互花米草入侵对盐城淤泥质潮滩湿地潮沟系统影响研究

Study on the Impact of Spartina Alterniflora Invasion on Tidal Creek System in the Coastal Wetland of Yancheng

潮沟既是滨海湿地特有的地貌因子,也是输送水分与盐分的重要通道,对植被的生长与空间分布有重要的影响。为探究互花米草入侵对盐城滨海湿地潮沟系统演变的影响,本文利用遥感与地理信息系统(Geographic Information System,GIS)技术,分析了1989年至2020年江苏盐城典型淤泥质潮滩湿地互花米草沼泽时空变化过程与潮沟系统演变特征。研究结果表明:①互花米草扩张经历了入侵初期的斑块阶段、中期连续带状分布阶段及现状阶段过程,入侵影响的景观类型也从光滩转变为碱蓬沼泽;②互花米草入侵过程对潮沟系统产生的影响主要表现为潮沟平均宽度与长度减小、互花米草内潮沟的数量与分支增多;③潮沟系统的变化与互花米草的平均面积、平均周长等存在较大的相关性,表明互花米草的入侵是潮沟系统变化的重要影响因素。

Tidal creeks are unique geomorphic feature in coastal wetlands,and also important channels for transporting water and salt,which have great influence on the growth and the spatial distribution of vegetation.In order to investigate the influence of invasive Spartina on the evolution of tidal creek system in Yancheng coastal wetland,the spatial and temporal changes of Spartina marsh and the evolution of tidal creek system in Yancheng typical silty tidal wetland from 1989 to 2020 were analyzed with remote sensing and GIS technology.The results showed that:the expansion of Spartina alterniflora experienced a patchy stage at its early invasion,then a continuous band distribution stage during its development,and finally the status quo stage,in which the landscape type affected by the invasion has changed from mudflat to Suaeda salsa marsh.The invasion process of Spartina alterniflora affected the tidal creek system with decreasing of the average width and length of tidal creeks and increasing of the number and branches of tidal creeks within Spartina alterniflora.The changes of tidal creek system were correlated with the average area and average perimeter of Spartina alterniflora,indicating that the invasion of Spartina alterniflora was an important factor influencing the changes of tidal creek system.