Characteristics and Response of Soil-leaf Ecological Stoichiometry of Suaeda Microphylla and Apocynum Pictum Under Different Salt Habitats

Abstract

[Objective] The change trend and main limiting factors of the ecological stoichiometric characteristics of soil and leaves in different saline habitats were analyzed in order to provide basic research data for the study of nutrient limiting factors and adaptation mechanisms in the growth and development of halophytes in arid areas, and to provide references for ecological conservation and restoration of desert plants. [Methods] The euhalophyte Suaeda microphylla and the pseudohalophyte Apocynum pictum were selected from Ebinur Lake Wetland National Nature Reserve. Soil pH value, water content, salinity, available phosphorus, ammonium nitrogen, organic carbon, total nitrogen, total phosphorus, plant leaf organic carbon, total nitrogen, and total phosphorus were measured in the selected halophytes. The relationship between the ecological stoichiometry of the leaves of the two plants and the soil of their habitats was analyzed to investigate the soil limiting factors on the ecological stoichiometry of plant leaves. [Results] ① Soil phosphorus decreased with increasing salinity, organic carbon, nitrogen, and stoichiometric ratio showed an increasing trend. Salinization degree had a significant effect on soil nutrient content; ② Leaf nitrogen for the two plants was significantly affected by soil salt, and showed a decreasing trend with decreasing soil salt content, which was consistent with the change trend of soil nitrogen content. The mean value of leaf N/P was less than 14, indicating that both plants in the study area were limited by soil nitrogen content. [Conclusion] There were differences in the coupling relationship of soil-plant ecological stoichiometric characteristics among different types of halophytes. The euhalophyte S. microphylla was mainly affected by soil pH value and water content, while the pseudohalophyte A. pictum was mainly affected by soil phosphorus and ammonium nitrogen content.

Keywords

• ebinur lake
• ecological stoichiometry
• saline plants
• salt stress
• limiting factors