The response of seed dispersal pattern to human reclamation in salt marshes

The tide is the major vector of seed dispersal in salt marshes. The movement of seeds drove by tidal wave along elevation gradient generates seed flow. Land reclamation in salt marshes generates threats on seed dispersal pattern by disturbing tidal wave. However, these is little empirical study can identify the response of seed dispersal to land reclamation, even clearly elucidate the pattern of seed dispersal in salt marshes. Here, this study observed the flux of the seed flow of Suaeda salsa in low-, mid- and high-marsh and established a quantitative framework to address the seed dispersal pattern in study salt marshes and its response to land reclamations. The results showed the S. salsa seeds in low and middle marsh zones were transported to land-forward and sea-forward by tidal wave. The upside of low marsh zones were the source of seed flow and the downside of middle marsh zones became the sink of seed flow. The land reclamations in high marshes shifted the pattern of seed dispersal in all regions of salt marshes. This study identified the potential threats of seed dispersal change to the downside of middle marsh zones in which the seed flow changed from sink to source and endured much seeds net outflow.