The Holzbauforschung Mainz and their partners made an active contribution to climate protection with the development of unused building material resources by upgrading a "problematic" hardwood range. The interdisciplinary team with different research focuses has set themselves a common goal: the development and provision of new raw material sources for high-quality building products in structural timber construction as part of the sustainable forest management and ecological forest conversion.

Forests cover a third of Germany's land area. They are valuable ecosystems, recreational areas and important suppliers of raw materials at the same time. Global warming is also affecting the forest ecosystem. Extreme weather events are already leaving clear traces. Increasing dry periods and extreme weather are affecting the stability, vitality and performance of the forest. In order for the forest to be able to provide its diverse ecosystem services such as wood production, filtering and storing groundwater, storing carbon and preserving biodiversity, management must be sustainable. By establishing the Forest Climate Fund, the Federal Government was underlining the importance of our forest ecosystems and the positive effects of sustainable forest management and wood use on climate protection.

The Holzbauforschung Mainz is also making an active contribution to this together with its partners as part of the joint research project GreenOakBuilding. In this project, an interdisciplinary team of scientists with their different research focuses on forest utilization and wood physics, construction and digital construction as well as wood-hybrid construction and wood mechanics have set themselves a common goal: the development and provision of new raw material sources for high-quality building products in structural timber construction as part of the sustainable management of our native forests and ecological forest conversion.

These resources include small-diameter logs from oak, which are economically uninteresting for the rapidly growing construction sector due to its growth characteristics and long rotation period until harvest. By combining traditional processes and knowledge of the forestry and carpentry trades with the latest results of component and material research, from field studies to non-destructive component testing with optical measurement value recognition to the validation of results from X-ray volume tomography, these previously unused hardwood assortments receive an "upgrade" to a sought-after renewable raw material via their digital twin and form an environmentally friendly, carbondioxide-storing and resource-saving alternative to the dominant mineral or metallic building materials. For test and demonstration purposes, a reference building in the form of a hall that can be used for forestry purposes has being built. The findings obtained will be checked and validated on the demonstration object. This is intended to create the basis for the use of small oak wood or similar assortments for higher-quality use in the construction sector in order to introduce the previously hardly used and problematic raw wood assortments to a multi-stage cascade use.

Today, it is in line with the ecological understanding of many people to use resources as efficiently as possible. This understanding is also the basis of the joint research project GreenOakBuilding. According to the 2020 logging statistics, a fifth of the timber harvest was either thermally recycled or not recycled at all. This also includes the "problematic" assortment examined here. Half of the total logging was carried out as damaged timber. The effects of climate change with long dry periods in previous years favored the rapid spread of the bark beetle with massive damage mainly to Norway spruce, Nordman fir and Douglas fir. One goal of ecological forest conversion is therefore to mix coniferous forest cultures with more resistant hardwood species. Perhaps the interdisciplinary research project GreenOakBuilding can make a small contribution here by using the necessary increase in the number of climate-resilient hardwood assortments sustainably in the coming decades and using modern classification methods as part of forest management to ensure long-term and high-quality use in construction.

Read the full story at Hochschule Mainz: Klimawandel als interdisziplinäre Herausforderung | ZEIT ONLINE (in German), or check out our project page GreenOakBuilding - Holzbauforschung Mainz  |  Timber and Plastics Research Group (holzbauforschung-mainz.de).