Development of a Multi-Attribute Spatial Decision Support System in Selecting Timber Harvesting Systems

Nacrtak Strategic and tactical decisions in timber harvesting planning have long-term consequences on the further development of forests. Decisions about harvesting activities are often based on intuition and the consequences of these actions cannot be determined exactly. A GIS based evaluation model was designed to support the timber harvesting decision making process. It compares harvesting systems and selects the best suitable system in consideration of stakeholder interests and environmental conditions. The developed model is made up of four stages. First, the area of interest is defined. Then, a technological evaluation of harvesting systems capability determines their compatibility with location factors. Only acceptable systems are included into the third stage, the utility analysis. Using evaluation criteria, it transforms them into comparable values and ranks these values. The last stage of the model provides a metric that estimates consequences of different treatment scenarios. The main processes have been automated in ESRI® ArcGIS by using ModelBuilderTM extension. The model has been demonstrated in a 1100 ha sized forest enterprise in steep terrain in the South of Lower Austria. One scenario determined the possible benefits of implementing »cable forwarders« as new harvesting technology. Five of seven criteria could be improved; including a reduction of stand damage by 2 percent points and an increase of contribution margin from 40 to 46 /m3. Improving forest road network generated a positive effect on productivity and fuel consumption, but the overall economic benefit was too low to recommend the construction of the road. The model suggests that a combination of increasing forest road density and technology improvement could lead to tripling productivity, increasing contribution margin from 40 to 56 /m3 and lowering the damage rate by 53% and injury rate by 93%. This example shows that this SDSS can help the user to determine the best suitable alternatives.