盐池湾高寒湿地景观格局演变及其影响因素

Landscape pattern evolution and its influencing factors of alpine wetland in Yanchi Bay

高寒湿地是重要的水源涵养和生物多样性聚集地,研究其湿地景观格局演变及其影响因素有助于认识湿地生态系统的独特功能、演变规律以及环境影响机制。本研究基于1989—2019年的6期Landsat遥感影像数据,结合GIS技术、景观格局指数以及相关性分析等研究方法,分析了盐池湾高寒湿地景观格局时空演变特征及其影响因素。结果表明:(1)1989—2019年盐池湾湿地总面积呈增加趋势,沼泽化草甸、永久性河流和内陆盐沼分别增加31.02%、17.53%和3.77%,草本沼泽和裸斑分别减少54.28%和9.5%。(2)类型水平上,1989—2019年永久性河流和沼泽化草甸的破碎化降低,其余各类型湿地的破碎化增加;景观水平上,湿地景观形状趋于简单化,湿地破碎化程度增加,蔓延度和香浓多样性指数减少,湿地景观分布向均衡方向发展。(3)气温和降水与湿地面积、景观格局指数之间存在差异化的相关关系。气候变化是导致盐池湾高寒湿地面积变化和景观格局演变的关键因素。研究高寒湿地景观格局时间序列动态演变特征,对于理解湿地的生态功能和生态过程具有重要的理论意义,对湿地可持续发展和景观规划管理具有实践意义。

Alpine wetlands are an important water conservation and biodiversity resource. Studying the evolution of wetland landscape patterns and its driving factors helps understand the unique functions, evolutionary processes, and environmental impact mechanisms of the wetland ecosystem. Using six periods of Landsat remote sensing image data from 1989 to 2019, combined with GIS technology, landscape pattern indices, and correlation analysis, this study analyzed temporal and spatial evolution of alpine wetland landscape patterns in Yanchi Bay.The results showed that(1) the total area of Yanchi Bay wetland showed an increasing trend from 1989 to 2019.The swamp meadows, permanent rivers, and inland salt marshes increased by 31.02%, 17.53%, and 3.77%,respectively, and herbaceous marshes and naked spots decreased 54.28% and 9.5%, respectively.(2) For wetland types, fragmentation of permanent rivers and swamp meadows decreased from 1989 to 2019 and fragmentation of other types of wetlands increased. At the landscape level, wetland shape was simplified, while the degree of wetland fragmentation increased, the spread and Shannon. s diversity index decreased, and wetland landscape distribution developed evenly.(3) Further, there was a differential correlation among temperature and precipitation,wetland area, and landscape pattern index. Climate change was a key factor leading to changes in the area of the alpine wetland and evolution of landscape patterns in Yanchi Bay. Studying dynamic evolution characteristics from time series of the alpine wetland landscape has important theoretical significance for understanding ecological functions and ecological processes, as well as practical significance for sustainable development of wetlands and landscape planning and management.