Study On The Productivity Of Chinese Boreal Forest Ecosystem Under Global Change And Ecosystem Service Assessment

Study on the Productivity of Chinese Boreal Forest Ecosystem Under Global Change and Ecosystem ServiceJiang YanlingAbstractValidated CENTURY model based on the observational data from Larix gmelinii forest, the boreal forest in China. And also simulated the dynamic of carbon cycle of Larix gmelinii forest. Simulated the impacts of global climate change on the biomass, productivity, and carbon sink capacity of Chinese boreal forest based on the predicted results of global change. And also predicted the impacts of natural factor (i.e. forest fire) and human activities (i.e. forest felling & litter removal) on the carbon cycle of Larix gmelinii forest. Developed an FID-based NPP model which reflected the growth of Larix gmelinii forest (i.e. age & volume). Evaluated the value of ecosystem services of the forests in China, and built the regress equation between ecosystem service and NPP. The main results list as follows:(1) The gross biomass of the boreal forest in China is 112.1 lt-hm"2, and its NPP(Net Primary Productivity) is 403.07gC'm"2'a~1.(2) Developed an FID-based NPP model for Larix gmelinii forest:NPP=(0.33181n(V/A))+0.4747)x30(l-e-?0009695E)It provided a method for estimating forest NPP based on forest inventory data(FID) and climate data.(3) Larix gmelinii forest ecosystem sequestered about 2.65 tons of carbon form the atmosphere per hectare per year and served as an important net carbon sink.(4) Doubled CC>2 in the atmosphere would increase the NPP of Larix gmelinii forest by 9.8%, and enhance its carbon sink capacity.(5) Elevated temperature would increase the biomass and NPP of Larix gmelinii forest and enhance its carbon sink capacity. The main restricted factor in this area is temperature but not precipitation.(6) Forest fire would decrease the biomass of Larix gmelinii forest. At the same time, fire could increase the NPP for it stimulated the regeneration and the growth of young trees.' The more the trees were burnt, the more thebiomass decreased, and the longer the restoration needed.(7) Regular forest felling was beneficial for the geneneration and the growth of young trees in Larix gmelinii forest. We could not only get direct economic benefits through forest felling but also maintain some ecological benefits.(8) Litter-removal stimulated the growth of Larix gmelinii forest in short time. But long-term litter-removal would make the soil barren and barren and unfit for the trees' growth.(9) The gross value of the ecosystem services of Larix gmelinii forest was about 2409.96><106US$-a~1. Its values of ecological and social benefits were 3.03 times as more as those of its economic benefits. This result reflects importance of forests' ecological and social benefits, ces.(10) Based on the Evaluation of ecosystem services of the forests in China, we built the regress equation between ecosystem service and NPP:Va=108.25xl06x(Tp)?93 It was helpful for simplifying the procedure of estimating the value of ecosystem servi...