Forest Ecosystem and Desert ecosystem

Terrestrial ecosystem 

A terrestrial ecosystem is a land-based community of organisms and the interactions of biotic and abiotic components in a given area.

Division of Terrestrial Ecosystem

This ecosystem is of following types

1.Forest ecosystem.

2.Grassland ecosystem.

3.Desert ecosystem.

4.Tundra ecosystem.

1.Forest ecosystem

• These ecosystems have an abundance of flora or plants and hence in these ecosystems a large number of organisms live in a small space.

• This means that these ecosystems have a high density of living organisms

Classification of Forests in India

1. Moist Tropical forests

• Tropical Wet Evergreen Forests.

• Tropical Semi-evergreen Forests.

• Tropical Moist Deciduous Forests.

• Littoral and Swamp Forests.

2. Dry Tropical forests

• Tropical dry deciduous forest.

• Tropical thorn forests.

• Tropical dry evergreen forests.

3. Montane Subtropical Forests

• Subtropical broad-leaved hill forests.

• Subtropical pine forest.

• Subtropical dry evergreen forests

4. Montane Temperate Forests

• Montane wet temperate forests.

• Himalayan moist temperate forests.

• Himalayan dry temperate forests.

5. Alpine Forests

• Sub alpine forests.

• Moist-Alpine Scrub.

• Dry-Alpine Scrub.

1. Moist Tropical forests

Tropical Wet Evergreen Forests

• Tropical wet evergreen forests are characterized by dense vegetation and a tall canopy structure that can reach 30-45 meters.

• These forests typically occur in regions that receive high rainfall, ranging from 2000 to over 3000 millimeters per year.

• These forests are known for their high diversity of tree species, which contributes to their ecological importance and value for conservation.

• The distribution of tropical wet evergreen forests is discontinuous, with most occurrences found along the Western Ghats, northeastern India, and the Andaman and Nicobar Islands.

• Examples- jackfruit, betel nut palm, jamun, mango, and hollock , Rosewood, Mahogany, Aini, Ebony, etc.

Tropical Semi-evergreen Forests

• These forests occur in areas adjoining tropical wet evergreen, and form a transition between the evergreen and moist deciduous forests.

• Area-  Western Ghats, Andaman and Nicobar Islands, and the Eastern Himalayas.

• Lower canopy is evergreen, whereas canopy species are deciduous for short periods during the dry seasons.

• Bamboos, canes, ferns, climbers are common. Epiphytes are abundant including many ferns and orchids.

• These are not climate climax formations, but occur as edaphic sub climax on shallow poor soils.

• Tropical Semi-evergreen Forest type comprises 13.79% of the Indian forest types.

Tropical Moist Deciduous Forests

• The trees shed their leaves in winter months, again become flushed in March-April.

• These forests comprise 19.73% of India’s forest types.

• The aforementioned forests are extensively spread across both the southern and northern regions of India, encompassing states such as Tamil Nadu, Arunachal Pradesh, Assam, Meghalaya, Mizoram, Bihar, West Bengal, Odisha, and Uttarakhand.

• Example-Teak,Sal,sheesham etc.

Littoral and Swamp Forests

• Littoral and swamp forests are composed of evergreen species with different densities and heights, typically found in mesic environments.

• These forests are mostly in their developmental stage and are seral in nature.

• The tidal and swamp forests (mangrove scrub) are dominated by several evergreen and semievergreen species in deltas of the Ganga and the Brahmaputra River.

2. Dry Tropical forests

Tropical dry deciduous forest

• These are largest forest type of India covering about 38.2% of the forest area of the country.

• Tropical dry forests occur in climates exhibiting a marked seasonality in rainfall and prolonged drought period over the annual cycle.

• Example - Teak, sal, shisham, hurra, mahua, amla, semul, kusum, and sandalwood etc. are the main species of these forests.

Tropical thorn forests

• Tropical thorn forests are characterized by short, open trees and are dominated by thorny tree species.

• They typically occur in areas that receive less than 50cm of annual rainfall.

• Region - These forests are commonly found in regions with black soil, including North, West, Central, and South India.

• Examples- Babul, Acacia, Kokko, Khair, Khajuri, Ber, Neem, Khejri, Palas, etc.are common species of the forests.

Tropical dry evergreen forests

• The forests are restricted in distribution to Karnataka coast, also reported from the east coast in AP.

• There is a high diversity of trees, shrubs and herbs in these forests.

3. Montane Subtropical Forests

 Subtropical broad-leaved hill forests

• It occur in Hills of south india and Lower portion of Himalayas.

• climbers and epiphytes are common.

Sub-tropical Moist Pine Forests

• Distribution-Western Himalayas and Some hilly regions of Arunachal Pradesh, Manipur, Naga Hills and Khasi Hills.

• Chir or Chil is the most dominant tree

Sub-tropical Dry Evergreen Forests

• Sub-tropical Dry Evergreen Forests are typically found in the Bhabar, the Shiwaliks, and the western Himalayas up to around 1000 meters above sea level.

• The annual rainfall in these forests ranges from 50-100 cm.

• These forests are characterized by low scrub and small evergreen stunted trees and shrubs.

• Olive, Acacia modesta, and Pistacia are the most predominant species in this forest type.

4. Montane Temperate Forests

Montane Wet Temperate Forests

• It Grows at a height of 1800 to 3000 m above sea level.

• Examples- Deodar, Chilauni, Indian chestnut, birch, plum.

• The southern Montane wet temperate forests are closed evergreen forest, trees are mostly short and highly branched.

• The branches are clothed with mosses, ferns and other epiphytes, woody climbers are common.

• The northern Montane wet temperate forests are a characteristic feature of the eastern Himalaya and are found between 1800 m and 3000 m elevation in high rainfall areas ( >2000mm rainfall).

Shola Forest

• These forests are found in patches in the more sheltered sites on rolling grasslands.

• Occur in high hills of Tamil Nadu and Kerala on the, Anamalai, Palni and Tirunelveli hills from about 1,500 m upwards.

Himalayan Moist Temperate Forests

• These forests extend the whole length of the Himalayan region between the sub-tropical pine forest and sub-alpine forests.

• Altitude ranges from 1500m to 3300m.

• These are concentrated in the central and western Himalaya, except in areas where rainfall is below 1000 mm.

• Distributed in Kashmir, Himachal Pradesh, Punjab, Uttrakhand, Darjeeling district of west Bengal, Assam, and Sikkim

• Example-Pines, cedars, silver firs, spruce, etc.

Himalayan Dry Temperate Forests

• It has Conifers predominance.

• It is distributed on 1700 to 3000m altitude, in the inner ranges of Himalaya, rainfall usually less than 1000mm mostly received as snow in winter months.

• Distributed in Kashmir, Ladhakh, Lahaul, Chamba, inner Garhwal, and Sikkim.

• Example- deodar, oak, ash, olive, etc.

5. Alpine Forests

Sub-Alpine Forests

• Subalpine forests are found across the Himalaya above 3000 m elevation up to the tree limit.

• These forests receive rainfall between 83-600mm.

• Evergreen trees are the primary component of these forests, with Rhododendron being a common constituent.

Moist- Alpine Scrub

• Moist Alpine Scrub can be found throughout the Himalayas, growing above the timberline up to an altitude of 5,500 meters.

• This type of vegetation is predominantly made up of Rhododendron species, with some birch (Betula) and other deciduous trees present.

• The trees are characterized by short trunks and highly branched structures, while the ground is covered in moss and ferns.

• The soil in this type of vegetation is generally wet, with a thick layer of humus present.

Dry- Alpine Scrub

• It is a xerophytic formation, having predominance of dwarf shrubs; rainfall < 370mm per year

• Example- Juniper, silver fir etc.,

Uses of Forests

A.Direct uses of forest products

• Fruits – mango, jamun, awla.

• Roots – Dioscoria.

• Medicine – Gloriosa, Foxglove.

• Fuelwood – many species of trees and shrubs.

• Small timber for building huts and houses.

• Wood for farm implements.

• Bamboo and cane for baskets.

• Grass for grazing and stall feeding livestock.

B.Indirect uses of forest products

• Building material for construction and furniture for the urban sector.

• Medicinal products collected and processed into drugs.

• Gums and resins processed into a variety of products.

• Raw material for industrial products and chemicals.

• Paper from bamboo and softwoods.

Deforestation and its causes

• Deforestation is the clearing or permanent removal of forest areas so that it is available for other uses.

• Deforestation is the root cause for land degradation, soil erosion and desertification.

Causes of Deforestation

1. Natural causes -

• Such as hurricanes, fires, parasites and floods

2. Agriculture and plantations-

• The agricultural intensification, often called as industrial agriculture, has significantly increased the rate of deforestationb, impacted terrestrial and aquatic ecosystems , and resulted in large scale biodiversity loss as well.

3. Urbanization-

• Urbanization is a leading cause of deforestation that occurs due to growing populations, globalization, and capitalism.

• The expansion of residential areas, industries, commercial hubs, and development projects such as roads and railways often requires the clearing of forests.

4. Illegal logging-

• Illegal logging is a widespread problem in many forest regions around the world.

• The practice involves the unlawful harvesting of trees for various purposes, including decorative and medicinal uses.

• Illegally harvested wood from these regions often find their way into major markets in the US and Europe.

5. Forest Fires-

• Both natural and man made fires are also another reasons for Deforestation.

6. Mining-

• Mining has emerged as a crucial economic activity in response to the growing demand for metallic resources.

• The use of open-pit mining methods in large-scale mining operations has led to widespread deforestation.

Desert ecosystem

• The desert ecosystem is characterized by extremely low levels of rainfall, making it the driest ecosystem on Earth.

• As a result of this arid climate, there is generally less vegetation and a lower overall diversity of life in these regions.

Deserts in India

1. Thar desert

• The Thar Desert is one of the smallest deserts in the world, but it exhibits a wide variety of habitats and biodiversity.

• It is the most thickly populated deserts in the world.

• It is considered an important desert in terms of its location where Palaearctic, Oriental and Saharan elements of biodiversity are found.

Fauna

• The Great Indian Bustard., the blackbuck, wild ass, chinkara, caracal, Sandgrouse and desert fox inhabit the open plains, grasslands, and saline depressions.

• The nesting ground of Flamingoes and the only known population of Asiatic wild Ass lies in the remote part of Great Rann, Gujarat.

Flora-

• The desert vegetation is mostly herbaceous or stunted scrub; drought-resistant trees occasionally dot the landscape, especially in the east.

• On the hills, gum arabic acacia and euphorbia may be found. The khajri (or khejri) tree (Prosopis cineraria) grows throughout the plains.

2. Cold Desert of the Indian Trans-Himalayas-

• The Indian Trans-Himalayas, also known as the Indian cold desert, support very sparse vegetation.

Flora-

• Based on the physiognomy, three categories of natural vegetation are clearly discernible namely, Alpine Arid Scrub or Steppe formations, Alpine Arid Pastures and Marsh Meadows

• Examples-Junipers, Birch, Rhododendron with grasses, Oak, pine, deodar, birch and rhododendron are the important trees.

Fauna-

• This desert consists of significant faunas like Asiatic Ibex, Tibetan Argali, Ladakh Uriyal , Bharal, Tibetan Antelope (chiru), Tibetan Gazelle, Wild Yak, Snow Leopard, Brown Bear etc.

Desertification and its Causes

Desertification

• Desertification is an extreme case of land degradation in which semidry regions, becomes increasingly arid resulting in loss of water bodies, vegetation and wildlife.

• It is caused by a variety of factors, which includes both anthropogenic activities as well as climate change.

Causes of Desertification

• Overgrazing.

• Deforestation.

• Wrong farming Practices.

• Excessive Use of Fertilizers and Pesticides.

• Exploitation of groundwater.

• Land degradation due to mining.

• Global scale climate change

• Natural disasters.

Important one Liner on Forest Ecosystem.

What is a terrestrial ecosystem?

A terrestrial ecosystem is a land-based community of organisms and the interactions of biotic and abiotic components in a given area.

What are the different types of terrestrial ecosystems?

The different types of terrestrial ecosystems are forest, grassland, desert, and tundra.

What is a forest ecosystem?

A forest ecosystem is an ecosystem with an abundance of flora or plants, where a large number of organisms live in a small space, and hence has a high density of living organisms.

What are the different types of forests in India?

The different types of forests in India are moist tropical forests, dry tropical forests, montane subtropical forests, montane temperate forests, and alpine forests.

What are moist tropical forests?

Moist tropical forests are characterized by dense vegetation and a tall canopy structure that can reach 30-45 meters. These forests typically occur in regions that receive high rainfall, ranging from 2000 to over 3000 millimeters per year.

Where are tropical wet evergreen forests found in India?

Tropical wet evergreen forests are found along the Western Ghats, northeastern India, and the Andaman and Nicobar Islands.

What are some common tree species found in tropical wet evergreen forests?

Some common tree species found in tropical wet evergreen forests include jackfruit, betel nut palm, jamun, mango, Rosewood, Mahogany, Aini, and Ebony.

What are tropical semi-evergreen forests?

Tropical semi-evergreen forests occur in areas adjoining tropical wet evergreen forests, and form a transition between evergreen and moist deciduous forests.

What are tropical moist deciduous forests?

Tropical moist deciduous forests comprise 19.73% of India’s forest types and are extensively spread across both the southern and northern regions of India, encompassing states such as Tamil Nadu, Arunachal Pradesh, Assam, Meghalaya, Mizoram, Bihar, West Bengal, Odisha, and Uttarakhand.

What are littoral and swamp forests?

Littoral and swamp forests are composed of evergreen species with different densities and heights, typically found in mesic environments, and mostly in their developmental stage and are seral in nature.

What are tropical dry deciduous forests?

Tropical dry deciduous forests are the largest forest type in India, covering about 38.2% of the forest area of the country, and occur in climates exhibiting a marked seasonality in rainfall and prolonged drought periods over the annual cycle.

What are tropical thorn forests?

Tropical thorn forests are characterized by short, open trees and are dominated by thorny tree species. They typically occur in areas that receive less than 50cm of annual rainfall.

What are tropical dry evergreen forests?

Tropical dry evergreen forests are restricted in distribution to the Karnataka coast, and there is a high diversity of trees, shrubs, and herbs in these forests.

What are montane subtropical forests?

Montane subtropical forests include subtropical broad-leaved hill forests, subtropical pine forests, and subtropical dry evergreen forests, and are found in hills of South India and the lower portion of the Himalayas.

What are alpine forests?

Alpine forests include sub-alpine forests, moist-alpine scrub, and dry-alpine scrub and are found in high altitude areas of the Himalayas.