Geography NCERT 7th chapter 6 to 8 key points

                        IAS Prelims(GS) Preparation 2018

Day # 16 (April 8, 2017)

Topics of the day: Geography 7^th NCERT chapter 6 to 8 key points

Natural vegetation is generally classified in to three broad categories as follows:

(a) Forests: Which grow where temperature and rainfall are plentiful to support a tree cover. Depending upon these factors, dense and open forests are grown.

(b) Grasslands: Which grow in the region of moderate rain.

(c) Shrubs: Thorny shrurbs and scrubs grow in the dry Region.

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.

Tropical Deciduous Forests:

 Tropical deciduous are the monsoon forests found in the large part of India,northern Australia and in central America.

 These regions experience seasonal changes.

 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.

Temperate Evergreen Forests

 The temperate evergreen forests are located in the midlatitudinal 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.

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.

Mediterranean Vegetation

 Mediterranean regions are known as ‘Orchards of the world’ for their fruit cultivation.

 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.

 These regions are marked for hot dry summers and mild rainy winters.

 Citrus fruits such as oranges, figs, olives and grapes are commonly cultivated here because people have removed the natural vegetation in order to cultivate what they want to. There isn’t much wildlife here.

Coniferous Forests

 In the higher latitudes (50° – 70°) of Northern hemisphere the spectacular Coniferous forests are found. These are also called as Taiga.

 These forests are also seen in the higher altitudes.

 There are tall, softwood evergreen trees.

 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.

GRASSLANDS

Tropical grasslands:

 These occur on either side of the equator and extend till the tropics.

 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.

Temperate grasslands:

 These are found in the midlatitudinal 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

1. East Africa- Savanna

2. Brazil- Campos

3. Venezuela- Llanos

Temperate Grasslands

1. Argentina- Pampas

2. N. America- Prairie

3. S. Africa- Veld

4. C. Asia- Steppe

5. Australia- Down

Thorny bushes:

 These are found in the dry desert like regions.

 Tropical deserts are located on the western margins of the continents.

 The vegetation cover is scarce here because of scanty rain and scorching heat.

 Settlements are places where people build their homes.

 The place where a building or a settlement develops is called its site.

 The natural conditions for selection of an ideal site are- 1.

favourable climate 2. availability of water 3. suitable land 4. fertile soil.

 Settlements can be permanent or temporary.

 Settlements which are occupied for a short time are called temporary settlements. The people living in deep forests, hot and cold deserts and mountains often dwell in such temporary settlements.

 They practice hunting, gathering, shifting cultivation and transhumance.

 However more and more settlements today are permanent settlements. In these

settlements, people build homes to live in.

 Transhumance: It is a seasonal movement of people. People who rear animals move in search of new pastures according to changes in seasons.

 Manali-Leh highway in the Himlayan Mountains is one of the highest roadways in the world.

 The Trans-Siberian Railway is the longest railway system connecting St. Petersburg in Western Russia to Vladivostok on the Pacific coast.

AMAZON BASIN

 When Spanish Explorers discovered the Amazon river, they were attacked by a group of local tribes wearing headgears and grass skirts. These people reminded them of the fierce tribes of women warriors known in ancient Roman Empire as the

Amazons. Hence the name Amazon.

 The tropical region lies very close to the equator; between 10°N and 10°S. So, it is referred to as the equatorial region. The river Amazon flows through this region.

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 Amazon Basin stretches directly on the equator and is characterized by hot and wet climate throughout the year. Both day and nights are almost equally hot and humid.

 It rains almost everyday. As it rains heavily in this region, thick forests grow.

 Orchids, bromeliads grow as plant parasites. Bromeliads are special plants that store water in their leaves. Animals like frogs use these pockets of water for laying their eggs.

 Birds such as toucans, humming birds, are found here.

 Animals like monkeys, sloth and ant-eating tapirs are found here.

 They practice “slash and burn agriculture”. The staple food is manioc, also known as cassava that grows under the ground like the potato. They also eat queen ants and egg sacs. Cash crops like coffee, maize and cocoa are also grown.

 Some families live in thatched houses shaped like beehives. There are other large apartment-like houses called “Maloca” with a steeply slanting roof.

 In 1970 the Trans Amazon highway made all parts of the rainforest accessible.

GANGA BRAHMAPUTRA BASIN:

 The tributaries of rivers Ganga and Brahmaputra together form the Ganga

Brahmaputra basin in the Indian subcontinent.

 The tributaries of the River Ganga like the Ghaghra, the Son, the Chambal, the Gandak, the Kosi and the tributaries of Brahmaputra drain it.

 The plains of the Ganga and the Brahmaputra, the mountains and the foothills of the Himalayas and the Sundarbans delta are the main features of this basin.

 The monsoon brings rains from mid-June to mid-September.

 The summers are hot and the winters cool.

 The main crop is Paddy. Wheat, maize, sorghum, gram and millets are the other crops that are grown.

 Cash crops like sugarcane and jute are also grown.

 Banana plantations are seen in some areas of the plain.

 In West Bengal and Assam tea is grown in plantations.

 Silk is produced through the cultivation of silk worms in parts of Bihar and Assam. Thick bamboo groves are common in the Brahmaputra plain.

 In parts of Uttarakhand, Sikkim and Arunachal Pradesh, coniferous trees like pine, deodar and fir can be seen because the climate is cool and the slopes are steep.

 The one-horned rhinoceros is found in the Brahmaputra plain.

 In the delta area, Bengal tiger, crocodiles and alligator are found.

 The most popular varieties of the fish are the rohu, catla and hilsa.

 In the fresh waters of River Ganga and River Brahmaputra, a variety of dolphin locally called Susu (also called blind dolphin) is found.