ENVIRONMENT
◙The crust forms only 1 per cent of the volume of the earth.
◙Biotic components=Plants/Animals/Birds etc
◙Abiotic components=Land/Mountains/Rivers etc
◙The word environment is derived from french word "Environer" meaning "Neighborhood".
◙World environment day=5 June
◙Barter system =in which, goods are exchanged without the use of money
◙Ecosystem: It is a
system formed by the
interaction of all
living organisms with
each other and with
the physical and
chemical factors of
the environment in
which they live, all
linked by transfer of
energy and material.
INSIDE OUR EARTH
Layers of Earth
1.Crust
◙uppermost layer
◙Thinnest layer
◙35 km on continental masses and about 5 km on ocean floors
◙Main minerals of continental mass=silica and alumina. It is thus called SiAl.
◙Main mineral of oceanic crust= Silica and Magnesium. It is thus called SiMa.
2.Mantle
◙It extends upto depth of 2900 km.
3.Core
◙Radius =3500 km
◙Consists mainly Nickel and Iron. It is thus called NiFe.
◙The crust forms only 1 per cent of the volume of the earth.
◙84 per cent consists of the mantle.
◙15 per cent makes the core.
◙The radius of the earth is 6371 km.
ROCKS AND MINERALS
1.Igneous (Latin word
Ignis meaning fire)
◙Also called primary rocks.
◙Intrusive ones cool slowly. E.g Granite
◙Extrusive ones are found in Deccan plateau. e.g Basalt
◙Also called primary rocks.
◙Intrusive ones cool slowly. E.g Granite
◙Extrusive ones are found in Deccan plateau. e.g Basalt
2.Sedimentary (Latin
word sedimentum
meaning settle down.)
e.g Sandstone
◙Red fort is made from Red Sandstone.
e.g Sandstone
◙Red fort is made from Red Sandstone.
3.Metamorphic (Greek
word metamorphose
meaning change of form.)
◙Igneous and sedimentary rocks can change
into metamorphic rocks under great heat and
pressure. e.g clay changes into
slate and limestone into marble.
Fossils: The remains
of the dead plants and
animals trapped in
the layers of rocks are
called fossils.
EARTHQUAKES
◙Similarly, when the Lithospheric plates move, the
surface of the earth vibrates. The vibrations can travel
all round the earth. These vibrations are called
earthquakes.
◙The place in the crust where the movement starts is called the focus.
◙The place on the surface above the focus is called the epicentre.
◙Greatest damage is usually closest to the epicentre and the strength of the earthquake decreases away from the centre.
EARTHQUAKE WAVES
There are three types
of earthquake waves:
1. P waves or longitudinal waves (PRIMARY)
2. S waves or transverse waves (SECONDARY)
3. L waves or surface waves (LOVE)
(*after A.E.H. Love, a British mathematician)
The other kind of surface wave is the Rayleigh wave,
◙Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.
◙An earthquake is measured with a machine called a seismograph.
◙ The magnitude of the earthquake is measured on the Richter scale.
◙An earthquake of 2.0 or less can be felt only a little. An earthquake over 5.0 can cause damage from things falling. A 6.0 or higher magnitude is considered very strong and 7.0 is classified as a major earthquake.
◙There are thousands of small waterfalls in the world. The highest waterfall is Angel Falls of Venezuela in South America.
◙The other waterfalls are Niagara falls located on the border between Canada and USA in North America and Victoria Falls on the borders of Zambia and Zimbabwe in Africa.
MAJOR LAND FORMS
MEANDERS
As the river enters the plain it twists and turns forming large bends known as meanders.
In due course of time the
meander loop cuts off from the river and
forms a cut-off lake, also called an ox-bow
lake.
LEVEES
At times the river overflows its banks. This leads to the flooding of the neighboring areas. As it floods, it deposits layers of fine soil and other material called sediments along its banks. This leads to the formation of a flat fertile floodplain. The raised banks are called levees.
DISTRIBUTARY
As the river approaches the sea, the speed of the flowing water decreases and the river begins to break up into a number of streams called distributaries.
DELTA
The river becomes so slow that it begins to deposit its load. Each distributary forms its own mouth. The collection of sediments from all the mouths forms a delta.
MUSHROOM ROCKS
◙An active agent of erosion and deposition in the deserts is wind. In deserts you can see rocks in the shape of a mushroom, commonly called mushroom rocks. Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top.
SAND DUNES
◙When the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill – like structures. These are called sand dunes
LOESS
◙When the grains of sand are very fine and light, the wind can carry it over very long distances. When such sand is deposited in large areas, it is called loess. Large deposits of loess is found in China.
COMPOSITION OF THE ATMOSPHERE
1.NITROGEN (78%)
2.OXYGEN (21%)
3.ARGON (0.93%)
4.CO2 (0.04%)
◙When we inhale, we take some amount of nitrogen into our lungs and exhale it. But plants need nitrogen for their survival. They can not take nitrogen directly from the air. Bacteria, that live in the soil and roots of some plants, take nitrogen from the air and change its form so that plants can use it.
STRUCTURE OF THE ATMOSPHERE
Troposphere: This layer is the most important layer of the atmosphere. Its average height is 13 km. The air we breathe exists here. Almost all the weather phenomena like rainfall, fog and hailstorm occur in this layer.
Stratosphere: Above the troposphere lies the stratosphere. It extends up to a height of 50 km. This layer is almost free from clouds and associated weather phenomenon, making conditions most ideal for flying aeroplanes. One important feature of stratosphere is that it contains a layer of ozone gas.
Mesosphere: This is the third layer of the atmosphere. It lies above the stratosphere. It extends up to the height of 80 km. Meteorites burn up in this layer on entering from the space.
Thermosphere: In thermosphere temperature rises very rapidly with increasing height. Ionosphere is a part of this layer. It extends between 80-400 km. This layer helps in radio transmission. In fact, radio waves transmitted from the earth are reflected back to the earth by this layer.
Exosphere: The upper most layer of the atmosphere is known as exosphere. This layer has very thin air. Light gases like helium and hydrogen float into the space from here.
◙Thermometer: Measures the temperature
◙Barometer: Measures atmospheric pressure
◙Rain Gauge: Measures the amount of rainfall
◙Wind Vane: Shows the direction of the wind
◙An important factor that influences the distribution of temperature is insolation. Insolation is the incoming solar energy intercepted by the earth. The amount of insolation decreases from the equator towards the poles.
◙A wind is named after the direction from which it blows, e.g. the wind blowing from the west is called westerly.
◙Winds can be broadly divided into three types.
1. Permanent winds – The trade winds, westerlies and easterlies are the permanent winds. These blow constantly throughout the year in a particular direction.
(The trade winds are so named because ships have historically taken advantage of them to aid their journies between Europe and the Americas.)
2. Seasonal winds – These winds change their direction in different seasons. For example monsoons in India.
3. Local winds – These blow only during a particular period of the day or year in a small area. For example, land and sea breeze. The hot and dry local wind of northern planes of India is called loo.
RAINFALL
On the basis of mechanism, there are three types of rainfall: 1.the convectional rainfall
2.the orographic rainfall
3.the cyclonic rainfall
https://www.youtube.com/watch?v=i36U3LpJjzU
PRECIPITATION
MAP COMPANION (LOCATIONS TO REMEMBERS)
1.Amazon river
2. Mississippi river
3.Caribbean sea
4.Great bear lake
5.Great slave lake
6.Lake Huron
7.Lake superior
8.Niger river
9.Congo river
10.Orange river
11.Nile river
12.Mediterranean sea
13.Black sea
14.Red sea
15.Lake Victoria
16.Caspian sea
17.Arabian sea
18.South china sea
19.East china sea
20.Darling river
21.Murray river
DISTRIBUTION OF WATER BODIES
We all know that three-fourth of the earth surface is covered by water. If there is more water than land on this earth, why do so many countries face water scarcity?
◙Salinity is the amount of salt in grams present in 1000 grams of water. The average salinity of the oceans is 35 parts per thousand.
◙Dead sea in Israel has salinity of 340 grams per litre of water. Swimmers can float in it because the increased salt content makes it dense.
◙March 22 is celebrated as World Water Day
◙Tsunami is a Japanese word that means “Harbour waves” as the harbours get destroyed whenever there is tsunami
◙The tsunami of 2004 caused wide spread damage in the coastal areas of India. The Indira point in the Andaman and Nicobar islands got submerged after the tsunami.
TIDES
The rhythmic rise and fall of ocean water twice in a day is called a tide.
◙It is high tide when water covers much of the shore by rising to its highest level.
◙It is low tide when water falls to its lowest level and recedes from the shore.
https://www.youtube.com/watch?v=pwChk4S99i4
The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides. The water of the earth closer to the moon gets pulled under the influence of the moon’s gravitational force and causes high tide. During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides. But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and moon resulting in low tides. These tides are called neap tides
OCEAN CURRENTS
1.WARM OCEAN CURRENTS
2.COLD OCEAN CURRENTS
◙Generally, the warm ocean currents originate near the equator and move towards the poles.
◙The cold currents carry water from polar or higher latitudes to tropical or lower latitudes.
◙ The Labrador Ocean current is cold current while the Gulf Stream is a warm current.
◙The ocean current influence the temperature conditions of the area. Warm currents bring about warm temperature over land surface.
◙The areas where the warm and cold currents meet provide the best fishing grounds of the world. Seas around Japan and the eastern coast of North America are such examples. The areas where a warm and cold current meet also experience foggy weather making it difficult for navigation.
Natural Vegetation and Wild Life
The two factors on which the growth of vegetation mostly depends are— temperature and moisture.
Natural vegetation is generally classified in to three broad categories as follows:
1.FORESTS
Which grow where temperature and rainfall are plentiful to support a tree cover
a) Tropical Evergreen Forests
These forests are also called tropical Rainforests.
◙These thick forests occur in the regions near the equator and close to the tropics. These regions are hot and receive heavy rainfall throughout the year. As there is no particular dry season, the trees do not shed their leaves altogether. This is the reason they are called evergreen.
◙The thick canopies of the closely spaced trees do not allow the sunlight to penetrate inside the forest even in the day time.
◙Hardwood trees like rosewood, ebony, mahogany are common here.
◙The tropical evergreen forest in Brazil is so enormous that it is like the lungs of the earth
◙The Amazon River which runs through the Amazon rainforest is the world’s second longest river after the Nile. It is also the world’s largest by water volume.
b) Tropical Deciduous Forests
◙Trees shed their leaves in the dry season to conserve water.
◙The hardwood trees found in these forests are sal, teak, neem and shisham.
Hardwood trees are extremely useful for making furniture, transport and constructional materials. Tigers, lions, elephants, langoors and monkeys are the common animals of these regions.
c) Temperate Evergreen Forests
The temperate evergreen forests are located in the mid latitudinal coastal region. They are commonly found along the eastern margin of the continents, e.g., In south east USA, South China and in South East Brazil.
◙They comprise both hard and soft wood trees like oak, pine, eucalyptus, etc.
d) Temperate Deciduous Forests
As we go towards higher latitudes, there are more temperate deciduous forests . These are found in the north eastern part of USA, China, New Zealand, Chile and also found in the coastal regions of Western Europe.
◙They shed their leaves in the dry season.
The common trees are oak, ash, beech, etc. Deer, foxes, wolves are the animals commonly found.
Birds like pheasants, monals are also found here
e)Mediterranean Vegetation
◙Most of the east and north east
margins of the continents are covered by temperate
evergreen and deciduous trees. The west and south west
margins of the continents are different. They have
Mediterranean vegetation.
◙They have Clear skies and high temperatures; hot, dry summers and cool, wet winters.
◙It is mostly found in the areas around the Mediterranean sea in Europe, Africa and Asia, hence the name
◙This kind of vegetation is also found outside the actual Mediterranean region in California in the USA, south west Africa, south western South America and South west Australia.
◙There isn’t much wildlife here
https://www.pmfias.com/mediterranean-climate-warm-temperate-western-margin-climate-warm-temperate-west-coast-climate/#A_dry_warm_summer_with_off-shore_trades
◙Mediterranean trees adapt themselves to dry summers with the help of their thick barks and wax coated leaves which help them reduce transpiration.
◙Mediterranean regions are known as ‘Orchards of the world’ for their fruit cultivation.
f) Coniferous Forests
◙In the higher latitudes of Northern hemisphere the spectacular Coniferous forests are found . These are also called as Taiga. These forests are also seen in the higher altitudes.
Taiga means pure or untouched in the Russian language
◙The woods of these trees are very useful for making pulp, which is used for manufacturing paper and newsprint. Match boxes and packing boxes are also made from softwood.
◙Chir, pine, cedar are the important variety of trees in these forests.
◙Silver fox, mink, polar bear are the common animals found here.
2.GRASSLANDS
Which grow in the region of moderate rain.
a) Tropical grasslands:-
◙This vegetation grows in the areas of moderate to low amount of rainfall. The grass can grow very tall, about 3 to 4 metres in height.
Savannah grasslands of Africa are of this type.
Elephants, zebras, giraffes, deer, leopards are common in tropical grasslands
b) Temperate grasslands:-
◙These are found in the mid-latitudinal zones and in the interior part of the continents.
◙Usually, grass here is short and nutritious.
◙Wild buffaloes, bisons, antilopes are common in the temperate region.
Grasslands are known by different names in different regions.
Tropical Grasslands
East Africa- Savanna.
Brazil- Campos
Venezuela- Llanos
Temperate Grasslands
Argentina- Pampas
N. America- Prairie
S. Africa- Veld
C. Asia- Steppe
Australia- Down
3.SHRUBS
◙Thorny shrurbs and scrubs grow in the dry region.
◙The vegetation cover is scarce here because of scanty rain and scorching heat.
TUNDRA VEGETATION
If you reach the polar region you will find the place extremely cold. The growth of natural vegetation is very limited here. Only mosses, lichens and very small shrubs are found here.
◙It grows during the very short summer. This is called Tundra type of vegetation.
◙This vegetation is found in the polar areas of Europe, Asia and North America. The animals have thick fur and thick skin to protect themselves from the cold climatic conditions.
◙Seal, walruses, musk-oxen, Arctic owl, Polar bear and snow foxes are some of the animals found here
HUMAN SETTLEMENT
.
◙Transhumance: It is a seasonal movement of people. People who rear animals move in search of new pastures according to changes in seasons.
◙The Golden Quadrilateral connects Delhi, Mumbai, Chennai and Kolkata.
◙The Trans-Siberian Railway is the longest railway system
connecting St. Petersburg in Western Russia to Vladivostok on the
Pacific coast.
◙4 Means of transport are
a)Roadways
b)Railways
c)Waterways
d)Airways
LIFE IN THE AMAZON BASIN
The river Amazon flows from the mountains to the west and reaches the Atlantic Ocean to the east. The place where a river flows into another body of water is called the river’s mouth.
◙Numerous tributaries join the Amazon River to form the Amazon basin. The river basin drains portions of Brazil, parts of Peru, Bolivia, Ecuador, Columbia and a small part of Venezuela.
◙The Rainforest is rich in fauna. Birds such as toucans, humming birds are found.
◙Animals like monkeys, sloth and ant-eating tapirs are found here.
◙Various species of reptiles and snakes also thrive in these jungles. Crocodiles, snakes, pythons, Anaconda and boa constrictor are some of the species.
◙Several species of fishes including the flesh eating Piranha fish is also found in the river.
LIFE IN THE GANGA-BRAHMAPUTRA BASIN
◙The tributaries of rivers Ganga and Brahmaputra together form the Ganga-Brahmaputra basin in the Indian subcontinent.
◙The basin lies in the sub-tropical region that is situated between 10°N to 30°N latitudes. The tributaries of the River Ganga like the Ghaghra, the Son, the Chambal, the Gandak, the Kosi and the tributaries of Brahmaputra drain it.
◙In the Ganga and Brahmaputra plain tropical deciduous trees grow, along with teak, sal and peepal. Thick bamboo groves are common in the Brahmaputra plain.
◙Elephants, tigers, deer and monkeys are common. The one-horned rhinoceros is found in the Brahmaputra plain. In the delta area, Bengal tiger, crocodiles and alligator are found. Aquatic life abounds in the fresh river waters, the lakes and the Bay of Bengal Sea. The most popular varieties of the fish are the rohu, catla and hilsa. Fish and rice is the staple diet of the people living in the area.
◙In the fresh waters of River Ganga and River Brahmaputra, a variety of dolphin locally called Susu (also called blind dolphin) is found. The presence of Susu is an indication of the health of the river. The untreated industrial and urban wastes with high amount of chemicals are killing this species.
◙The Ganga-Brahmaputra plain has several big towns and cities. The cities of Allahabad, Kanpur, Varanasi, Lucknow, Patna and Kolkata all with the population of more than ten lakhs are located along the River
◙The place in the crust where the movement starts is called the focus.
◙The place on the surface above the focus is called the epicentre.
◙Greatest damage is usually closest to the epicentre and the strength of the earthquake decreases away from the centre.
EARTHQUAKE WAVES
1. P waves or longitudinal waves (PRIMARY)
2. S waves or transverse waves (SECONDARY)
3. L waves or surface waves (LOVE)
(*after A.E.H. Love, a British mathematician)
The other kind of surface wave is the Rayleigh wave,
◙Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.
◙An earthquake is measured with a machine called a seismograph.
◙ The magnitude of the earthquake is measured on the Richter scale.
◙An earthquake of 2.0 or less can be felt only a little. An earthquake over 5.0 can cause damage from things falling. A 6.0 or higher magnitude is considered very strong and 7.0 is classified as a major earthquake.
◙There are thousands of small waterfalls in the world. The highest waterfall is Angel Falls of Venezuela in South America.
◙The other waterfalls are Niagara falls located on the border between Canada and USA in North America and Victoria Falls on the borders of Zambia and Zimbabwe in Africa.
MAJOR LAND FORMS
MEANDERS
As the river enters the plain it twists and turns forming large bends known as meanders.
LEVEES
At times the river overflows its banks. This leads to the flooding of the neighboring areas. As it floods, it deposits layers of fine soil and other material called sediments along its banks. This leads to the formation of a flat fertile floodplain. The raised banks are called levees.
DISTRIBUTARY
As the river approaches the sea, the speed of the flowing water decreases and the river begins to break up into a number of streams called distributaries.
DELTA
The river becomes so slow that it begins to deposit its load. Each distributary forms its own mouth. The collection of sediments from all the mouths forms a delta.
MUSHROOM ROCKS
◙An active agent of erosion and deposition in the deserts is wind. In deserts you can see rocks in the shape of a mushroom, commonly called mushroom rocks. Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top.
SAND DUNES
◙When the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill – like structures. These are called sand dunes
LOESS
◙When the grains of sand are very fine and light, the wind can carry it over very long distances. When such sand is deposited in large areas, it is called loess. Large deposits of loess is found in China.
 |
| LOESS HIILS |
COMPOSITION OF THE ATMOSPHERE
1.NITROGEN (78%)
2.OXYGEN (21%)
3.ARGON (0.93%)
4.CO2 (0.04%)
◙When we inhale, we take some amount of nitrogen into our lungs and exhale it. But plants need nitrogen for their survival. They can not take nitrogen directly from the air. Bacteria, that live in the soil and roots of some plants, take nitrogen from the air and change its form so that plants can use it.
STRUCTURE OF THE ATMOSPHERE
Troposphere: This layer is the most important layer of the atmosphere. Its average height is 13 km. The air we breathe exists here. Almost all the weather phenomena like rainfall, fog and hailstorm occur in this layer.
Stratosphere: Above the troposphere lies the stratosphere. It extends up to a height of 50 km. This layer is almost free from clouds and associated weather phenomenon, making conditions most ideal for flying aeroplanes. One important feature of stratosphere is that it contains a layer of ozone gas.
Mesosphere: This is the third layer of the atmosphere. It lies above the stratosphere. It extends up to the height of 80 km. Meteorites burn up in this layer on entering from the space.
Thermosphere: In thermosphere temperature rises very rapidly with increasing height. Ionosphere is a part of this layer. It extends between 80-400 km. This layer helps in radio transmission. In fact, radio waves transmitted from the earth are reflected back to the earth by this layer.
Exosphere: The upper most layer of the atmosphere is known as exosphere. This layer has very thin air. Light gases like helium and hydrogen float into the space from here.
◙Thermometer: Measures the temperature
◙Barometer: Measures atmospheric pressure
◙Rain Gauge: Measures the amount of rainfall
◙Wind Vane: Shows the direction of the wind
◙An important factor that influences the distribution of temperature is insolation. Insolation is the incoming solar energy intercepted by the earth. The amount of insolation decreases from the equator towards the poles.
◙A wind is named after the direction from which it blows, e.g. the wind blowing from the west is called westerly.
◙Winds can be broadly divided into three types.
1. Permanent winds – The trade winds, westerlies and easterlies are the permanent winds. These blow constantly throughout the year in a particular direction.
(The trade winds are so named because ships have historically taken advantage of them to aid their journies between Europe and the Americas.)
2. Seasonal winds – These winds change their direction in different seasons. For example monsoons in India.
3. Local winds – These blow only during a particular period of the day or year in a small area. For example, land and sea breeze. The hot and dry local wind of northern planes of India is called loo.
RAINFALL
On the basis of mechanism, there are three types of rainfall: 1.the convectional rainfall
2.the orographic rainfall
3.the cyclonic rainfall
https://www.youtube.com/watch?v=i36U3LpJjzU
PRECIPITATION
MAP COMPANION (LOCATIONS TO REMEMBERS)
1.Amazon river
2. Mississippi river
3.Caribbean sea
4.Great bear lake
5.Great slave lake
6.Lake Huron
7.Lake superior
8.Niger river
9.Congo river
10.Orange river
11.Nile river
12.Mediterranean sea
13.Black sea
14.Red sea
15.Lake Victoria
16.Caspian sea
17.Arabian sea
18.South china sea
19.East china sea
20.Darling river
21.Murray river
DISTRIBUTION OF WATER BODIES
We all know that three-fourth of the earth surface is covered by water. If there is more water than land on this earth, why do so many countries face water scarcity?
◙Salinity is the amount of salt in grams present in 1000 grams of water. The average salinity of the oceans is 35 parts per thousand.
◙Dead sea in Israel has salinity of 340 grams per litre of water. Swimmers can float in it because the increased salt content makes it dense.
◙March 22 is celebrated as World Water Day
◙Tsunami is a Japanese word that means “Harbour waves” as the harbours get destroyed whenever there is tsunami
◙The tsunami of 2004 caused wide spread damage in the coastal areas of India. The Indira point in the Andaman and Nicobar islands got submerged after the tsunami.
TIDES
The rhythmic rise and fall of ocean water twice in a day is called a tide.
◙It is high tide when water covers much of the shore by rising to its highest level.
◙It is low tide when water falls to its lowest level and recedes from the shore.
https://www.youtube.com/watch?v=pwChk4S99i4
The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides. The water of the earth closer to the moon gets pulled under the influence of the moon’s gravitational force and causes high tide. During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides. But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and moon resulting in low tides. These tides are called neap tides
OCEAN CURRENTS
1.WARM OCEAN CURRENTS
2.COLD OCEAN CURRENTS
◙Generally, the warm ocean currents originate near the equator and move towards the poles.
◙The cold currents carry water from polar or higher latitudes to tropical or lower latitudes.
◙ The Labrador Ocean current is cold current while the Gulf Stream is a warm current.
◙The ocean current influence the temperature conditions of the area. Warm currents bring about warm temperature over land surface.
◙The areas where the warm and cold currents meet provide the best fishing grounds of the world. Seas around Japan and the eastern coast of North America are such examples. The areas where a warm and cold current meet also experience foggy weather making it difficult for navigation.
Natural Vegetation and Wild Life
The two factors on which the growth of vegetation mostly depends are— temperature and moisture.
Natural vegetation is generally classified in to three broad categories as follows:
1.FORESTS
Which grow where temperature and rainfall are plentiful to support a tree cover
a) Tropical Evergreen Forests
These forests are also called tropical Rainforests.
◙These thick forests occur in the regions near the equator and close to the tropics. These regions are hot and receive heavy rainfall throughout the year. As there is no particular dry season, the trees do not shed their leaves altogether. This is the reason they are called evergreen.
◙The thick canopies of the closely spaced trees do not allow the sunlight to penetrate inside the forest even in the day time.
◙Hardwood trees like rosewood, ebony, mahogany are common here.
 |
| AMAZON RAINFOREST |
◙The tropical evergreen forest in Brazil is so enormous that it is like the lungs of the earth
◙The Amazon River which runs through the Amazon rainforest is the world’s second longest river after the Nile. It is also the world’s largest by water volume.
◙The Amazon River System meanders through nine South America countries.
Brazil, Bolivia, Peru,
Ecuador, Colombia, Venezuela,
Guyana, Suriname and French Guiana.
b) Tropical Deciduous Forests
◙Trees shed their leaves in the dry season to conserve water.
◙The hardwood trees found in these forests are sal, teak, neem and shisham.
Hardwood trees are extremely useful for making furniture, transport and constructional materials. Tigers, lions, elephants, langoors and monkeys are the common animals of these regions.
c) Temperate Evergreen Forests
The temperate evergreen forests are located in the mid latitudinal coastal region. They are commonly found along the eastern margin of the continents, e.g., In south east USA, South China and in South East Brazil.
◙They comprise both hard and soft wood trees like oak, pine, eucalyptus, etc.
d) Temperate Deciduous Forests
As we go towards higher latitudes, there are more temperate deciduous forests . These are found in the north eastern part of USA, China, New Zealand, Chile and also found in the coastal regions of Western Europe.
◙They shed their leaves in the dry season.
The common trees are oak, ash, beech, etc. Deer, foxes, wolves are the animals commonly found.
Birds like pheasants, monals are also found here
e)Mediterranean Vegetation
◙They have Clear skies and high temperatures; hot, dry summers and cool, wet winters.
◙It is mostly found in the areas around the Mediterranean sea in Europe, Africa and Asia, hence the name
◙This kind of vegetation is also found outside the actual Mediterranean region in California in the USA, south west Africa, south western South America and South west Australia.
◙There isn’t much wildlife here
https://www.pmfias.com/mediterranean-climate-warm-temperate-western-margin-climate-warm-temperate-west-coast-climate/#A_dry_warm_summer_with_off-shore_trades
◙Mediterranean trees adapt themselves to dry summers with the help of their thick barks and wax coated leaves which help them reduce transpiration.
◙Mediterranean regions are known as ‘Orchards of the world’ for their fruit cultivation.
f) Coniferous Forests
◙In the higher latitudes of Northern hemisphere the spectacular Coniferous forests are found . These are also called as Taiga. These forests are also seen in the higher altitudes.
Taiga means pure or untouched in the Russian language
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| TAIGA VEGETATION |
◙The woods of these trees are very useful for making pulp, which is used for manufacturing paper and newsprint. Match boxes and packing boxes are also made from softwood.
◙Chir, pine, cedar are the important variety of trees in these forests.
◙Silver fox, mink, polar bear are the common animals found here.
2.GRASSLANDS
Which grow in the region of moderate rain.
a) Tropical grasslands:-
◙This vegetation grows in the areas of moderate to low amount of rainfall. The grass can grow very tall, about 3 to 4 metres in height.
Savannah grasslands of Africa are of this type.
Elephants, zebras, giraffes, deer, leopards are common in tropical grasslands
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| TROPICAL GRASSLANDS |
b) Temperate grasslands:-
◙These are found in the mid-latitudinal zones and in the interior part of the continents.
◙Usually, grass here is short and nutritious.
◙Wild buffaloes, bisons, antilopes are common in the temperate region.
Grasslands are known by different names in different regions.
Tropical Grasslands
East Africa- Savanna.
Brazil- Campos
Venezuela- Llanos
Temperate Grasslands
Argentina- Pampas
N. America- Prairie
S. Africa- Veld
C. Asia- Steppe
Australia- Down
3.SHRUBS
◙Thorny shrurbs and scrubs grow in the dry region.
◙The vegetation cover is scarce here because of scanty rain and scorching heat.
TUNDRA VEGETATION
If you reach the polar region you will find the place extremely cold. The growth of natural vegetation is very limited here. Only mosses, lichens and very small shrubs are found here.
◙It grows during the very short summer. This is called Tundra type of vegetation.
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| TUNDRA VEGETATION |
◙This vegetation is found in the polar areas of Europe, Asia and North America. The animals have thick fur and thick skin to protect themselves from the cold climatic conditions.
◙Seal, walruses, musk-oxen, Arctic owl, Polar bear and snow foxes are some of the animals found here
HUMAN SETTLEMENT
.
◙Transhumance: It is a seasonal movement of people. People who rear animals move in search of new pastures according to changes in seasons.
◙The Golden Quadrilateral connects Delhi, Mumbai, Chennai and Kolkata.
◙4 Means of transport are
a)Roadways
b)Railways
c)Waterways
d)Airways
LIFE IN THE AMAZON BASIN
The river Amazon flows from the mountains to the west and reaches the Atlantic Ocean to the east. The place where a river flows into another body of water is called the river’s mouth.
◙Numerous tributaries join the Amazon River to form the Amazon basin. The river basin drains portions of Brazil, parts of Peru, Bolivia, Ecuador, Columbia and a small part of Venezuela.
◙The Rainforest is rich in fauna. Birds such as toucans, humming birds are found.
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| toucan |
◙Animals like monkeys, sloth and ant-eating tapirs are found here.
◙Various species of reptiles and snakes also thrive in these jungles. Crocodiles, snakes, pythons, Anaconda and boa constrictor are some of the species.
◙Several species of fishes including the flesh eating Piranha fish is also found in the river.
LIFE IN THE GANGA-BRAHMAPUTRA BASIN
◙The tributaries of rivers Ganga and Brahmaputra together form the Ganga-Brahmaputra basin in the Indian subcontinent.
◙The basin lies in the sub-tropical region that is situated between 10°N to 30°N latitudes. The tributaries of the River Ganga like the Ghaghra, the Son, the Chambal, the Gandak, the Kosi and the tributaries of Brahmaputra drain it.
◙In the Ganga and Brahmaputra plain tropical deciduous trees grow, along with teak, sal and peepal. Thick bamboo groves are common in the Brahmaputra plain.
◙Elephants, tigers, deer and monkeys are common. The one-horned rhinoceros is found in the Brahmaputra plain. In the delta area, Bengal tiger, crocodiles and alligator are found. Aquatic life abounds in the fresh river waters, the lakes and the Bay of Bengal Sea. The most popular varieties of the fish are the rohu, catla and hilsa. Fish and rice is the staple diet of the people living in the area.
◙In the fresh waters of River Ganga and River Brahmaputra, a variety of dolphin locally called Susu (also called blind dolphin) is found. The presence of Susu is an indication of the health of the river. The untreated industrial and urban wastes with high amount of chemicals are killing this species.
◙The Ganga-Brahmaputra plain has several big towns and cities. The cities of Allahabad, Kanpur, Varanasi, Lucknow, Patna and Kolkata all with the population of more than ten lakhs are located along the River
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