Spatiotemporal heterogeneity of soil salinity after the establishment of vegetation on a coastal saline field

Abstract

Changes in plant community composition resulting from ecological restoration can affect the spatial pattern and variability of soil salinity. Understanding and quantifying the temporal and spatial heterogeneity of soil salinity is essential before decisions can be made about the cost-effective management measures for plant communities following restoration on coastal saline filed. In this study, we selected three types of vegetation and conducted soil bulk electrical conductivity (ECb) by a hand held device in the topsoil (0–20cm) at regular 1m intervals across the field over a year period. Conventional statistics and geostatistics were used to analyze the data. The results showed significant differences and high coefficients of variation in top-soil salinity among different vegetation types. Simple mean ECb comparison revealed that soil salinity varied from spring to winter and tended to be higher in autumn. The generalized semivariogram for soil salinity indicated that woodland possessed a much smaller effective range (1.9m) and nugget/sill ratio (7.37%) than that for other plant communities. Krigged contour maps showed different spatial distribution patterns among three types of vegetation and the consistently high and low salinity areas of the field at different seasons for the same vegetation. These results suggest that plant communities have significant influences on the temporal and spatial variability of soil salinity when vegetation is established in coastal saline field. The selection of plant species and management measures to plant should be special attention in the reclamation of saline land.