滨海盐沼植物种子扩散过程对潮流阻断的响应机制

滨海盐沼湿地中，种子扩散模式主要由潮汐作用决定，在潮汐沿高程梯度的运动中形成了种子流。滨海围垦活动可以直接影响到盐沼湿地的潮汐作用，进而造成盐沼湿地中种子扩散模式的变化。本研究对不同高程盐沼湿地的种子流通量进行调查，阐明了潮流干扰下盐沼湿地中植物种子扩散模式的响应机制。本研究发现在潮流驱动下，低位盐沼和中位盐沼的种子将会向海陆两端迁移，低位盐沼上部是重要的种子源区，中位盐沼下部成为了种子汇区。而高位盐沼的围垦活动将会改变盐地碱蓬种子扩散模式。中位盐沼下部的种子扩散模式受到的影响最为严重。围垦活动占据或破坏高位盐沼之后，中位盐沼下部将由种子的汇区变为源区，大量的种子净流出将给该区域盐地碱蓬定植造成潜在威胁。 

Response of seed dispersal pattern to human reclamation in salt marshes

The tidal wave is a major vector of seed dispersal in salt marshes.Seed movements driven by tidal waves along elevation gradient generate seed flow. Land reclamations in salt marshes change seed dispersal pattern by disturbing tidal wave.In the present work we observed the seed flow/flux of Suaeda salsa in low-,mid-and high-marshes,and established a quantitative framework to address seed dispersal pattern and pattern response to land reclamation projects.Suaeda salsa seeds in low and middle marsh zones were found to be transported 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 was the sink of seed flow.Land reclamations in high marshes shifted pattern of seed dispersal in all regions of salt marshes.This study therefore identified the potential threats of seed dispersal change to downside of middle marsh zones:seed flow changed from sink to source resulting in net seed outflow.