Succession in soil and vegetation caused by coastal embankment in southern Laizhou Bay, China-Flourish or degradation?

摘要

Coastal wetland degradation and loss caused by intensive human activities, such as land reclamation and embankment, is a serious environmental problem. In this paper, we studied the succession of soil and vegetation in a coastal wetland dominated by Chinese tamarisk (Tamarix chinensis) community after the construction of a seawall. When the intertidal wetland became supratidal wetland, soil salinity firstly decreased and the gradient from sea to land became weaker. Next, the area of vegetation and plant species diversity increased, and the phenomenon of plant zonation disappeared. We reasoned that the rooted cause of soil and vegetation succession was the change in hydrological environment. Moreover, a Drivers-Pressures-State-Impacts-Response (DPSIR) model was used to analyze the relationship between human activities and coastal wetland. Using this model, we presented the potential problems that might arise in this wetland and predicted that vegetation flourishing was only a short term phenomenon but wetland degradation was the final consequences due to excessive exploitation of groundwater. At last, we proposed a few of operable measures as responses to these potential problems from the perspective of coastal management.