Forest loss and degradation
Major threats to the northern boreal forest include fragmentation (see box below), forest fires and insect outbreaks. Spruce bark beetles have killed a significant portion of the spruce forests in Alaska, and decadal outbreaks of the autumn moth Epirrita autumnata in Fennoscandia have caused large-scale defoliation (CAFF 2001). Insects can leave dry, dead timber more susceptible to fire, the occurrence of which is already increasing as a result of an increase in temperature and decrease in precipitation. The impacts of insect outbreaks and fires can be severe. For example, in Canada, 6.3 million ha were affected by insect defoliation and 0.6 million ha were burnt in 2000 (Natural Resources Canada 2001).
| Forest fragmentation in the Arctic | |||
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Fragmentation, which hinders ecosystem functioning and results in loss of important wildlife habitat, and encroachment are serious threats to Arctic boreal forests, including the forested regions of the Russian Federation (FFS 1998, Lysenko, Henry and Pagnan 2000). In Scandinavia, there has been a long-term trend of converting forest land to other uses, especially agriculture, and ditch digging has increased the leaching of nutrients and run-off from soils. This in turn has caused siltation in rivers and lakes, decreasing their productivity as spawning areas for fish (CAFF 2001). The coastal areas of Finnmark, Norway, are important calving and summer feeding grounds for the semi-domesticated reindeer of the Saami indigenous people. The maps below illustrate the gradual fragmentation of these areas as a result of expanding road networks. Hydroelectric installations, power lines, military bombing ranges and tourist resorts have had additional impacts (UNEP 2001).
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