Abstract:

Multiple-species nonlinear matrix growth model was developed for larch-spruce-fir forests using 20 long-term permanent plots with 5-year period observations in Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province, northeastern China. We found that mortality, upgrowth and ingrowth probability was significantly affected by medium of diameter class, stand basal area, biodiversity in terms of tree species and size, number of trees in minimum diameter class and elevation. The parameters of upgrowth, mortality and ingrowth models are estimated through ordinary least square(OLS) method and seemingly unrelated linear regression(SUR), but the differences in parameter estimate values between them were not significant. The model was validated in short term by comparing the observed with predicted number of trees in each diameter class and species group, and was statistically reasonable and subsequently was applied to predict timber yield, tree species diversity, tree size diversity, and aboveground carbon storage under 13 management scenarios in 50 years. The three single objectives are contradictory and should be compromised with the framework of multiple use management. The simulation results showed that the scenario with long cutting cycle(15 years)and low intensity(5 percent volume) could meet the needs of timber yield, protecting biodiversity and increasing carbon stock simultaneously. The simulation demonstrated that multiple objectives could be realized through reasonable forest management, and matrix model is a valuable tool for simulations of forest management scenarios.

Key words: larch-spruce-fir forests, matrix growth model, tree species and size diversity, above-ground carbon storage, harvest scenario