Research On Carbon Sequestration Of Different Tree Species Based On Digital Tree-tray Images In Songshan Area In Beijing

Deforestation due to the construction of snowy roads,technical roads,and stadium facilities for the Beijing 2022 Winter Olympics and Winter Paralympics resulted in a reduction in the area of local forests and a loss of carbon sink capacity.For future ecological restoration,understanding the carbon sink capacity of common local species can be used for carbon offsetting and afforestation,Therefore,the image of tree-trees in the local tree species in Songshan was obtained for the analysis of the digitalization and carbon sink capacity of the tree plates.Image digitization was implemented in the process of tree-stemming,tree-sanding,tree-panning,image insertion,precision setting,and annual ring width measurement.Combining CAD measurement functions to realize high-precision digitization of the image of the tree disk(accuracy can reach 0.01mm).Based on the measured high-precision annual ring width data combined with the tree analytical analysis method,the above-ground biomass of individual tree trees was accurately calculated.Substituting the above-ground biomass data into the biomass inventory formula,the carbon stocks of common tree species at different growth stages were obtained.Because the research sample ages are mostly about 50 years,and every 15 years before and after the cents 1s a growth phase,the following conclusions are drawn about the carbon sink capacity of common local tree species:(1)The carbon sequestration capacity throughout the growth cycle:Betula dahurica>Juglans mandshurica>Populus davidiana in high altitude>Quercus mongolica>Ulmus macrocarpa>Populus davidiana in low altitude>Pinus tabuliformis>Tilia mongolica>Fraxinus rhynchophylla,The average annual carbon fixation of the large leaf wax is at least 1.62kg/a,and the annual average carbon fixation of the birch is 4.90kg/a.;(2)The carbon sequestration capacity in the early stage of growth:Quercus mongolica(10.85kg)>Ulmus macrocarpa(10.63kg)>Populus davidiana in high altitude(6.88kg)>Betula dahurica(5.30kg)>Fraxinus rhynchophylla(3.56kg)>Tilia mongolica(3.20kg)>Pinus tabuliformis(1.29kg)>Juglans mandshurica(0.88kg)>Populus davidiana in low altitude(0.41kg);(3)The carbon sequestration capacity in the medium stage of growth:Quercus mongolica(55.74kg)>Betula dahurica(52.24kg)>Ulmus macrocarpa(31.86kg)>Fraxinus rhynchophylla(22.57kg)>Populus davidiana in high altitude(20.39kg)>Tilia mongolicaC 19.30kg)>Juglans mandshuricaC 15.91kg)>Pinus tabuliformis(11.85kg)>Populus davidiana in low altitude(6.70kg);(4)The order of carbon sink capacity at the end of growth period is from high to low Birch(161.56kg)>High Altitude Area of Poplar(85.95kg)>Chinese Pine(73.53kg)>Walnut(65.75kg)>Large Fruit(39.95kg)>Large leaf white wax(38.53kg)>Mongolian cockroach(31.82kg)>Low-altitude area of poplar(23.09kg);(5)Inquire the Beijing carbon sink price to calculate the carbon sink value of the common tree species in Songshan.The study found that the carbon sink value of black birch and walnut was higher,reaching 0.24 yuan/year,and the carbon sink value of Mongolian oak and Chinese pine was low,at 0.08 yuan/year.,Songshan area plant carbon accumulation value of about 9 yuan.The study found that the digitization of tree-pan images can effectively improve the precision of annual ring widths measurement,thereby improving the accuracy of carbon sequestration,and can complete the calculation of carbon sequestration in small-scale.Tree species with excellent carbon sequestration capacity in Songshan area are Juglans mandshurica Maxim.and Betula dahurica,and it is recommended to use these two species constructing Shelterbelt in the northern Beijing.