Correlations between the distribution of salt-tolerant plants and soil chemical factors in wetland of Tianjin Coastal New Area, northern China

ObjectiveTianjin Coastal New Area wetland of northern China has rich resources of salt-tolerant plants. These salt-tolerant plants can not only enrich the species of landscaping plants in salinity area, but also provide a theoretical basis for the ecological restoration of saline soil. Through the investigation of salt-tolerant plant resources and the analysis of soil chemical properties in this area, the correlations between salt-tolerant plant distribution and soil properties can be revealed.

MethodThe species data and environmental data of 74 sample plots in Tianjin Coastal New Area wetland were selected to study the relationship between salt-tolerant plant diversity and soil chemical factors (pH, the total amount of soil soluble salt, TN, TP, SOM, K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, HCO₃^-) by one way ANOVA, two-way indicator species analysis, canonical correspondence analysis.

ResultA total of 80 species, 65 genera and 34 families of salt-tolerant plants were investigated in Tianjin Coastal New Area wetland. The species number in the top three of dominant families were Compositae, Gramineae and Chenopodiaceae, and the important value and frequency of occurrences of Phragmites australis were the largest. The life type of salt tolerant plant in this area is mainly herbs; the abundance of salt-tolerant plants in the supralittoral zone wetland was much larger than the intertidal wetland; The community of the study area can be divided into 4 plant community types: Salsola komarovii-Messerschmidia sibirica+Suaeda salsa, Phragmites australis-Suaeda glauca+Setaria viridis, Echinochloa crusgalli+Suaeda glauca-Polygonum lapathifolium, Scirpus planiculmis+Typha angustifolia-Suaeda glauca; the total amount of soil soluble salt, total nitrogen and water soluble salt ion contents is the key soil environmental factors affecting the distribution of plant species. There was a significantly negative correlation between the diversity index of plant community and the total amount of soil soluble salt (including Na⁺, Mg²⁺, Cl^-, SO₄^2- and HCO₃^-).

ConclusionThe distribution pattern of plant species determines the distribution pattern of plant community types to a certain extent, The higher the contents of soil salt and soluble salt ions are, the lower the species diversity indexes are, the greater the impact on the species diversity is.