通过江苏滨海平原典型淤泥质潮滩湿地断面定位观测和样品测试数据与潮位变化关系研究,探讨海平面上升导致淤泥质潮滩湿地生态演替的可能情景。结果表明,淤泥质潮滩湿地的潜水水位和水质、土壤盐分和养分以及潮滩植物种类和生产量等生态组分与潮位变化之间均存在良好的相关关系。据此关系推断,海平面上升,不仅将直接通过增加潮滩湿地的潮浸频率,而且还通过抬高潜水的水位与矿化度,引起潮滩湿地表土积盐和植被退化,进而导致潮滩湿地生态发生逆向演替：生物多样性减少、生产量下降和生态类型趋于单一。上部的茅草(imperata cylindrica var. major) 滩,已淋洗脱盐的表土因重新返盐 (次生盐渍化作用),茅草生长受到抑制,将逐步被较低一级的盐蒿(artemisia schrenkiana)取代,同时由于海堤的阻碍,损失的草滩得不到相应的补偿,最终将可能消失;下部的大米草(Spartina angelica)沼泽,其外缘将不断为光滩所取代,内缘上侵由于受到其繁殖速度的限制,在海平面上升速率较大时补偿速度可能赶不上其退化速度,而导致其分布逐渐变窄,甚至消失;中部的盐蒿滩则由于得到上部草滩退化的补偿和下部大米草沼泽退化的缓冲,范围不断扩大,生态类型多样的潮滩湿地最终将由单一的盐蒿控制。

Mud flat is the typical sensitive ecological area, while its morphological feature responds to the change of sea level, the ecological structure and function also adjust to adapting to the change of coastal environment. Based on the fixed observation, sampling and analysis of the typical profile in Jiangsu coastal plain, this paper lays emphasis on discussing the principles of ecological adverse succession of mud flat caused by sea level rise. The research results show that both sea level and the phreatic water level are related to water quality, the salt content and the nutrient of soil, as well as vegetation composition and capacity of mud flat. Through not only directly increasing the frequency of tidal inundation, but also resulting in the rise in phreatic water level and increase in salinity, sea level rise will bring a series of adverse effects on ecological succession of mud flat, such as salt accumulation and decrease in nutrient of surface soil of mud flat, poor growth or degradation of vegetation and so on, till the adverse succession of the whole ecosystem, i.e., decrease in biodiversity, decline of biological capacity and ecological type tending to be single. In the study area, the imperata cylindrica var. major marsh near sea-wall will be replaced by the artemisia schrenkiana marsh due to soil salinization. Moreover, because of limitation of sea-wall, the range of imperata cylindrica var. major marsh can not expand to inland and at last will possibly disappear. The Spartina angelica swamps near the sea will become narrow because the outer part of them will gradually be replaced by bare bank and the inner part can not extend landward quickly due to the limit of its slow speed of natural reproducing, if the rate of sea level rise exceeds its natural reproducing speed, it will disappear. The artemisia schrenkiana marsh in the middle will continually expand both inward and outward, and the distribution range will gradually enlarged. The original mud flat with various ecological types will tend to be single along with sea level rise.