What is an old-growth forest?
Answer: An old-growth forest is a forest with a distinct proportion of old trees, often with a large intermixture of dead wood. The forest is relatively unaffected and it plays a critical role for the forest’s threatened and rare flora and fauna. An old-growth forest can for instance be a valuable broadleaved forest in the southern Swedish province Götaland, or an old pine-dominated forest in the northern province Norrland.
The unaffected forest is a complicated dynamic biological system, a type of society characterized by big species richness and irregular disturbance regimes such as forest fires, wind thrown forests and insect outbreaks. Many species are favored by disturbances. For instance, a regeneration of spruce is favored by storm-windows, and birch and pine trees are favored by fires. Every species has its own characterized life cycle. It can take for example 1 000 years for a pine tree to fully go through its whole life cycle, from a seed to an old tree that dies and is biodegraded. But with a modern harvester it only takes a few seconds to end this life cycle. (see definition list at the bottom of this page)
Aren’t there lots of forests in Sweden? Haven’t enough been protected already?
Answer: It can seem like there are many forests in Sweden, but: More than 90 % of all forests in Sweden are more or less affected by forestry and are young. Almost 2 000 forest and tree living species are threatened or near threatened in Sweden. A big part of them are dependent of the dynamics of a natural forest. Only about 5 % of the forests below the montane region consist of old natural forests, according to estimations of nature conservation authorities. Note that older forests with conservation values or forests with potential to develop high conservation values are not included in these numbers. The inventories of the authorities are not comprehensive. Nature conservationists still find new forests with high conservation values that lack protection and threatened by logging. More mapping is needed.
-Aren’t the authorities and the forest industry supposed to deal with the work protecting the values of the forest?
Answer: According to the Swedish Forestry Act and environmental forest certifications like Forest Stewardship Council (FSC) it should be like that. However, the situation in the forests is very critical. The government does not allocate enough resources to forest protection and parts of the forest industry do not follow the law or live up to their commitments under the FSC. Our work with highlighting the critical situation of the forest and putting pressure on politicians and the forest industry is needed!
Natural-like forest (also see natural forest): Old cultural forest that has not been managed over a long time and therefore has regained features of a natural forest’s dynamics. The concept is most applicable in the south and in the central of Sweden where most forests historically have been affected by forestry and might have been felled repeatedly during the 1700s to the 1900s. They have thereafter regained their important features associated to unaffected forests, such as being multi-layered, uneven-aged, open here and there, having an intermixture of old trees, suppressed trees that grow slowly, dead wood etc.
Natural forest – 1: Forest that has arised from natural regeneration and is more or less affected by different kinds of selective logging. It does not necessary have to be an old virgin forest, but it often has many of the features an unaffected forest has, such as being multi-layered, uneven-aged, open here and there, intermixture of old trees, suppressed trees that grow slowly, dead wood etc. It can also be an even-aged forest regenerated after fire that has lost all its old trees, or a hard selectively logged old-growth forest, that is a residual forest.
Natural forest – 2: Forest that has arised by spontaneous, natural regeneration on virgin forest land and that has been unaffected by man for such a long time that it in general has developed features (tree structure, species composition etc) of a virgin forest.
Virgin forest: Forest that has never been affected by systematic forest management. Single trees might have been felled and there might be other traces of culture, but is has not affected the natural structure of the forest. This is also applicable to younger unaffected forest successions after natural disturbances. There is no uniform definition of a virgin forest, but several similar definitions, which usually only cover the late forest succession stages.
Virgin-like forest: In general old “virgin-like” natural forest, which includes many of the features that are typical of virgin forests such as logs (lying dead wood), dead trees and very old trees. The concept also comprises unaffected or nearly unaffected forests that have arised after natural disturbances, mostly fire. The level of management has been so small that the natural structure of the forest has not been affected and the forest is therefore fully comparable with a completely unmanaged forest.