Degeneration Mechanism Research of Suaeda Heteroptera Wetland of the Shuangtaizi Estuary National Nature Reserve in China

Abstract

Recently, Suaeda heteroptera wetland of the Shuangtaizi River Estuary national nature reserve in China degenerated seriously, and this has led to a decrease in the Saunders’ Gull population. In this study, the nitrogen, phosphor, organic matter and soluble salt contents in soil were determined, and the biomass(dry weight) and plant height were determined too aiming to explore the mechanism of degeneration of the Suaeda heteroptera population. The nitrogen, phosphor and organic matter contents in four types of wetland were all at D level and fertility degree was lower, It could be inferred that nutrients in soil was not the reason of degeneration of Suaeda heteroptera wetland. However, the soluble salt in mudflat soil reached as high as 2.51% in the spring and was significantly higher than that in other three types of wetland. This might be an important reason that the wetland degenerates into mudflat. We could conclude that the long time of no flooding and strong evaporation caused the increasing of salinity of soil and eventually cause the death of Suaeda heteroptera. In addition to human factors, the natural succession with the enlargement of new mudflat is one of the important reasons that make Suaeda heteroptera wetland disappear somewhere. The restoration measures must conform to the direction of natural evolution, otherwise, this restoration may be not sustainable.