Simulation of Forest Residual Position at the Cutting Area Using the Technology of Wood Harvesting with Branch Cutting at the Stump

Abstract

Introduction. A vast amount of forest residual is left in the course of timber cutting. The system of machines and  the processing sequence of  primary process of  commercial timber harvesting influence  the process of residual formation. Managing organization and technology of primary process , it is possible to  prepare forest residual  to their effective harvesting  at the stage  of commercial timber harvesting. The goal of the research is to  implement  the model of  distribution of branch timber  over the cutting area  by way of software. Starting position, assumptions, and methods of simulation. MS Visual Studio 2005 was used to develop the targeted software.  The offered software makes it possible to simulate distribution of a stand   and branch timber over the cutting area depending on felling direction of trees as well as to visualize  the results of simulation. Basic data are set in the software, they include number of trees in the cutting area, species composition, length of cutting area, swath width and width of trail, number of swaths, minimum distance between the trees,  tree diameter at  1.3 m height is set as distribution of random  value which follows the law of normal distribution. The possibility to find a tree  in this particular place includes the following conditions: the stand of the tree  is in the area of swath; the distance from the stand  of the tree to the stand of the nearest trees is no less the set minimum distance between the trees. The reference data are specified: dependence of stem height, tree weight, and fraction of total mass of the canopy on the stem diameter at 1.3 m height. The crown cover in a plane of cutting  for four species (pine, spruce, birch, aspen) are given. The simulative variants of cutting are offered. Results. The system makes it possible to simulate  the branch wood position if the  tree crown is  symmetric about the axis of the stem and the branches free fall on the ground. The system gives the possibility to show in graphic form the data of simulation  as the position of trees in the cutting area and the  density of branch wood, where different concentration of branch wood is reflected in color and it makes it possible to reveal the area of swaths with a certain number of residues (kg/m²). Conclusions. The system is a tool to analyze various  manufacturing situations,  it enables to reveal the zones of branch wood accumulation with the maximum density under various conditions, to analyze the amount of residues  which is viable for harvesting  and  to calculate possible  irrecoverable loss of residues  as secondary resource.