征,包括:健康与动态潮间带湿地系统、碱蓬生态系统生产力与弹性、复杂景观镶嵌与相互作用、潮间带底栖动物丰富与鸟类觅食基地,以及濒危与关键水鸟种群保护。在此基础上,将围垦与土地利用、水管理、全球变化与海平面上升作为驱动区域湿地生态变化的三大外部因素;海岸侵蚀与沉积、区域水格局变化、地形地貌变化、湿地空间变化与连通性丧失,以及互花米草入侵等是影响湿地生态系统变化的内在压力因子;基于这些压力因子与湿地生态系统变化之间复杂作用关系分析,形成了外部驱动力-内在压力源-生态影响-生态特征之间联合作用下的区域湿地恢复概念生态模型。此模型以复杂因果关系研究为基础,直观展示了湿地恢复需要去除或减缓各种压力因子的一般路径,有利于指导大规模盐沼湿地恢复规划与实践。

A conceptual ecological model for large-scale salt marsh restoration: A case study of Yancheng.

Large-scale wetland ecological restoration is a huge and complex systematic project. It is necessary to set the restoration of wetland structure and function as the basic goal,systematically sort out the research results scattered in time and space,and form a regular understanding of regional wetland ecological change and its driving factors. In this study,we took Yancheng coast as a case study area,and the salt marsh wetlands in 1987 as no or less interference state.The key ecological characteristics of regional wetland restoration were quantified from the perspective of structure-process-function coupling,including healthy and dynamic intertidal wetland system,Suaeda salsa ecosystem productivity and resilience,complex landscape mosaic and interaction,intertidal benthos abundance and bird foraging base,and endangered and key water bird population protection. Reclamation and land use,water management,global change and sea level rise are regarded as external factors driving regional wetland ecological changes. Coastal erosion and deposition,regional water regime change,topography change,wetland spatial change and loss of connectivity,and Spartina alterniflora invasion are the internal pressure factors affecting the change of wetlands. Based on the analysis of the complex relationship between these pressure factors and the changes of wetlands,a conceptual ecological model of regional wetland restoration was formed under the combination of external driving force,internal pressure source,ecological impact and ecological characteristics. This model intuitively shows the general path of removing or reducing various pressure factors in wetland restoration,which is helpful to guide the planning and practice of large-scale salt marsh wetland restoration.