关键词: 择伐, 保留木, 损伤率, 模型, 油锯伐木, 针阔混交林

Abstract:

How to decrease the damage rate of residual standing trees in the selective cutting sites is quite important for forest land owners to reduce the wood production waste and to develop and utilize forest resources in a sustainable way. The damage rate of residual standings in a selective cutting site with conifer-broadleaved forest in Xiaoxing’anling Forest Region, which was caused by chainsaw felling operations, was studied through modeling analysis and case study. At first, after the theoretical system analysis for influencing factors according to data, the mathematical modeling(RDM)was established, which described the impacts of harvesting intensity(HI), the initial stands density(SD)and stem volume of each tree planned to be cut down(VTPC) to the damage rate of residual standing trees(DRRT)in the operation sites. Secondly the theoretical model was tested, verified and validated by a practical case study in Dongfanghong Forest Farm of Dailing Forestry Bureau in Xiaoxing’anling. The research results showed that the model(RDM)was valid with high correlation between two group data for describing DRRT and HI, SD and VTPC, e.g. one group from modeling simulation and another one from case study site survey. The results also indicated that DRRT was changed following HI in a parabola curve and following the time of SD and VTPC in a linear trend,and the three-dimensional(3D)curve surface for describing DRRT and HI, SD and VTPC was simulated according to survey data. The case study demonstrated that the loggers could decrease the DRRT around 9% by controlling the tree felling direction. At last the suggestions for reducing DRRT have been proposed according to the modeling analysis and case study results.

Key words: selective cutting, residual trees, damage rate, modeling, chainsaw felling, conifer-broadleaved forest