Biosphere Online test 11th Geography Lesson 5 Questions in English

The earth was formed 4.6 billion years ago. Geographers are concerned about the earth and its various spheres. These spheres did not exist on the primitive earth as they are today. They evolved over a long period of time after the earth was formed.

Scientists believe that the first life forms on earth came into existence about 3.5 billion years ago. Which marked, ‘The birth of the biosphere’

In the last 100 years, man has had used, overused and misused the natural resources of the earth. This has disturbed the ecological balance of the earth. The realization about the damage caused to earth by our action came when we began to experience global warming, desertification, increase in disease and distress and recurrence of severe natural disasters.

It was in 1962 that Rachel Carson published the book ‘Silent Spring’ which inspired an environmental movement thatled International agencies to focus their attention on protecting and sustaining the biosphere.

In 1971, UNESCO launched the Man and the Biosphere Program to study our impact on nature and how it could be minimized. Even after several decades the program still continues to shape the future of sustainability of the earth

The word Biosphere originates from the Greek words bios = life and sphaira = sphere.

Earth is the only planet in the solar system that supports life. There are many reasons that contribute to this and the most important being the earth’s distance from the sun, the presence of oxygen in the atmosphere and the presence of water

Existence and interaction of the three spheres of the earth (the lithosphere, hydrosphere and atmosphere) gives rise to the fourth sphere which is the life sphere or biosphere.

The term Biosphere was coined by Eduard Suessin 1875. Later contributions to the study of biosphere were from, Charles Darwin and many other scientists.

Thus, in the biosphere, life exists on land, water and air and life forms range from microorganisms to plants, animals, birds, amphibians, reptiles and mammals including human beings. The biosphere is formed of biotic components. It consists of organisms, population, community and ecosystem.

Biosphere: Living matter on earth including all plant and animal lifeforms. Hydrosphere: The water on the surface of the earth in oceans, rivers, lakes, rain and mist. Atmosphere: The thin, fragile layer of gases that surrounds the earth. Lithosphere: the earth’s crust including landforms, rocks and soils.

Organism – includes animals, plants and microorganisms. Population – is a group of similar plants or animals living in an area.

Life cannot exist in isolation. It flourishes in an environment which supplies and fulfills its material and energy requirements. A biotic community and its physical environment in which matter and energy flow and cycle is called as ecosystem.

The term ecosystem was first proposed by Arthur George Tansley in 1935. Tansley defined ecosystem as, ‘the system resulting from the integration of all living and non-living factors of the environment’. The ecosystems can vary in size. It can be very small, extending to about a few square centimeters or it can extend over many square kilometers. Example; tropical forests.

The ecosystem is made up of two main components: A. Abiotic Component and B. Biotic Component

This component of the ecosystem includes the non-living substance of the environment. Example; light air, soil, water, climate, minerals, etc. Sun is the main source of energy for the earth.

Biotic Component includes a variety of living organisms such as microorganisms, plants and animals. The biotic component of an ecosystem can be further divided into producers, consumers and decomposers based on their capacity to sustain themselves.

Organisms that can produce or manufacture their own food are known as producers. Plants that have green pigments or chlorophyll, produce their own food in the presence of CO2 in the atmosphere, water from the soil and sunlight through a process called ‘photosynthesis’.

The green plants are called as ‘autotrophs’ (auto – self; trophs – nourishing) as they manufacture their own food.

Consumers are organisms that cannot manufacture their own food and get their food and nutrients from producers directly or from other organisms. They are called as ‘heterotrophs’ (hetero – others; trophs – nourshing).

Consumers can be divided into primary, secondary and tertiary consumers.

Organisms that feed on producers (green plants) are called primary consumers. They are also called as ‘herbivores’ or plant eating organisms.

Examples of terrestrial herbivore are grasshopper, sheep, goats, cow, rabbit, deer, elephant etc. Examples of aquatic herbivores are zoo plankton, krill, squid, small fish, sea urchin, etc.

Animals that kill and eat the herbivores or plant eating animals are called secondary consumers. They are also called as ‘carnivores’, Example; lion, tiger, foxes, frogs, snakes, spider, crocodiles.

They are top predators in a food chain. They are carnivores at the topmost level in a food chain that feed on other carnivores or secondary consumers. Example: an owl eats a snake but an owl is eaten by a hawk, therefore a hawk is a tertiary consumer.

Tertiary consumers that occupy the top trophic level, and are not predated by any other animals are called ‘apex predators’. However, when they die their bodies will be consumed by scavengers besides the decomposers Example.

Some organisms eat both plants and animals. These animals are called as ‘omnivores. Example; cockroach, foxes, seagull and human.

When tertiary consumers die their bodies will be consumed by scavengers besides the decomposers Example; alligator andhawk.

Some omnivores are ‘scavengers’, which eat food that other animals have left behind Example; hyena and vultures.

Plants and animals that live on or inside other plants or animals are called as Parasites. Example; mistletoe lives on other plants. Other examples are tapeworms, round worms, lice, ticks, flea etc.

‘Detritivores’ are consumers that feed on detritus. Detritus includes fallen leaves, parts of dead trees and faecal wastes of animals. Ants, termites, earthworms, millipedes, dung beetle, fiddler crabs and sea cucumbers are detritivores.

Decomposers are organisms that help decompose dead or decaying organisms. Decomposers are also heterotrophs.

Decomposers are nature’s built-in recycling system. By breaking down materials – decomposers return nutrients to the soil. They, in turn, create another food source for producers within the ecosystem

Decomposers are organisms that help decompose dead or decaying organisms. Mushrooms, yeast, mould, fungi and bacteria are common decomposers.

Every living creature in an ecosystem has a role to play. Without producers, the consumers and decomposers would not survive because they would have no food to eat. Without consumers, the populations of producers and decomposers would grow out of control. And without decomposers, dead producers and consumers would accumulate as wastes and pollute the environment. All organisms of an ecosystem depend on one another for their survival. Each organism living in an ecosystem plays an important role in the flow of energy within the system.

Organisms need energy for respiration, growth, locomotion, and reproduction. This movement of energy is usually understood through food chains or food webs.

Movement of energy is usually understood through food chains or food webs. While a food chain shows one path along which energy can move through an ecosystem

A food chain starts the movement of energy from one trophic level to the next.

A food chain shows one path along which energy can move through an ecosystem, food webs show all the overlapping ways that organisms live with and depend upon one another.

Plant (primary producer) is eaten by a rabbit (herbivores, primary consumer), rabbit is eaten by a snake (carnivores, consumer or primary carnivore) and the snake is eaten by a hawk (tertiary consumer).

In a food web, the mouse might eat seeds, but it also might eat some grains, or maybe even some grass. The mouse might be eaten by a snake, or the eagle, or even a fox. The snake could be eaten by the eagle, but also might be eaten by a fox in the forest.

Each organism can eat multiple organisms and be eaten by multiple organisms, a food web is a much more realistic scheme of the transfer of energy within an ecosystem. Food chains and food webs are found in both terrestrial and aquatic ecosystems

Organisms in a food chain or food web are linked and dependent on one another for survival. If organisms in one trophic level become threatened, it impacts the organisms in other trophic levels. Primary consumers get less food due to loss or destruction of habitat.

If organisms in one trophic level become threatened, it impacts the organisms in other trophic levels. Primary consumers get less food due to loss or destruction of habitat. This in turn means less primary consumers for secondary and tertiary consumers to feed on. The plant and animal species in such an environment could become endangered or even extinct. For this reason, it is vital that an ecosystem remains balanced containing an appropriate proportion of producers and consumers.

Energy in an ecosystem flows from producers to consumers. The available energy in a food chain decreases with each step or trophic levels up in the food chain. As such, there is less energy available to support organisms at the top of the food chain. That is why the tertiary and quaternary consumers are far less in number in an ecosystem than organisms at lower trophic levels.

Energy pyramids are another tool that ecologists use to understand the role of organisms within an ecosystem. As you can see, most of the energy in an ecosystem is available at the producer level. As you move up on the pyramid, the amount of available energy decreases significantly. It is estimated that only about 10% of the energy available at one trophic level gets transferred to the next level of the energy pyramid.

The remaining 90 percent of energy is either utilized by the organisms within that level for respiration and other metabolic activities or lost to the environment as heat. The energy pyramid shows how ecosystems naturally limit the number of each type of organism it can sustain

Nutrients move through the ecosystem in cycles is called ‘biogeochemical cycles’. A biogeochemical cycle is a circuit or pathway by which a chemical element moves through the biotic and the abiotic components of an ecosystem.

All life processes are associated with the atmosphere by important cycles such as the Carbon, Oxygen, Nitrogen cycles etc. Through these cycles energy and materials are transferred, stored and released into various ecosystems.

Carbon is exchanged, or cycled among all the spheres of the earth. All living organisms are built of carbon compounds. It is an important component of many chemical processes

Carbon is an essential element in all organic compounds and since there is only a limited amount available it must be recycled continuously. This takes place in the biosphere.

Atmospheric carbon is fixed in green plants through photosynthesis. This carbon is passed on to other living organisms through the food chain. The carbon food compound is utilized and later released to the atmosphere through the process of respiration. By-products of respiration are carbon dioxide and water which are returned to the air.

A carbon cycle is completed by decomposers like bacteria and fungi which break down dead plants and animal tissues there by releasing some carbon to the air, water and soil.

All producers and consumers are not decomposed. The organic matter of some of them is preserved in fossil fuels such as coal and petroleum for millions of years.

In a carbon cycle, carbon moves between reservoirs. Carbon reservoirs include the atmosphere, the oceans, vegetation, rocks, and soil

Today, the carbon cycle is changing. Human activities have added more carbon into the atmosphere. More carbon is moving to the atmosphere when fossil fuels, like coal and oil, are burned. More carbon is moving to the atmosphere as humans destroy the forest

Increase in carbon in the atmosphere causes the earth to warm up more than the normal level, leading to climate change and many problems connected with it.

A carbon sinkis a natural or artificial reservoir that accumulates and stores carbon for an indefinite period. The process by which carbon sinks remove carbon dioxide (CO2) from the atmosphere is known as carbon sequestration

An ecosystem as already explained consists of a biological community and an abiotic environment. Ecosystem may be broadly divided into terrestrial ecosystem and aquatic ecosystem

Ecosystem may be broadly divided into land or terrestrial ecosystem and water or aquatic ecosystem. The aquatic ecosystem can be further divided into freshwater and marine ecosystem

An ecosystem becomes a biome when it extends over a large area. According to I.G. Simmons (1982) the most extensive ecosystem unit which is convenient to designate is called a ‘Biome’. It may be concluded that a biome is in fact a large ecosystem where we study the total assemblage of plant and animal communities.

Since vegetation is the most dominant component of a biome and as vegetation and climate are very intimately related, the world is divided into a number of biomes based on major world climatic types

World Biomes are mega ecosystems existing and operating over large areas. These divisions are based on climate pattern, soil types, and the animals and plants that inhabit an area. Basically, biomes are classified into two major groups such as Aquatic biomes and Terrestrial biomes.

To understand the earth biomes, it is necessary to understand the following - The distribution of flora in the area. The distribution of fauna in the area and their adaptation to the environment.

Fresh water biomes include areas of ponds, lakes, streams, rivers and wetlands. Lakes and ponds are stagnant water bodies and are smaller in their area. Many types of species live in the water, it is one of the most important natural resources that need to be protected.

These biomes are spread over all parts of the earth and have different set of species depending on their location and climate. Fresh water biomes include areas of ponds, lakes, streams, rivers and wetlands. Lakes and ponds are stagnant water bodies and are smaller in their area. The diversity of life forms in river changes with increasing water volume. For example, Dolphins are found in the river Ganges, Brahmaputra and the Indus which carry huge volumes of water.

Marine biome is an aquatic biome which is salt water biome occupying seas and oceans of the world. Marine biome plants have various roles, plants such as sea grasses and macro algae give shelter and nutrient for many animals.

Marine plants are sources of nutrients for the corals and help corals to build up reefs. The reefs are kept intact by plants like coralline algae. Corals are marine invertebrates which live in compact colonies. They inhabit tropical oceans and seas.

Corals cannot survive in waters below 20°C but grow optimally in temperatures between 23°–29° Celsius.

Coral reefs are marine ecosystems which are held together by structures made of calcium carbonate secreted by the corals

Sea grasses are plants that live in saltwater. There are over 50 species of sea grasses. Sea grasses have flowers, roots, and specialized cells to transport nutrients within a plant. This makes them similar to land plants and different from algae or seaweeds

Coral reefs are mainly classified into three types – Fringing reef, Barrier reef and Atoll

Barrier reefs also border the shoreline but are separated from the coast by an expanse of water or lagoon.

Atolls are coral reefs that are circular in shape enclosing a lagoon with absence of an island in the center. Fringing reefs grow seaward from the shore along the coast forming a fringe, they are the common type of reefs.

Marine biome includes fishes, whales, crustaceans, molluscs, sea anemones, fungi and bacteria. Marine species are continuously impacted by change in climatic condition and the oceans are frequently disturbed by ocean waves and currents.

Crustaceans are chiefly aquatic arthropods having a body covered with a hard shell or crust and several pairs of legs. Example: crab, lobsters, crayfish, barnacles shrimps, krill etc.

Molluscs are organisms with soft bodies. Often their bodies are covered by hard shells. Example: snail, slug, squid, cuttlefish, mussel, clams, oysters, octopuses etc.

A wetland is an area of land which is permanently or periodically saturated with water and exists as a distinct ecosystem.

Wetlands play many roles in the environment, such as water purification, flood control, carbon sink and shoreline stability. Wetlands are home to a wide range of aquatic plants and animal life

Wetlands can be freshwater, brackish, or saltwater. Examples of aquatic vegetation that thrive in wetlands are milkweed, bald cypress trees, mangroves and cattails.

A Bog is a type of wetland ecosystem characterized by wet, spongy, poorly drained peaty soil formed from dead plants specially moss

Bogs have moss, sedges, grasses, such as cotton grass; insectivorous plants like pitcher plants; and many orchids. The gradual accumulation of decayed plant material in a bog functions as a carbon sink.

A Fen is a low land that is covered wholly or partly with water. They receive nutrients from ground water and have peaty alkaline soil. Their characteristic flora are sedges and reeds.

Mangrove forests are found along the coast of Tamil Nadu in Pichavaram, Muthupet, Ramnad, Gulf of Mannar and Punnakayal

Mangrove swamps are coastal wetlands found in tropical and subtropical regions. These wetlands are often found in estuaries, where fresh water meets salt water. Mangrove trees dominate this wetland ecosystem due to their ability to survive in both salt and fresh water

The Sundarbans is the largest Mangrove region in the world and a UNESCO World Heritage Site.

Terrestrial biomes are very large ecosystems over land and they vary according to latitude and climate. They can be divided into numerous sub-types.

This forest biome has innumerable insects, birds, reptiles and furless animals. At the edge of the forest animals like gorilla, and monkey are found.

This biome is seen in the Amazon Basin of South America, Congo Basin of Africa and the Indo Malaysian Region of Southeast Asia (Java, Sumatra, Borneo, Malaysia and Guinea)

This biome receives direct sunlight throughout the year and so temperatures are high year round

The average annual temperature is 20°C to 30°C. The average annual rainfall of the tropical evergreen rain forest is 200cm.

The Tropical Evergreen Rain Forest Biome has the largest number of plant and animal species. Broad leaved, tall evergreen hard wood trees are found in this biome. Trees grow up to 20 to 35 meters high.

The forest is characterized by thick undergrowth and creepers. The main trees in this biome are mahogany, rose wood, ebony, cinchona, rubber, coconut palm, cane, bamboo etc. This forest biome has innumerable insects, birds, reptiles and furless animals. At the edge of the forest animals like gorilla, and monkey are found.

Important tribes inhabit in tropical evergreen forest biome, for example the Pygmies in the jungles of Africa and the Yanomani and Tikuna tribes of the Amazon region. Traditionally they live by hunting and gathering food.

The forests of the Silent Valley National Park in Kerala on the Western Ghats are the last remaining tropical evergreen forests in India. It is part of the Nilgiris Biosphere Reserve.

In the recent years in South East Asia, the tropical evergreen rainforest has been slowly replaced by rubber and sugarcane plantations

Tropical deciduous forest is found in the regions experiencing monsoon climate. This biome is also called as the dry forest or monsoon forest biome

This is found in South and South East Asia in parts of India, Myanmar, Vietnam, Thailand, Cambodia and southern coastal China. It is also found in eastern Brazil and in smaller areas in South and Central America, the West Indies, southeastern Africa, and northern Australia.

In this biome, the temperature varies from one season to another season. In summer the maximum temperature ranges from 38°C to 48°C. Summer season is warm and humid. In the dry winter season temperature ranges between 10°C to 27°C.

The total amount of precipitation is 75 to 150 cm/year and this affects the natural vegetation of the tropical deciduous forest biome.

The plants shed their leaves during the dry season. Trees here have huge trunks with thick rough barks. The plants grow at three different levels. The common trees are teak, sal, sandalwood, mahua (illupai), Mango, Wattle, Bamboo, semal (Illavamaram), sheesham (Karuvellamaram) and banyan.

The monsoon forest biome faces rapid rate of deforestation and is, therefore, one of the most disturbed ecosystem in the world. Large tracts of forests have been destroyed for agriculture and urban development. Several species of precious animals have now become endangered Example: lions, tigers, leopards, etc.

The temperate deciduous forest is a biome that is always changing. This biome lies in the mid- latitude areas of the earth, between the tropics and Arctic Circle i.e., between 30° and 50° north and south of the equator

The temperate deciduous forest biome can be seen in the eastern United States, most parts of Europe, China, Japan, North and South Korea. The average annual temperature is 10°C

These biomes have four seasons such as winter, spring, summer and fall. Winters are cold and summers are warm. As winter approaches, the duration of day light decreases. In this biome, deciduous trees shed their leaves in the fall..

The production of chlorophyll in the leaves slows and eventually stops revealing leaves having bright red, yellow and orange colors. These forests are also known as broad leaved forest, because the trees have wide flat leaves

Some important trees found in temperate deciduous forest are oak, maple, beech, hickory, cedar and chestnut.

Inhabiting the temperate deciduous forest are ants, insects, flies, bees, wasps, cicadas, walking sticks, moths, butterfly, dragon flies, mosquitoes and praying mantises. Frogs, toads, snakes and salamanders are some of the reptiles in this biome. Common birds found in this biome are woodpecker, robin, jays, cardinals, owls, turkeys, hawks and eagles

Small mammals like rabbits, otters, monkeys, beavers, squirrels and porcupine are also seen in this biome along with bears, grey fox, wolves, white tailed deer and moose. Animals that live in this biome adapt to the changing seasons. Some animals migrate or hibernate in winter

Most of this forests on the earth are cleared for agriculture. The soil here is very fertile. This is one of the most important agricultural regions of the world.

Grasslands are found bordering the deserts and make up for one fourth of the natural vegetation of the earth. Those that lie in the low latitudes are called tropical grasslands and the ones which lie in the mid latitudes are called temperate grasslands

The tropical grass land biome is generally referred to as the Savanna biome. A savanna is a rolling topography that features vast open grasslands scattered with small shrubs and isolated trees.

It is found between the tropical rainforest and desert biome. Tropical grassland biomes are mainly found in Africa, South America and Australia.

Tropical grasslands in Africa is known as the savannas. Tropical grasslands are called as llanos in Columbia and Venezuela and as Campos in Brazil of South America.

Savanna biomes experience warm temperature year around. It has very long and dry winter season and a very wet summer season. The grass here is very tall often one or two meters

Savanna biomes experience warm temperature year around. The grass here is very tall often one or two meters tall scattered with small shrubs and isolated umbrella shaped trees like the acacia and the baobab trees which store water in their trunks.

In many parts of the savannas of Africa people have started using the grassland for grazing their cattle and goats. Due to overgrazing in this region most of the tropical grasslands here are lost to the Sahara desert year after year

The temperate grassland biomes are generally found in the interior of the continents in the mid latitudes. These grassland biomes are found in the transitional zone between the humid coastal areas and the mid latitude deserts

The temperate grasslands are known as Steppes in Europe and Asia, Prairies in North America (Canada and USA), Pampas in South America, Veldts in South Africa, Downs in Australia and Puszta in Hungary

The annual range of temperature is quite large with summer temperature reaching as high as 38°C and winter temperatures falling down to -40° C.

The rainfall is moderate from 25 cm to 50 cm. Grasses form a major part of the vegetation in the temperate grasslands. The height of the grasses depends upon the amount and distribution of rainfall.

The animals in this area include the bison, wolves of the Prairies of North America. The other animals and birds are coyotes, prairie dog, foxes, mice, rabbits, badgers, rattle snakes, pocket gophers, weasel, grasshoppers, quails and hawks.

A tropical desert is the hottest and driest place on earth where rainfall is very scanty and irregular. This biome is typically found in the western parts of the continents within the tropics.

In the northern hemisphere, the Afro – Asian deserts form the longest belt which includes the Sahara desert, Arabian desert and the Thar deserts

In the northern hemisphere, the Afro – Asian deserts form the longest belt which includes the Sahara desert, Arabian desert and the Thar deserts. In North America the tropical deserts cover, California, Arizona and New Mexico states of USA and it further extends to Mexico.

The deserts in the southern hemisphere are, the Atacama desert west of Andes mountains in South America, the Namibian and the Kalahari deserts in southern Africa and the Great Australian desert in the central and southern parts of Australia.

The tropical deserts are not conducive for the growth of vegetation due to shortage of water. The plants found here are the xerophytes which have their own moisture conserving methods such as long roots, thick barks, waxy leaves, thorns and small leaves so as to avoid evapotranspiration.

The main trees and bushes found in desert region are acacia, cacti, date palm, kikar, babul etc.

The animals in this biome are limited in number. They are able to bear the drought and the heat of the desert. Animals like the camel, antelopes, fox, spotted hyena, fallow deer, cape hare, hedgehog etc., live in the desert.

The people in the deserts are generally nomads living in tents and moving from place to place. They are the Berbers of North Africa

The people in the deserts are generally nomads living in tents and moving from place to place. They are the Berbers of North Africa, the Bedouins of the Arabian deserts, the Damara in Namibia, the Bushman of the Kalahari Desert and the Aborigines of Australia

The nomads in desert region practice food gathering and hunting while some herd cattle, goats and camel and some of them practice very simple subsistence farming.

One of the toughest foot races in the world is held in Sahara every year in April. This race is called The Marathon des Sables (MDS) and participants have to cover a distance of 250km over Sahara desert in southern Morocco in a span of 7 days. About 1500 participants aged between 16 to 79 from all over the world participate in this race.

The taiga biome is the largest terrestrial biome and extends across Europe, North America and Asia

The taiga biome is also known as coniferous forest or boreal forest biome. It extends from about 50° to 55° North to 65 ° to 70° North latitudes.

This region lies between the temperate grassland in the south and the polar tundra in the north. The taiga region is absent in the southern hemisphere mainly because of the narrowing of continents towards the South Pole.

The taiga biome has short wet summer and long cold winters. The taiga region has low mean annual precipitation ranging between 35 cm and 60 cm and the rainfall occurs mostly in summer. It receives plenty of snow during winter.

The taiga or boreal forest biome consists mainly of evergreen coniferous forests. The important coniferous trees in this biome are pines, spruces, firs, maples and cedars. During the short summer season snow melts and this helps lichens, mosses and short grasses to grow and cover the ground. These are called ‘meadows’.

Taiga is the home of some larger animals like moose, deer, and bears, while smaller animals like bobcats, squirrels, chipmunks, ermine, and moles are also found. Animals of the taiga have specialized adaptation including lot of thick fur or feathers and the ability to change colors during different seasons. Example ermine.

The ermine is a small mammal, which is covered with thick dark brown fur in summer. This changes to white in the winter, an adaptation which helps the ermine to blend into its surroundings and makes it more difficult for the predators to spot them.

Lumbering is the main occupation of the people in areas which are easily accessible. The softwood from the coniferous forests is widely used in the manufacture of wood pulp and paper, newsprint, matches, furniture and building materials.

The hunting of fur bearing animals like musk rats, ermine, and silver fox are important economic activities. The taiga forest is endangered due to logging and mining by humans. When trees are cut down in the taiga it takes a very long time to restore itself because of the very short growing season.

Tundra is a Finnish word which means barren land. The tundra region is a vast bowl lying beyond the Arctic Circle (66.5° North latitude) in the northern hemisphere along the shores of the Arctic Ocean. The Arctic tundra extends southwards from North Pole to the Taiga forest.

Tundra is also found in the high altitudes especially in the Alpine region.Due to long and severe cold winters, this region is treeless and has very little vegetation. The growing season for plants is very short.

The main features of this climate in the tundra region are the general absence of insolation and presence of very low temperature throughout the year. The average annual temperature is about -12°C. The ground surface is covered with snow for at least 8 to 9 months in a year.

In this tundra biome, the sub soil remains permanently frozen and is known as permafrost. Permafrost tundra covers vast barren areas of northern Russia and Canada. Algae and fungi are found on the rocky cliffs and rosette plants grow in rock and gravel beds. Spongy turf and lichen develop in the drier inland tundra

Animals common to Arctic tundra are the polar bear, arctic wolf, arctic fox, arctic hare and arctic weasel. Large herbivores such as musk oxen, caribou and reindeer are found. Lemmings are also found in this Biome. Insects like moths, butterflies, beetles, mosquitoes and black flies are common in the Arctic tundra. Migratory birds include tundra swans, harlequin

The Antarctic region is covered with ice sheets. It is too cold and dry to support vegetation. However, some portions of the continent have areas of rocky soil that support plant life. Vegetation comprises of mosses, lichens and liver worts. This area is referred to as Antarctic tundra. Seals and Penguins inhabit the shore areas of Antarctica.

The term biological diversity was used as early as 1968 by wildlife conservationist Raymond F. Dasmann. Latter in 1988, entomologist E.O. Wilson used the term Biodiversity and this term has been used since then.

Biodiversity refers to the variety of life on Earth. This includes the number of species of plants, animals and microorganisms along with the diversity of genes in these species. Moreover, it embodies the different ecosystems on the planet, for example forests, deserts, coral reefs and wetlands

Biodiversity can be identified at three levels: A. Genetic diversity, B. Species diversity and C. Ecosystem diversity

Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of a species. Example: Each human being is very different from others. Genetic diversity helps the population to adapt to changes in the environment or adapt to different environments. Domestication of dogs can be taken as a common example.

Species diversity is the number of different species of plants and animals that are present in a region. A community with more number of species enjoys species richness naturally undisturbed forests have greater species richness than reforested areas or plantations

Endemic species - is one whose habitat is restricted only to a particular area because of which it is often endangered. It differs from “indigenous,” or “native,” which although it occurs naturally in an area, is also found in other areas.

Exotic Species - is any species intentionally or accidentally transported and released by man into an environment outside its original range. These are often the most severe agents of habitat alteration and degradation, and a major cause of the continuing loss of biological diversity throughout the world.

It is a species that is found to be distributed over most regions of the earth example: cats, dogs, human beings. The killer whale is considered as the most cosmopolitan species in the world.

Ecosystem diversity refers to the variety of life forms in a prescribed ecosystem. Ecosystems may be both terrestrial and aquatic. Distinctive terrestrial ecosystems include forests, grasslands, deserts, etc. while aquatic ecosystems are rivers, lakes, oceans etc

Of this only about 2 million are known to us ranging from microorganisms to giant mammals and reptiles. New species are being discovered while many species are also disappearing from the face of the earth.

Areas that are rich in species diversity are called as “Hotspots”. The hottest spots for species diversity are the tropical rainforests. Tropical rainforests comprise of only 7% of all land on earth, yet are home to nearly 50% of all the species on Earth! India is among the World’s 17 nations that are exceptionally rich in species diversity.

The British biologist Norman Myers coined the term ‘biodiversity hotspot’ in 1988. According to him, a biodiversity hotspot is a biogeographic region characterized both by exceptional levels of plant endemism and by serious levels of habitat loss

Conservation International (CI) adopted Myers concept of ‘hotspots’ and it made an extensive global study of hotspots in 1999. According to CI, to qualify as a hotspot a region must meet two strict criteria: (i) It must contain at least 1,500 species of endemic plants, and (ii) It must have lost at least 70% of its original habitat

In 1999, CI’s book ‘Hotspots: Earth’s Biologically Richest and Most Endangered Terrestrial Ecoregions’, identified 34 biodiversity hotspots in the different countries of the world.

Norman Myers (born 24 August 1934) is a British environmentalist specializing in Biodiversity hotspots. Professor Norman Myers was the first to alert global community to tropical deforestation, the mass extinction underway and environmental security

Endemism is an ecological word meaning that a plant or animal lives only in a particular geographical location, such as a specific island, habitat type, country or any defined zone. For example, The Asiatic Lion of the Gir forest of Gujarat

The Kashmir Stag known as Hangul, which is found in the riverine forests of Kashmir Valley and Chamba in Himachal Pradesh.

The Lion Tailed Macaque is India’s most threatened monkey which is endemic to the Western Ghats of South India

Currently there are 34 biodiversity hotspots that have been identified and, most of them occur in tropical forests. They represent just 2.3% of Earth’s land surface, but between them they contain around 50% of the world’s endemic plant species and 42% of all terrestrial vertebrates

India has 4 biodiversity hotspots: the Western Ghats, the Himalayas, the Indo-Burma region and the Sundaland [includes Nicobar group of Islands]

CI has helped to support 1,200 protected areas across 77 countries, safeguarding more than 601 million hectares of marine and coastal areas.

The International Union for the Conservation of Nature (IUCN) has identified and classified species based on the nature of their depleting numbers. The IUCN’s Red List of Threatened Species, identified in 1964, is the world’s most important inventory of the global conservation status of biological species

They are Extinct, Extinct in the wild, Critically Endangered, Endangered, Vulnerable, Near threatened, Least concern, Conservation dependent, Data deficient.

Species are classified by the IUCN Red List into nine groups specified through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation

Extinct (EX) – The species has disappeared and no known individuals remaining. Extinct in the wild (EW) – Known only to survive in captivity, or as a naturalized population outside its historic range

Endangered (EN) – High risk of extinction in the wild. Vulnerable (VU) – High risk of endangerment in the wild

Conservation dependent (cd) – This group has now merged with near threatened. Least concern (lc) – Lowest risk widespread and abundant

Data deficient (dd) – Not enough data to assess the risk of extinction of the species. Not evaluated (ne) – Species not yet been evaluated against the criteria.

In the context of the IUCN Red List, ‘threatened’ embraces the three categories of Critically Endangered, Endangered, and Vulnerable.

According to the IUCN those species that have dwindled drastically are called as Critically Endangered and are included as Red List. Species that have disappeared are called as extinct species.

In the Red List of 2012 that was released on 19 July 2012 at Rio+20 Earth Summit 19,817 species were threatened with extinction.

The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded in 1964, is the world’s most comprehensive inventory of the global conservation status of biological species.

The International Union for Conservation of Nature (IUCN) is the world’s main authority on the conservation status of species. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.

A Hawaiian plant species called Alula locally referred to as cabbage on a stick has moved from Critically Endangered to Extinct in the Wild.

It is one of the 38 Red Listed Hawaiian plant species with less than five wild individuals remaining. It used to grow on the windy sea cliffs of Kauai

Alula was destroyed by hurricanes Iwa and Inki in 1982 and 1992 leaving only less than 10 plants alive

The majority of the great ape species are now Critically Endangered. The Eastern Gorilla the largest living primate is endemic to the Eastern Democratic Republic of Congo, south western Uganda and Rwanda.

This species which was listed as Endangered has moved to Critically Endangered in 2016 due to an ongoing population decline. This decline is due to illegal hunting and destruction of forests for agriculture. If this trend continues, around 93% of Eastern Gorillas will be eliminated by 2054.

The Pygmy Hog: It is the smallest and rarest wild pig on earth and it is a Critically Endangered species previously spread across Bangladesh, Bhutan, India and Nepal. But now only found in Assam, India.

In 1995, the Pygmy Hog Conservation Program was started by Goutam Narayan of Ecosystems-India, with the help of the Assam government and now their numbers have increased to about 150

Critically Endangered bird species in India 2016- Siberian crane. Indian vulture, Himalayan quail, Pink-headed duck

Critically Endangered species in India 2016 Arthropod - Rameshwaram parachute spider, Peacock tarantula. Reptiles and amphibians -Madras spotted skink Gharial, Toad-skinned frog, Charles Darwin’s frog, White-spotted bush frog, Munnar bush frog, Ponmudi bush frog, Anaimalai flying frog