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
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).
| Spread of road networks in Finnmark, northern
|Source: UNEP 2001