Soil characteristics and ecological thresholds of Suaeda salsa wetlands

Abstract

Suaeda salsa is an annual euhalophyte, with a wide ecological amplitude and strong adaptability to environmental stresses, that is commonly found in estuarine wetlands. Soil properties of wetlands have an important influence on S. salsa growth. Therefore, knowledge of the soil ecological thresholds is valuable for the restoration of degraded S. salsa wetlands. The objectives of this present study were to analyze the soil physicochemical properties and evaluate the soil ecological thresholds in the typical degraded areas for S. salsa growth. Soil text components became coarser with increased sand contents and less clay contents, as the higher degree of wetland degradation. Meanwhile, the salt contents in different soil depths gradually increased with the increased degree of degradation of wetlands. Evident changes of soil water content, organic matter content, and cations (Na+, K+, Ca2+, and Mg2+) concentrations were not observed, while the concentrations of these factor was higher in the soil layer of 0–10 cm than those in the 20–30 cm. The soil pH in the 0–10 cm soil layer was lower than that in the 20–30 cm soil layer. The content of the three available nutrients in the soil did not change evidently with the increasing degree of degradation. The optimum thresholds of soil salinity and water content for S. salsa growth were 7.073–16.613 g/kg and 31.8–63.2%, respectively.

Keywords

• suaeda salsa
• soil characteristics
• ecological thresholds
• liaohe river estuary