Mixed forest
The mixed forest Ligth green : the Borealie
Dark green :
the mixed forest
Mixed forest species :
The mixed, or temperate, forest is made up mainly of hardwoods which, following an annual cycle, lose their leaves in autumn, become dormant in winter, bud in the springtime and, finally, develop leaves and flowers in summer. Amongst the species we find are the birch, oak, maple, beech, ash, linden, to name but a few. Depending on the region, the presence of deciduous trees will be more or less significant, since total precipitation and temperature play a role in their development. Examples of conifers would be the spruce, pine, fir, eastern hemlock, white cedar, etc. 1,2,3
This biome is characterized by high temperatures in summer, low temperatures in winter and a yearly average temperature of between 8 and 10oC. Total precipitation is significant, between 700 and 1700 mm (28 to 67 in.) per year, and sometimes more, and is fairly evenly spread over the year. Zones with harsher winters and less precipitation are densely populated with conifers. 1,2,3
The floor of the temperate forest is rich in organic matter derived from the annual accumulation of dead leaves fallen from hardwood trees, and conifer needles. However, the organic matter decomposes rather slowly, especially in high conifer-content forests. 2,3
Woodlands are stratified vertically. The strata to be found are herbaceous plants, bushes, trees growing away from the sun and, finally, large mature trees. In America, these levels of plant cover are inhabited by a range of mammals, such as squirrels, racoons, black bear, white-tailed deer, to name just a few. However, the most important organisms are those that pass unseen, like bacteria and fungi. They play a crucial role, because they help recycle organic matter both on and within the soil, thus ensuring the health of the whole forest. This makes up an ecological partnership for those involved. 2,3
This biome has been seriously affected by human intervention. There remain only a few scattered pockets of the whole mature forest. The arrival of the European made a lasting impact on the biome. Trees were used for building and cut down for agriculture. In fact, the major North American urban centres were carved out of the forest. What remains of the original woodlands is now the focus of attention for ecologists, who hope that they will be protected… 2,3
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.
