Comparison of remote sensing based RFID and standard tree marking for timber harvesting

Forest inventory is the basis for creating forest management plan. In Europe, forest inventory data is usually collected manually by standard survey methods based on sampling procedures. The information from forest management plan to execute silvicultural and harvesting treatments is transferred to the field by standard tree marking methods e.g. marking spray, marking tape, chalk, bark blazer and plastic shim. A new computer-aided approach based on UAV (Unmanned Aerial Vehicle) and TLS (Terrestrial Laser Scanner) technology was developed to generate a 3D forest model, which replaces standard survey procedures and is the basis for tree marking with RFID (Radio Frequency IDentification)-tags. The goal of the developed survey and tree marking method was to increase timber harvesting efficiency in mountain forests by implementing a higher degree of mechanization, automation and intelligent technologies. The objective of this study was to analyse the practical applicability and the advantages and disadvantages of standard and innovative procedures as well as performing a comparison based on requirements, efforts and costs. For this purpose, tree marking was executed for a negative selective thinning in a forest stand in Austria. The costs for marking the trees with RFID tags amounted to 1.55 EUR per tree. In comparison to that standard tree marking of the same trees with spray by experienced forester amounted to 0.36 EUR per tree. The results had shown that the new tools were already applicable from a technological point of view, but efforts and costs are still high, especially survey costs. Therefore, further improvement has to be made to transform the innovative method into a marketable and competitive tool.