Carbon Stocks Of Harvested Wood Products In China

Forest harvesting and wood products utilization alter the natural carbon cycle between the forest ecosystem and the atmosphere. Carbon is released during forest harvesting and manufacturing of wood products and in using and discarding of wood products. Land use, land-use change and forestry (LULUCF) is necessary content of National Greenhouse Gas Inventory (NGGI), and harvested wood products (HWP) is an important part of the negotiation of LULUCF. In order to enhance the quality of LULUCF of NGGI and the understanding of the carbon stocks of HWP in China, this paper determines the carbon accounting factors such as basic density, carbon fraction and intensity of consumption and so on from released papers and field investigations, and measured the conversion factors of wood-based panels. This paper gives the definite scope of HWP in order to fair principle. Besides, the concept of carbon quality is firstly put forward and applied for evaluating the effect of carbon storage of HWP.Based on different classification of HWP and methodology suggested by IPCC, i.e. stock-change approach (SCA), production approach (PA) and atmospheric-flow approach (AFA), the carbon stocks of HWP was estimated firstly by using the stock-data methods and step regression methods. The uncertainty associated with carbon accumulation estimated in this study was evaluated with the Monte Carlo analysis, more specifically with the crystal ball software. Based on the use category, the forecasting methods of intensity of consumption of wood was applied for the prediction of different department consumption. And then carbon stocks of roundwood consumed from different industry was estimated by country-specific methods. In the view of the ultimate results and our national conditions, the stock change approach is more intuitive and would favor our country. Finally the paper analyzes the carbon dynamics and provides conclusions as followings:(1) The HWP is a significant carbon pool in China, and it is increasing. The carbon stocks of HWP consumed in industry and construction department is also increasing, and the growing trend was fluctuated during 1980-2000. The results, which estimated by SCA, is the highest among the three alternative approaches while the results of PA is the lowest according to the results of carbon accumulation and annual mean carbon stock-change. This mainly because China is the net import of HWP. The reduction potential of substituting action and prolonging life would be magnitude in China.(2) The difference of tree species results to the diversity of basic density and fraction of carbon. The average carbon fraction, basic density and moisture content in wood-based panels are 0.466, 0.67t·m-3 and 5% respectively. The carbon fraction of paper is 0.34.(3) If the lifetime is limited to less than 20 years, the carbon quality of HWP evaluation shows: construction formwork