关键词: 生态化学计量, 土壤, 盐沼湿地, 理化性质

Abstract:

Ecological stoichiometry is an important means of studying the dynamics of energy flow and nutrient cycling in ecosystems， and is also one of the important fields of ecological research. This study focuses on the surface soil （0-20 cm） of Baidunzi Salt Marsh National Wetland Park in Jingtai， Gansu Province. Based on the distribution characteristics of 8 typical plant communities， 24 sample points were set up to collect soil samples and analyze the differences and correlations between the stoichiometric characteristics of soil organic carbon （SOC）， total nitrogen （TN）， total phosphorus （TP）， and total potassium （TK）. The aim is to reveal the soil ecological stoichiometry characteristics （SOC， TN， TP， TK， C/N， C/P， N/P， N/K） of Baidunzi Salt Marsh National Wetland Park and their relationship with community types and soil physicochemical factors， in order to provide theoretical basis and data support for the scientific management and ecological regulation of Baidunzi Salt Marsh National Wetland Park. The results showed that： （1） the average values of soil SOC， TN， TP， and TK in the study area were 8.20， 0.96， 0.21， 1.85 g·kg^-1， respectively； The mean values of stoichiometric ratios C/N， C/P， N/P， and N/K are 10.34， 52.96， 7.54， and 0.99， respectively； （2） There were significant differences （P<0.05） in the ecological stoichiometry of soil among different plant communities， with soil SOC content being highest in the Tamarix chinensis community and lowest in the Phragmites australis community； The soil TN content is the highest in the Salicornia europaea community， which is twice that of the Suaeda glauca community； The soil TP content in the Tamarix chinensis community is the highest， which is 4.50 times that of the Salicornia europaea community； The soil TK content in the Tamarix chinensis community is the highest， 8.8 times that of the Nitraria sibirica community； （3） There is a highly significant correlation （P<0.01） between soil SOC， TN， and TP content in the study area； （4） Redundancy analysis （RDA） shows that soil available phosphorus， pH， and aboveground biomass are important factors in explaining the variation of soil ecological stoichiometry characteristics， with a contribution rate of 68.1% to soil ecological stoichiometry characteristics. In summary， the soil SOC， TN， TP， and TK contents in the study area are lower than the average level of Chinese swamp wetland soil， indicating that the soil SOC， TN， TP， and TK contents in the study area are relatively scarce； There are significant differences in soil ecological stoichiometry among different plant communities， and soil available phosphorus， pH， and aboveground biomass are the main soil physicochemical factors affecting the soil ecological stoichiometry characteristics of Baidunzi Salt Marsh National Wetland Park； The soil N/P ratio was significantly lower than 14， indicating that soil TN content is the main factor limiting the growth of shrubs in wetland parks.

Key words: ecological stoichiometry, soil, salt marsh wetlands, physicochemical properties