Assessment of Carbon Sequestration Capacity and Carbon Offsetting Effect of Arbors in Urban Green Spaces
The quantitative measurement of carbon sequestration capacity and carbon offsetting effects of trees in urban green spaces can provide supports for the decision-makings on tree species'selection and configuration in forest city building.With high-definition satellite remote sensing image and relevant economic and social statistical data,combined with the data from field investigations,the paper uses the method of biomass model to calculate the carbon sequestration capacity of landscaping trees in the urban area of Nanchong,based on which the interactions of community structure and carbon sequestration capacity are explored,and also analyzes the effects of carbon offsetting the emission of the energy sector in the city.The results show that:1)There are 269 species of woody plants in the green spaces of the urban area of Nanchong,belonging to 163 genera in 76 families.The 10 tree species with the highest presence are Osmanthus fragrans,Ginkgo biloba,Ficus virens Aiton,Cinnamomum japonicum,C.camphora,Prunus serrulata,F.concinna,P.cerasifera,F.atropurpurea,Acer palmatum Michelia×alba;2)The average density of forest stands in various green spaces is 677±425 plants·hm-2,with an average diameter at breast height at 21.01±7.15 cm and an average tree height at 8.52±2.06 m;3)The average carbon density of the trees in green spaces can be ranked as square＞affiliated green spaces＞park green spaces＞protective green spaces.Affiliated green spaces have the highest carbon sequestration rate(2.54 t·ha-1·a-1),while the lowest is in park green spaces(1.64 t·ha-1·a-1);and 4)The amount of carbon sequestrated by the trees in green spaces in the urban area of Nanchong City in 2020 is 9 347 t,and the total energy-related CO2 emissions are 1 016.55×104 t,which means that the trees in green spaces approximately offset 0.09%of carbon emitted by urban energy use.It is suggested that Nanchong should prioritize the mixed use of multiple tree species in its building of urban forest,and the tree community density should be adjusted in a timely manner to optimize the forest structure,improve habitat conditions,promote the growth of trees,and thereby enhance the carbon sequestration capacity.In addition,close-to-nature and extensive management methods should be adopted as much as possible to reduce the carbon emission.
urban green spacearborcarbon densitycarbon sequestration ratebiomassNanchong city
NETL
NSTL
万方数据
