泉州滨海次生林不同结构植物群落的生态化学计量特征及土壤养分影响机制OA

Studying the correlation between plants and soil nutrients in coastal secondary forests from the perspective of plant community ecological stoichiometric characteristics helps explore the adaptive strategies of plants to the environment.Three plant communities with different structures in Quanzhou coastal secondary forests(arbor-shrub-herb mixed community(QGC),arbor-shrub community(QG),and arbor-herb community(QC))were selected as research objects.Their eco-logical stoichiometric characteristics and soil nutrients were compared and analyzed to explore the influence of soil nutrients on community ecological stoichiometric characteristics.The results showed that the ecological stoichiometric characteristics of plant communities with different structures exhibited organ-specific differentiation.The leaf nitrogen content of the arbor-shrub community(QG)was significantly higher than that of the arbor-shrub-herb mixed community(QGC).The fine root carbon and nitrogen contents of the arbor-herb community(QC)were significantly higher than those of QGC and QG,but its fine root phosphorus and sulfur contents were the lowest among the three communities.The soil carbon,nitrogen,and phosphorus contents of QGC and QG were significantly higher than those of QC.There were no significant differences in soil stoichiometric ratios between QC and the other two communities.Significant correlations existed between plant and soil eco-logical stoichiometric characteristics.In QGC,fine root nitrogen content was significantly positively correlated with soil car-bon content(P＜0.05),and leaf carbon-to-nitrogen ratio was significantly negatively correlated with soil nitrogen-to-sulfur ratio(P＜0.05).In QG,leaf carbon content was extremely significantly negatively correlated with soil carbon content(P＜0.01).In QC,the correlation between plant and soil ecological stoichiometric characteristics was weak,but the fine root carbon-to-nitrogen ratio was significantly positively correlated with soil nitrogen-to-sulfur ratio(P＜0.05).QG enhanced photosynthetic carbon assimilation efficiency by increasing leaf nitrogen content,while QC relied on a high fine root carbon-to-nitrogen ratio to achieve metabolic balance under low phosphorus stress,and the latter was co-limited by nitrogen and phosphorus elements.Soil nutrient accumulation was significantly affected by vegetation structure.QGC significantly im-proved soil carbon,nitrogen,and phosphorus contents through the input of litter diversity,and its lower soil carbon-to-phosphorus ratio indicated that litter turnover in the herb layer could alleviate the biological fixation of phosphorus.The in-hibitory effect of the saline environment on organic matter mineralization stabilized the ratios of carbon,nitrogen,phosphor-us,and sulfur contents in saline-alkali soil.Plant communities with different structures had the ability to adapt to changes in soil nutrients by adjusting their own ecological stoichiometric characteristics,and soil nutrient supply played a regulatory role in plant growth.