Room for all species to thrive
Holmen works hard to ensure that all the species which has the Swedish forests as their original habitat can continue to thrive. We have therefore been working actively for many years on nature conservation that makes a positive contribution to biodiversity. Biodiversity is made up of a complex interaction between many species in different natural habitats and different types of forest environments must be nurtured in order to preserve it.
20 per cent nature conservation areas
Of Holmen’s over 1 000 000 hectares of forest-clad land, we use about 80 per cent for wood production. The remaining 20 per cent is used for nature conservation purposes. Our nature conservation work can be divided into three different categories:
Areas voluntarily set-aside for nature conservation
Part of our forest land is exempt from harvesting and is only used for nature conservation purposes. These forests are known as set-aside areas. They are carefully chosen for their nature conservation potential and often have high conservation value. Holmen’s land set aside for nature conservation is spread across all our forest holdings. Larger cohesive areas are prioritised.
We leave the majority of the set-aside areas entirely untouched so they can develop freely, while others have to be managed to retain the natural assets that are the reason why the forest has been set aside. The measures we carry out are intended to promote specific processes and create biologically important structures on which some species are wholly dependent and which are favourable for many others. Without targeted nature conservation felling, broadleaf forest, for example, risks being outcompeted by spruce. Judicious felling and burning can also be used to increase the quantity of dead wood, which is often in short supply in the forests.
We assess the conservation benefits of various methods aimed at promoting biodiversity. For 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).
In Sweden all forest land that produces one cubic metre of growing stock, solid over bark, per hectare per year is counted as productive. In Holmen’s forests, areas set aside for nature conservation make up around 5 per cent of the productive forest land. On the website forestindustries.se, Holmen and several other major forest owners show their formal and voluntary set-aside areas in Sweden.
Non-productive forest land
Non-productive forest land is forest where the trees grow extremely slowly (less than one cubic metre of forest per hectare per year) due to a lack of nutrients or water. Non-productive forest land consists of bogs, marshes, mossy areas, rocky areas and exposed rock. 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 there and coupled with the set-aside forest, non-productive forest land can create large, beautiful and richly varied areas.
Environmental considerations in managed forests
In addition to set-asides and non-productive forest land, there are additional nature conservation areas where forest thinning and harvesting leaves behind small biotopes, buffer zones and groups of trees.
Forest-dwelling species are dependent on different habitats and structures for their survival. For example, many species depend on mature broadleaved trees and large living, dying and dead trees. When managing our forests we therefore save all dead trees and favour nature conservation trees and conservation-promoting trees.
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 thinning and harvesting, we create stumps about three metres high from living trees in addition to the trees that died naturally.
Trees that have died less than a year ago and that may be a breeding ground for pests, such as the spruce bark beetle, are, however, removed from the forest to prevent these pests massively increasing in number and becoming a threat to living forest.
We also create valuable buffer zones around non-productive forest, coastlines, lakes, watercourses and agricultural land. These environments are often particularly rich in species, partly thanks to shifting sunlight levels, soil types and moisture levels. And partly because plants and animals from the forest are mixed with those from bogs, the water or the open landscape.
This, coupled with the set-aside areas and non-productive forest land, forms a band of habitats for different species across the whole forest landscape. In total, it creates a conservation area spanning around 20 per cent of Holmen’s forest land.
Forests with special assets
Some forests have large or unique assets that should be preserved. At Holmen we have procedures in place to identify such forests, within Holmen’s own holdings, when purchasing wood from other forest owners and through group certification of private forest owners. Forests have high conservation value for various reasons. For Holmen these include:
- Areas with high concentrations of endangered species and/or key biotopes and that the Swedish Environmental Protection Agency has classified as being of national interest for nature conservation
- Forest along the tree line
- Forest in water protection areas
We take the assets of these forests into account in our forest management and this is incorporated in our ecological landscape plans. When harvesting in water protection areas, we follow the requirements set for activities in the area.
Planning is the basis of active and sustainable forestry that takes into account natural, cultural and social assets.
Every ten years we conduct a survey of all of our forest holdings and calculate the potential harvest in a hundred years’ time. The calculations also take into account montane forests, conservation efforts, reindeer husbandry and social values. Both volumes of standing forest and the forest’s growth continue to increase.
Holmen’s forests and their values are also described extensively in local ecological landscape plans. These are living documents kept constantly up to date. The plans contain strategies on how to plan areas set aside for nature conservation, and how the forests are to be managed in the long term in order to preserve natural assets and create new ones.
Wetlands and watercourses
Wetlands are important for the balance of nature. They clean the water and benefit biodiversity, not least birdlife. Wetlands also offer an attractive environment for recreation and birdwatching.
In partnership with the Swedish Wetlands Fund, Holmen has so far created or restored around 40 wetlands. These form habitats for a wealth of animal and plant species. Many birds nest here and the wetlands also serve as stopover sites on long migrations.
The extensive system for floating timber in Sweden resulted in many smaller watercourses being cleared or straightened. Later forest road construction also affected many watercourses, creating obstacles for fish and aquatic organisms because of poor culvert designs. Extensive work has been carried out to address such obstacles to migration in different parts of Sweden.