FAQ

How much wood can we harvest in the future?

Andreas Bolte, Karsten Dunger, Joachim Rock | 09.03.2026

WO Institute of Forest Ecosystems

The WEHAM baseline scenario uses recent data to simulate how Germany's forests could develop over the coming decades. This FAQ explains implications of the results and limitations of the projections.

A close-up of a tree trunk with annual rings, with a pile of wood in the background. — Researchers use WEHAM to simulate how Germany's forests could develop.

What would happen if more hardwood than softwood is used in Germany in the future? How would the expansion of protected forest areas alter timber volumes and harvesting rates? How can we adapt forests in the best way to climate change? Possible answers are provided by the Thünen Institute's Forest Development and Timber Supply Modelling (WEHAM).

Using data from the fourth National Forest Inventory (NFI) carried out in 2022, researchers simulated how forests and timber supply could develop over the next 40 years. The model allows, e.g. to estimate the growth of individual trees, the effects of forestry interventions, natural mortality, and the regeneration of forest stands.

WEHAM was developed almost 30 years ago and has been continuously improved and adapted to new requirements ever since. In our FAQ, we explain what conclusions can be drawn from the results and what they mean for forestry in the coming decades.

The WEHAM baseline scenario shows how forests in Germany could develop if growth conditions remain the same and the expected forest management is implemented. This includes, for example, the conversion of pure spruce stands to mixed forests.

The assumptions used in the simulation are determined by experts from the federal and state governments. The assumptions reflect how forestry is likely to operate under current guidelines and management plans.

The WEHAM baseline scenario does not provide predictions for the future of forests, but merely a reference for possible utilisation scenarios. On this basis, researchers can compare the results of other scenarios, such as increasing storm damage or changes in management, and assess their consequences. This allows appropriate recommendations for action to be derived for policy-makers and forestry.

We cannot predict exactly how the climate in Germany will develop. It therefore remains unclear when and which damages will affect forests. A realistic baseline projection that includes various interacting disturbance agents is therefore not possible.

WEHAM provides the projected raw wood potential, i.e. the amount of wood that can be used if the management assumed in the scenario is fully implemented. However, experience shows that the amount of wood harvested is never as high as it could be in theory.

The scenario for the next ten years shows that an average of 88 million cubic metres (solid cubic metres/Efm) of raw timber will be available annually. This is about 21 per cent more than the actual use from 2012 to 2022, as recorded in the National Forest Inventory.

The actual raw wood potential utilised in 2022 is lower than the projected potential up to 2062.

No, because the baseline scenario assumes ideal conditions in which forestry operations and forest owners can fully implement their planned uses. For example, the WEHAM baseline scenario for 2012 showed a high raw wood potential of around 84 million cubic metres (m³) per year for the period 2013 to 2022. The actual volume harvested between 2012 and 2022, at 73 million cubic metres (m³) per year, is 13 per cent below the raw wood potential calculated in the model. The past shows that the raw timber potential has rarely been made full use of. At the same time, the potential has even been exceeded in certain regions or for individual tree species or age classes. One reason for this was the additional spruce wood produced as a result of prolonged drought or bark beetle infestation.

Market demand for timber determines how much forest wood is sold and at which price. Medium trunk diameters of 20 to 50 centimetres are particularly in demand, as current timber industry production is geared for these sizes. On the other hand, there are hardly any buyers for large-diameter timber.

Another challenge is the high proportion of small-scale private forests: about 25 per cent of forest areas in Germany belong to approximately 1.8 million private forest owners, who own less than 20 hectares of forest each. These forests are often only managed to a limited extent, as many forest owners only use the wood for their personal needs, have little access to the technology and logistics required for felling, or live far away from their forest. As a result, less timber is sold than would theoretically be available.

However, forests are not only sustainable sources of raw materials. They also store large amounts of carbon, promote biodiversity and serve as recreational areas. Society's expectations of these so-called ecosystem services are constantly increasing.

Spruce trees with a medium trunk diameter are particularly in demand.