The Boreal forest (Taiga)

The Boreal forest is characterized by long, cold winters (at least 6 months below 0 ^oC) and by short summers that may be quite hot in some regions. The average summer temperature is 10 ^oC. In spite of the short summers, plant growth can be quite significant because of the long hours of sunshine, up to 18 hours per day at certain latitudes. Total precipitation is moderate, from 200 to 600 mm (8 in. to 2 ft.) and falls mainly as snow.

The physical aspect of the Boreal forest is that of a mosaic of forests, lakes and rivers, along with wetland such as peat bogs. There is a smaller variety of trees and the woodland is dominated by species that include the spruce, fir, larch and pine. The very occasional hardwoods are generally circumscribed within the wetland (lakes, rivers, peat bogs) or in areas that have been ravaged by fire or by human beings (the alder, birch, poplar and willow). The fires break out at the dryer time of the year and constitute a key element for forest regeneration. Herbaceous plants are very rare in this dense woodland. As for bushes, they are mainly members of the heath family, and include the blueberry or the Labrador tea. ^1,2,3

The biome soil is acid (because of the conifers), thin and poor in nutritional elements. However, the trees have adapted well to these conditions over thousands of years of evolution. In the first place, they have a widespread root network, close to the surface of the thin layer of soil, and can thus absorb elements required for their survival. In the second place, the trees have developed a fraternal relationship between their roots and the mycete (a form of mushroom) and form what is known as mycorrhiza. Both parties benefit from this association, the mycete absorb the elements produced by the trees and in return they increase the collector surface of the roots, allowing the trees to optimize their ability to absorb water and minerals.  ^2,3

This biome may appear less complex if one only takes into account the variety of plants found there, but a closer look will open up a fascinating world, full of surprises. Plant life, for example, is very diversified and includes many invertebrates, birds and mammals. The most “celebrated” representatives of the invertebrates are certainly the biting insects.1  Some bird species, such as the spruce grouse, live permanently in the taiga, but most species only make a stopover during migration or use it as a mating ground. Hares, black bears, grizzlies, moose, elks, wolves and wolverines are some of the mammals that reside in this area. ^2,3

Until quite recently, this biome suffered less than others from the impact of human beings. However, the taiga is now undergoing heavy exploitation of its plant and wildlife resources. Trees are cut down for lumber and pulp and paper. The paths thus torn through the woodlands allow human beings to penetrate even further into the forest, to trap and hunt, and this increases pressure on animal populations. ^2,3 Fortunately, human beings are also concerned with resource management and there are many who deal with these problems on a day-do-day basis in order to ensure the durability of the biome.  

References

1. Borcard, Daniel.  Department of Biological Sciences.  University of Montreal. http://biol10.biol.umontreal.ca/BIO1803/Biomes.html  Consulted on April 16, 2003
2. Following reference: Dajoz, R.  1996.  Précis d'écologie.  6th edition. Dunod.  Paris.
3. Campbell, Neil A.  1995.  Chapter 46 : L’écologie : Distribution et adaptation des organismes.  IN  Biologie.  Éditions du Renouveau Pédagogique Inc. Quebec. Canada.
4. Molles, Manuel C. Jr.  1999.  Chapter 2: Life on land.  IN  Ecology : Concepts and Applications.  McGraw-Hill.  Toronto.  Canada.