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

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.