WBBSE Notes For Class 8 School Science Chapter 10 Biodiversity Environmental Crisis and Conservation of Endangered Animals

Chapter 10 Biodiversity Environmental Crisis and Conservation of Endangered Animals

 

Introduction

Living organisms are characterized by diversity. Our earth supports nearly 5 to 10 million species of plants and animals.

Biodiversity (or Biological diversity) is defined as the variability among living organisms from all sources including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part.

Biodiversity is the foundation of life on earth. It is crucial for the functioning of ecosystems which provide us with products and services without which we couldn’t live.

Oxygen, food, fresh water, fertile soil, medicines, shelter, protection from storms and floods, stable climate and recreation – all have their source in nature and healthy ecosystems.

But biodiversity gives us much more than this. We depend on it for our security and health; it strongly affects our social relations and gives us freedom and choice.

WBBSE Class 8 Biodiversity notes

Conservation is the protection, preservation, management, or restoration of wildlife and natural resources such as forests and water.

Through the conservation of biodiversity, the survival of many species and habitats which are threatened due to human activities can be ensured.

Other reasons for conserving biodiversity include securing valuable Natural Resources for future generations and protecting the well-being of ecosystem functions.

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Forest

A forest is a large area of land covered with trees or other woody vegetation. Hundreds of more precise definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function.

According to the widely- used United Nations Food and Agriculture Organization definition, forests covered an area of approximately 30.6 percent of the world’s land area in 2015.

Components of forests

 

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Plants: A forest has many plants (including trees) that are called producers or autotrophs.

Animals: The animals of a forest are called consumers. They may be herbivores or carnivores. The animals are together called heterotrophs.

Decomposers: The microorganisms which break down the dead parts of plants and dead bodies of animals into simple substances such as mineral salts, C02, and water (which can be reused by plants) are called decomposers. These include fungi, bacteria, etc which are saprotrophs.

The decomposers return the nutrients present in dead plants and animals to the soil to maintain the supply of nutrients to the plants. prevent the piling up of dead plants, dead animals, and animal wastes inside the forest by carrying out decomposition.

Scavengers: Those animals which eat dead animals are called scavengers. Vultures, crows, jackals, etc are scavengers. They eat up dead bodies to keep the forest environment clean.

The forest is an ecosystem of self-sufficient units of living things and nonliving environment

Classification of forests

Forests can be classified in different ways and to different degrees of specificity. One such way is in terms of the biome in which they exist, combined with the leaf longevity of the dominant species (whether they are evergreen or deciduous).

Another distinction is whether the forests are composed predominantly of broadleaf trees, coniferous (needle-leaved) trees, or mixed. Forests come in all shapes and sizes. The many different types of forests are generally classified according to location and climate.

1. Tropical rainforests: Year-round high temperatures and abundant rainfall make this a dense, lush forest. Tropical rainforests are found near the equator.

They are vital storehouses of biodiversity on the planet, and yet face severe threat today, with much of their original extent depleted.

Trees in tropical rainforests grow between 82 and 115 feet tall and are typically broad-leafed trees. Other plants include ferns, vines, mosses, palms, and orchids.

2. Subtropical dry forests: These are found to the south and north of the tropical forests. The climate here is warm year-round with low rainfall. The trees here are adapted to resist the summer drought.

3. Mediterranean forests: These forests are found to the south of the temperate regions around the coasts of the Mediterranean sea, California, Chile, and Western Australia.

The growing season is short and almost all trees are evergreen, but mixed hardwood and softwood. Pine, Oak, and Berber tree are found here.

4. Temperate forests: Found in such places as eastern North America, Northeastern Asia, and Western and Eastern Europe. Temperate forests need only the input of sunlight for their functioning.

The nonliving things are air, water, and soil. Living organisms like plants interact with soil, water, air, and sunlight to carry out photosynthesis.

Living organisms like plants, and animals interact with each other through food chains. Decomposers play their role when the living components of a forest die.

This process goes on and on like an unending chain. are a mix of deciduous and coniferous evergreen trees. There are well-defined seasons with a distinct winter and sufficient rainfall.

 

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Maple, oak, and birch trees are some examples of the deciduous trees that dominate these forests. There are also small numbers of evergreen trees such as pines and fir.

Animals living in temperate deciduous forests must be adapted to cold winters. Common species found in temperate deciduous forests include red foxes, hawks, woodpeckers, and cardinals.

5. Coniferous forests: Coniferous forests inhabit the cold, windy regions around the poles. There are both hardwoods and conifers found in this region.

The conifers are evergreen and structurally adapted to withstand the long drought-like conditions of the long winters, whereas the hardwoods are deciduous.

Evergreen conifers dominate these forests. Due to the high levels of precipitation and moderate temperatures, there is a long growing season, resulting in trees that grow very tall.

Dominant tree species found in temperate coniferous forests include cedar, cypress, Douglas fir, pine, spruce, and redwood. There are some deciduous trees such as maple, and mosses and ferns are common.

Examples of animals that live in temperate coniferous forests are deer, marmot, elk, black bear, salmon, spotted owl, etc.

6. Montane forests: These are also known as cloud forests because they receive most of their precipitation from the mist or fog that comes up from the lowlands.

Some of these montane woodlands and grasslands are found in high-elevation tropical, subtropical, and temperate zones. Plants and animals in these forests are adapted to withstand the cold, wet conditions and intense sunlight. Trees are mainly conifers.

Coniferous trees like pine, deodar, silver fir, spruce, and cedar abound in such forests. Kashmir stag, spotted deer, wild sheep, jackrabbit, Tibetan antelope, yak, snow leopard, squirrels, Shaggy horn wild ibex, bear, rare red panda, sheep, and goats are the common animals in these forests.

Plantation forests: There are around 140 million hectares of “plantation forests” in the world, accounting for around 7% of global forest cover.

The productivity of planted forests, in terms of supplying a sustainable volume of timber and fiber, is usually greater than natural forests. Plantations produce around 40% of industrial wood.

Both the plantation area and contribution to world wood production are projected to continue to increase in the foreseeable future.

7. Grasslands: Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees.

There are two main divisions of grasslands: Savanna is grassland with scattered individual trees.

1. Savannas of one sort or another cover almost half the surface of Africa (about five million square miles, generally central Africa) and large areas of Australia, South America, and India.

The climate is the most important factor in creating a savanna. Savannas are always found in warm or hot climates where the annual rainfall is from about 50.8 to 127 cm (20-50 inches) per year.

The savannas experience a surgery of new life at this time. For example, many antelope calves are born. With so much grass to feed on, mothers have plenty of milk.

Calves die if the rains fail to come. Other animals (which do not all occur in the same savanna) include giraffes, zebras, buffaloes, kangaroos, mice, moles, gophers, ground squirrels, snakes, worms, termites, beetles, lions, leopards, hyenas, and elephants.

2. Temperate grasslands are characterized as having grasses as the dominant vegetation. Trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less in temperate grasslands than
in savannas.

The fauna (which do not all occur in the same temperate grassland) include gazelles, zebras, rhinoceroses, wild horses, lions, wolves, prairie dogs, jackrabbits, deer, mice, coyotes, foxes, skunks, badgers, blackbirds, grouses, meadowlarks, quails, sparrows, hawks, owls, snakes, grasshoppers, leafhoppers and spiders.

9. Mangrove forests: Mangrove forest is found in silt-rich, saline (brackish water) habitats worldwide, generally along large river deltas, estuaries, and coastal areas.

It is characterized by low tree diversity, almost exclusively mangroves, with a low broken canopy. Mangroves are evergreen trees and shrubs that are well adapted to their salty and swampy habitat by having breathing roots (pneumatophores) that emerge from the oxygen-deficient mud to absorb oxygen.

Mangrove swamps are home to numerous bizarre amphibious fish species like the mudskippers of eastern Africa to Australia. In West Bengal, these forests can be seen at Sunderbans.

The Vertical stratification of a forest

Evergreen forests, such as the Amazon Rainforest and the tropical rain forests have a peculiar structure, in terms of the layers in which the trees are organized.

This organization is shaped mainly by abiotic factors such as humidity, sunlight, wind, etc. There are six basic layers namely the emergent, canopy, understory, shrub layer, herb layer, and forest floor.

The Emergent layer: The Emergent layer is made up of the tallest trees, spaced out, usually with straight branch-free trunks (large trees are about 16ft in diameter), with a crown on the tops.

They are about 100 ft – 200 ft tall with supporting buttress roots spreading up to about 20-30ft. The trees have small pointed leaves, which are adapted to withstand wind action over tree tops.

Trees here are in constant sunlight. Birds such as hummingbirds and parrots are common. Animals here tend to be lightweight and include the Sloth and the Spider, Monkey. The Brazil Nut tree and Kapok Tree are common trees in this emergent layer.

 

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The Canopy: The Canopy is the layer that stops sunlight and rainwater from getting to the layers below it.

The trees grow up to about 130 ft and have broader leaves and drip spouts. This leaf feature makes rainwater drip down quickly rather than staying on the leaves.

There are millions of insects and animals in this layer as they have enough food to keep them there. Common animals include squirrels, monkeys, reptiles, bats, and a variety of birds.

Visibility is low from the thickness of leaves and the network of branches. As a result, animal sounds are loudest in this layer because they communicate with sounds.

The Understory: The Understory has fewer trees, but lots of shrubs and small trees growing up to about 12 ft high – The area is made up of carnivores, many of which have climbing abilities.

Animals are also larger in size and heavier than animals in the other layers. They include scorpions, armadillos, wild cats, mongooses, lizards, snakes, and a variety of insects.

The Shrub layer: The shrub layer consists of mature shrubs and bushes and lies just below the understory. It has a smaller vegetation which is between 3 ft to 6 ft in height from the forest floor.

The animals such as deer and bears obtain a lot of food from the shrub layer of vegetation. Many of the shrubs depend on animals for the dispersal of their seeds. There is not much sunlight in the shrub layer.

The Herb layer: The herb layer is the lowest layer of vegetation in the forest having leafy plants belonging to herbs, ferns, and grasses.

This layer ranges from the forest floor to about 3ft in height. Very little sunlight remains for the plants in the herb layer.

The plants grow and flower early in the season so as to get sufficient sunlight before the canopy leaves open and obstructs sunlight. Most of the plants in the herb layer have short life cycles.

The Forest Floor: The forest floor is the ground level of the structure. It has shallow soils of poor quality, with microorganisms and life- forms feeding on decaying matter on the floor.

The moist, dark conditions aid decomposition of organic matter, and nutrients are quickly absorbed by the trees and other plants on them. There is very little light here. Animals that are found here are herbivores and

Importance of Forests

Forests and biodiversity are key to all life forms. Forests have always had great importance to people. Prehistoric people got their food mainly by hunting and gathering wild plants.

Many of these people lived in the forest and were a natural part of it. With the development of civilization, people settled in cities. But they still went to the forest to get timber and hunt. Below is some more importance of forests:

Watershed: Forests serve as a watershed. This is because almost all water ultimately comes from rivers and lakes and from forest-derived water tables. Some rivers running through forests are also kept cool and prevented from drying out.

Habitat and Ecosystems: Forests serve as a home (habitat) to millions of animals. Think . of the many types of reptiles (snakes and lizards) wild animals, butterflies and insects, birds, and tree-top animals as well as all those that live in the forest streams and rivers.

Animals form part of the food chain in the forests. All these different animals and plants are called biodiversity, and the interaction with one another and with their physical environment is what we call an ecosystem.

Healthy ecosystems can better withstand and recover from a variety of disasters such as floods and wildfires.

Economic benefits: Forests are of immense economic importance to us. For example, plantation forests provide humans with timber and wood, which are exported and used in all parts of the world.

They also provide tourism income to inhabitants (people living in or close to forests) when people visit to see the best of nature.

Climate control: Climate control and atmosphere purification are key for human existence. Trees and soils help regulate atmospheric temperatures through a process called evapotranspiration. This helps to stabilize and cool the climate.

Additionally, they enrich the atmosphere by absorbing bad gases (for example C02 and .other greenhouse gases) and producing oxygen. Trees also help to remove air pollutants.

Control of soil erosion and flood: The roots of trees and plants growing in the forest bind the topsoil particles and hold the soil together. Due to this, strong winds and flowing rainwater are not able to carry away the topsoil. Hence soil erosion is prevented.

The cover of trees and many layers of vegetation in the forest softens the effect of heavy rain on the soil due to which the soil does not become loose. Thus, forest help in the conservation of soil.

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The forest floor is covered with a lot of decaying material and small vegetation which absorbs most of the rainwater which falls down during heavy rain.

The roots of trees help the rainwater to seep into the forest ground and raise the water table. The forest releases this absorbed water slowly and steadily into rivers through the soil.

By holding back rainwater and then releasing it slowly into rivers, the forests prevent the occurrence of floods in the rivers.

Uses of forests

People began life on this planet as forest dwellers. They were food gatherers and depended on the forest for all their needs: food, clothing, and shelter.

They gradually became food growers, clearing a small patch in the forest to grow food. But they continued to depend on forests to meet a lot of their needs. Even today people depend on the forest for paper, timber, fuelwood, medicine, and fodder.

Fuel wood: For the rural population, wood is an important source of energy for cooking and heating. They prefer smaller stems as these are easier to collect and carry. Some of the wood is converted to charcoal and used for cooking.

Fodder: Fodder from the forest forms an important source for cattle and other grazing animals in hilly and arid regions and during a drought.

There are many varieties of grasses, trees, and shrubs that are nutritious for livestock. Trees that produce a large crown above the reach of cattle are preferred.

Fencing: Fences created with trees and shrubs are preferred in developing countries as they are cheap to maintain yet give protection.

Species that have thorns or are prickly and have stiff branches and leaves that are not edible are preferred. These species should be fast-growing, hardy, and long-lived.

Windbreaks and shelter belts: Trees grown for windbreaks should be bushy and sturdy to withstand strong winds, both hot and cold.

Along the Saurashtra coast in India, Casuarina has successfully been planted to check degradation due to salt-laden coastal winds. A species of Prosopis planted along the desert border in Haryana and Gujarat has successfully halted the advance of the desert.

Soil erosion check: Tree roots bind the soil and prevent erosion caused by wind or water. Leaf fall also provides a soil cover that further protects the soil. Casuarina planted coastal region has helped in binding the sand and stabilizing the sand dunes in the area.

Soil improvement: Some species of trees have the ability to return nitrogen to the soil through root decomposition or fallen leaves. Such trees are planted to increase the nitrogen content of the soil.

Forest products and their uses

Timber: More than 1500 species of trees are commercially exploited for timber in different parts of India. It is used in timber-based industries such as plywood, sawmilling, paper and pulp, and particle boards.

Bamboo: These are common in the northeastern and southwestern parts of India, growing along with the deciduous or evergreen forest.

The main commercial uses of bamboo are as timber substitutes, fodder, and raw material for baskets, paper and pulp, and other small-scale industries.

Cane: Cane or rattan are the stems of a climber plant and are used for a large number of household items. It is used to make walking sticks, polo sticks, baskets, picture frames, screens, and mats.

Grasses: There are hundreds of varieties of grasses in the country that are used for a number of purposes. Lemon grass, Palmrose grass, bhabhi, and khus grass are some of them.

Fruit: Fruit trees are an important source of income and food for the rural house hold. In some areas, fruit trees are commonly planted along the field borders and around the wells. Mango, coconut, orange, pear, jackfruit, and many others grow wild in the forest.

Medicinal use: Since time immemorial humans have been depending on the forest to cure them of various ailments.

Even today man is dependent on the forest for herbs and plants to fight against disease. Of all the medicinal trees found in India, the neem is the most important.

Leaves, bark, and other parts of many other trees also have medicinal value and are used to make various ayurvedic medicines.

Fiber: Plant fiber has many different uses. Soft fibers such as jute are derived from the stems of the plant. Hard fiber from the leaves of hemp and sisal is used to make fabrics for various applications.

Coir, another form of fiber from the fruit of the coconut, is used to make ropes.

Floss: The fruits of many species of Indian trees produce silky floss. The most common of these is simul. It is used to make cotton wool, mattresses, and pillows.

Essential oils: Tropical grasses such as lemongrass, citronella, and khus are the source of essential oils. Oil is distilled from the wood of various species such as sandalwood, agar, and pine.

Oil is also derived from the leaves of certain plants and trees such as eucalyptus; camphor, wintergreen, and pine. These oils are used for making soaps, cosmetics, incense, pharmaceuticals, and confectionery.

Problems of Forest

In the last 8000 years, about 45% of the Earth’s original forest cover has disappeared, most of which was cleared during the past century.

The Food and Agriculture Organization of the United Nations (FAO) recently estimated that about 13 million hectares of the world’s forests are lost due to deforestation each year.

The annual net loss of forest area between 2000 and 2005 was 7.3 million hectares (equivalent to the net loss of 0.18 percent of the world’s forests).

The mechanisms that cause deforestation, fragmentation, and degradation are varied and can be direct or indirect. However, the most important factors associated with the decline of forest biological diversity are of human origin.

The conversion of forests to agricultural land, overgrazing, unmitigated shifting cultivation, unsustainable forest management, the introduction of invasive alien plant and animal species, infrastructure development (e.g. road building, hydro-electrical development, urban sprawl), mining and oil exploitation,

Forest fires

Forest fire causes imbalances in nature and endangers biodiversity by reducing faunal and floral wealth.

Causes of a forest fire: Traditionally Indian forests have been affected by fires. The menace has been aggravated by the rising human and cattle populations and the consequent increase in demand for forest products by individuals and communities.

Causes of forest fires can be divided into two broad categories: environmental (which is beyond control) and human-related (which is controllable).

 

1. Environmental causes

These are largely related to climatic conditions such as temperature, wind speed, and direction, level of moisture in soil and atmosphere, and duration of dry spells.

Other natural causes are the friction of bamboo swaying due to high wind velocity, rolling stones that result in sparks setting off fires in highly inflammable leaf litter on the forest floor, volcanic eruption, lightning, etc.

2. Human-related cause

These result from human activity as well as methods of forest management. These can be intentional or unintentional, for example-

fire set by grazers and gatherers of various forest products to facilitate the gathering of minor forest produce like flowers of Madhuca indica and leaves of Diospyros melanoxylon.

1. The centuries-old practice of shifting cultivated land by firing forest.
2. The use of fires by villagers to ward off wild animals.

Deforestation

Deforestation is the permanent destruction of forests in order to make the land available for other uses. anthropogenic forest fires, pollution, and climate change are all having negative impacts on forest biological diversity.

As forests are degraded, so to is biological diversity. This degradation lowers the resilience of forest ecosystems and makes it more difficult for them to cope with changing environmental conditions.

fires lit intentionally by people living around forests for cooking. It has been estimated that 90% of forest fires in India are man-made.

Effects of a forest fire: Fires are a major cause of forest degradation and have wide-ranging adverse ecological, economic, and social impacts, including:

1. Loss of valuable timber resources, Loss of biodiversity, and extinction of plants and animals,
2. Loss of wildlife habitat and depletion of wildlife,
3. Loss of natural regeneration and reduction in forest cover,
4. Loss of carbon sink resources and increase in the percentage of C02 in the atmosphere,
5. Ozone layer depletion, soil erosion, frequent flooding, climate change, etc.
6. Health problems leading to diseases,
7. Loss of livelihood for tribal people.

Causes: There are many causes of deforestation. The WWF reports that half of the trees illegally removed from forests are used as fuel.

Some other common reasons are:

1. To make more land available for housing and urbanization,
2. To harvest timber to create commercial items such as paper, furniture, and homes,
3. To create ingredients that are highly prized consumer items, such as the oil from palm trees,
4. To create room for cattle ranching.

Deforestation and climatic change: The main problem caused by deforestation is the impact on the global carbon cycle. Gas molecules that absorb thermal infrared radiation are called greenhouse gases.

If greenhouse gases are in large enough quantity, they can force climate change The deforestation of trees not only lessens the amount of carbon stored, but it also releases carbon dioxide into the air.

This is because when trees die, they release the stored carbon. Deforestation is the second largest anthropogenic (human-caused) source of carbon dioxide in the atmosphere, ranging between 6 percent and 17 percent.

Carbon isn’t the only greenhouse gas that is affected by deforestation. Water vapor is also considered a greenhouse gas.

The impact of deforestation on the exchange of water vapor and carbon dioxide between the atmosphere and the terrestrial land surface is the biggest concern with regard to the climate system. Changes in their atmospheric concentration will have a direct effect on climate.

Other effects of deforestation: Forests are complex ecosystems that affect almost every species on the planet. When they are degraded, it can set off a devastating chain of events both locally and around the world.

North Bengal forests and their problems

In North Bengal, the forest areas are mainly situated in the Terai-Duars region. However, the zone is interspersed with human settlements, tea gardens, rail, and roadways.

This region of the state is the habitat of other large mammals like the Rhinoceros, Tigers, Gaur, and many other smaller vertebrates. The forests here host 50-60% of the species richness of the state.

Notified Protected Areas to cover 1225 sq. km i.e., 55% of the forests in Northern Bengal, There is nearly 2200 sq. km of elephant habitat in Northern West Bengal.

Eastern Duars Elephant Reserve was constituted in 2002 for better management of the elephant population here. The railroad cuts across 1 National Park, 1 Tiger Reserve, and 3 sanctuaries of this region.

Northern Bengal houses about 1.5% of the total elephant population in India. The Terai (“moist land”) is a belt of marshy grasslands, savannas, and forests at the base of the Himalayas range in India.

The Terai zone is inundated yearly by the monsoon-swollen rivers of the Himalayas The Dooars or Duars are flood plains at the foothills of the eastern Himalayas.

Duar means door in both Assamese and Bengali languages. This region is divided by the Sankosh river into the eastern and the western Duars consisting of an area of 8,800 square kilometers (3,400 square mile).

Dooars Jungle in North Bengal is- Buxa, Gorumara, Jaldapara, Neora Valley, Bindu, Jaldhaka, Jhalong, Malbazar, and Samsung.

In earlier times, the wild elephant management problem was endemic only in the Duars region of North Bengal. As time passed, the problem surprisingly erupted in Southern Bengal, in 1987.

A large number of elephants (gradually increasing) from Dalma hills in Jharkhand have started migrating to the densely populated Midnapore, Bankura, and Purulia districts during August- September (now July- August), every year.

Man-animal conflict is a major concern for wildlife management in North Bengal. The tea industry and the timber industry have resulted in a large number of settlements close to forest areas.

Increased demand for cultivable land, newer railway tracks, highways, etc have resulted in large-scale deforestation.

Uncontrolled poaching and illegal trade of animal products are major threats. Man-animal conflicts are mainly the attacks of elephants in agricultural fields and nearby human settlements, attacks of bison and rhinoceros, and those involving leopards.

 

 

Mangrove forests

Mangroves are various large and extensive types of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics.

The Mangrove tidal forests are found in the areas of coasts influenced by tides. Mud and silt get accumulated on such coasts. Dense Mangroves are common varieties with roots of plants submerged underwater.

In the Ganga-Bramhaputra delta, Sundri trees are found, which provide durable hard timber. Palm, coconut, kora, and agar, also grow in some parts of the delta.

The Sundarbans mangrove forest, the largest such forest in the world (140,000 ha), lies on the delta of the Ganges, Brahmaputra, and Meghna rivers on the Bay of Bengal.

It is adjacent to the border of India’s Sundarbans World Heritage site inscribed in 1987. The area is known for its wide range of fauna, including 260 bird species, the Bengal tiger, and other threatened species such as the estuarine crocodile and the Indian python.

Importance of Mangroves

The mangrove’s massive root system is efficient at dissipating wave energy. Likewise, they slow down tidal water so that its sediment is deposited as the tide comes in, leaving all except fine particles when the tide ebbs. Mangroves protect coastal areas from erosion, storm surges (especially during hurricanes), and tsunamis.

Sundarban Biosphere Reserve: Special features Sundarbans is the only mangrove tiger land on the globe.

Sundarban mangrove forests comprising more than 60% of the total Indian mangroves form the largest nursery for fish and shellfish and are responsible for the coastal fishery of the whole of eastern India.

Mangrove plant association of Sundarbans exhibit more generic/species diversity than any large mangrove reserve on the earth.

Sundarban harbors a good number of endangered plants and animals, e.g., the Bengal Tiger, Estuarine crocodile, fishing cat, Salvador Lizard, Gangetic Dolphin, Batagur (river terrapin), Marine turtles, horseshoes, etc.

It saves Kolkata and neighboring metropolises from annual low-pressure catastrophes, acting as an effective wind barrier.

Crisis of mangrove forest: One of the largest serious threat to its ecosystem from poaching mangrove forests in the world and a unique tiger and rampant felling of trees habitat, the Sunderbans in West Bengal is facing

Global warming compounds the dangers to the Sundarbans. These low-lying mangrove forests are highly susceptible to the effects of sea-level rise—including inundation of coastal areas, increased exposure to storm surges, increased coastal erosion, and rising salinity in ground and surface waters.

Presently both the height of water and salinity of the water is increasing with the rapid rate of global warming. Due to this, several trees have started decreasing in significant numbers. The lives of animals like tigers, estuarian crocodiles, and river turtles are also threatened for the same reason.

Another problem threatening the Sunderbans’ mangrove ecology is the collection of tiger prawn seeds. People of the region have no alternative sources of income from farming.

Thus, people have turned to collecting tiger prawn seeds, using nylon nets, which are dragged along the river banks. In the process, apart from destroying mangrove seedlings and eliminating the possibility of a regeneration of mangroves along the river banks, several species of fish are also destroyed.

 

 

Life Under the Sea

An ocean is a body of saline water that composes much of a planet’s hydrosphere. On Earth, an ocean covers seven-tenths of the planet’s surface. Oceans cover about 70% of the Earth’s surface.

The oceans contain roughly 97% of the Earth’s water supply. Life on Earth originated in the seas, and the oceans continue to be home to an incredibly diverse web of life. The oceans of Earth serve many functions, especially affecting the weather and temperature.

Ocean zones

The Ocean is not just one habitat, it is many habitats. Some ocean habitats get lots of sun and some get none We can classify ocean habitats by the amount of sunlight that they get we call them ocean zones exclusively for waters not lying over the continental shelf and neritic refers to those coastal waters over the shelves.

In the oceans, the benthic open water of the ocean is known as the limnetic or pelagic zone; the oceanic zone refers to Life on Earth originating in the seas, and the oceans continue to be home to an incredibly diverse web of life. The oceans of Earth serve many functions, especially affecting the weather and temperature.

Zones are the littoral, which here means the area between high tide and 100 m deep and has nothing to do with plant life; it includes the continental shelf, which extends to about 100 m deep; the bathyal zone which extends to 2000 m (below the photic zone), the abyssal zone from 2000 to 4000 m, and the deep oceans or hadal zone from 4000 to 10,000 m.

 

Marine Life Zones

The littoral zone can refer to the shoreline of a body of fresh or saltwater and also means any area close to the water or influenced by the water.

For a freshwater biome, the littoral zone is the area with abundant light close to the shore. The littoral zone in a pond or lake allows for prolific photosynthetic activity and consequently hosts almost all of the aquatic plant life.

Because the water is so near to littoral zones, both freshwater and saltwater, the organisms existing here are often found in dunes or estuaries.

Everything except areas near the coast and the sea floor is called the pelagic zone. The opposite term is the demersal zone which is the water near and affected by the coast or the sea floor. The pelagic zone is divided into epipelagic, mesopelagic, bathypelagic, abyssopelagic, and hadopelagic zones.

The epipelagic zone stretches from the surface down to 200 m and is home to the greatest biodiversity in the sea, largely because of the availability of sunlight that enables photosynthetic organisms to thrive. Both marine plants and animals are found here.

 

 

Bioluminescence

Bioluminescence is the production and emission of light by a living organism. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial invertebrates such as fireflies.

 

From 200-1,000 m is the mesopelagic zone, a twilight zone where some light filters through but does not reach a level of brightness necessary for photosynthesis to occur.

The bathypelagic zone is from 1,000-4,000 m and is completely dark. Bioluminescent organisms are some of the strangest marine creatures of the deep life here.

Most animals in the abyssopelagic zone, located from 4,000 m down, are blind and colorless due to the complete lack of light. The name, “abyssopelagic” comes from the Greek meaning “bottomless abyss”, in times when it was thought that the deep ocean never ended.

The photic zone (with light) of the open ocean consists of the epipelagic and mesopelagic zones. The aphotic zone (without light) of the open ocean consists of all the zones lower in the ocean.

The lower zones are often simply grouped into the aphotic zone by marine biologists due to their similarities. The uses of bioluminescence by animals include counter-illumination camouflage, mimicry of other animals, for example, to lure prey, and signaling to other individuals of the same species, such as to attract mates.

Deep in the ocean, where sunlight can no longer penetrate, lies an incredible world of darkness. And against all odds, this just happens to be the location of one of nature’s most impressive artificial light shows.

The creatures here have evolved their own ways of dealing with the darkness. Through a process known as bioluminescence, they have developed the ability to use a chemical called Luciferin within their bodies to produce light.

Luciferin is a protein-bound pigment and Luciferase is an enzyme. In presence of this enzyme, a chemical reaction between luciferin and oxygen occurs transforming chemical energy into light energy.

If you have ever seen a firefly then you have witnessed the same process in action. Bioluminescence is mainly a marine phenomenon. It is not found in

Marine life

There are thousands of species of marine life, from tiny zooplankton to enormous whales. Each is adapted to the specific habitat it occupies. Marine biology classifies species based on the environment rather than on taxonomy.

Throughout the oceans, marine organisms must deal with several things that are less of a problem for life on land:

1. Regulating salt intake
2. Obtaining oxygen
3. Adapting to water pressure
4. Dealing with wind, waves, and changing temperatures
5. Getting enough light.

Planktons: Plankton is the foundation of the ocean food web. The word plankton comes from the Greek word “plankton” which means drifting.

Plankton, marine and freshwater organisms that, because they are non-motile or because they are too small or too weak to swim against the current, exist in a drifting, floating state.

The term plankton is a collective name for all such organisms and includes certain algae, bacteria, protozoans, crustaceans, mollusks, and coelenterates, as well as representatives from almost every other phylum of animals.

Large floating seaweeds (for example, Sargassum) and various related multicellular algae are not considered plankton but pleuston. Organisms resting or swimming on the surface film of the water are called neuston (e.g., the alga Ochromonas).

There are two types of plankton: tiny plants- called phytoplankton, and weak-swimming animals-called zooplankton. Plankton is the basic food source for a variety of marine species, from tiny fish larvae such as cod all the way up to giant baleen whales.

Both zooplankton and phytoplankton not only play a vital role in the stability of the marine ecosystem, but they also serve as an indicator of water health, since they are affected by slight changes in the environment.

Plants

Various plants are found-

1. Phytoplankton: Phytoplankton is made of very tiny-usually one-celled plants. Since plants make their own food and release oxygen as a byproduct, all the other living things in the ocean depend on them directly or indirectly for food or oxygen.

It is estimated that 80% of the oxygen on earth is produced by phytoplankton.

2. Diatoms are the most common type of phytoplankton. They are single-celled yellow algae whose cell walls contain a lot of silica, a glass-like substance.

The actual diatom fits inside this cell wall, with one half of the wall fitting over the second half, like a lid. The name diatom actually means “cut in two” in Greek.

There are many different kinds of diatoms, and they come in a variety of shapes—disk-shaped, needle-shaped, or linked together in chains.

 

3. Dinoflagellates: are like both plants and animals. They can move through the water using two flagella in grooves along their body, yet they can also produce their own food like plants.

 

Two species of dinoflagellates, Gonyaulax and Gymnodinium, are the cause of the dangerous red tide. When their populations get large, the reddish-colored dinoflagellates not only make the surrounding water appear to be tinted red, they can produce a variety of toxic effects, including fish mortality and paralytic shellfish poisoning.

4. Kelp: Kelp also known as brown algae, is a herb that comes from deep under the sea. It is, essentially, seaweed that thrives on sunlight and takes in the host of nutrients and minerals present in the water around it.

This makes kelp an interesting and necessary supplement for those seeking to adopt a healthier lifestyle; indeed kelp is believed to have many benefits and serves a multitude of purposes. Kelp is the number one herb for supplementing iodine.

 

 

Animals

Oceans are by far the largest animal habitat on earth. The oceans are so huge it is hard for scientists to explore them. Information on ocean animals is not as complete as information on land animals.

It is known that animal life can be found at all depths of the ocean, from the surface to the deepest trenches that are over seven miles below the surface.

Some ocean animals spend most of their life in the waters near the land. Others live most of their life in the deeper open sea. Even though the open sea is the largest habitat, it is estimated that only five percent of the world’s animal species live there.

Some interesting marine animals are-

1. Zooplankton: Zooplanktons are heterotrophic (Sometimes detritivorous) plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water.

The word zooplankton is derived from the Greek ‘zoon’ meaning ‘animal’ and ‘plankton’, meaning ‘wanderer’ or ‘drifter’. Individual zooplankton is usually microscopic, but some (such as jellyfish) are larger and visible to the naked eye.

2. Sea Anemone: Although Sea Anemones look like flowers, they are predatory animals. These invertebrates have no skeleton at all.

They live attached to firm objects in the seas, usually the sea floor, rock, or coral, but they can slide around very slowly. Sea anemones are very long-lived.

Hermit crabs sometimes attach sea anemones to their shells for camouflage. Sea Anemones come in many shapes, sizes, and colors. Radially symmetric, they have a columnar body with a single body opening, the mouth, which is surrounded by tentacles.

The tentacles protect the anemone and catch its food; they are studded with microscopic stinging capsules. Sea Anemones are usually about 1 to 4 inches (2.510 cm) across, but a few grow to be 6 feet (1.8 m) across.

 

Biodiversity and its importance for Class 8

3. Sea Pen: Sea pens, is any of the 300 species of colonial invertebrate marine animals of the phylum Cnidaria. The sea pen was named after the quill pen which it looks like.

The sea pen is not actually one animal but rather consists of many separate animals called polyps living in a colony. The polyps look like miniature sea anemones each with eight tentacles.

They live at many depths from shallow waters down to deep seas in tropical and temperate waters worldwide. They prefer deeper waters where turbulence is less likely to uproot them. Sea pens can have a chunky, more club-like appearance or a feather-like appearance.

 

 

4. Jellyfish: Jellyfish are the major non-polyp form of individuals of the phylum Cnidaria. They are typified as free-swimming marine animals consisting of a gelatinous umbrella-shaped bell and trailing tentacles.

The bell can pulsate for locomotion while stinging tentacles can be used to capture prey. Jellyfish are found in every ocean, from the surface to the deep sea.

Jellyfish have tiny stinging cells in their tentacles to stun or paralyze their prey before they eat them. Inside their bell-shaped body is an opening that is their mouth. They eat and discard waste from this opening.

 

 

5. Corals: Corals are animals. However, corals make a calcium carbonate skeleton that looks similar to a rock and have a symbiotic relationship with plant-like cells called zooxanthellae.

The zooxanthellae living in the soft tissue of a coral polyp use sunlight to produce food through photosynthesis and create a byproduct that the coral can use as food.

Thus, zooxanthellae provide corals with food; in return, the coral provides the zooxanthellae with shelter and nutrients. Hard corals are often called reef builders because their skeletons provide support for other corals and other organisms.

 

 

6. Lobsters: Lobsters are invertebrates with a hard protective exoskeleton. Lobsters have 10 walking legs; the front three pairs bear claws, the first of which is larger than the others.

Although, like most other arthropods, lobsters are largely bilaterally symmetrical, some genera possess unequal, specialized claws.

They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pair? pf legs have claws, including the first pair, which are usually much larger than the others.

Highly prized as seafood, lobsters are economically important and are often one of the most profitable commodities in the coastal areas they populate.

 

 

Octopus: An octopus is a cephalopod mollusk. It has two eyes and four pairs of arms and it is bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of its arms.

An octopus has no internal or external skeleton, allowing it to squeeze through tight places. Octopuses are among the most intelligent and behaviorally flexible of all invertebrates.

Octopuses inhabit many diverse regions of the ocean, including coral reefs, pelagic waters, and the ocean floor. They have numerous strategies for defending themselves against predators,

including the expulsion of ink, the use of camouflage and displays, their ability to jet quickly through the water, and their ability to hide. An octopus trails its eight arms behind it as it swims.

 

 

8. Squid and Cuttlefish: The Squid is an invertebrate (animal without a backbone) that swims in the oceans. This mollusk is closely related to the octopus.

Squids can change the color of their skin to mimic their environment and hide from predators. Squids are soft-bodied cephalopods.

They move by squirting water from the mantle through the siphon, using a type of jet propulsion. When in danger, squid squirt a cloud of dark ink in order to confuse their attacker and allow the squid to escape. Squids reproduce by releasing eggs into the water.

Cuttlefish have a unique internal shell, the cuttlebone. Despite their name, cuttlefish are not fish but mollusks. Cuttlefish have large, W-shaped pupils, eight arms, and two tentacles furnished with denticulated suckers, with which they secure their prey.

Cuttlefish eat small mollusks, crabs, shrimp, fish, octopodes, worms, and other cuttlefish. Their predators include dolphins, sharks, fish, seals, seabirds, and other cuttlefish.

 

 

9. Starfish: Starfish are interesting animals that also live along the beaches. Starfish have many different colors. Starfish usually have 5 arms.

Each arm has rows of tube feet that are used in crawling, attaching to things, and feeding. All starfish can grow back arms, that they have lost. Starfish have flattened bodies with their mouth located underneath its body.

Their skin is rough and leathery and usually have spines. Starfish eat and digest food outside of their bodies. Most starfish are scavengers, feeding on a lot of different plants or animals.

Although sea stars live underwater and are commonly called “starfish,” they are not fish. They do not have gills, scales, or fins like fish do and they move quite differently from fish.

 

10. Sharks: Sharks are a group of fish characterized by a cartilaginous skeleton, five to seven-gill slits on the sides of the head, and pectoral fins that are not fused to the head.

They range in size from the small dwarf lantern shark, a deep sea species of only 17 centimeters (6.7 in) in length, to the whale shark, the largest fish in the world, which reaches approximately 12 meters (39 ft) in length.

Sharks are found in all seas and are common to depths of 2,000 meters (6,600 ft). There are more than 465 known species of sharks living in our oceans today.

Sharks are apex predators at or near the top of their marine food chains, and they regulate the populations of species below them.

Sea turtles: Sea turtles, sometimes called marine turtles, are reptiles. Sea turtles are one of the Earth’s most ancient creatures.

The seven species that can be found today have been around for 110 million years, since the time of the dinosaurs. The sea turtle’s shell or “carapace” is streamlined for swimming through the water.

Unlike other turtles, sea turtles cannot retract their legs and head into their shells. Their color varies between yellow, greenish and black depending on the species.

 

12. Whales: Whales are large, intelligent, aquatic mammals. They breathe air through blowhole(s) into their lungs (unlike fish who breathe using gills).

Whales have sleek, streamlined bodies that move easily through the water. They are the only mammals, other than sea cows, that live their entire lives in the water, and the only mammals that have adapted to life in the open oceans.

The biggest whale is the blue whale, which grows to be about 94 feet (29 m) long – the height of a 9- story building. These enormous animals eat about 4 tons of tiny krill each day, obtained by filter feeding through baleen.

Adult blue whales have no predators except men. The smallest whale is the dwarf sperm whale which as an adult is only 8.5 feet (2.6 m) long.

 

 

Ocean pollution

From plastic bags to pesticides – most of the waste we produce on land eventually reaches the oceans, either through deliberate dumping or from runoff through drains and rivers. This includes:

Oil: Oil spills cause huge damage to the marine environment. Crude oil contains various toxic substances. The layer of oil deters oxygen to get dissolved in water.

As a result, marine life dies due to wanting oxygen. Oil spills cause lesions on the skin, and inflammation in the eyes, mouth, nose, and the organs of marine animals.

Oil spills destroy the heat and water-insulating capacity of marine animals. As a result, they die easily after coming in direct contact with very cold ocean water. When the birds preen their oil-soaked feathers with their beak, the oil enters their body and damages the internal organs.

 

Fertilizers: Fertilizer runoff from farms and lawns is a huge problem for coastal areas. The extra nutrients cause eutrophication – the flourishing of algal blooms that deplete the water’s dissolved oxygen and suffocate other marine life.

Garbage: Solid garbage also makes its way to the ocean. Plastic bags, balloons, glass bottles, shoes, and packaging material – if not disposed of correctly, almost everything we throw away can reach the sea.

Big-sized plastic bags get stuck in the alimentary canal of marine animals creating a block in the path of food. As a result, animals die due to starvation or infection.

Sewage disposal: This sewage can also lead to eutrophication. In addition, it can cause human disease and lead to beach closures.

Toxic chemicals: Almost every marine organism, from the tiniest plankton to whales and polar bears, is contaminated with man-made chemicals, such as pesticides and chemicals used in common consumer products.

CO emission: The sea absorbs C02. With the increase of C02 in the environment, the acidity of seawater is increasing. This affects aquatic animals like squids, fishes, etc as they find it difficult to get the dissolved oxygen from the acidic ocean for respiration through their gills.

Excessively acidic seawater destroys the carbonate shells of snails, oysters, and corals. These animals are facing increasing difficulty in forming their shells.

Deserts cover about one-fifth of the Earth s surface and occur where rainfall is less than 50 cm/year. Although most deserts, such as the Sahara of North Africa and the deserts of the southwestern U.S.,

Mexico and Australia, occur at low latitudes, and another kind of desert, cold deserts, occur in the basin and range area of Utah and Nevada and in parts of western Asia.

such as the deserts have a considerable amount of specialized vegetation, as well as specialized vertebrates and occur invertebrate animals The biggest desert is northern Africa’s Sahara Desert;

it covers roughly 3,500,000 square miles (9,065,000 square kilometres). The driest deserts are the Atacama desert of northern Chile, South America, and the Lut Desert in eastern Iran; these extreme deserts get less than half an inch (about 1 centimeter) of precipitation each year – and it is from condensed fog, and not from rain.

 

Types of deserts

There are two major types of deserts: hot and dry, and cold.

1. Hot and dry desert

The four major North American deserts of this type are the Chihuahuan, Sonoran, Mojave, and Great Basin. Others outside the U.S. include the Southern Asian realm, Neotropical (South and Central America), Ethiopian (Africa), and Australian.

The seasons are generally warm throughout the year and very hot in the summer. The winters usually bring little rainfall. Temperatures exhibit daily extremes because the atmosphere contains little humidity to block the Sun’s rays.

Desert surfaces receive a little more than twice the solar radiation received by humid regions and lose almost twice as much heat at night.

The mean annual temperatures range from 20-25° C. The extreme maximum ranges from 43.5-49° C. Minimum temperatures sometimes drop to -18° C.

Canopy in most deserts is very rare. Plants are mainly ground-hugging shrubs and short woody trees. Leaves are “replete” (fully supported with nutrients) with water-conserving characteristics.

They tend to be small, thick, and covered with a thick cuticle (outer layer). In the cacti, the leaves are much reduced (to spines) and photosynthetic activity is restricted to the stems.

Some plants open their stomata (microscopic openings in the epidermis of leaves that allow for gas exchange) only at night when evaporation rates are lowest.

These plants include yuccas, ocotillo, turpentine bush, prickly pears, false mesquite, sotol, ephedras, agaves, and brittlebush. The animals include small nocturnal (active at night) carnivores.

The dominant animals stay inactive in protected hideaways during the hot day and come out to forage at dusk, dawn, or at night when the desert is cooler.

 

2. Cold desert

These deserts are characterized by cold winters with snowfall and high overall rainfall throughout the winter and occasionally over the summer.

They occur in the Antarctic, Greenland, and the Nearctic realm. They have short, moist, and moderately warm summers with fairly long, cold winters. The mean winter temperature is between 2 to 4° C and the mean summer temperature is between 21-26° C.

The winters receive quite a bit of snow. The mean annual precipitation ranges from 15-26 cm. Annual precipitation has reached a maximum of 46 cm and a minimum of 9 cm.

The heaviest rainfall of the spring is usually in April or May. In some areas, rainfall can be heavy in autumn. The soil is heavy, silty, and salty.

It contains alluvial fans where the soil is relatively porous and drainage is good so that most of the salt has been leached out.
The plants are widely scattered. Plant heights vary between 15 cm and 122 cm.

The main plants are deciduous, most having spiny leaves. Widely kangaroo mice, pocket mice, grasshopper mice, distributed animals are jackrabbits, kangaroo rats, and antelope ground squirrels.

Oasis

An oasis is an area made fertile by a source of fresh water in an otherwise dry and arid region. Oases (more than one oasis) are irrigated by natural springs or other underground water sources.

They vary in size from a cluster of date palms around a well or a spring to a city and its irrigated cropland. Dates, cotton, olives, figs, citrus fruits, wheat, and corn (maize) are common oasis crops.

Underground water sources called aquifers supply most oases. In some cases, a natural spring brings the underground water to the surface. At other oases, manmade wells tap the aquifer.

Rivers that flow through some deserts provide permanent sources of water for large, elongated oases. The fertile Nile River valley and delta in Egypt, supplied with water from the Nile River, is an example of this type of large oasis. At 22,000 square kilometers, it might be the largest oasis in the world.

 

Biodiversity examples for Class 8 students

Desert adaptations

Plants and animals living in the desert need special adaptations to survive in harsh environments. Plants tend to be tough and wiry with small or no leaves, water-resistant cuticles, and often spines to deter herbivory.

Some annual plants germinate, bloom, and die in the course of a few weeks after rainfall while other long-lived plants survive for years and have deep root systems able to tap underground moisture.

Animals need to keep cool and find enough food and water to survive. Many are nocturnal and stay in the shade or underground during the heat of the day.

They tend to be efficient at conserving water, extracting most of their needs from their food, and concentrating their urine. Some animals remain in a state of dormancy for long periods, ready to become active again when the rare rains fall.

They then reproduce rapidly while conditions are favorable before returning to dormancy. People have struggled to live in deserts and the surrounding semi-arid lands for millennia.

Nomads have moved their flocks and herds to wherever grazing is available and oases have provided opportunities for a more settled way of life.

The cultivation of semi-arid regions encourages the erosion of soil and is one of the causes of increased desertification. Desert farming is possible with the aid of irrigation and the Imperial Valley in California provides an example of how previously barren land can be made productive by the import of water from an outside source.

Many trade routes have been forged across deserts, especially across the Sahara Desert, with caravans of camels carrying salt, gold, ivory, and other goods. Some mineral extraction also takes place in deserts and the uninterrupted sunlight gives the potential for the capture of large quantities of solar energy.

Desert Plants

Desert plants have two main adaptations- the ability to collect and store water, and features that reduce water loss. Plants that have adapted by altering their physical structure are called xerophytes.

Xerophytes, such as cacti, usually have special ways of storing and conserving water. They often have few or no leaves, which reduces water loss.

Phraetophytes are plants that have adapted to living in the desert by growing very long roots, allowing them to get their moisture deep within the earth, at or near the water table.

Below are a few of the plants you will see in the desert. Interesting facts are also given for each plant

Cactus: The cactus family is one of the most easily recognized plant families in the world. Their beautiful blossoms, thick stems, and unusual shapes attract thousands of people to the desert each year. Cacti show variations between the individual species.

They range from the three-inch fishhook cactus nestled in a rock crevice to the towering saguaro cactus which reaches heights of 30 to 40 feet. Cactus grow on rocky hillsides, alluvial fans, and in barren washes throughout the desert.

Cactus take advantage of the lightest rainfall by having roots close to the soil surface. The water is quickly collected by the roots and stored in thick, expandable stems for the long summer drought.

The fleshy stems of the barrel cactus are pleated like an accordion and shrink as moisture is used up. These pleats also channel water to the base of the plant during rain showers.

When water is no longer available in the summer, many desert shrubs drop their leaves and become dormant. Cactus continue to photosynthesize because they have fixed spines instead of leaves.

The green stems produce the plant’s food but lose less water than leaves because of their sunken pores and a waxy coating on the surface of the stem. The pores close during the head of the day and open at night to release a small amount of moisture.

 

 

Joshua plants: The Joshua tree, the largest of the yuccas, grows only in the Mojave Desert. Natural stands of this picturesque, spike-leafed evergreen grow nowhere else in the world.

Its height varies from 15-40 feet with a diameter of 1-3 feet. They grow 2 to 3 inches a year, take 50 (2)to 60 years to mature, and can live 150 years. It is a large desert plant with spiky leaves.

It also has a fruit which is food for desert animals. The Joshua tree provides food and shelter for many desert animals.

 

 

Saguaro cactus: The Saguaro cactus, is composed of a tall, thick, fluted, columnar stem, 18 to 24 inches in diameter, often with several large branches (arms) curving upward.

The stem of the Saguaro Cactus stores all of its water. The stem is green Photosynthesis occurs in the top area of the stem instead of in the leaves.

This plant has another adaptation that is hidden from us. This is its large network of roots – that extend far away from its trunk. The roots collect water after rain.

Stored in the pleated expandable stem, the water keeps the saguaro alive until the next rain. Saguaro fruit is used in jam and woody skeletons are used in building materials.

The skin is smooth and waxy, and the trunk and stems have stout and 2-inch spines clustered on their ribs. When water is absorbed, the outer pulp of the Saguaro can expand like an accordion, increasing the diameter of the stem and in this way, can increase its weight by up to a ton.

 

 

Mesquite plants: Mesquite trees are usually in most of their range they are the size of a shrub. Older trees can reach a height of 20 to 30 ft.

They have narrow, compound leaves 50 to 75 mm (2 to 3 inches) long that are sharply pointed. Mesquite is an extremely hardy, drought-tolerant plant because it can draw water from the water table through its long taproot (recorded at up to 190 ft in depth).

However, it can also use water in the upper part of the ground, depending upon availability. The tree can regenerate from a piece of root left in the soil. New growth of mesquite has tough, needle-sharp thorns up to 3 inches

 

 

Desert Animals

Lack of water creates a survival problem for all desert organisms, animals, and plants alike. But animals have an additional problem — they are more susceptible to extremes of temperature than plants.

Animals receive heat directly by radiation from the sun, and indirectly, by conduction from the substrate (rocks and soil) and convection from the air.

Among the thousands of desert animal species, there are almost as many remarkable behavioral and structural adaptations developed for avoiding excess heat.

Some interesting desert animals are-

Camel: A camel stands from 1.8 m to just over 2 meters tall at the shoulders, and weighs from 250 to 680 kilograms.

Its rope-like tail is over 50 centimeters long. Camels seem larger than they are because of their thick, woolly fur, which may be all shades of brown, from nearly white to almost black.

An Arabian camel’s fur is short and helps protect its body from heat. A Bactrian camel’s fur is longer. It may grow about 25 centimeters long on the animal’s head, neck, and humps.

Camels have many adaptations that allow them to live successfully in desert conditions. Deserts are hot and dry. Common adaptions are-

A camel can go a week or more without water, and they can last for several months without food. They can drink up to 32 gallons (46 liters) of water in one drinking session.

Camels store fat in the hump, not water. The fat can be metabolized for energy.

Unlike most mammals, a healthy camel’s body temperature fluctuates (changes) throughout the day from 34°C to 41.7°C (93°F-107°F.) This allows the camel to conserve water by not sweating as the environmental temperature rises.

1. Camels’ feet are wide so they can walk on the sand more easily. Their huge feet help them to walk on sand without sinking into it.
2. Camels have thick lips so they can eat the prickly desert plants without feeling pain.
3. The color of their bodies helps them to blend into their environment.
4. Camel’s ears are covered with hair, even on the inside. The hair helps keep out sand or dust that might blow into the animal’s ears.
5. Winds blow sand all around, so a camel has long eyelashes. It has nostrils that can open and close.

 

Horned lizards: The numerous species of horned lizards, all members of the genus Phrynosoma, have very wide, flattened, toad-like bodies.

The tail is short but broad at the base. In most species, the back of the head and temples are crowned with a prominent row of sharp, pointed horns. The tail and sides are fringed with sharp spines.

To the uninitiated, their dragon-like appearance is quite formidable. The squat form and head armor has given rise to the name “horny toad,” “horned toad” and “horned lizards.” However, since there is a true toad with horns, it is best that we speak of this genus as the “horned lizards.”

 

Their colors are pleasing. The back and head are soft desert gray. The markings are in pastel shades of tan, brown, red, or yellow.

The underparts are pale, yellowish-gray. The overall colors are generally close to the predominant color of the soil. Color changes from light to dark (or reverse) can occur within a few minutes.

Rattlesnake: Rattlesnakes are easily recognized animals. There are 32 known species of rattlesnakes that live in North and South America.

Rattlesnakes are mainly associated with arid and desert rocky areas, but they can be also found in forests, prairies, and swampy habitats. Rattlesnakes are known for their relatively heavy bodies and diamond-shaped heads.

They are considered to be the newest or most recently evolved snakes in the world. Rattlesnakes have either a rattle or a partial rattle made of interlocking rings, or segments of keratin,

The same material our fingernails are made of When vibrated, the rattle creates a hissing sound that warns off potential predators. It is an extremely effective and highly evolved predator-avoidance system.

Another rattlesnake characteristic is the “pit” on each side of the head, which is a heat-sensitive organ for locating prey.

 

 

Gerbil: The gerbil (kangaroo rat) is a small rodent, similar in many ways to the mouse and the hamster. Gerbils have long tails like a mouse which the gerbil is able to shed should the tail get trapped.

This self-defense mechanism allows the gerbil to escape predators, leaving them with just a tail. Gerbils have sharp claws which the gerbils use to burrow their way into the sandy grounds of the temperatures may get very cold at night.

Gerbils tend to stay inside their burrows during the hottest parts of the day and the coolest parts of the night. The temperatures within the burrow are more moderate than the temperatures outside.

 

Some other desert animals are-

1. Desert Bighorn Sheep,
2. Scorpion,
3. Ostriches,
4. Addax Antelope.

Thar, the great Indian desert also called the ocean of sand is home to many species of birds, reptiles, and wild animals. The various desert animals and plants are adapted to survive in adverse climatic conditions.

The animals of the great thar desert include numerous species of reptiles, desert scorpions, mongoose, red foxes, chinkara, and falcons.

Indian Bustard, Blackbuck, and wild cat are a few species that are fast vanishing in other parts of India but can be spotted here. The ship of the desert, Camels are the first animal that comes to mind when talking about a wildlife safari in the desert.

Some people grow crops like bajra, jawar, wheat, and mustard seeds. There are also many industries (textiles, sugar, cement, fertilizers, etc.) and mines (lead, zinc, iron ore, etc.) that provide people of this region with means of livelihood.

Handicrafts and jewelry made in Rajasthan are sold in many parts of India and the world. The women of Rajasthan wear colorful with an odhani or chunni.

The men wear dhoti-kurta with turbans to protect themselves from the harsh sun. People in the desert travel on camels or carts pulled by camels.

The camel is a very useful animal in the desert. Most houses in the desert region have flat roofs and small windows. The walls are thick to keep the heat out and let the house remain cool.

The main festivals of Rajasthan are the Desert Festival, Gangaur, Teej, Holi, Dussehra, Diwali, and Id. Jaipur is the capital of Rajasthan.

Life in Polar Region

The Polar Regions are the most inhospitable places on the planet. For centuries humankind has tried and often failed to reach and study both the Arctic and Antarctic Circles, losing life and limb in the process.

Polar habitats are located at the very top and very bottom of the earth. They are cold, and windy and have a lot of snow and ice.

It’s even too cold for trees to grow. Tundra takes up a lot of the area of polar habitats. It’s the only place where any plants can grow, but the ground only thaws just enough for short grasses and moss-tree roots can’t go as far down into the ground as they need to because it’s frozen.

Animals who live in polar regions have adapted by having thick fur or feathers, and hunting fish or each other rather than relying on plants.

Even though they are both at the “ends of the earth,” the Arctic and Antarctic differ in many ways. The Antarctic is a vast ice-covered ocean surrounded by land.

The pack ice ranges in thickness from a few inches to over 6 feet, below which are the two-mile-deep basins of seawater just above the freezing point.

The icy surface of the Arctic Ocean is thin enough to be traversed by icebreakers, especially in summer when the extent of the ice is at a minimum. Since the ice sheets are constantly shifting, there is no actual pole marking 90 degrees north.

 

Facts of the polar region

1. Polar habitats are located in the very north and very south of the globe – the two pole ends of the Earth.
2. The northern polar region is called the Arctic, and in the south, the polar region is the continent of Antarctica.

Polar habitats have just two seasons – summer and winter (but even summer is normally very cold). In the summer, it is light for 24 hours a day (right at the north and south poles, the sun doesn’t set for six whole months when it is summer) and in the winter it is dark for 24 hours a day.

Polar habitats have tundra, which is ground that is nearly always frozen. The very top of it will thaw in the summer months so grasses and mosses can grow, but there isn’t enough room for tree roots in the non-frozen soil.

Because it is too cold for trees to grow in arctic habitats, animals find other places to live such as holes in the ground, or in caves made from snow.

Animals in the arctic also can’t rely too much on eating plants. Most are carnivores (they eat meat) and hunt for fish as well as smaller animals.

Polar habitats get very, very cold – it can get as cold as -50°C in the Arctic, and temperatures in Antarctica have been as cold as -89°C.

Animals in polar regions have adapted to survive in these extreme conditions. They have thick fur or feathers, blend in with the white snow, or hibernate during the coldest winter months.

The mass of ice at the very tip of the north and south poles is called the polar ice cap. It is always frozen, although the size of the ice cap changes when bits on the edge of it melt during the summer months.

Global warming is changing polar habitats, especially in the Arctic. This means that animals like the polar bear and Arctic fox are becoming endangered.

Some terminologies associated with polar region

Hibernation – a deep sleep that animals take during cold months; they don’t need to eat much or to be too warm, so hibernating helps them survive times when it’s very, very cold in the winter.

1. Iceberg – a big lump of ice that has broken off from the polar ice cap and floated away. Icebergs are very dangerous for ships.
2. Ice shelf/ice sheet – a thick layer of ice on top of the land.

Tundra – a region without any trees and where the subsoil is always frozen (the soil below topsoil); topsoil will defrost just enough for lichen, moss, and some grasses to grow.

Migration- Polar landscapes are home to a rich diversity of wildlife, both on land and within the seas. Some polar animals have evolved to survive life in the deep cold while others,

such as birds and whales, migrate long distances each summer, drawn by the abundant food supply or ideal nesting grounds in the Arctic. Animals change their living areas because they may get more food, better places to build nests, or more sunlight somewhere else.

 

 

Animals of the Polar region

Polar bear: Polar bears roam the Arctic ice sheets and swim in that region’s coastal waters. They are very strong swimmers, and their large front paws, which they use to paddle, are slightly webbed.

Some polar bears have been seen swimming hundreds of miles from land—though they probably cover most of that distance by floating on sheets of ice.

Polar bears live in one of the planet’s coldest environments and depend on a thick coat of insulated fur, which covers a warming layer of fat.

Fur even grows on the bottom of their paws, which protects against cold surfaces and provides a good These powerful predators typically prey on seals.

In search of this quarry they frequent areas of shifting, cracking ice where seals may surface to breathe air.

 

 

 

Polar fishes: Polar fishes, whose body temperatures are close to that of their environment, survive the freezing of their body fluids through the secretion of a range of antifreeze molecules.

One class of fish antifreeze, the antifreeze glycoproteins (whose activity is critically dependent on the presence of specific sugars), is particularly remarkable in that essentially identical molecules are synthesized in grip on ice.

The bear’s stark white coat provides camouflage in the surrounding snow and ice. But under their fur, polar bears have black skin—the better to soak in the sun’s warming rays. presumably function to inhibit the potentially lethal growth of ice crystals internalized through injury.

 

Penguins of Antarctica: There are 17 species of penguins some of which are found as far north as the equator.

Penguins are categorized into three families:

Brush-tail, crested, and king/ emperor penguins. Of the 17 species only six are found in Antarctica (Adlies, Chinstraps, Emperors, Gentoos, Macaronis, and Rockhoppers).

Penguins often are referred to as “flippered flyers” due to their effortless movement through the water and their possible evolution from gull-like birds.

 

Its believed that 40-50 million years ago, while Antarctica broke away from Gondwanaland, penguins also were separating to form their own species.

Originally, indigenous to warmer climates, penguins adapted to the cold as Antarctica made its move southward.
Part of their adaptation to the cold includes oily, unwettable feathers which cover the outer layers of penguins (and what gives that distinguished, well-dressed look).

Underneath is a layer of soft down feathers and under that a thick layer of fat. This keeps the penguins so warm they will actually fluff their feather to release trapped heat in order to cool down.

In addition to their fine attire, penguins are well known for their swimming abilities. Using their flippers for propulsion and their feet as a rudder, penguins can swim in excess of 12 mph (20 kph).

Through the use of air sacs to protect their lungs, penguins can stay underwater for 15 to 20 minutes and dive as deep as 275 feet (900 meters).

In the water, penguins typically feed on krill and fish. The dietary habits of penguins are relatively easy to monitor.

Krill-eating penguins excrete pink guano, while those eating fish leave behind white guano. The yolks of penguins’ eggs often are red denoting the consumption of krill.

How is a climatic change affecting Antarctic penguins?

The Antarctic continent is warming as a whole, but the Antarctic Peninsula—the northernmost region that juts out towards South America—is warming faster than any other place in the Southern Hemisphere.

Because of this rapid warming, sea ice along the western Antarctic Peninsula is shrinking in size, and the sea-ice season is shorter.

The loss of sea ice is harming Emperor penguin chicks and adults. Emperor penguins rear their chicks on land-locked sea ice.

When sea ice breaks up before their chicks have matured and grown their waterproof feathers, chicks that are swept into the ocean are likely to die.

For adults, the loss of sea ice can lead to lower food availability, which can result in increased mortality.

People of the Arctic region

Life in the planet’s polar regions can be incredibly difficult. Bitterly cold winds whip across the landscape. Winter temperatures can reach deep into the negatives and the winter night can last for months.

But these seemingly barren landscapes are home to a rich diversity of wildlife— both on land and under the sea surface—that has evolved to survive these harsh conditions.

 

Millions of people also live in the Arctic, but Antarctica has no permanent inhabitants. Antarctica is protected by a 1959 treaty that established the continent as a place to be used only for peace and science—through several thousand scientists and support staff periodically inhabiting the area in the pursuit of research.

Residents of the Arctic include a number of indigenous groups as well as more recent arrivals from more southern latitudes.

In total, only about 4 million people live in the Arctic worldwide, and in most countries, indigenous people make up a minority of the Arctic population.

Pollution in polar regions

Arctic people today face many changes to their homes and environment. Climate change is causing sea ice to melt and permafrost to thaw, threatening coastal villages with bigger storms and erosion.

And the declining sea ice means that the Arctic Ocean could open up for commercial shipping or tourist cruises.
Antarctica and the surrounding Southern Ocean provide scientists with a unique place to study what is happening with the environment and global warming.

Using ice cores drilled out from deep in the Antarctic ice sheet, they can find information about the world’s climate and weather going back thousands of years.

Both the Antarctic and Arctic regions provide us with an excellent example of what pollution is doing to our global environment.

Ice is melting and breaking away at alarming rates and threatening these delicate ecosystems. Studying these effects will help scientists develop models that may lead to solutions for dealing with pollution and climate change.

 

 

Some interesting facts about Antarctica and the Environment:

The ozone hole above Antarctica covers 27 million km[ Global warming — This results in a loss of sea ice and land-based ice, which is the greatest long] [term threat to the region.

Already some ice shelves have collapsed and ice slopes and glaciers have retreated. Oceanic acidification (from extra dissolved carbon dioxide) is already leading to the loss of some marine snails thought to have a significant part to play in the oceanic carbon cycle. The breeding].

Antarctic ice which at its thickest reaches 5 km in depth, comprises almost 70% of the earth’s fresh water. If all of the ice in Antarctica melted, sea levels would rise between 50 and 60 m.

This may not seem like a lot, but coastal cities like New York, London, and Hong Kong would be flooded. We can all do our part by trying to be environmentally friendly in our day-to-day activities.

1. This way we can help ensure that the penguins (in the South) and the polar bears (in the North) will thrive in their natural habitats.
2. Oil spills from tourist ships and fishing boats have affected animals in Antarctica. Because of the oil spills, life in Antarctica will get sick or die.
3. The people in Antarctica have been dropping rubbish and pollutants. This has affected animals in Antarctica.
4. Eco-tourists traveling to Antarctica are adding to global warming which is melting the polar ice caps, new research has found.
5. Both science and tourism have the potential to damage the very qualities that draw them to Antarctica.

 

 

The main threats facing Antarctica

Global warming —This results in a loss of sea ice and land-based ice, which is the greatest long-term threat to the region.

Already some ice shelves have collapsed and ice slopes and glaciers have retreated. Oceanic acidification (from extra dissolved carbon dioxide) is already leading to the loss of some marine snails thought to have a significant part to play in the oceanic carbon cycle.

The breeding Oil spills from tourist ships and fishing boats have affected animals in Antarctica. Because of the oil spills, life in Antarctica will get sick or die.

The people in Antarctica have been dropping rubbish and pollutants. This has affected animals in Antarctica.
Eco-tourists traveling to Antarctica are adding to global warming which is melting the polar ice caps, new research has found.

Both science and tourism have the potential to damage the very qualities that draw them to Antarctica. The main threats facing Antarctica populations and ranges of some penguin species have already been altered.

Increased tourism — with the accompanying pollutants that accompany ships and aircraft, the possibility of oil spills, and the effects of lots of people and infrastructure on wildlife and the wider environment.

Pollution — CFCs and other ozone depleters are responsible for the ozone hole that has appeared over Antarctica for over 30 years, chemicals produced thousands of miles away are found in Antarctic ice and in the bodies of wildlife.

Discarded equipment, chemicals, and oil can degrade the landscape. Fishing nets, plastic, lines, hooks, etc. carried by sea can result in great suffering or loss of life by birds, fish, and marine mammals.

Exploration and exploitation of mineral reserves, oil, and gas- Not currently economically viable, but as the need becomes greater and as technology advances, this will become an increasing threat.

The Antarctic Treaty bans all mining and mineral exploitation indefinitely, though this comes up for review in 2048 (in other words, it isn’t really banned indefinitely at all).

Direct impacts associated with the development of infrastructure for scientific bases and programs- The construction of buildings and related facilities such as roads, fuel storage, runways, etc. are damaging the natural ecosystems of the entire area.

Conservation of Wildlife

What is wildlife?

Wildlife traditionally refers to non-domesticated animal species but has come to include all plants, fungi, and other organisms which grow or live wild in an area without being introduced by humans.

Wildlife can be found in all ecosystems. Deserts, forests, rain forests, plains, grasslands, and other areas including the most developed between 1970 and 2014, according to a report by the World Wildlife Fund.

Wildlife of India

The wildlife in India comprises a mix of species of different types of organisms. India is home to Bengal tigers, Indian lions, deer, pythons, wolves, foxes, bears, crocodiles, camels, wild dogs, monkeys, snakes, antelope species, varieties of bison, and the Asian elephant.

The region’s rich and diverse wildlife is preserved in 89 national parks, 18 Bio-reserves, and 400+ wildlife conservation societies and organizations that work tirelessly to save wild lands and wildlife through international conservation and education.

They also work to promote more efficient use of the Earth’s resources and energy to reduce pollution. Human influence over the Earth’s ecosystems has been so extensive within the last 10,000 years

Wildlife conservation

Wildlife conservation is the science of analyzing and protecting the Earth’s biological diversity. Biodiversity on Earth today consists of many millions of distinct biological species.

Wildlife conservation is the process of individuals and organizations protecting and preserving these species through conservation education, and preservation of habitat.

There are many wildlife urban sites, all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that much wildlife is affected by human activities.

The global wildlife population has decreased by 52 percent from conservation societies and organizations work tirelessly to save wild lands and wildlife through international conservation and education.

They also work to promote more efficient use of the Earth’s resources and energy to reduce pollution. Human influence over the Earth’s ecosystems has been so extensive within the last 10,000 years that scientists have difficulty estimating the total number of species lost in this era.

The rates of deforestation, reef destruction, wetlands filling, and other human acts are proceeding much faster than a human assessment of the Earth’s species.

The overpopulation of humans on the Earth has been the main threat. With overpopulation comes mass agriculture, deforestation, overgrazing, slash-and-burn urban development, pesticide use, and global warming.

An endangered species is a population of an organism that is at risk of becoming extinct because it is few in number and/or is threatened by changing environment.

Many countries have laws offering protection to these species.

IUCN and its role in conservation

The International Union for Conservation of Nature and Natural Resources (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources.

It is involved in data gathering and analysis, research, field projects, advocacy, lobbying, and education. lUCN’s mission is to “influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable.”

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

1. Extinct (EX) – No known individuals remaining.
2. Extinct in the wild (EW) – Known only to survive in captivity, or as a naturalized population outside its historic range.
3. Critically endangered (CR) – Extremely high risk of extinction in the wild.
4. Endangered (EN) – High risk of extinction in the wild but not in the near future.
5. Vulnerable (VU) – High risk of endangerment in the wild in the distant future.
6. Near Threatened (NT) – Likely to become endangered in the near future.
7. Least concern (LC) – Lowest risk and does not qualify for a more at-risk category. Widespread and abundant taxa are included in this category.
8. [Taxa=A taxonomic category or group, such as a phylum, order, family, genus, or species.]
9. Data Deficient (DD) – Not enough data to make an assessment of its risk of extinction.
10. Not evaluated — rids evaluated against the criteria.

When discussing the IUCN Red List, the official term “threatened” is a grouping of three categories-Critically Endangered, Endangered, and Vulnerable

Why is biodiversity in crisis?

Every day species’ extinctions are continuing at up to 1,000 times or more the natural rate. The extinction of not only individual species but also habitat destruction, land conversion for agriculture and development, climate change, pollution, and the spread of invasive species are only some of the threats responsible for today’s crisis.

Threats to biodiversity are numerous and human activity is responsible for most of them.

Habitat loss and degradation affect 86% of all threatened birds, 86% of the threatened mammals assessed, and 88% of the threatened amphibians.

Introduction of Invasive Alien Species that establish and spread outside their normal distribution. Some of the most threatening invasive species include cats and rats, green crabs, zebra mussels, the African tulip tree, and the brown tree snake.

Introductions of alien species can happen deliberately or unintentionally, for example, by organisms “hitch-hiking” in containers, ships, cars, or soil.

Over-exploitation of natural resources. Resource extraction, hunting, and fishing for food, pets, and medicine.
Pollution and diseases. For example, excessive fertilizer use leads to excessive levels of nutrients in soil and water.

Human-induced climate change. For example, climate change is altering migratory species patterns and increasing coral bleaching.

Conservations of Biodiversity

Conservation is the protection, preservation, management, or restoration of wildlife and natural resources such as forests and water.

Through the conservation of biodiversity and the survival of many species and habitats which are threatened due to human activities can be ensured. There is an urgent need, not only to manage and conserve biotic wealth but also to restore degraded ecosystems.

Types of Conservation

Conservation can broadly be divided into two types: In-situ conservation and Ex-situ conservation. Biodiversity Conservation

in-situ Conservation: In-situ conservation is on-site conservation or the conservation of genetic resources in natural populations of plant or animal species, such as forest genetic resources in natural populations of tree species.

It is the process of protecting an endangered plant or animal species in its natural habitat, either by protecting or cleaning up the habitat itself or by defending the species from predators.

It is applied to the conservation of agricultural biodiversity in agro-forestry by farmers, especially those using unconventional farming practices.

In-situ conservation is being done by declaring the area as a protected area. In India following types of natural habitats are being maintained:

1. National parks
2. Wildlife sanctuaries
3. Biosphere reserves

India has over 600 protected areas, which include over 90 national parks, over 500 animal sanctuaries, and 15 biosphere reserves.

Ex-Situ Conservation; Ex-situ conservation is the preservation of components of biological diversity outside their natural habitats.

This involves the conservation of genetic resources, as well as wild and cultivated species, and draws on a diverse body of techniques and facilities.

Such strategies include the establishment of botanical gardens, zoos, conservation strands and genes, pollen seeds, seedlings, tissue cultures, and DNA banks.

Some endangered animals in India

The world is filled with endangered species of animals, many of which can be found in India. While some of these species are critically endangered, some are near threatened and some are even extinct.

There are some species that are left in such few numbers that the next generation may not be able to ever see them if nothing is done for their conservation.

While we hope that more efforts are taken to conserve these species, here’s a list of some endangered animals that you can find in different parts of India.

1. Bengal Tiger

The Bengal Tiger is the national animal of both, India and Bangladesh. The tiger’s coat is yellow to light orange, with stripes ranging from dark brown to black. The number of tigers has reduced dramatically in the past few years, due to poaching and human-tiger conflict.

Can be spotted at Tadoba National Park, Ranthambore National Park, Sundarbans National Park, Sariska Tiger Reserve, Jim Corbett National Park, and Bandhavgarh National Park. [Snow Leopard The snow leopard is a large cat native to the mountain ranges in Central and South Asia.

Snow leopards have long, thick fur, and their base color varies from smoky gray to yellowish tan, with whitish underparts.

Can be spotted: at Hemis National Park, Ladakh, Nanda Devi National Park, Uttarakhand, Dibang Wildlife Sanctuary, Arunachal Pradesh,]

2. Asiatic Lion

Asiatic Lion aka the Indian Lion or Persian Lion is a lion subspecies that is endangered. It differs from the African lion by less inflated auditory bullae, a larger tail tuft, and a less developed mane.

Can be spotted: at Gir Forest National Park, Gujarat.

 

3. Snow Leopard

The snow leopard is a large cat native to the mountain ranges in Central and South Asia. Snow leopards have long, thick fur, and their base color varies from smoky gray to yellowish tan, with whitish underparts.

Can be spotted at: Hemis National Park, Ladakh, Nanda Devi National Park, Uttarakhand, Dibang Wildlife Sanctuary, Arunachal Pradesh, Kibber Wildlife Sanctuary, Lahaul Spiti, Himachal Pradesh, Pin Valley National Park, Great Himalayan National Park, Kullu, Himachal Pradesh.

4. Blackbuck

The Blackbuck is an ungulate species of antelope and it is near threatened. The main threat to this species is poaching, predation, habitat destruction, overgrazing, inbreeding, and sanctuary visitors.

Can be spotted: at Guindy National park, Tamil Nadu, Rollapadu, Andhra Pradesh, Chilka, Odisha.

 

Understanding environmental crisis for Class 8

5. Red Panda

Red Panda is also known as a lesser panda or red cat-bear. It is an arboreal mammal native to the eastern Himalayas. Red Panda’s population is on a decrease given to habitat loss and fragmentation, poaching, and inbreeding depression.

Can be spotted: at Sikkim, Arunachal Pradesh, and West Bengal’s Khangchendzonga and Namdapha National Park.

 

6. The Nilgiri Tahr:

The Nilgiri Tahr is an ungulate, endemic to the Nilgiri Hills. Nilgiri tahrs are stocky goats with short, coarse fur and a bristly mane.

Can be spotted: at Eravikulam National Park, Nilgiri Hills, Anaimalai Hills, Periyar National Park, and Palni Hills.

 

 

7. Kashmir Red Stag (Hangul)

The Kashmir stag also known as Hangul is a critically endangered species. This deer has a light rump patch without including the tail. Each of its antlers consists of 5 tines.

Wildlife Sanctuary, OveraAru, Sind Valley, and in the forests of Kishtwar and Bhaderwah, all of which are a part of Jammu and Kashmir.

8. Lion-Tailed Macaque

The Lion-tailed macaque is an Old World Monkey, endemic to the Western Ghats of South India. Its outstanding characteristic is the silver-white mane that surrounds the head from the cheeks down to the chin.

Can be spotted: at Silent Valley National Park, Kerala, Papanasam part of the KalakkadMundanthurai Tiger Reserve, Tamil Nadu, and Sirsi-Honnavara rainforests of NorthWestern Ghats in Karnataka.

 

9. Indian Bison (Gaur)

Indian Bison is the largest extant bovine, native to South Asia and South-East Asia. The bison are highly threatened by poaching for trade to supply international markets.

Can be spotted: at Arignar Anna Zoological Park, Chennai, and Chinnar Wildlife Sanctuary, Kerala.

10. Vultures

Vultures were once the most abundant large birds of prey and nature’s scavengers across the world, including the Indian subcontinent.

But today they are one of the most endangered bird species. This has not only resulted in the near-total disappearance of a magnificent bird from our skies but also jeopardized health and cleanliness in the countryside and caused unnatural changes in the natural food chain.

The species breeds mainly on cliffs but is known to use trees to nest in Rajasthan. Like other vultures it is a scavenger, feeding mostly on carcasses of dead animals which it finds by soaring over the savannah and around human habitation.

They often move in flocks. For centuries, vultures have been silently performing a very important task in the cycle of nature.  They are Nature’s Custodians of Cleanliness. They have been revered in most ancient cultures for the role they play in the ecosystem.

For instance, in India, they appear as Jatayu and Sampati in the great epic Ramayan. They have been playing a lion’s share in disposing of the carcasses of dead animals, both wild and domestic, along with other lesser scavengers such as jackals, hyenas, dogs, crows, and kites.

Between 2000-2007 annual decline rates of this species and the slender-billed vulture averaged over sixteen percent. The cause of this has been identified as poisoning caused by the veterinary drug diclofenac.

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) and when given to working animals it can reduce joint pain and so keep them working for longer.

The drug is believed to be swallowed by vultures with the flesh of dead cattle who were given diclofenac in the last days of life.

Diclofenac causes kidney failure in several species of vultures. In March 2006 the Indian Government announced its support for a ban on the veterinary use of diclofenac.

Another NSAID, meloxicam, has been found to be harmless to vultures and should prove to be an acceptable substitute for diclofenac.

When meloxicam production is increased it is hoped that it will be as cheap as diclofenac. As of August 2011, the ban for veterinary use for approximately a year did not prevent diclofenac use across India.

Small numbers of birds have bred across peninsular India, in Karnataka and Tamil Nadu. Captive breeding programs for several species of Indian vulture have been started.

The vultures are long-lived and slow in breeding, so the programs are expected to take decades. Vultures reach breeding age at about five years old.

It is hoped that captive-bred birds will be released to the wild when the environment is clear of diclofenac.

 

 

11. Gangetic Dolphins

The Ganges River dolphin (or susu, blind dolphin, Gangetic dolphin, South Asian River Dolphin) inhabits the Ganges-Brahmaputra- Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh.

This vast area has been altered by the construction of more than 50 dams and other irrigation-related projects, with dire consequences for the river dolphins. The scientific name is – Platanista gangetica.

Physical Description: A long thin snout, rounded belly, stocky body, and large flippers are characteristics of the Ganges River dolphin.

Although its eye lacks a lens (this species is also referred to as the “blind dolphin”), the dolphin still uses its eye to locate itself.

The species has a slit similar to a blowhole on the top of the head, which acts as a nostril. The dolphin has the peculiarity of swimming on one side so that its flipper trails the muddy bottom.

Females are larger than males and attain a maximum size of 2.67 m. Males are about 2.12 m. The color of the dolphin is grayish brown. The calves and young ones are dark in color but as the animal grows in size, the color lightens.

Ecology and Habitat:

The species is found exclusively in freshwater habitats. In Nepal, it inhabits Clearwater and rapids. In Bangladesh and India, individuals live in rivers that flow slowly through the plains.

The Ganges River dolphin favors deep pools, eddy counter-currents located downstream of the convergence of rivers and of sharp meanders, and upstream and downstream of mid-channel islands/

Susu shares its habitat with crocodiles, freshwater turtles, and wetland birds, many of which are fish eaters and potential competitors. with dolphins.

Why is this species important? The presence of dolphins in a river system signals a healthy ecosystem. Since the river dolphin is at the apex of the aquatic food chain,

Its presence in adequate numbers symbolizes greater biodiversity in the river system and helps keep the ecosystem in balance.

What are the main threats to the Ganges River dolphin? Dolphins are in danger because of less habitat area due to the construction of dams, fishing, and pesticide.

They are also killed for meat and oil. Dolphins in India come under extinct animals due to polluted rivers and poaching.

Every year nearly 100 Dolphins are getting killed by humans. If anyone kills the Dolphin, or if anyone has the body parts of the Dolphin, will be treated as a crime they will be punished.

Conservation: India has declared Ganga Dolphin as the National Aquatic Animal of India. The Ganges River Dolphin is a rare species of dolphin found only in India and neighboring countries.

There are various conservation works going on in the Sanctuary Areas to protect the National Aquatic Animal of India. Vikramshila Gangetic dolphin sanctuary is the only protected area for the endangered Gangetic dolphins in Asia.

It is located in the Bhagalpur District of Bihar, India. Only a few hundred dolphins remain in India, of which half are found here.

WWF-India and Aaranyak an NGO have been working closely with various government departments to protect these blind river Dolphins of India.

One horned rhinoceros

The Indian rhinoceros (Rhinoceros unicornis), also called the greater one-horned rhinoceros and Indian one-horned rhinoceros.

Listed as a vulnerable species, the large mammal is primarily found in India’s Assam, West Bengal, and in protected areas in the Terai of Nepal, where populations are confined to the riverine grasslands in the foothills of the Himalayas.

The Indian rhinoceros once ranged throughout the entire stretch of the Indo-Gangetic Plain, but excessive hunting reduced their range drastically. Today, more than 3,000 rhinos live in the wild.

 

Physical description: The Indian rhinoceros has thick grey-brown skin with pinkish skin folds and a black horn. Its upper legs and shoulders are covered in wart-like bumps.

It has very little body hair, aside from eyelashes, ear fringes, and tail brushes. Males have huge neck folds. Its skull is heavy with a basal length above 60 cm (24 in) and an occiput above 19 cm (7.5 in).

Its nasal horn is slightly back-curved with a base of about 18.5 cm (7.3 in) by 12 cm (4.7 in) that rapidly narrows until a smooth, even stem part begins about 55 mm (2.2 in) above the base. In captive animals, the horn is frequently worn down to a thick knob.

The rhino’s single horn is present in both males and females but not in newborns young. The black horn is our keratin, like human fingernails, and starts to show after about six years.

In most adults, the caches have a length of about 25 cm (9.8 in), but has been recorded up to 57.2 cm (22.5 in) in length.

Distribution and habitat: One-homed rhinos once ranged across the entire northern part of the infant Subcontinent along the Indus, Ganges, and Brahmaputra River basins, from Pakistan to the Indian-Burmese border, including Bangladesh and the southern parts of Nepal and Bhutan.

They may have also occurred in Myanmar, southern China, and Indochina. Today, their range has further shrunk to a few pockets in southern Nepal, northern Bengal, and the Brahmaputra Valley.

Ecology and behavior: Rhinos are mostly solitary creatures, with the exception of mothers and calves and breeding pairs, although they sometimes congregate in bathing areas.

Dominant males tolerate males passing through their territories except when they are in mating season when dangerous fights break out. They are active at night and early morning.

They are very good swimmers. Indian rhinos bathe -regularly. The folds in their skin trap water and hold it even when they come back on land.

Indian rhinos have few natural enemies, except for tigers, which sometimes kill unguarded calves, but adult rhinos are less vulnerable due to their size.

They have excellent senses of hearing and smell, but relatively poor eyesight. The Indian rhinoceros makes a wide variety of vocalizations.

Diet: Indian rhinoceros are grazers. Their diets consist almost entirely of grasses, but they also eat leaves, branches of shrubs and trees, fruits, and submerged and floating aquatic plants. They feed in the mornings and evenings.

Reproduction: Captive males breed at five years of age, but wild males attain dominance much later when they are larger.

In one five-year field study, only one rhino estimated to be younger than 15 years mated successfully. Captive females breed as young as four years of age but in the wild,

They usually start breeding only when six years old, which likely indicates they need to be large enough to avoid being killed by aggressive males. Their gestation period is around 15.7 months, and their birth interval ranges from 3451 months.

Threats: Sport hunting became common in the late 1800s and early 1900s. Indian rhinos were hunted relentlessly and persistently.

Poaching for rhinoceros horn became the single most important reason for the decline of the Indian rhino after conservation measures were put in place from the beginning of the 20th century when legal hunting ended. From 1980 to 1993,692 rhinos were poached in India.

Poaching, mainly for the use of the horn in traditional Chinese medicine, has remained a constant and has led to decreases in several important populations.

The enormous reduction in the range of rhinos was mainly caused by the disappearance of alluvial plain grasslands. Today, the need for land by the growing human population is a threat to the species.

Many of the protected areas with rhinos have now reached the limit of the number of individuals they can support. This leads to human-rhino conflict as rhinos leave the boundaries of the protected areas to forage in the surrounding villages.

Conservation: The Indian and Nepalese governments have taken major steps towards Indian rhinoceros conservation, especially with the help of the World Wide Fund for Nature (WWF) and other non-governmental organizations. In 1910, all rhino hunting in India became prohibited.

In 1984, five rhinos were relocated to Dudhwa National Park — four from the fields outside the Pabitora Wildlife Sanctuary and one from Goalpara.

Thanks to rigorous conservation efforts, their numbers have increased dramatically since 1975. By 2012, conservation efforts saw the population grow to over 3,000 in the Terai Arc Landscape of India and Nepal and the grasslands of Assam and north Bengal in northeast India.

Fishing Cat

Larger than a domestic cat, the Fishing Cat Prionailurus vibe minus is well adapted to catching fish, its primary prey.
One remarkable feature is the layered structure of their fur, a crucial adaptation to life in the water. Next to the skin lies a layer of short hair so dense that water cannot penetrate it.

1. Like snug-fitting thermal underwear, this coat helps keep the animal warm and dry even during chilly fishing expeditions.
2. Sprouting up through the first coat is another layer of long guard hairs which gives the cat its pattern and glossy sheen.

Distribution: Fishing Cats have a discontinuous distribution in South East Asia, northern India, and Sri Lanka. On the island of Java, it has become scarce and apparently restricted to a few coastal wetlands.

Threats: Expansion of roads, housing, shopping malls, and human habitation is reducing bushy jungles or wetlands. Factories and brick kilns are also being constructed here and there. As a result, the habitat and source of natural food for fishing cats are decreasing day by day.

They are also being killed by humans when they are compelled to intrude upon human habitat in search of ducks and hens. Hence their number is endangered.

Conservation: Locally common in some areas of eastern India and Bangladesh, they have become increasingly difficult to locate throughout the remainder of their range.

The scarcity of recent records suggests that over the past decade, they have undergone a serious and significant population decline.

Even in protected wetlands and former Fishing Cat study areas, researchers have been unable to document their presence. Fishing cats are listed as endangered on the lUCN’s Red List of Threatened Species.

They are threatened by habitat loss and hunting for food and fur. People have drained many wetland areas to make room for farmland and roads.

Pollution from industries has poisoned rivers and streams where fishing cats once fed. However, fishing cats appear to do well in suburban habitats, so they may prove more adaptable to human activities than some other species.

The fishing cat is the state animal of West Bengal. In the Bengali language, the fishing cat is known as ‘mach-baghrol’.’ mach means fish, and ‘bagha’ means tiger. The name is due to their tiger-like appearance and fish-eating habit.