We have been working actively for many years on nature conservation initiatives that encourage biodiversity. Our aim is to ensure that all naturally occurring species are able to thrive in the forest landscape. Our forests cover 1.3 million hectares, of which around a fifth is used for nature conservation purposes. This includes voluntary set-asides, non-productive forest land and environmental consideration in managed forests.
Some of Holmen’s productive forest is used exclusively for nature conservation. These areas are carefully chosen for their nature conservation potential and often contain a wealth of natural assets. The set-aside areas of forest are spread across Holmen’s forest holdings, providing habitats that vary greatly in terms of content, size and composition. The goal, however, is for the areas set aside for nature conservation purposes to remain viable over the long term, which makes it undesirable to set aside areas on too small a scale.
Some of the set-aside areas are left entirely untouched, while others have to be managed to retain the natural assets that are the reason why the forest has been set aside. Without targeted nature conservation felling, broadleaf forest, for example, risks being outcompeted by spruce. Judicious felling can also be used to increase the quantity of dead wood, which is often in short supply in the forests. There is a process under way to assess the conservation benefits of various methods aimed at promoting biodiversity. As an example, Holmen is taking part in a major research project run by Future Forests, in which various measures are being carried out in 30 set-aside areas. These measures are being monitored by researchers at the Swedish University of Agricultural Sciences (SLU).
Non-productive forest land is forest where the trees grow extremely slowly due to a lack of nutrients or water. Non-productive forest land can be divided into two categories: bogs and rocky areas. There is often a high proportion of old, slow-growing and dead trees, which are important for a large number of species. Around 2 per cent of forest-dwelling species have their main habitat in non-productive forest land. No forestry is undertaken on non-productive land which, coupled with the set-aside forest, can create large, beautiful and richly varied areas.
Forest-dwelling species are dependent on forest habitats and structures for their survival. For example, over half of all forest-dwelling species depend on mature broadleaved trees and large living, dying and dead trees. In order to create the right conditions for these species, Holmen protects nature conservation trees and conservation-promoting trees, while also preserving all dead trees in the managed forests. Nature conservation trees include large aspens, broadleaved trees north of the Dalälven river and trees that are unusually large or old or in some other way different from the norm. In cases where there are no nature conservation trees growing, conservation-promoting trees are instead left in order to improve the natural assets of the site over the long term. During general clearing and regeneration felling, high stumps are created from living trees in addition to the trees that died naturally.
Holmen also creates valuable buffer zones around non-productive forest, coastlines, lakes, watercourses and agricultural land. These support a wealth of species, since the habitat varies in terms of light conditions, soil type and humidity, and because the flora and fauna of the forests is mixed with those associated with the bogs, water or open landscape. This, coupled with the set-aside areas and non-productive forest land, creates a band of habitats for different species across the whole forest landscape.