Spatial variability of soil salinity in Bohai Sea coastal wetlands, China: Partition into four management zones

Abstract

Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0–30, 30–60 and 60–100 cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland.

Keywords::

• Bohai Sea coastal wetland
• soil salinization
• spatial variability
• management partition
• vegetation

Acknowledgements

Special thanks are given to the referees and the editors for their instructive comments, suggestions and editing of the manuscript.

Additional information

Funding

This research was funded by the Public Welfare Project of Marine Science Research [grant number 201105020], the National Natural Science Foundation of China [grant numbers 41171178 and 41171181] and the Public Welfare Project of Agriculture Science Research [grant number 200903001].