Foresters exploring the Rosskopf Marteloscope in cooperation with ConFoBi researchers
by Bettina Joa
ConFoBi (Conservation of Forest Biodiversity in Multiple-Use Landscapes of Central Europe) is a research project of the University of Freiburg and the Forest Research Institute Baden-Württemberg (FVA) that focuses on the effectiveness of structural retention measures for biodiversity conservation in multi-functional forests. Researchers work in a common pool of 135 study plots located in the Black Forest. In the course of ConFoBi’s yearly information event for foresters managing those forest areas that contain one of the 135 plots, a Marteloscope training exercise was conducted with 10 foresters from Forst-BW.
Frank Krumm (Swiss Federal Institute for Forest, Snow and Landscape Research WSL) and Andreas Schuck (European Forest Institute) introduced the Marteloscope concept as a training tool for thinning exercises revealing common challenges and trade-offs in integrative forest management. Marteloscopes are one hectare forest sites where all trees have been numbered, mapped and measured. With the help of the “I+”software that runs on mobile devices, trees can be virtually harvested and retained. Thereby the results of the individual tree selection, namely the ecological and economic consequences, can be immediately displayed, initiating discussions as well as learning processes.
The training exercise on March 22nd took place at the Rosskopf, which belongs to the Freiburg City Forest. The Rosskopf Marteloscope comprises of a multi-layered, about 105 year old stand, consisting mainly of silver fir, beech and Douglas fir. Some of the Douglas fir trees having reached the target diameter of 100 cm, were already harvested in the course of past management operations.
During the exercise, the foresters worked together in 2-person teams. They had been given the task (1) to harvest 30m³ Douglas fir having reached the target diameter, (2) to remove 20m³ beech with the aim of supporting Douglas fir regeneration and (3) to retain 10 habitat trees, ideally showing ecological valuable microhabitat structures. While trade-offs and different decision options were already intensively discussed during the one-hour thinning exercise within the teams, the final discussion with all 10 participants went even more vivid. When asked to present their decisions for specific trees, participants gave very different, yet comprehensible justifications for either retaining, harvesting or leaving the tree.

The results of the exercise confirmed that there are diverse approaches to effectively integrate conservation objectives in forest management. Thereby, individual strategies may both be influenced by different goals and preferences, stand and landscape structures, background experiences and maybe also by a pinch of gut feeling. To make oneself more aware about this, Marteloscope exercises can be very illustrative and may even stimulate changes of perspective.
Even after spending a whole afternoon in the “forest classroom”, there is still much to discuss and learn about integrative forest management. Thus, this will certainly not have been the last ConFoBi Marteloscope exercise.
