Forest Ecosystem

Tundra

Word Tundra means barren land since they are found where environmental conditions are very severe. There are 2 types of Tundra:

Arctic Tundra

• Northern most region adjoining the ice bound poles
• Region below polar ice caps & above the tree line in northern hemisphere.
• On the South Pole tundra is very small as most of it is covered by oceans.
• Devoid of trees except stunted scrubs which includes mainly lichens, Birches, mosses & sedges.

Alpine Tundra

• Occurs at high mountains above the tree line at all the latitudes (because mountains are found at all latitudes with variation in day & night temperature)
• Mammals of tundra have large body size covered with furs and small tail & ear to avoid loss of heat.
• Found mostly at Canada, Alaska, Russia, Siberia & island group of Arctic Ocean.

Taiga or Boreal or coniferous Forests

• Found mostly in Northern Europe, Asia, Northern America
• Moderate temperature than Tundra (Cold regions with high rainfall, long winters & short summers) with dominating vegetation being coniferous (needle-leaved ) evergreen, mostly spruce with some pine & firs
• Soil is deficient in humus content as litter derived from conifer leafs decompose slowly & is not rich in nutrients and weathering of rocks in persisting cold climate also proceeds slowly
• Soils are mainly acidic & mineral deficient due to water logged area & without significant evaporation essential soluble nutrients leaches deep down beyond the reach of roots.

Temperate deciduous forests

• Extends over central & southern Europe, Eastern North America, Western China, Japan, New Zealand etc.
• Moderate temperature & moderate rainfall, shed their leaves during fall, are bare over winters & grow new foilage in spring.
• Generally, the most productive areas on the earth, Trees include mainly Beech, Oak, Maple & Cherry

Littoral & Swamps

• Found along A & N islands & at deltas
• Have roots which consist of soft tissues so that plant can breathe in water

Tropical Rain Forests

• Equatorial regions with high temperature & high rainfall.
• Covers approx 7 % of earth’s surface & 40 % of world’s plant & animal species.
• Abundant in multiple story broad leaved evergreen trees with epiphytic plants concentrated in canopy or trees top zones

Grassland

Steppe (semi-arid)

• Sandy & saline soil
• rainfall less than 20 cm a year
• 10 months dry season

Savannah

• Rainfall is aprox. 50 cm a year
• dry season 6 – 8 months

Characteristics of Desert’s Flora & Fauna

Flora

• Mostly shrubs
• leaves are absent or small in size
• leaves & stem are succulent or water storing
• Root system is well developed & spread over large area.

Fauna

• Nocturnal
• Fast runners
• Conserve water by excreting conc. Urine
• Long legs to avoid hot grounds.

For more information, refer to geography section