土地利用与土地覆盖变化对湿地景观的结构和功能产生深刻的影响。选择江苏盐城海滨地区为研究对象,应用遥感和地理信息系统技术,分析20年来土地利用变化对湿地景观连通性的影响,并以2007年湿地景观生态系统服务功能为基础,采用阻力面模型探讨湿地景观连通性优化途径及其效应。结果显示:①1987—2007年间,盐城海滨区域土地利用结构变化显著。其中耕地面积比重由36.72％上升为46.17％,自然湿地持续减少,面积由44.4％减为26.01％,人工湿地持续增加,面积由9.96％上升为18.72％;②随着区域人类土地利用活动的加强,光滩、碱蓬沼泽和芦苇沼泽的空间连通性降低,区域土地利用导致湿地景观之间生态流阻隔,景观生态服务功能减弱;③2007年湿地景观生态功能强度空间差异显著,以累积耗费距离面、生态源地、耗费路径为依据,对湿地景观连通路径优化结果表明,废黄河口和大丰港附近等关键区域对景观连通性和生态流影响最大,是景观生态节点优化的首要对象;④加强连通路径的关键区域优化、提高景观连通度是实现景观优化的关键。

Land use and land cover change have been strongly affecting the function and structure of landscape ecosystem. Landscape pattern aims to build some optimized landscape which could make landscape eco-efficiency maximize and stabilize. Therefore, in this paper, the Yancheng coast is chosen as a study area and the technologies of remote sensing (RS) and geographical information system (GIS) are applied. Meanwhile, the valuation of wetlands landscape ecosystem services are used to analyze the landscape pattern. Based on ecological processes and resistance model, some proposals were put forward to optimize the wetlands landscape pattern. The results show: 1) The land use structure in the coastal zone of Yancheng has undergone significant change from 1987 to 2007. It is demonstrated that the percentage of farmland area ascends from 36.72 to 46.17, and the percentage of artificial wetland area ascends from 9.96 to 18.72,while that of natural wetland area declines from 44.4 to 26.01. 2) With more land use activities, the intensity of human disturbance to land increased from 1987 to 2007. A series of landscape ecological problems were caused by the increase of human disturbance to land, such as landscape shape complexity, low landscape ecological connectivity and more serious fragmentation of natural wetlands landscape. As a result of landscape ecological connectivity, function and the ecological process, such as energy flow in a landscape was declined. Ecological process and functions of wetlands in the coastal area were different in spatial distribution in 2007. The total value of ecosystem services is 77.09 billion yuan/a. The rate of contribution to the reed marsh, Saline seepweed marsh and Spartina alterniflora marsh is the highest, accounting for 86.91% of the total value, and they are mainly distributed between Sheyang Estuary and Doulong Port, and secondly distributed to south of Doulong Port, while the mud flat, paddy field and aquiculture pond is lower. 3) Based on an accumulative cost distance model, the calculation of the cost distance, and identification of the sources, the critical ecological positions, corridors, and sources were designed in the study area, and the landscape pattern optimization further discussed, such as protecting of nature resources, constructing the buffer region, rehabilitating suitable vegetation types to improve connectivity of landscape. 4) Optimization of wetlands landscape pattern improved flow and connectivity of landscape. The critical ecological positions for flow and connectivity of landscape close to the bays of the Old Huanghe River estuary and Dafeng Port was most important, and it was the primary object to be optimized. 5) According to the principles of landscape ecology, the key to optimize the landscape pattern is to strengthen protection of nature sources, and maintain high landscape connectivity in Yancheng coastal zone so as to realize the objectives of sustainable development in land-use and environmental protection.