We have used controlled burning in felling areas of company forests. In 2014 April, for example we burnt roughly 4 hectares in Äänekoski in Central Finland and just over 8 hectares in Ruokolahti in Eastern Finland. Controlled burning aims to benefit both the forest and the environment.
Controlled burning requires proper planning, expertise, careful execution and attention to weather conditions. Areas designed for controlled burning are usually marked off by fire lanes and corridors. Fire lanes are 1- to 4-metre-wide strips created at the edges of the burning site by exposing the mineral soil. Their purpose is to stop the ground fires from spreading.
Controlled burning goals related to forestry:
The most important forestry-related goal of controlled burning is the improvement of regeneration outcome and forest growth. Burning enhances the nutrient and thermal conditions of the site, eliminating most of the felling residues and some of the humus layer.
Burning releases nutrients bound in the felling residues and humus layer, decreases the acidity of the soil for up to some decades, makes the heat-insulating humus layer thinner and improves the thermal conditions of soil. It also reduces competition among ground vegetation for a couple of years. Forest cultivation becomes easier to carry out after felling residues and waste are cleared out of the way.
Controlled burning goals related to nature management and forest biodiversity:
Earlier forest fires have been quite common. Dry heathland forests, in particular, could have burnt regularly. As a result, burnt areas have developed their own specialised species that depend on burnt wood matter. Many coniferous forest zone species, for instance, have adapted for life on burnt soil or wood matter that has been charred or damaged by burning.
Effective fire prevention methods have dramatically cut down the number of species inhabiting burnt areas. According to the most recent conservation status report, the number of endangered or near threatened species living in burnt forest habitats is over 120, the majority of which are invertebrates. It is estimated that hundreds of plant, fungi and insect species have benefited from controlled burning and forest fires. Controlled burning aims to maintain the habitats of endangered and near threatened species.
Examples of species benefiting from burnt habitats include:
- Vascular plants (tracheophytes): pulsatilla vernalis (spring pasqueflower), geranium bohemicum
- Aphyllophorales: dichomitus squalens
- Orthoptera: psophus stridulus (rattle grasshopper)
- Beetles: aradus signaticornis, stephanopachys linearis, sphaeriestes stockmanni
- Lichens: hertelidea botryosa, verrucaria carbonella
- Fungi: gyromitra esculenta (false morel)
- Ascomycota: rhodotarzetta rosea