Natural Larch Forest Multifunctional Forest Management Simulation Research In Daxing’anling Mountains

Forests provide ecological, economic and socio-cultural services functions for human societies, and we should as far as possible take account of the multiple functions in the process of forest management. The object of this research is larch forest of Pangu Forest Farm, Tahe Forestry Bureau, Daxing’an Mountains of Heilongjiang Province. Meanwhile, considering the principle of larch forest economical-ecology service function,constract objective function. This study analyzes the impact of four forest management plans (thinning intensity of5%,10%,15%,20%) for economic services(timber harvesting) and ecosystem services(biodiversity and carbon storage). Under condition of making comprehensive target of economic services and ecosystem services maximized, the reasonable multifunctional management plan is proposed with considering the effects of different thinning intensity.The main results were as follows:(1) According to the permanented sample data of16natural larch forest which built in2011, established natural larch organs (stem, and root, and branch and leaf) biomass model, the goodness of fit test of this model is very well and settle the heteroscedasticity in the process of study. This model could well estimate natural larch organs biomass and could estimate the natural larch organs carbon reserves by combining the carbon cofficient.(2) The tree root carbon reserves is a part of the trees overall carbon reserves, but the former research neglected tree root’s carbon reserves, this will lead to greater biased estimation of the carbon reserves. In order to improve the accuracy of carbon reserves estiamtion in forest management, this research carried on the trees root carbon reserves estimation.(3) In oreder to reasonable choice of thinning wood, this research inroduced individual scale health assessment, stared thinning from the minimum health index until the cumulative accumulation reaches the corresponding volume of different intensities. This will provides more room for high health index forest to grow, and improving the health of overall state of forest stands.(4) Forest health index, stand average diameter and average tree height tend to increase with increasing thinning intensity, while tree size diversity and species diversity show opposite results. There is no obvious difference between different management plans.Tree species diversity is decreased with the increasing of the share of main tree species in forest stands, and almost no effect on species diversity under different management plans.(5) Choosing wood, carbon sequestration, biodiversity as an operational target builds comprehensive objective function, simulate the effect of the management plans and determined after a comprehensive analysis of optimal operation schemes of forest stands, thinning intensity,10%,5%, and20%forest, accounting for37.5%,43..75%, and6.25%respectively. This indicates that when operating in the multiple functions of forests, the low intensity is the best plans. Under optimal management conditions, the mean thinning number is375strains/hm2; the mean size diversity reduces0.1758; species diversity on average is0.0127; the mean stand DBH increased0.81cm; the mean stand height increases by0.65m; the mean timber harvest is12.3m3/hm2; the mean carbon storage is47.84t/hm2.