Boreal Forests

The boreal forest landscape in Sweden has changed dramatically during the last 150 years. The standing volume of trees decreased up until the 1950's due to more and more intensive logging. Despite the intensive forest management after that time it has not yet reached the level of the late 19th century. Even more striking is the change in forest stand structure. The areal extent of forests older than 150 years has decreased dramatically. Figures from different regions of the boreal forest also indicate that the volume of dead standing trees has decreased by more than 90 % over the last 100 years. Large diameter specimens of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies), which characterized the virgin boreal forest, have decreased by more than 80 % during the same period.

Northern Sweden was very sparsely populated until the beginning of the 19th century. At that time an accelerating agrarian colonization took place, and later during that century a large-scale exploitation of the virgin forest began. The first forest resources to be exploited were those close to the Bothnian coast, and subsequently exploitation moved further inland. This exploitation affected almost all forest land in northern Sweden during the period 1850-1950.

In many areas of northern Sweden forest inventories preceded exploitation. They were often carried out as tree counts, i.e. measurements of large diameters trees as well as an estimation of their saw-timber quality. This inventories can, together with more accurate inventories carried out at a later time, be used to estimate the standing volume as well as tree diameter distribution in the unexploited forest. In some cases the number of dead standing trees was also recorded.



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