Forest expert: Climate change is changing European forests. We have to react.

„In Central Europe, forest is likely to recede in the lowest marginal areas but it will remain in most locations. However, there will be significant changes in the tree species composition, “ says Lukáš Bílek, Associate Professor from the Czech University of Life Sciences in Prague.

L. Bílek was one the panelists at the opening CLIMAFORCEELIFE conference in Bratislava, co-organized by WWF Slovakia. Conference focused on the future of the forest in Central and Eastern Europe and innovative management methods that can contribute to its preservation.

According to the EU Forestry Strategy for 2030 we can already see a shift in vegetation zones, the boreal/alpine forest is disappearing and the prediction assumes that the forests we know from the Mediterranean regions could eventually expand up to Hungary. How does climate change affect forests in Central Europe?

The change of climatic conditions is evident: temperature has been rising, precipitation regime is different, which does not always mean that the total precipitation has been decreasing, but rather the redistribution during the year has changed. Precipitation comes in a form of heavy rains and floods and these periods alternate with longer periods of drought. These extreme effects of the climate change are still more visible. These changing conditions are not favourable for our domestic tree species. They are more typical for Mediterranean climate in certain aspects. However, the change in conditions is happening much faster than the ability of plants and tree species to respond to it, e.g. by occurrence shift.

In Europe, the situation is even more complicated because the region is fragmented – there is a mosaic of smaller forests, not a continuum of forests across the continent from south to north. In such a scenario tree species migration would be easier. Mountains which stretch from east to west of the continent also create a barrier for an efficient movement of trees and plants from south to north. Hence we do not see a natural shift of the tree species composition yet. What we can see though, are the changing conditions. As foresters we can respond by changing the way we manage forests, including planting trees which are more suitable for the new climate conditions. This is what we call an assisted migration. If we do nothing, the change of tree species composition will occur only in hundreds of years.

The European strategy also analysed the species diversity in our forests.  52% of European forests consist of only 2-3 tree species, 26% of European forests consist of only one species while there are only 6% of forests that have more than six species. In Czechia and Slovakia it is the spruce which is dominant. How does it look across the continent?

We must distinguish between the composition of natural forests with no human interference and the composition of cultural forests which are a result of forest management practices in individual countries. Situation in natural forests changes across Europe according to climatic and soil conditions. In some parts of Europe, conditions allow forests to be naturally rich in tree species. In other parts, there are locations where natural development leads to the dominance of only a few or even just one tree species. These are e.g. the mountain spruce forests or the boreal forests in Scandinavia or the dominance of beech in moderate locations and pines in extreme locations in Slovakia. On the contrary, in places where soil and climatic conditions are altering or in alluvial forests, the tree species composition is naturally richer with 5-6 or even 10 species in place.

Obviously, it is different in cultural forests changed by human where the tree species diversity has been reduced mostly to only one because the forest management is much easier.

Which other aspects of climate change are changing our forests?

Another significant problem is the fragmentation which is even accelerated by climate change. Once the forest stands are fragmented, e.g. due to salvage logging, the thermoregulatory function of forests deteriorates and the landscapes start to overheat. Forests function as an “air conditioner” – solar energy falls on the forest surface, the forest draws water from the soil, water evaporates and thus  cools the entire ecosystem.

Change of climate conditions also shifts the occurrence areas of forest pests and pathogens. On one hand, there is a risk of the spread of new pests. On the other hand, there is also a threat that current pests can cause more damage, e.g.Ips typographus, typical spruce forest pest is now able to increase the number of its generations per year due to longer warmer periods.

Let’s talk about solutions. Within the CLIMAFORCEELIFE project, the innovative methods of forest management are being tested which may lead to an increase of forest resilience to climate change. There are three locations in Slovakia, among them the most challenging one is the pine forest in the south-west where the pine grows on sandy soil and the location is known for its high summer temperatures. What innovative methods are there to help the pine to stay there?

The south-western part of Slovakia (Záhorie) is a very specific region. There is no other area in Slovakia with such large pine forest stands. The pine occurs here mainly naturally but to a large extent there are many forest stands altered by humans although these were originally dominated by oak or oak in combination with pine. It is important to say that for pine forests clear-cut management is typical, which results from its biological requirements – pine is a light demanding species that is stress-resistant and can regenerate well on exposed soil where parent stand is fully logged-over.

However, climate change increases the extreme conditions in the region. During the hottest periods the surface temperature may rise up to 50-60 degrees! These conditions combined with lower precipition can lead to huge seedling losses. Therefore, we are trying to find alternative methods of pine restoration under a partial cover of the parent stands. And, of course, another goal is to change the species composition, especially return of oak trees into these forests.

In the presentation (video with presentation) at the CLIMAFORCEELIFE conference you were describing your experience with innovative approaches to the restoration of pine forests in the Czech Republic. What were your findings?

In the Czech Republic, we have several forest enterprises which have been already testing the new approaches for the last 20-30 years. Our team from the Czech University of Life Sciences in Prague entered this process to study the effects, the possibilities to go even further and the productive benefit of these management approaches.

In 2015, we also established an extensive experimental area together with Vojenské lesy a statky ČR (state military forest enterprise) to verify the effect of transition from clear-cut management to small-scale shelterwood regeneration methods. The first results are just coming. We see that such restoration of the pine is possible. It requires more wit, experience and enthusiasm from the foresters though. It’s a challenge for the forestry.

Many countries face forestry challenges nowadays. György Csóka from the Forest Research Center at Sopron University said at the CLIMAFORCEELIFE conference (video presentation): “forests cannot escape from harmful effects, we must help them there where they are – increase their resilience and stability. We have to manage forests but the main component must be the biodiversity growth, not just an afforestation.”

The solution should be perceived as a complex of different scenarios – one extreme pattern would be represented by plantations with fast growing non-native trees, which we harvest as soon as possible and then we plant them again. The other extreme would be a non-intervention management when we leave forests to self-management and our aim is to protect enough of the old growth forests where huge biodiversity is tied to. But there are lots of options between these two scenarios and it is important to take them into consideration and set up a strategic mix. And it is a political decision how to create this mix. Of course, there is a great deal of uncertainty but it is important to name the main risks and try to avoid them.

With growing efforts to replace plastics with natural materials and packaging, can we avoid plantations in Central and eastern Europe?

It’s hard to say, maybe we could avoid them for a while, but at the cost of importing wood over long distances, which would leave a large carbon footprint and we would not have control over what happens to natural resources in the logging areas. This is not a black and white topic.

It is true that so far in our country, the traditional forest management method has been oriented on quantity with maximum simplification of procedures and maximum efficiency and that is why we have large areas of monocultural and artificially restored stands. It is necessary to bring elements into these stands which are missing – larger species diversity, leaving more wood for natural decay, abandonment of clear-cut management, etc. We should make our forest management more ecological and it is important to set aside stands that should remain untouched. Creation of short rotation plantations on part of the agricultural land could also be considered as an option.

The EU aims to plant three million new trees by 2030 at places where they do not grow today. It is supposed to be “the right tree in the right place and for the right purpose“. How should this happen?

The declaration of the number itself sounds like a marketing declaration but the method of implementation is important. In the Czech Republic, the forester is obliged to restore the forest after it was harvested. There is now an ongoing discussion whether our minimum planting limits are not too high and if we don’t worsen the quality of the heavily forested stands. With our current approach, we can easily plant millions of trees and that’s why it is so important where and what trees we want to plant. It is important to plant the trees outside the forests in the agricultural landscape in order to consolidate the fragments of forest, to create larger forest units and to transform the agricultural landscape. Nowadays, agroforestry tries to combine both agriculture and forestry by growing trees in the landscape because it is essential for biodiversity, thermoregulation and erosion prevention.

EU forests should also store 350 million tonnes of carbon by 2030. According to some studies, the forest management methods can play an important role in achieving this goal.

I agree that it is possible to increase carbon sequestration by altering the forest management methods. We can achieve this by avoiding large-scale clear-cutting and trying to manage the forest in a way that would maintain the continuum of forest development. Close-to-nature forest management overlaps with climate-smart forest management because we fix carbon not only in the growing trees and in the “dead wood” but also in the soil. The principle of permanent land cover in the forest plays a crucial role.

But we also need to focus on what will happen to the carbon in the wood that is already harvested , try to produce long-lasting wood products and avoid using wood for energy purposes only. Also, using locally produced wood rather than  transporting it by car or ship over long distances is another aspect to consider.

Speakers at CLIMAFORCEELIFE conference several times mentioned that we have to increase the financial support for close-to-nature forest management. Professor Viliam Pichler from the Technical University in Zvolen in Slovakia said that there are financial mechanisms for agriculture but forestry is underfinanced. Radu Melu from WWF Romania (video presentation) said we need to admit that “a close-to-nature forest management is not profitable, we have to balance economic, social and environmental aspects and that will cost money. However, forests have also anothervalue than the price of wood. “

Close-to-nature forest management, especially the selective logging which is perceived as the superior type of this management, has been used by foresters in higher mountain areas with natural spruce-fir-beech stands mainly for economic reasons. Afforestation and expensive care of young stands is not needed with this approach, the forest regenerates without interference and just selected trees are harvested which should be ideally used for the production of long-lived products.

However, close-to-nature forest management may not be the most economically profitable everywhere and the question is how to motivate foresters to apply it. In the Czech Republic, there are several subsidy schemes for cultivation and harvest activities which are more expensive with close-to-nature forest management. The discussion is now about how to support non-productive forest functions. Society is more aware nowadays that the forest is not just a source of wood but it also helps to preserve biodiversity and has water management-, landscaping-, climatic and recreational function. The subsidies for these functions should not be automatically linked to forest ownership but they should be rather linked to premium approaches of ownership, e.g. when forest owner leaves the forest without intervention. This is already happening in protected areas.

Are you optimistic about the future of forests in our region?

I am counting with a scenario that is perceived as realistic. It is dramatic but still solvable from the forest’ point of view. In Central Europe, forest is likely to recede in the lowest marginal areas but it will sustain in most locations. However, there will be significant changes in the tree species composition, although it will still be possible to use wood as a sustainable source. It will require a more demanding maintenance though. And it will be necessary to change the way we perceive forests and understand that it also has other functions than just the wood production, particularly the ability of water retention in the country.

However, the future of our forests will also depend on rules and subsidy mechanisms for forest management practices set by politicians which should motivate forest owners to maintain forests in a shape that will correspond to climatic conditions.

Photo: Lukáš Bílek