– The tundra is characterized by a layer of permafrost; a layer of permanently frozen subsoil.
– A tundra consists of strong winds; low precipitation; short & soggy summers; long, cold & dark winters; poorly developed soils; permafrost.
– Ground-hugging plants such as mosses, lichens, sedges, & short grasses all participate in the dominant plant life of a tundra.
– Tundras are located in North America, Asia & Europe.
– During the short, cool summer, the ground thaws to a depth of a few centimeters & become soggy & wet.
– Along the northern edge of the temperate zone are dense evergreen forests of coniferous trees.
– Winters here are bitterly cold, but summers are mild & long enough to allow the ground to thaw.
– Needleleaf coniferous trees such as spruce & fir; some broadleaf deciduous trees; & small, berry-bearing shrubs all participate in the dominant plant life of a boreal forest.
– Distributed throughout North America, Asia, & northern Europe.
– A boreal forest is sometimes referred to as taiga.
– The forest is made up of a variety of conifers, ranging from giant redwoods along the coast of NorCal to spruce, fir, & hemlock farther north.
– Coniferous forests acquire mild temperatures; abundant precipitation during fall, winter & spring; relatively cool, dry summer; rocky, acidic soils.
– Dominant plant life in a coniferous forest consist of Douglas fir, Sitka spruce, western hemlock & redwood trees.
– They are usually found along the Pacific coast of northwestern United Sates & Canada, from NorCal to Alaska.
– Because of its lush vegetation, the northwestern coniferous forest is sometimes referred to as a “temperate rain forest.”
– Temperate forests contain a mixture of deciduous & coniferous trees.
– Temperate forests are located around the eastern United States,, southeastern Canada, most of Europe, & parts of; Japan, China, & Australia.
– Temp forests have cold to moderate winters; warm summers; year-round precipitation; & fertile soils.
– Broadleaf deciduous trees; some conifers; flowering shrubs;herbs; & a ground layer of mosses flourish in temperate forests.
– These forests have cold winters that halt plant growth for several months.
– This biome is characterized by a semiarid climate & a mix of shrub communities & open woodlands.
– Temp woodland & shrub-lands receive hot, dry summers; cool, moist winters; thin, nutrient-poor soils; & periodic fires.
– Temp woodland & shrub-lands are distributed over the western coasts of North & South America, areas around the Mediterranean Sea, South Africa, & Australia.
– Woody, evergreen shrubs with small, leathery leaves; fragrant, oily herbs that grow during the winter & die during the summer are some of the more dominant plant-life partaking in a temperate woodland & shrubland.
– The growth of dense, low plants that contain flammable oils make fires a constant threat.
– A temperate grassland is characterized by a rich mix of grasses & under laid by some of the world’s most fertile soils.
– Temperate grasslands obtain hot summers & cold winters with infrequent fires.
– Dominant plants include; lush, perennial grasses & herbs; most are resistant to drought, fire, & cold.
– Temp Grasslands spread out through central Asia, North America, Australia, central Europe, and South America.
– Periodic fires & heavy grazing by large herbivores manage the characteristic plant community in a temperate grassland.
– A desert biome is defined as having an annual precipitation of less than 25 cm.
– Deserts receive low precipitation; variable temperatures; & soils rich in minerals but poor in organic material.
– Deserts are dispersed over Africa, Asia, the Middle East, United States, Mexico, South America, & Australia.
-Cacti, creosote bushes, and other succulents inhabit a desert biome.
– Many deserts undergo extreme temperature changes during the day, fluctuating between hot & cold.