Earth’s Vegetation: Biomes

World Biomes

Biomes are the major regional groupings of plants and animals discernible at a global scale. Their distribution patterns are strongly correlated with regional climate patterns and identified according to the climax vegetation type.

However, a biome is composed not only of the climax vegetation, but also of associated successional communities, persistent subclimax communities, fauna, and soils.

1. RainforestA Rainforest can be described as a tall, dense

jungle. The reason it is called a "rain" forest is because of

the high amount of rainfall it gets per year. The climate of a rain forest is very hot and humid so the animals and plants that exist there must learn to adapt to this climate.

The use of rainforests

Layers of a Rainforest

Rainforest Facts

• 80% of the ancient forests have been destroyed

• only 20% of the ancient forests remain intact • Rainforests are home to more species of

plants and animals than the rest of the world put together.

2. Arctic Tundra

The word tundra is believed to come from the Finnish word "tunturia" which refers to a treeless plain.

Arctic tundra is found almost entirely in the Northern Hemisphere. In the southern hemisphere it is found on isolated islands off the coast of Antarctica as well as the Antarctic peninsula.

Characteristics of Tundra

Extremely cold climate Low biotic diversity Simple vegetation structure Limitation of drainage Short season of growth and reproduction Energy and nutrients in the form of dead

organic material Large population oscillations

3. Deserts

Deserts cover about one fifth of our planet, and are caused by extremely low rainfall over an area.

Theses biomes are nonetheless home to many plants and animals which have through the course of their evolution adapted to this dry environment.

• Arid deserts generally occur at low latitudes, and can be found in North-America, South-America, Africa, and Southern Asia.

• Semi-arid deserts are found in North-America, Europe, Russia, and Northern Asia.

• Coastal deserts are found in areas that are moderately warm to cool, such as the Neotropic and Nearctic realm.

4. Grasslands

Grassland biomes are unaltered areas of land where grass is the dominant plant life, as opposed to other terrestrial biomes where trees occupy most of the land surface.

Grassland are found around the globe and have served as grazing areas for a large number of animals, and have been exploited as farming grounds or plantations by humans.

Grassland are generally semi-arid areas with little or no trees.Prairies are generally humid and are densely

covered in tall grass. The steppe grassland is usually found in areas

of the world which are less prone to moisture. Savanna biomes are distinguished by their

warmer drier climates, and their seasonal droughts.

A grassland

5. Boreal or Taiga Biomes

The largest of the land biomes is the boreal, or Taiga biome.

Taiga biomes can be found in areas with shorter, warm summers and long winters; there are Taiga Biomes in Europe, Asia, Siberia, and North-America.

Because of the cold climates, plant life in the boreal forest is sturdy, consisting mainly of evergreens and other resilient vegetation.

A taiga

6. Water Biomes