辽河口潮滩典型盐沼植被退化影响因素分析

Analysis of Influence Factors of Typical Salt Vegetation Degradation in Tidal Wetland of Liaohe River Estuary

近年来辽河口出现了水体污染、湿地退化等生态环境问题,导致潮滩典型盐沼植被翅碱蓬退化。基于2017—2020年辽河口潮滩湿地盐度、滩涂沉积质盐度等数据,结合遥感影像数据,解析辽河口湿地翅碱蓬退化的主要原因。结果表明:与2017—2019年相比,2020年辽河口潮滩翅碱蓬面积显著增大;2017—2020年越靠近辽河口潮滩南部区域,翅碱蓬长势越差,直至退化为光滩;潮滩翅碱蓬面积与水体盐度变化趋势相反,辽河口水体盐度变化显著影响翅碱蓬的生长;辽河口潮滩湿地污染物具有同源性,主要来自于上游河流输送,潮滩湿地水体水质小范围内变化不会危害翅碱蓬生长;辽河口潮滩下游区域沉积质盐度显著高于上游区域的,沉积质盐度过高将抑制翅碱蓬生长,因此可通过调控沉积质盐度的方式促进翅碱蓬生长与定植。

In recent years,water pollution,wetland degradation and other eco-environmental problems occurred in the LiaoheRiver estuary(LRE for short),which leads to the degradation of Suaeda Heteroptera,a typical salt marsh vegetation on the tidal flat.The study analyzed the main causes of Suaeda Heteroptera degradation in the tidal wetland of LRE by using the data of water salinity,sediment salinity from 2017 to 2020,as well as remote sensing data.The results show that the area of Suaeda Heteroptera in the tidal wetland of LRE is increased significantly in 2020 compared to 2017-2019.From 2017 to 2020,with the advance to the south of the tidal wetland in LRE,the growth of Suaeda Heteroptera is gradually deteriorated until it degenerates into a smooth beach.The change trend of Suaeda Heteroptera area in the tidal flat is opposite to that of water salinity,indicating that the growth of Suaeda Heteroptera is greatly affected by the changes in water salinity in LRE.The pollutant concentrations in the tidal wetland of LRE are homologous,mainly from the upstream river transportation and the deterioration of water quality in a small range has no harm to the growth of Suaeda Heteroptera.The sediment salinity in the downstream area is higher than that in the upstream area of LRE,the growth of Suaeda Heteroptera will be inhibited if the sediment salinity value is too high.Therefore,the planting and growth of Suaeda Heteroptera can be promoted by regulating the salinity of sedimentary substance.