南京市常见树种的含碳率特征与固碳能力OA

To scientifically select tree species with strong carbon sequestration capacity for afforestation and greening and to enhance the forest carbon sink in Nanjing,this study selected 20 common tree species in Nanjing as research subjects.The carbon content in various organs such as trunks,branches,leaves,and roots were measured,and the differences in carbon content among tree species and organs were analyzed.Meanwhile,the growth factors of tree species were investigated,and biomass was estimated based on allometric growth models to evaluate the carbon sequestration capacity of each species.The results showed that both tree species and organs affected carbon content(P<0.01).The carbon content of different tree species ranged from 40.64%to 49.75%,being the highest in Pinus elliottii,the second in Eucommia ulmoides(P<0.05),and the lowest in Ulmus parvifolia.The carbon content across different organs exhibited the pattern of trunks>branches>leaves>roots,and the carbon content in trunks was higher than that in other organs(P<0.05).The carbon content in the leaves,branches,and roots of Pinus elliottii was higher than that of other tree species(P<0.05).The biomass of broad-leaved tree species was generally higher than that of coniferous species,with Platanus acerifolia,Populus,and Pinus elliottii showing higher biomass than other species(P<0.05).The distribution of biomass among organs followed the pattern of trunks>branches>roots>leaves,with trunk biomass accounting for 39.92%to 73.66%of the total.The carbon sequestration capacities varied among different tree species(P<0.05).The average annual carbon sequestration of Platanus acerifolia was 32.85 kg·a-1,far exceeding that of other species,while Cunninghamia lanceolata had the lowest average annual carbon sequestration(1.43 kg·a-1).Tree species,organ biomass,and their interactions significantly affected tree carbon sequestration capacity(P<0.05).Therefore,future afforestation and greening efforts in the hilly areas of southern Jiangsu should prioritize tree species with high biomass and high carbon content and expand the planting proportion of such species to improve the carbon sequestration capacity of forests.Additionally,a mixed coniferous and broad-leaved forest model is recommended to balance carbon sink with ecological diversity.