Great hopes are being placed in the forest to provide the raw materials that are needed for us to transition to a fossil-free society with a bio-based economy. Global Sustainable Development Goals concerning the environment as well as Sweden’s Environmental Quality Objectives set requirements for better governance and planning, and for economical use of resources.
In addition to today’s production of material for timber and paper manufacturing, we also see that the forest can help to save the climate, both through providing more bioenergy and by helping us to take up and sequester carbon from the atmosphere’s carbon dioxide. The sequestration occurs because trees build the carbon into their biomass when they grow. The trees in the forest may in the future also be processed into many other products that are currently made from oil.
“The forest is under strain from many directions”, says Cecilia Akselsson, researcher at Lund University’s Department of Physical Geography and Ecosystem Science. “If the pressure is increased on extracting forest biomass there can be a considerable impact on the environment, for example on biological biodiversity, soil chemistry, water quality and long-term productivity. There is a risk that different environmental and sustainability targets may conflict with each other. An example of such a conflict that can arise is between the production of bioenergy, the preservation biodiversity and the conservation of forests that we can use and enjoy.”
The forest as raw material producer
In economic terms, the forest has considerable significance in Sweden. According to the Swedish Forest Agency, just over half of the land area is used to some extent to produce timber and wood for pulp. However, it is already the case that traditional forestry is not only creating benefits, but leading to potential conflicts.
Of the 16 Environmental Quality Objectives decided by the Swedish Riksdag, six clearly apply to the forest. These are: Sustainable Forests, A Rich Diversity of Plant and Animal Life, Natural Acidification Only, Zero Eutrophication, A Non-Toxic Environment and Reduced Climate Impact.
To increase production, perhaps more forests need to be fertilised, which can result in an increase in nitrogen leakage from forestry land. Further intensification of forestry also means that more driving is required in the forest, leading to the risk of increased driving-related damage. This damage in turn leads to nutrients – carbon in the form of decomposed plant material – and toxins in the soil being released through erosion and discharged in run-off rainwater into watercourses and lakes.
The forest and climate – what is the net effect?
A hotter climate can entail that the forest grows more and production increases. This increased growth in the forest may help us to achieve the global sustainable development goal Climate Action. By storing more carbon in the form of biomass in growing forests and in the soil, the uptake of carbon dioxide from the air increases. However, a changed climate can also counteract such a production increase through a rise in damage to forests due to storms, drought and insect attacks.
Climate change is the reason why we are striving to reduce the use of fossil fuels and there is demand for renewable energy biomass. This has meant that the extraction of residual forest products such as branches and tops has increased over the past 15–20 years. This trend, however, may also have environmental consequences and Cecilia Akselsson and her colleagues have shown, among other things, that the acidification effect from forestry increases due to this increased extraction. This makes it more difficult for us to achieve the environmental quality goal Natural Acidification Only.
The degree of help we can obtain from the forest in terms of removing carbon dioxide from the atmosphere and storing carbon in trees’ biomass depends ultimately on both the climate’s direct effects, such as changes in temperature and humidity, and on other indirect effects, such as changes in how much forest is felled and the amount of residual forest products that are extracted.
“At present, it is difficult to assess what the net result of carbon sequestration will be”, states Cecilia Akselsson.
Weighing up production and environmental goals
It is clear then that you cannot think solely about how much the forest can produce – other ecosystem services and environmental goals must also be considered. Cecilia Akselsson, as part of work for the Swedish Energy Agency, has calculated the effects of increased extraction of branches and tops. The aim was to use the results from models and experiments to identify the extraction level of residual forest products that would provide the greatest energy benefit while not adversely affecting conditions for achieving the Swedish environmental quality objectives.
“Our assessment was that the highest extraction that would not have adverse effects on environmental quality objectives was extracting branches and tops from half of all cleared areas and an extraction of stumps from one in five cleared areas. However, it is only sustainable to take out so much if the rules and recommendations are followed. We already know that often the recommendations are not adopted and that it’s difficult to follow up if they are adopted.”
The forest is an important resource and is to continue to be so in the future
“The figures we arrived at for the proportion of cleared areas that can be used for extraction of residual forest products is a good start”, continues Cecilia Akselsson, “but then you have to consider how to plan for large areas of extraction, so that planning is not restricted to each individual site, but is seen as a part of the overall landscape.”
How can we obtain a sustainable agriculture landscape?
Cecilia Akselsson has now shifted the focus of her research from obtaining more exact figures on the environmental effects of forestry to working with the forest as a part of the overall landscape. Among other things, a so-called landscape perspective makes it easier to study how water quality and biodiversity changes over time, as both are affected by specific types of land, how they are managed and how they integrate with each other in the landscape.
In a new research project, Cecilia Akselsson wants to study how forestry and agriculture can be managed in a way that is optimal for the ecosystem services that are affected. What can be done so that researchers’ recommendations are actually implemented? Cecilia Akselsson plans to acquire more knowledge on these issues by collaborating with legal experts and political scientists.
“At present, it is difficult to plan from a landscape perspective – it is not possible to demand that landowners adapt because a neighbour has used their land in a certain way. I believe that there will be a need for some sort of policy instrument for this, something that encourages forest owners to adapt forestry to enable environmental and sustainability goals to be achieved.”
“The forest is an important resource and is to continue to be so in the future”, concludes Cecilia Akselsson. “But at the same time, we cannot think that the forest can solve every problem and that we can continue to waste energy. We must develop technology that reduces energy consumption and we must learn to save energy in order to achieve a sustainable society.”