Abstract:

The wooden biomass flow and the non-wood biomass flow are two major material flows in a log harvesting production system. Field test was taken in fast growing plantations with three species of Pinus massoniana , Cunninghamia lanceolata and Eucalyptus in the northwest region of Fujian Province of China. Different parts of trees were dried and weighed as roots, trunks, branches, leaves and barks. The dry masses of bushes, herbs, dead branches and fallen leaves were measured as well. The percentage distribution of biomass in a felling area was calculated. Based on specific proccess of log harvesting operation, the material consumption and the waste for producing unit volume of logs were computed. The resource efficiency of trees and the semi-product consumption in different stage for unit final products were derived. A time and space network was established to show the time and space distribution of the wooden biomass flow and the non-wood biomass flow. With the application of network analysis method, the optimum operation scheme can be drawn out for minimizing wooden material waste and maximizing biomass residue at slash. Furthermore, the space distribution of wooden material and biomass at the slash, the skidding road and the landing area was revealed with the analysis of the network. The time and space distribution of the wooden biomass flow and the non-wood biomass flow reveals the important characteristics of the material flow in a log harvesting production system. The time and space network can be used to analyze the charateristics of the material flow in a log harvesting production system and related input and output efficiency. By combining the time and space network of the log harvesting production system with the geographic information system(GIS) in a logging area, a simulation and optimization tool for forest harvesting and regeneration operation system can be developed.

Key words: log, harvesting, skidding, biomass material flow, time and space distribution, network analysis