Terrestrial Ecosystem

2020-04-29 10:50:49

Terrestrial Ecosystem

Q. What are the most limiting factors of terrestrial ecosys? A. Moisture and Temperature.

Terrestrial Ecosystem : Land based community of organisms and the interactions of biotic and abiotic components in a given areas.

An ecosystem is the interaction of pants and animals with non-living things whereas biome is a large region of the world that has similar plants, animals and other organisms that are adapted to the terrain and weather of that region. There are 7 types of land biomes.

1. Tundra

‘Tundra’ means barren land found where env conditions are scarce. They are treeless regions found in the arctic and on top of mountains where climate is cold and windy and rainfall is scant. They are also categorised as biomes

2 types of Tundras :

Arctic tundra near the polar ice caps. The south pole tundra is small as it is covered by the ocean. Polar bears, arctic foxes etc are found here.
- permafrost is a feature of it. They are regions of soil that are frozen for more than 2 years and extend 450 meters below the surface.
Alpine tundra : is there in all latitudes at high mountains and show variation in day and night temperatures.

2. Taiga

Also called boreal forest in North America and categorised as biomes. They are found in the sub arctic regions below Tundra.
They also have permafrost and along with bedrocks does not allow to drain top layer of the soil creating shallow bogs called muskegs.
Vegetation consists of coniferous forests, pines, spruces, larches etc.
Found only in northern hemisphere.

3. Forest

Coniferous aka Boreal forest

characterised by high rainfall, seasonal climate with long winters and short summers.
Soils have thin podzols, are acidic and mineral deficient.
Productivity and community stability is low.

Temperate deciduous forest

moderate climate and broad-leafed deciduous trees,
shed leaves in fall, soils are podzolic and deep.

Temperate evergreen forest

in regions with Mediterranean type climate of warm dry summer and cool moist winter
have low broad leaves, fires are common.

Temperate rain forest

rain is high fog is very high, diversity of plant and animal is low.
They are also classfied as biomes.

Tropical rain forest :

occur near equator, rainfall is more than 200cm and also categorised as biomes.
trees are vertically stratified, soils are red latosols and very thick
high rate of leaching makes it unfit for agri is however compensated by increased organic matter presence.

Tropical seasonal forests aka monsoon forest

have high rainfall but pronounced wet and dry periods.

Subtropical rain forests

trees are evergreen and broad leaved, ephiphytes are common, diff b/w winter and summer climate is less

Indian Forest Types

Name of Forest	Area found and Trees
Tropical Wet Evergreen Forests	Western Ghats, Nicobar and Andaman Islands and NE tall, straight and evergreen. Vegetation is stratified.
Tropical Semi-evergreen forests	Western Ghats, Andaman and Nicobar Islands, and the Eastern Himalayasmix of wet evergreen and moist deciduous and are dense.
Tropical Moist deciduous forests	throughout India except in the western and the north-western regions. tall, have broad trunks, branching trunks and roots firm to the ground.
Littoral and swamp	Andaman and Nicobar Islands and delta area of the Ganga, Brahmaputra. Roots have soft tissue to enable better breathing.
Tropical Dry deciduous forest	Forests found throughout India. Canopy does not exceed 25 mt.
Tropical Thorn forests	Forest found in areas with black soil: North, West, Central, and South India. Trees do not grow beyond 10 mts.
Tropical Dry Evergreen Forest	Tamil Nadu, Andhra Pradesh and Karnataka coast are hard-leaved evergreen trees with fragrant flowers, along with a few deciduous trees.
Sub-tropical Broad-leaved forests	Found in Eastern Himalayas and the Western Ghats, along the Silent Valley. They consists of wet forests and a sprinkling of deciduous.
Sub-Tropical Pine forests	Found in steep dry slopes of the Shivalik Hills, Western and Central Himalayas, Khasi, Naga, and Manipur Hills.
Sub-tropical Dry evergreen forests	Forests found in areas with prolonged hot and dry season and a cold winter.
Montane Wet Temperate Forests	Forests in east Nepal to Arunachal P where rainfall is > 200cm. Also found in higher reaches of Nilgiri.
Himalayan Moist Temperate Forest	These spread from the Western Himalayas to the Eastern Himalayas. West has broad leaved oaks, walnut etc and in East vegetation is thick ex ferns, bamboo etc.
Himalayan Dry Temperate Forest	Found in Lahul, Kinnaur, Sikkim and other parts of Himalayas, predominantly coniferous trees, along with broad-leaved trees such as the oak, maple, and ash.
Sub Alpine Forest	They extend from Kashmir to Arunachal Pradesh between 2900 to 3500 metres. In western part trees are juniper, willow etc and in East red fir, birch and larch.
Moist Alpine Scrub	Found all along the Himalayas and on the higher hills near the Myanmar border. Has low scrub, dense evergreen forest having mainly rhododendron and birch.
Dry Alpine Scrub	Are found from about 3000 metres to about 4900 metres. Dwarf plants predominate, mainly the black juniper, the drooping juniper, honeysuckle, and willow.

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State of Indian Forest Cover #Report 2019 #important

by Forest Survey of India under MoEFCC
Forest Cover (Area-wise) : Madhya Pradesh> Arunachal Pradesh> Chhattisgarh> Odisha> Maharashtra
Forest Cover (Percentage): Mizoram (85.4%)> Arunachal Pradesh (79.63%)> Meghalaya (76.33%)
Forest cover includes are with more than 10% canopy density and more than 1 hectare area.
Total forest cover is 712249 sq km ie 21.67% of total geographic area.
States with most increase are Karnataka (1,025 sq km) > Andhra Pradesh (990 sq km) > Kerala (823 sq km) > J&K (371 sq km) > Himachal Pradesh (334 sq km).
Forest Cover in NE is 65.05% of its geographic area.
Except Assam and Tripura all NE states showed decrease.
Tree cover is area with less than 1ha cover.
Indias tree cover is 2.89%. Maharashtra has the highest inc in tree cover.
Total Carbon stock of India is 7.124 bil tons.
Gujarat has the largest area of wetland followed by West Bengal.

Deforestation : Causes are Shifting cultivation, Development projects, fuel requirement from wood, raw material requirement of timber, overgrazing, agriculture, mining, urbanisation etc

4. Grassland :

rainfall 25-75 cm per year, found in temperate climates
In India, found mainly in high Himalayas rest of India has Steppes → forage only during wet season → grasses are always present
- Steppes occur in Western Rajasthan rainfall is 20cm. Soil is exposed, sometimes rocky w/ dunes
Savannas found in central and eastern Rajasthan rainfall is 50cm.
- Trees like Khetri grow.
- Serve as grazing land - leads to reduction of energy flow, breakdown of biogeochemical cycles.
- Fires are very common

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5. Desert :

There are 4 main types of deserts

Hot and Dry Deserts
- 25 cm of rainfall or regions with hot temperature, mid latitude regions
- perennial plant like creosote bush, cactus
- In shallow depressed areas with salt deposits - geesewood, seepwood (flora) and salt grasses are common.
- Siltation, salt accumulation is a problem
- Plants are mostly shrubs; leaves are absent or reduced, leaves and stems are succulent and store water. Stems could also contain chlorophyll. Roots are spread over large area.
- Animals are fast runners, nocturnal, excrete concentrated urine, have longs legs to keep away from hot ground, Seeds are imp source of water for animals.
Semi Arid Deserts
- are also known as steppe climate.
- are a little colder than deserts, summers are followed by winters with a little rain.
- mostly found in the fringes of subtropical deserts
Coastal Deserts
Cold Deserts
- rainfall 40cm and temp b/w 0 to -50 deg C.
- Soil : type is sandy to sandy loam, poor in organic matter, pH varies from neutral to alkaline with low water retention capacity.
- Asiatic Ibex, Tibetan Argali, Ladakh Uriyal, Bharal, Tibetan Antelope (chiru) etc are found.
- Trees are alpine mesophytes. Junipers, Birch, rhododendrons in Alphine zone are found. No vegetation found in perpetual snow zone.

Thar Desert

Flora in the Indian Thar desert could be divided into 2 :

Depending directly upon the rain :

Further divided into 2 types ephemerals and rain perennials.
Ephemerals are delicate annuals, do not have xerophilous adaptations, have a slender stem.
- Xerophilous adaptation are plant adaptation for very dry climated ex long roots, fleshy stems(cactii), thin leaves(acacia)
- they are short lived plants growing only when there is water availability or the climate is favorable.
Rain perennials are visible above ground only during rainy season, but have a perennial under ground stem.
- They grow throughout the year.

Depending on presence of subterranean water :

Well-developed root system, consists of slender woody tap root.
have xerophilous adaptations like reduced leaves, wax coatings, thick cuticles etc

Fauna in Indian Deserts

Great Indian Bustard, Blackbuck, wild ass, chinkara, caracal etc are found.
Flamingoes also found in Rann of Kutcch

Desertification :

Causes - Mining, over grazing, agriculture, Dev of activities, deforestation
Programs to counter - IWMP, NAP, NM for Green IN, National Watershed Dev, MGNREGA, Desert dev program