|Tundra||Ice frozen soil with severe climatic conditions|
|Tropical||Lying near the tropics or in equatorial region|
|Temperate||Between Tropics & Arctic circles i.e. from 23.5* to 66.5* approx.|
|Evergreen||Trees do not shed their leaves periodically & always looks filled|
|Deciduous||Trees which shed their leaves periodically|
|Coniferous||Needle leaved trees|
|Alpine||Relating to high mountains|
|Montane||Pertaining to mountainous region|
Word Tundra means barren land since they are found where environmental conditions are very severe. There are 2 types of 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.
- 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
- Sandy & saline soil
- rainfall less than 20 cm a year
- 10 months dry season
- Rainfall is aprox. 50 cm a year
- dry season 6 – 8 months
Characteristics of Desert’s Flora & Fauna
- 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.
- Fast runners
- Conserve water by excreting conc. Urine
- Long legs to avoid hot grounds.