Abstract:

Based on sixth and seventh national forestry inventory data of the six provinces,including Guangdong,Jiangxi,Guizhou,Shaanxi,Jilin and Beijing,the three methods(IPCC,continuous function for biomass expansion factor and weighted biomass regression model) were selected to estimate wood biomass in this paper. The estimation of the three methods were compared and analyzed from calculating process,method characters,repeatability and verifiability to stability of growth rate of biomass between two periods. The results showed the total biomass estimated by IPCC method with variable BEF2 was large, the total biomass estimated by IPCC method with constant BEF2 was small and the total biomasses estimated by continuous function for biomass expansion factor and weighted biomass regression model were middle. The biomass expansion factor derived from weighted regression model was most stable in the different provinces.Based on the seventh national forestry inventory data, the biomass expansion factors of various kinds of tree species derived from IPCC and the weighted regression model were more stable than the biomass expansion factors derived from continuous function method. The growth rate of biomass between two periods was the same regular pattern as the biomass expansion factors.

Key words: IPCC, continuous function for BEF(biomass expansion factor), weighted biomass regression model, forest biomass, estimation