Prescribed burning is an intentional and controlled burning of an area. In Nordic countries, the diverse palette of burnings with different targets can be divided in two main groups: silvicultural burnings of clear-cut areas and restoration burnings. 

Globally, prescribed burnings are especially aimed to reduce fuel load and fire risk, restore and maintain forest ecosystem types, and manage habitats for grazing and wildlife. 

Prescribed burning has been used as an NbS in forest ecosystems and cultural landscapes. 

Why

In Nordic countries, fire has in the past been largely responsible for the structural and functional diversity of large parts of the forests. Boreal biota is adapted to the variability of disturbance dynamics, with fire as one of the main disturbance agents. Nowadays, forest ecosystems seldom experience fire because of efficient fire suppression and intensive forest management, supported by dense forest-road networks. 

In Nordic ecosystems, prescribed burning addresses many societal challenges. Burning creates multiple habitats for fire-dependent species, thus enhancing biodiversity. In harvested areas, it ensures sustainable economic development by promoting natural forest regeneration.  

How  

The traditional silvicultural prescribed burning of logging slash and humus layer is aimed at improving conditions for forest regeneration by decreasing competition of seedlings and undergrowth with other understory vegetation, creating an ash-fertilization effect, and reducing the occurrence of certain pathogens. Nowadays silvicultural burnings have become also a part of nature management, aiming at safeguarding biodiversity through burning retention tree groups to create charred wood and habitat for fire-dependent species. In nature management and ecological restoration, prescribed burning aims at sustaining and enhancing biodiversity.  

So-called ‘impoverishment burnings’, or management burnings of sun-exposed, barren and xeric forests and esker slopes, are recommended as effective natural treatments to restore and enhance the biodiversity in these habitats that without human impact would burn more frequently. The main goals of these burnings are to reduce biomass, make moss and raw humus layers thinner, reveal mineral soil, and, in general, shift the environmental conditions towards extremes, which gives competitive advantage to species adapted to thrive in these conditions.   

Restoration burnings are performed in conservation areas with the aims of promoting natural succession after fire, diversifying stand structure and tree-species composition, improving the continuity of deadwood, and promoting suitable resources and habitats for fire-dependent species. In addition to benefitting fire-dependent species the aims can be to restore and maintain heathland forests, as well as the formerly common young post-disturbance successional forests, and old-growth pine-dominated multi-storied forests, which in lack of forest fires have gradually declined and developed into dense spruce-dominated forests. 

‘Cultural’ burning aims at managing traditional habitats created by old agricultural practices, such as slash-and-burn agriculture, and at restoring more or less open heathland habitats. 

The size of burned area can vary from a small patch of vegetation to few hectares depending on the aim of burning. In impoverishment burnings, which aim at sustaining the characteristics of sunny, dry, and barren habitats, moss, lichen and raw humus layers are burned as deep as possible.  

Restoration burnings aim to leave 25–75% of the trees in the prescribed area alive after the fire, and some unburned patches within the burned area, such as moist peatland patches. Restoration burnings are typically targeted at stands that previously were managed, young or middle-aged, pine-dominated, and nearly monocultural stands.