Bioenergy from boreal forests: Swedish approach to sustainable wood use

Active forest management has helped to expand Sweden’s forested areas and thereby boost the country’s wood and bioenergy resource base. While about three-quarters of annual growth is harvested, those areas are replanted. The other quarter of each year’s growth is left in place to provide ongoing carbon uptake and maintain ecological stability. Swedish experience offers valuable lessons for emerging markets. 

Wood is typically harvested around every sixty to one hundred years, allowing for faster-growing new trees to be planted, increasing forest mass. In this manner, the capacity of Swedish forests to absorb carbon dioxide (CO₂) and provide wood for energy and other uses has doubled over the last century. Actively managed and monitored forests are also more resistant to forest fires and infestations, reducing the risk of massive CO₂ release from such catastrophes.

As this report highlights, wood energy potential could be further enhanced by collecting a larger share of logging residues.  Just over half of Swedish forest fellings come in the form of roundwood from tree trunks, which are harvested for lumber, other wood products, pulp and paper. While processing residues are already converted to bioenergy, felling residues – such as tree stumps and “slash” from branches and small trees – could also provide a sustainable bioenergy source.

Among other findings:

• Sustainable wood use from Swedish logging could rise seven-fold through collecting 70% of slash and 30% of stumps.
• Wood growth in Swedish forests each year is twice what it was a century ago – on about the same land area.
• Every tonne of wood used in Swedish buildings avoids nearly three tonnes of CO₂ emissions.

Although the market for wood-based heat and power to displace fossil-based fuel oil is largely saturated in Sweden, further wood resources could be redirected to other biofuel production, including jet fuel. Meanwhile, the carbon uptake potential from forests could be enhanced through focused application of fertiliser. Further carbon uptake could be achieved in buildings by replacing materials like steel and concrete with more lumber and wood-residue composites, the report notes.