Salt marsh vegetation distribution patterns along groundwater table and salinity gradients in yellow river estuary under the influence of land reclamation

Abstract

Estuary protection is a fundamental part of watershed management. However, land reclamation activities affect species distribution patterns and cause ecological degradation. To improve watershed management, we studied the distribution patterns of three typical salt marsh species and their interspecific interactions along groundwater table depth and salinity gradients using an index of Field Box Dimension and a Relative Interaction Index. We also simulated the groundwater gradient after two typical land reclamation activities, sea reclamation and embanking, after ten years. Our results showed that sea reclamation will change the location of the groundwater salinity peak along a land-to-sea transect and that there is no salinity peak after embanking. Vegetation distribution patterns also differed, from a zonal pattern (in salt marsh) to a mosaic pattern (after embanking). The decrease in the salinity gradient of the non-core area is an important cause for the differences we found in vegetation patterns.