The dynamics of C,N,P stoichiometry of dominant wetland plant in the East Dongting Lake before and after flood
Flood plays an important part in soil-plant nutrient cycling in wetland.C,N,P stoichiometry are critical indicators of biogeochemical coupling in ecosystems.To clarify the dynamic characteristics in leaf SOC,TN,TP,the stoichiometric ratio and the driving factors of dominant plant Carex brevicuspis,Triarrhena lutarioriparia in East Dongting Lake wetland and explore the status of the wetland nutrient utiliazation and restrict,we took the dominant plant Carex brevicuspis and Triarrhena lutarioriparia in East Dongting Lake wetland as study objects.This study measured the C,N,P concentrations,density as well as aboveground plant biomass before flood and after flood in 2018.Besides,we analyzed the seasonal dynamics of TC,TN and TP in relation to the biomass of Carex brevicuspis plant and the physical and chemical characteristics of soil.The results indicated that the biomass and density of Triarrhena lutarioriparia in pre-flooding period were significantly higher than that of the post-flooding period,while no significant difference was detected for biomass and density of Carex brevicuspis before and after the flooding period.During post-flooding period,the contents of organic carbon for Carex brevicuspis and the Triarrhena lutarioriparia leaves was significantly higher than that of the pre-flooding period.The TN of Carex brevicuspis in pre-flooding period was significantly lower than that of the post-flooding period,while the contents of TN and TP for Triarrhena lutarioriparia leaves in pre-flooding period were significantly higher than that of the post-flooding period.The content of TP in Carex brevicuspis leaves displayed no difference before and after the flooding period.C∶N,C∶P,and N∶P of Carex brevicuspis leaves showed no significant difference before and after the flooding period,while C∶N and C∶P of Triarrhena lutarioriparia leaves were significantly lower in pre-flooding period than that of the post-flooding period,but the N∶P was not significant different before and after the flooding period.The growth of Carex brevicuspis,Tiarrhena lutarioriparia tended to be nitrogen limited in the East Dongting Lake as indicated by the N∶P<14 in the leaves.The N∶P in plants of Carex brevicuspis,Tiarrhena lutarioriparia showed no significant coorelation with soil N and P.The results had important implications in the influence of flood on stoichiometry of typical wetland plants.
East Dongting Lakewetlandstoichiometrynutrient limitation
NETL
NSTL
万方数据
