It could prove to be a valuable tool in the assessment of forests managed according to the principles of close-to-nature forestry.
Martelloscopes are areas, typically 1 hectare in size, in the forest where the height and diameter of all trees are recorded, along with other parameters such as tree species and indicators of biodiversity. All data is entered into a programme that allows the simulation of thinning interventions or the designation of eternal trees. For example, it is possible to assess the value of felling a tree or leaving it standing.
In Denmark, we now have 4 martelloscopes, and the establishment is the work of Thomas Nord-Larsen, Andrew Stratton, and Prescott Huntley Brownell from the Department of Geosciences and Natural Resource Managment IGN, which is a partner in LIFE 4forest. The martelloscopes are used in teaching and collecting new knowledge about forestry and biodiversity.
What Is a Martelloscope?
In 1 hectare of the forest, all trees are numbered with a small metal sign, mapped, measured, and scored in terms of the tree's value and its content of microhabitats. In other words, there is a piece of forest where you know the entire standing timber volume, the value of the tree, and have a measure of the potential biodiversity value of the trees.
The economic value is an assessment of what each individual tree can be used for - the yield - and the local prices.
The biodiversity value is scored based on a registration of microhabitats on the tree, such as holes or damage to the tree, witch's brooms, and fungi. Rare microhabitats, which take a long time to develop, score higher than more common ones. Microhabitats are defined in a catalog published by the European Forest Institute, EFI.
Combined in an App
Information about each martelloscope is stored in a program and made digitally accessible. So, with a tablet or smartphone, you can simulate different types of thinning in the forest and see the consequences in terms of the amount harvested, expected value, and loss of microhabitats.
Information about each martelloscope can be downloaded from the and installed on any mobile phones or tablets with an Android operating system.
4 Martelloscopes in Denmark
The LIFE 4Forest project has funded two martellockopers: one in Rold Skov and one in Løvenholm. However, it was originally two students who brought the concept to Denmark.
While on a study trip, they encountered the martelloskop in the Schwartzwald in Germany and found it so interesting that they brought it back with them. As part of their thesis, they established two martelloscopes, one at Salten Langsø and one at Stenholt Vang.
Measuring the Climate Effect of Logging
The first two martelloscopes in Salten Langsø and Stenholt Vang were part of a thesis. It involved establishing the two mentioned martelloscopes and developing a concept for how climate could be included as a third dimension in decision-making in forestry.
Climate Effect of the use of Wood
The climate calculations are based on the distribution of each tree's carbon content, expressed in CO2 equivalents. The climate effect of felling the tree depends on its use ie. distribution to different assortments - i.e., the wood products that can be created from the tree - and how these individual assortments are used in different wood products.
The climate effect then depends on how quickly wood products are consumed and which products the tree replaces. For example, paper is consumed quickly, while a beam in a house can last for many years before being burned after use. At the same time, the tree in a building potentially replaces climate-expensive materials such as concrete and steel and can have a significant climate benefit.
By also taking into account the trees' absorption of CO2, resulting from their growth, the so-called "Carbon Parity Time" is calculated - a measure of how long it takes from the tree is removed from the forest and thus emits CO2 into the atmosphere until the total climate impact of the intervention becomes less than if the tree had been left standing.
In this way, the students' thesis has shown the way to introduce an additional dimension to forestry: the climate effect of wood use. Thus, martelloskopes can contribute to finding scientific answers to whether the cultivation of forests according to close-to-nature principles can result in a smaller climate footprint, for example, due to a persistent forest cover.
117 Martelloscopes Across Europe
Martelloscopes and the accompanying software were developed as part of the Integrate+ project at the European Forest Institute (EFI). A total of 117 martelloscopes have been created across Europe. So, you can visit different parts of Europe and conduct thinning exercises in a variety of forest types.
Information about each martelloscope can be downloaded from the Integrate+ and installed on any mobile phones or NotePads with an Android operating system.
Do You Want to Try It Yourself?
As part of the grant, IGN has purchased 10 NotePads and installed the software needed to simulate forest treatment. If you are part of a group interested in forestry, you can borrow them by contacting Thomas Nord-Larsen (tnl@ign.ku.dk).
Written by Janne Bavnhøj