A terrestrial ecosystem is an ecosystem found only on the land. These are:
- Taiga.(Northern coniferous forest)
- Temperate Deciduous forest.
- Tropical rainforest.
- Tropical deciduous forest
What are the factors on which the nature and extent of a biome depends?
The nature and extent of a biome is depends on the physical factors such as: –
- Temperature range.
- Intensity and duration of light.
- Nature of soil.
- Geographic barriers like mountains Rivers and seas.
- Latitude and longitude.
- Climax vegetation depends on the above physical factors and they both determine the kinds of animals and microorganisms found in a biome.
- Extent – lies between Arctic Ocean and coniferous forests. Stretches across North America, Europe and Asia.
- Climate – extremely cold with a temperature range of -30°C to 40°C in winter. The ground usually remains frozen as permafrost. Summers are very brief consisting of only 60 days with highest temperature of 10°C.
- Flora – Vegetation is sparse and tundra is often called Arctic desert. There are no trees. Lichens and mosses constitute the characteristic vegetation. Fauna – Few species of insect, birds and mammals. Birds include snow owl and snow browse. Mammals are represented by musk ox, reindeer, Arctic fox, polar bear, arctic wolf and weasels. There are no amphibians and reptiles.
Northern Coniferous Forest (Taiga) –
- Extent – Stretches as an East-West band across North America, Europe and Asia just south of the tundra. The coniferous forest is also found in the southern hemisphere in the South Island of New Zealand.
- Climate – cold with an average temperature of 60°C in winters and 20°C in summer. Winter is longer and severe. Summer is mild.
- Flora – Tall evergreen cone bearing trees with needle like leaves is the dominant vegetation. This gives taiga its name of coniferous forest.
- Fauna –. Insects and reptiles (snakes and lizards), insectivorous birds (grouse, jay cross bill) and mammals such as moose deer, elk, Puma, Wolf, bear, mink etc.
3. Temperate deciduous forests –
- Extent – Occurs in northern hemisphere in eastern United States, north-central Europe and Eastern Asia (south-eastern China, Korea and Japan), southern hemisphere in eastern Australia and New Zealand.
- Flora – Trees like elm, Maple, beech, oak , hickory birch, Magnolia and chestnut at are found here. Trees are present here in two storeys – canopy and understory.
- Fauna – Mammals include deer, bear, fox, squirrel, flying squirrel, rabbit, hare, wildcat, raccoon and skunk. Among the insects are found spiders and centipedes. Amphibians (salamanders and frogs) and reptiles ( snakes lizards and turtles) are fairly common. .
4. Tropical Rainforests (tropical evergreen forests) –
- Extent – Tropical rainforest lies near the equator. They are found in Central America, Amazon on and Orinoco River basins of South America, Congo River basin of Africa and Southeast Asia.
- Climate – warm and moist and seasonal variations are not found.
- Flora – the dominant vegetation is dense evergreen trees with broad leaves. . Many type of epiphytes (orchids )(air plants) and lianas(Woody climber)grow on the trees to reach light for photosynthesis.
- In India, trees in the tropical rainforests include – rubber trees, figs, timber trees( rosewood, ebony and mahogany); spice plants ( cloves, cinnamon and nutmeg) ; palms, plantations, bamboos and cycads.
- Fauna – brilliantly coloured birds like parakeets, birds of paradise etc. other animals include monkeys, Lemurs, bats, sloths, anteaters, arboreal reptiles, amphibians, insects, centipedes, scorpions, snails and leeches. Leopards, jaguars, deer, antelope, forest goat, elephants and tapirs are also seen in these forests. Fishes of many varieties inhabit the rivers.
- Tropical rainforests are rich in biodiversity and about 200 species of trees 70 to 80% of world’s insect species and 80 to 85% of all bird species can be found here.
5. Tropical Deciduous Forests –
- Extent – found in the West Indies, Eastern region of Brazil, Central Plateau of India , Indochina and north-eastern projection of Australia.
- Flora – Trees shed their leaves during the dry season hence the name tropical deciduous.There is a dense undergrowth of shrubs and herbs as the sunlight reaches the bottom of the forest.
- In India trees in the tropical deciduous forests are – Saal, teak, mahua ,semul, Jamun, goose berry and palash.
- Fauna – Rich diversity of animal life is found as abundant vegetation provides enough food for it. The common animals are – deer, elephants, pigs, bear, Tiger, lion, variety of birds, reptiles(lizards snakes and tortoises), insects and worms.
6. Mediterranean Scrub Forest –
- Extent – it extends along the Mediterranean, Pacific Coast of North America, coastal Chile southern tip of Africa and South Australia.
- . Bushfires are common in this biome.
- Flora – evergreen and broadleaved plants in the form of small trees or shrubs are found here. Some of the examples are sage, oak, aromatic plants whose leaves contain volatile inflammable organic compounds.
- Fauna lizards, snakes, birds and mammals such as rat, rabbit, chipmunk, deer, Tiger etc.
7. Grassland biome-this biome is further studied under two heads namely: –
i) Tropical Grassland(Savannah) –
- Extent- It is present mainly in South America, Africa and Australia. It is a treeless meadow like plain biome.
- . The climate is generally warm. However, rainfall is too low to support any trees.
- Flora – Trees like Acacia, Phoenix, eucalyptus are found here. The entire biome is covered with coarse grass and scattered small trees and shrubs.
- Fauna – A great variety of hoofed herbivore mammals are found here for example antelope, gazelle, zebra, rhinoceros, giraffes and elephant. Mice, rabbit and carnivores like Fox, Wolf, Tiger, lion are also present here. Kangaroos occur in Australian savannas only. Savannas of South Africa are called as the cradle of human evolution.
8. Temperate grassland (prairies) –
- Extent – these grasslands are present in North America (Canada and USA), South America, Eastern Europe, Central Asia, South Africa and Australia. They are known by different names in different countries for example these are called as prairies in North America, Pampas in South America, stapes in Europe and Asia, velds in Africa and tussocks in Australia.
- Cimate: remains cold in winter and hot in summer.
- Flora – Short and tall grasses, legumes are the dominant vegetation. Shrubs and trees are scattered or are present as a band in depressions or along rivers and streams.
- Fauna – grazing and burrowing mammals are common in grasslands.
- Extent – Desert areas are located around 20 to 30° North and South. About one fifth of the Earth surface is covered by the Desert biome. The deserts of the northern hemisphere are – Great Western Desert(death Valley) of United States, the Sahara Desert of North Africa, Gobi Desert in Tibet, Arabian and Thar deserts of Asia. The deserts of the southern hemisphere are – coastal areas of Chile and Peru in South America and in Central Western Australia.
- Flora – Plants are widely spaced with large areas between them. They show xero- phytic adaptations with succulent leaves.
- Fauna – Animals are mostly nocturnal as they want to avoid the heat of the day when they may face dehydration. Some examples are – scorpions, spiders, centipedes, ants, locusts, wasps, lizard, coral snake and rattlesnake,Road Runner ,Cactus woodpecker,camel, white tailed deer, jackrabbit etc..