Promoting forest biodiversity

Biological diversity provides a basis for the supply of a multitude of ecosystem services and an opportunity to utilise the various benefits of nature. Furthermore, biodiversity supports the functioning and restorability of ecosystems, for example the ability to withstand damage and reduce the threat of alien species.

Biodiversity relies on the ecological network

Safeguarding and promoting biodiversity is an integral part of forestry at Metsähallitus. The majority of the area in forestry use consists of multiple-use forests which are suited as habitats for most of our forest species.

Multiple-use forests include special sites of the ecological network with the purpose of maintaining valuable habitats characteristic of the area as well as their species, some of which are quite demanding. The sites of  the ecological network are excluded from forest management activities, or they are treated carefully considering their special nature.

Valuable habitats are totally excluded from forest operations

The core of the ecological network is made up of protected areas, valuable habitats as well as occurrences of certain species.

Valuable habitats include herb-rich forests, stands of broadleaved deciduous species, old-growth forests, heathland forests with plenty of decaying wood, sunlit slopes on sandy esker ridges, wooded heritage biotopes, wooded cliffs and bluffs, fertile mires as well as the surroundings of small water bodies such as springs, brooks, rivulets and small ponds. Some of these valuable habitats are defined in the Forest Act and the Nature Conservation Act.

Ecological corridors and buffer zones enhance the spread of species

The core areas excluded from commercial forestry are linked by ecological corridors and stepping stones. Besides these, the ecological network includes various buffer zones such as environmentally valuable forests and biodiversity enhancement areas. Recreational and landscape sites also support the ecological network. The planning and treatment of special sites are tailored processes. The management of forests adjacent to protected areas is planned in co-operation with experts from Metsähallitus Natural Heritage Services.

Metsähallitus has many kinds of special sites established by its own decision. Site-specific planning is a way to safeguard their special environmental values. The ecological value of small protected areas or concentrations of valuable habitats may be enhanced by locating special sites in their vicinity.

Retention trees are important for species dependent on decaying wood

Many threatened forest species need decaying wood. Leaving retention trees is a way to secure a sufficient supply of deadwood also in future phases of stand development. Retention trees are also very significant to the landscape.

Ideal retention trees include exceptionally large and prominent individuals as well as cavity trees. Groups of retention trees should preferably consist of large-diameter broadleaves, especially larger aspens and goat willows. Large-diameter pines are also important as potential nest trees for large birds of prey.

Groups of retention trees are placed by ecological and landscape criteria. Regarding species dependent on decaying wood, larger concentrations of retention trees are more effective than single trees or groups of a few trees.

Active management of habitats

Metsähallitus promotes biodiversity in multiple-use forests by actively managing important habitats. Habitat management is generally practised on a small scale, and focused on key sites in terms of biodiversity. Active habitat management includes prescribed burning, burning of retention tree groups, restoration of mires as well as management of sunexposed esker habitats and herb-rich forests. Metsähallitus is involved in the restoration of brooks and streams in joint projects with other actors.