Study on carbon density and its dynamic change of forest types in Huanglong Montain Forestry Region

【Objective】 This paper calculated the carbon storage and density in Caijiachuan forest farm in Huanglong Mountains,which would provide reference to research the function of forest carbon sink in this area.【Method】 The research built the regression equation of biomass and volume and analyzed the relationship between biomass and carbon storage,carbon density of different forest types,with the forest resource inventory data for management.This paper also calculated and analyzed the carbon storage and density of main forest types(including Cypress,Populus,Betula,Quercus,Pinus tabulaeformis,Nonmerchantable woods) in this forest farm,and compared with the carbon density of the same forest types in whole country and five provinces in northwest of China.【Result】 In this forest farm,the average carbon storage was 387 740 t and the average carbon density being 17.7 t/hm2 in 1997 and 1986;The total carbon storage decreased by 9.65% and the average carbon density increased by 3.38% in 1997 compared with that in 1986;The average carbon density of main forest types was in the order of oaks(28.06 t/hm2),Chinese Pine forest(24.35 t/hm2),Birch Forest(21.04 t/hm2),weed tree forest(11.86 t/hm2),Cupressus funebris forest(11.03 t/hm2) and Poplar forest(10.04 t/hm2).The average carbon density of main forest types was in the order of near-mature forest(25.56 t/hm2),young forest(25.49 t/hm2),medium forest(24.77 t/hm2),mature forest(13.53 t/hm2),and over-mature forest(12.84 t/hm2).【Conclusion】 This forest farm had good ability in carbon sink,but the change of the ability of carbon sink was not significant in 1986 and 1997;The ability of carbon sink was different among different ages and types of forest.Protecting and managing oaks,Chinese pine forest and birch forest well and carrying out the management and forest tending of young forest,medium forest,and near-mature forest contributes greatly to carbon sink in this forest farm.