Terrestrial Biomes

In addition to recognizing biogeographic regions, ecol-ogists also classify communities of organisms into biomes, ecosystem types that are based on the structure of their dominant vegetation. The vegetation of a biome has a similar appearance wherever on Earth that biome is found, but the plant species in these communities, despite their physical similarities, may not be evolutionarily closely related. Bio-mes are named for and identified by their characteristic vegetation, sometimes supplemented by a description of their location or climate, but each biome contains many species in all other taxonomic groups.

Location Tropical Savanna BiomeBoreal Evergreen Forest

Tropical evergreen forest

Tropical deciduous forest

Thorn forest

Savanna

Hot desert

Chaparral

Cold desert

High mountains (boreal forest and tundra)

Tropical evergreen forest

Tropical deciduous forest

Thorn forest

Savanna

Hot desert

Chaparral

Cold desert

High mountains (boreal forest and tundra)

Temperate evergreen forest

Temperate deciduous forest

Boreal forest

Arctic tundra

Temperate grassland

Polar ice cap

56.9 Biomes Have Distinct Geographic Distributions The distribution of biomes is strongly influenced by patterns of temperature and rainfall.

The distribution of biomes on Earth is strongly influenced by annual patterns of temperature and rainfall (Figure 56.9). In some biomes, such as temperate deciduous forest, precipitation is relatively constant throughout the year, but temperature varies strikingly between summer and winter. In other biomes, both temperature and precipitation change seasonally. In still other biomes, such as tropical rainforest, temperatures are nearly constant, but rainfall varies seasonally. In the Tropics, where seasonal temperature fluctuations are small, annual cycles are dominated by wet and dry seasons (see Figure 56.5).

It is easiest to grasp the similarities and differences among terrestrial biomes by means of a combination of photographs and graphs of temperature, precipitation, and biological ac tivity, supplemented by a few words that describe the species richness and other attributes of those biomes. We use this method in the following pages to describe the major terrestrial biomes of the world.

► Each biome is represented by a map showing its locations and two photographs that illustrate either the biome at different times of year or representatives of the biome in different places on Earth.

► One set of graphs plots seasonal patterns of temperature and precipitation at a site in the biome.

► Other graphs show how active different kinds of organisms are during the year. (For high-latitude biomes, patterns in the Southern Hemisphere are six months out of phase with those shown, which represent the Northern Hemisphere.) Levels of biological activity, shown by the width of the horizontal bars, change either because resident organisms become more or less active (produce leaves, come out of hibernation, hatch, or reproduce) or because organisms migrate into and out of the biome at different times of the year.

► A small box describes the growth forms of the plants that dominate the vegetation in the biome and its patterns of species richness.

These descriptions are very general and cannot describe the variation that exists within each biome.

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Responses

  • macario
    Where climate regions are found artic tundra hot desert rainforest and deciduous forest?
    8 years ago
  • ITALA MANCINI
    Where is the evergreen forest located on earth?
    8 years ago
  • elga
    Which of the following attributes is NOT shared among all the terrestrial planets?
    7 years ago
  • ROBIN
    Where are some hot and cold deserts on a world map?
    7 years ago
  • benigna
    Where the tropical thorny forests in the poltical map?
    7 years ago

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