侵蚀型与淤长型海岸湿地景观时空演变特征及差异研究

A Study on Landscape Evolution Characteristics and Differences between Erosional and Depositional Coast Wetland

在盐城国家级自然保护区,选取侵蚀型和淤长型海岸湿地代表区。根据1987年、1997年、2007年3个时相的景观资料,运用RS、G IS技术和景观生态学方法,分析不同海岸类型湿地景观格局演变差异。结果表明:(1)侵蚀型海岸湿地:碱蓬湿地退化消失,人工湿地减少,向光滩集中。景观破碎化指数上升,景观异质性指数降低。景观格局演替呈现多样性特征,1987—1997年,从陆地向海洋方向演替;1997—2007年,从海洋向陆地方向演替。(2)淤长型海岸湿地,景观破碎化指数下降,景观异质性指数上升,景观格局从陆地向海洋方向单向演替。(3)地貌过程和植物群落演替过程等呈连续性变化,导致景观演变呈带状连续性发展;人为干扰往往使生态过程的连续性发生突变,从而使景观演变呈现逆向特征。

The paper conducts a study on erosional and depositional coast wetland in Yancheng National Nature Reserve,and analyses differences of wetland landscape pattern characteristics and evolution in different-type coasts using RS and GIS technology and landscape ecology method based on landscape data of 1987,1997 and 2007.The results show that：（1） In erosional coast wetland,salsa wetland has been degraded and disappeared,artificial wetland is reduced and concentrated to the mudflat,landscape fragmentation index is on the increase,and landscape heterogeneity index is on the decrease;the landscape spatial evolution is from the land to the sea from 1987 to 1997,but it is the opposite from 1997 to 2007.（2）In depositional coast wetland,artificial wetland is on the increase,major landscape proportion generally has arrived at a balance;landscape fragmentation index is on the decrease,and landscape heterogeneity index on the increase;landscape spatial evolution is only from the land to the sea.（3） Geomorphologic processes which are resulted from sediment conditions and marine dynamics are decisive factors in the landscape pattern evolution,whereas human impact is an important driving force behind the landscape pattern change.