Nearctica - Ecology - Biomes - Introduction to Biomes

Naturalists have also noted that as one goes up a mountain, the vegatation zones tend to mirror the larger biomes as the temperature and precipitation change. These changes in vegetation types are sometimes called "life zones". The classic example is the San Francisco Mountains in northern Arizona. On the north side of the mountains the vegetation at the base is a scrub desert changing to a desert dominated by the dry adapted trees pinyon pine and juniper. As the elevation increases the forest changes to Ponderosa Pine, then to a spruce-douglas fir habitat very similar to the taiga, and finally changes to an alpine zone similar to tundra in its appearance on the top of the mountain peaks.

TAIGA The taiga is characterized by a climate of long, severe winters, and a constant cover of snow and short, cool summers. The vegetation is dominated by conifers such as spruce, fir, and hemlock. Characteristic animals are elk, moose, mule deer, black bears, and grizzly bears. The taiga occurs in the northern reaches of North America and Eurasia.

The taiga is also sometimes referred to as boreal forest or northern coniferous forest. Taiga-like vegetation occurs on the upper elevations of mountain ranges.

TEMPERATE DECIDUOUS FOREST Temperate deciduous forest is characterized by a warm to hot growing season with moderate precipitation, followed by a winter that is not as cold or as long as in more northerly regions. The dominant trees in this zone avoid water loss during the winter by shedding their leaves. The temperate deciduous forests are much richer in plant and animal species than the taiga or tundra zones. A rich variety of tree and other plant species characterize the temperate deciduous forest. Temperate deciduous forest is primarily characteristic of the eastern United States and Canada, and also occurs in Europe, Japan, parts of Australia, and the mountainous regions of Patagonia at the southern tip of South America. [www.nearctica.com/ecology/habitats/biointro.htm]

Earth Floor: Biomes

Starting with the most northerly of forest biomes, there is the boreal coniferous forest, which we have discussed. Called taiga in Russia, boreal coniferous forests often are bordered on the north by tundra, discussed later in the context of nonforest ecosystems. An important subset of the boreal coniferous grouping is the montane forest, which also is dominated by conifers but which most often is found on mountains, at subalpine altitudes where the climate is cool and moist. ice sheet & polar desert tundra taiga temperate broadleaf forest temperate steppe subtropical rainforest Mediterranean vegetation monsoon forest arid desert xeric shrubland dry steppe semiarid desert grass savanna tree savanna subtropical dry forest tropical rainforest alpine tundra montane forest

Tropical and subtropical moist broadleaf forests · Tropical and subtropical dry broadleaf forests · Tropical and subtropical coniferous forests · Temperate broadleaf and mixed forests · Temperate coniferous forests · Mediterranean forests, woodlands, and scrub · Boreal forests/taiga · Mangrove · Tropical and subtropical grasslands, savannas, and shrublands · Temperate grasslands, savannas, and shrublands · Flooded grasslands and savannas · Montane grasslands and shrublands · Deserts and xeric shrublands · Tundra [www.answers.com/topic/biome]

Biomes

1. Boreal Forests or Taiga: are located in northern areas of the world and near the tops of high mountains. They have long, dry, cold winters and short, warm summers. In winter, thick, snow covers the ground. It acts as a blanket and prevents the ground from freezing. Conifers or evergreens as well as bushes, shrubs, ferns and mosses grown in boreal forests. Carnivores, including weasels, mink, wolves, wolverines, owls, and hawks hunt in the taiga. Deer, bear, and squirrels live in taiga all year around, while caribou live there in the winter. [www.animalsoftheworld.ecsd.net/biomes.htm]

Biomes

B. BOREAL FOREST (TAIGA): dense evergreen needle-leafed forest Typical plants include white spruce, black spruce, and jack pine. Typical animals include moose, black bears, wolves, and migrant birds. Cold winters with deep snow, but longer growing season than tundra. Warm-month average temperature greater than 10 oC. Periodic fires common. [www.geo.arizona.edu/Antevs/biomes/]

Major Biomes of the World — FactMonster.com

The coniferous forest biome is south of the Arctic tundra. It stretches from Alaska straight across North America to the Atlantic Ocean and across Eurasia. The largest stretch of coniferous forest in the world, circling the earth in the Northern Hemisphere, is called the “taiga.” It supplies the bulk of the world's commercial softwood timber, which is used to make paper. [www.factmonster.com/ipka/A0769052.html]