| In order to protect the unique ecological environment of Yuncheng Salt Lake,the city of Yuncheng in Shanxi Province has launched a project to "return salt to the lake",while scientifically assessing and identifying the role of salt lake wetlands in carbon neutrality.In order to explore the carbon sink background and potential of Yuncheng Salt Lake Wetland and enhance its ability to adapt to climate change,sampling and analysis of vegetation,soil and sediment of the Salt Lake Wetland were carried out from July to November 2022.Weigh the dry weight of vegetation,determine the organic carbon of vegetation,soil and sediment,soil total nitrogen and soil total phosphorus.Landsat 8remote sensing images of the salt lake wetlands were used to pre-process for radiometric calibration,atmospheric correction,image cropping.Extraction of Landsat 8 remote sensing image feature information of the study area,including band selection,vegetation index,principal component analysis and texture features.Based on the correlation analysis of remote sensing image feature information and actual measurement data,and the construction of relevant multiple linear regression estimation models,the vegetation biomass,vegetation carbon stock,soil carbon stock,sediment carbon stock,total carbon stock and their economic value of the salt lake wetland were estimated.The technology of carbon fixation and sink enhancement is put forward from three aspects: vegetation,soil and microorganism.Finally,the countermeasures and suggestions of wetland management to adapt to climate change,reasonable protection and development are put forward.The results show that(1)In the correlation analysis between the feature information extracted from remote sensing image data and the measured vegetation biomass,the wetland vegetation biomass estimation model constructed with four independent variables,namely Ratio Vegetation Index(RVI),Normalized Diference Vegetation Index(NDVI),Mean(ME)and Second Principal Component(PCA2),is the best,and the vegetation carbon density estimation model can be obtained by multiplying the vegetation biomass by the vegetation carbon content.The model accuracy and test results meet the requirements and the modeling effect is good.(2)In the correlation analysis between soil organic carbon influence factors and measured soil organic carbon content,the soil organic carbon content model with two factors,vegetation above-ground biomass(AGB)and total soil nitrogen content(STN),is more effective,and the soil organic carbon density estimation model can be obtained by substituting average total soil nitrogen,average soil bulk and soil layer thickness.(3)The sediment carbon stock can be calculated based on the average content of organic carbon in each sediment layer measured and the sediment capacity.(4)At present,the total carbon stock in the Salt Lake wetland is about 4.133-11.141 Tg C,and the total carbon stock value is about3.968-10.69 billion yuan;the carbon sink potential of the Salt Lake wetland can be increased from vegetation carbon sequestration and sink technology,soil carbon sequestration and sink technology,and microbial carbon sequestration and sink technology.(5)The main countermeasures for adapting salt lake wetlands to climate change include exploring effective measures to deal with major threat factors,improving the protection and compensation system for salt lake wetlands,strengthening legislation and management of salt lake wetlands,increasing funding for wetland protection and research,and strengthening education and international cooperation on salt lake wetlands.In conclusion,the salt lake wetlands vegetation,soil and sediment have a large carbon sink capacity.However,as the climate warms,it faces the risk of increasing evaporation and shrinking lake surface.In order to adapt to the climate change trend,we should actively explore the carbon sink potential and strengthen the reasonable planning and protection of the salt lake wetlands. |
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