BOREAL FOREST

also called taiga vegetation composed primarily of cone-bearing, needle-leaved, or scale-leaved evergreen trees, found in regions that have long winters and moderate to high annual precipitation. The boreal (meaning northern) forest region occupies about 17 percent of the Earth's land surface area in a circumpolar belt of the far Northern Hemisphere. Northward beyond this limit, the boreal forest merges into the circumpolar tundra. The boreal forest is characterized predominantly by a limited number of conifer speciesi.e., pine (Pinus), spruce (Picea), larch (Larix), fir (Abies)and to a lesser degree by some deciduous genera such as birch (Betula) and poplar (Populus). These trees reach the highest latitudes of any trees on the Earth. Boreal plants and animals are adapted to short growing seasons of long days that vary from cool to warm. Winters are long and very cold, the days are short, and a persistent snowpack is the norm. The boreal forests of North America and Eurasia display a number of similarities, even sharing some plant and animal species. The northern forests of Russia, especially Siberia, are referred to as taiga, meaning little sticks, a term now widely accepted as an alternative to boreal forest. Additional reading Herman H. Shugart, Rik Leemans, and Gordon B. Bonan (eds.), A Systems Analysis of the Global Boreal Forest (1992), covers ecosystem processes, forest patterns in space and time, and computer models, including chapters on the Eurasian boreal forest, tree and shrub reproduction, and fire in the boreal forest. The Plant Cover of Sweden (1965), is the most complete reference on the original condition of the boreal forest of Sweden, focusing on the landscape pattern of native vegetation and on plant indicators of various forest regions and ecosystem types. Deborah L. Elliott-Fisk, The Boreal Forest, in Michael G. Barbour and William Dwight Billings (eds.), North American Terrestrial Vegetation (1988), pp. 3362, is a basic reference on the forest types and communities found across the North American boreal region and includes the historical development of the forest and the ecological characteristics of individual tree species. K. Van Cleve et al. (eds.), Forest Ecosystems in the Alaskan Taiga: A Synthesis of Structure and Function (1986), looks at recent investigations of one of the best-studied parts of the boreal forest, describing both upland and floodplain ecosystems; an update in a special issue of Canadian Journal of Forest Research, vol. 23, no. 5 (May 1993), contains the results of a multidisciplinary research project on ecological succession of a productive river floodplain in central Alaska, including a detailed discussion on soil. J.S. Rowe, Forest Regions of Canada (1972), well illustrated, is the best reference on the overall distribution and classification of boreal forest types in Canada. James A. Larsen, The Boreal Ecosystem (1980), focuses on properties of the middle boreal forest of central Canada. Edward A. Johnson, Fire and Vegetation Dynamics: Studies From the North American Boreal Forest (1992), is a well-illustrated treatment of fire weather, fire behaviour, and fire effects in the North American boreal forest. Lennart Hansson (ed.), The Ecological Principles of Nature Conservation: Applications in Temperate and Boreal Environments (1992), also well illustrated, discusses the effects of forest management on biodiversity, focusing particularly on the boreal forest of northern Europe. Glenn Patrick Juday