Q.1. Describe the major vegetation types found in the Himalayas.
Why does mountain vegetation change with altitude ? Explain with example . (CBSE 2010)
Ans. In mountainous areas, the decrease in temperature with increase in altitude leads to corresponding changes in natural vegetation. As such, there is a succession of vegetation and a distinct arrangement ranging from the tropical to the tundra region in the montane forests of hilly and mountainous regions of the Himalayas. Tropical evergreen forests with rosewood, ebony and ironwood are found in rainier parts of the foothills and in higher altitudes upto above 1000 metres. Tropical deciduous forests of sal, teak, palas and bamboo are found in the foothills upto a height of 1000 metres. Wet temperate forests with evergreen broad-leafed trees like oaks and chestnut predominate between a height of 1000 and 2000 metres. Temperate coniferous forests with softwood trees like pine, deodas silver fir, spruce and cedar grow at altitude between 1500 and 3000 metres. They are followed by temperate grasslands at higher elevation. At high altitude of more than 3600 metres temperate forests and grasslands give way to alpine vegetation. Silver fir, junipers, pines and birches are common trees. As they approach the snowline they get progressively stunted. Shrubs, scrubs and then alpine grasslands are found at higher elevations. At still higher altitudes in shaded slopes, moss and lichens, typical of Tundra vegetation, grow.
Q.2. Describe how rainfall and relief influence the vegetation of an area.
Ans. Factors like rainfall and relief influence the natural vegetation of an area
Rainfall : Climate plays an important role in determining the natural vegetation of a region.
Rainfall determines the type, character and extent of vegetation in an area. Areas of heavy rainfall have dense vegetation with rich forests while arid areas and semi-arid areas with less rainfall have thorny and scrub vegetation. Areas with more than 200 cm of annual rainfall have tropical evergreen rainforests. Tropical moist deciduous forests are found in areas with 100 to 200 cm of rainfall. Tropical dry deciduous forests are found in areas receiving rainfall between 100 cm and 70 cm. In regions with less than 70 cm of rainfall the natural vegetation consists of thorny trees and bushes.
Relief : The type of vegetation found in an area depends upon the relief or landform of the area. The fertile level lands of plains are generally devoted to agriculture. Much of the natural vegetation is cleared or altered in such areas. Grasslands and woodlands develop in areas with undulating and rough terrains. Mountainous areas have succession of vegetation types according to the altitude of the area.
Relief and Rainfall. Windward slopes of Western Ghats are covered with thick forests because they receive heavy rainfall. The eastern slopes do not have thick forests because they are on the leeward side and receive less rainfall.
Q.3. Give a brief account about the wildlife of India.
Ans. Our country, India, has a rich natural heritage of fauna – 89,000 animal species, 1200 species of birds, 2500 species of marine and freshwater fish and 5 to 8 per cent of the world’s amphibians, reptiles and mammals are found in India.
The wildlife in the different natural habitats are varied and rich. They include :
(i) The majestic Indian lions found in the Gir forest of Gujarat, the last remaining habitat of Asiatic Lion. India is the only country in the world that has both lions and tigers.
(ii) Tigers found in the national parks and wildlife sanctuaries in the forests of Madhya Pradesh, the Sunderbans of West Bengal and Himalayan region.
(iii) The large Asian elephants of the hot wet forests of Assam, Karnataka and Kerala.
(iv) The endangered one-horned rhinoceroses found in the swampy and marshy lands of Assam and West Bengal.
(v) Indian wild ass of the Rann of Kachchh.
(vi) Camels found in Thar desert.
(vii) Ladakh’s freezing high altitudes are home to yak, the shaggy horned wild ox, the Tibetan antelope, the bharal (blue sheep), wild sheep and the kiang (Tibetan wild ass), ibex, bear, snow leopard and rare red panda are found in some areas of the Himalayas.
(viii) Indian bison, nilgai, chousingha (four-horned antelope), gazel, different species of deer and several species of monkeys are found in India.
(ix) Many colourful birds, including peacock which is our national bird, are found in India.
(x) Turtles, crocodiles and gharials are found in rivers, lakes and coastal areas. Snakes like cobras and others are found in different areas.
Q.4. Why are some of the animals and plants endangered in India? How can they be protected? (Important)
What steps have been taken by the government to protect flora and fauna of the country. (CBSE 2010)
Write three measures to protect wildlife. (CBSE 2010)
Write any three measures to conserve ecosystem. (CBSE 2010)
Ans. Endangered species are those species of flora and fauna which are in the danger of extinction. In India, about 1,300 plant species are endangered. Quite a few animal species, like the onehorned rhino, Indian tiger, Indian wild ass, black buck, red panda, Asiatic elephants, Indian bustard, are endangered.
The main causes that have lead to threat upon. India’s flora and fauna, endangering many species are :
(i) Hunting and poaching for illegal trade of animal tusks, horns, bones, skin, etc.
(ii) Reckless cutting of forests to bring land under cultivation and settlement have destructed the natural habitats of wild creatures and wiped off valuable species of trees.
(iii) Pollution due to chemical and industrial waste, acid deposits, have brought down numbers of plants and animals.
(iv) Introduction of alien species that may be hostile to existing species. Understanding the grave threat, conservation of forests and wildlife have been taken up.
Government, NGOs, wildlife organisations and volunteers have taken up activities to protect wildlife and plants. They include :
(i) Fourteen biosphere reserves to protect biodiversity.
(ii) Project Tiger, Project Rhino, Project Great Indian Bustard and other eco-development projects to protect endangered species.
(iii) Setting up of 89 National Parks, 492 Wildlife Sanctuaries, Zoological Gardens, Protected and Reserved Forests, Botanical Gardens to protect the endangered species along with other types of flora and fauna.
(iv) Wildlife Protection Acts to safeguard wildlife.
(v) Affortestation, social programmes and awareness campaigns can also help to protect endangered species.
Q.5. Write a note on the formation and distribution of mangrove forests in India. (Important)
Mention two regions in India where you will find mangrove forests. What are the features of the mangrove forests? (CBSE 2010)
Ans. The mangrove or tidal forests are found in coastal areas under the influence of tides. The deltaic areas with clayey soil and saline water during tides have mangrove forests. The plants of these areas have adapted themselves to the alteration of freshwater and saline water as well as to the sticky mud and silt. The roots of these plants are submerged under water. They have breathing roots protruding on the surface. The trees have stilt like roots to support the trunk of the tree in the wet soil.
The forest are dense with hardwood trees like sundari, keora, agar, palm and coconut in some parts. The mangrove forests are found in :
(i) The Ganga-Brahmaputra delta which are known as Sunderbans on account of the sundari trees that predominate here. It provides durable hard timber.
(ii) Deltas of the rivers Mahanadi, Godavari, Krishna and Kaveri on the east coast of India.
Q.6. Write a note on the importance of biosphere reserve. What are its objectives?
Ans. Biosphere reserves are a series of multipurpose protected areas linked through a global network, intended to demonstrate the relationship between conservation and developement. Their sole purpose is conservation of flora and fauna.
The biosphere reserves play an important role in maintaining the ecological balance in the ecosystem. In the biosphere, all living beings are interrelated and interdependant on each other for survival. This life supporting system is called ecosystem. Vegetation and wildlife are two valuable resources of the biosphere. The biosphere reserves are set up to protect them and maintain diversity.
The main objectives of the biosphere reserves are :
(i) to protect and conserve the biological diversity, i.e., preserving plant and animal species of the area in natural forms.
(ii) to protect flora and fauna from over-exploitation.
(iii) to undertake research and experimentation in forestry.
(iv) to save endangered species and prevent extinction of valuable species. There are fourteen such biosphere reserves in India.
Q.7. Give the main causes for depletion of biodiversity in India. (CBSE 2010)
Ans. The varied climate and landform of India support of rich variety of natural vegetation. But only about 23 per cent of the land area of India is at present under forests. It is far lower than the desired 33 per cent outlined in the National Forest Policy.
The main reasons behind the reduction of the natural vegetation of India are as follows :
(i) Deforestation. Large areas of forests have been recklessly cleared by man due to the following reasons :
(a) to meet the growing demand for cultivated land,
(b) to acquire land for setting up industries,
(c) to provide land for settlement and urbanisation.
(ii) Shifting cultivation in hilly areas of northeast and Central India.
(iii) Mining. Large areas are cleared of natural vegetation for the purpose of mining.
(iv) Constructional activities like building of dams submerge areas of valuable forests and destruct the natural vegetation.
(v) Natural hazards like forest fires and landslides affect natural vegetation in hilly areas. The Tsunami of 2004.
(vi) Cyclonic storms affect plant cover of the areas where they strike. Overgrazing of pastures.
(vii) Wiped off valuable rainforests in the Andaman and Nicobar Islands. These above mentioned human-made and natural factors have accelerated the process of extinction of natural vegetation in India.
Q.8. What type of dangers does the wildlife sanctuaries of India face? How can they be protected better? Write a brief note on each.
Ans. 492 Wildlife Sanctuaries have been set up in India to protect and conserve wildlife. The government has demarcated them and maintains them. But certain external factors and loopholes in internal management of these areas creates problems and affect their purpose.
Dangers faced by wildlife sanctuaries of India are as follows :
(i) Poaching or illegal killing of animals for trade of their hides, skins, tusk, horns and bones.
(ii) Hunting of animals for game.
(iii) Killing of animals by villagers in instances of migration of animals to inhabitated areas during floods. In North Bengal often elephants move out from the forests to cultivated fields and are killed by the villagers.
(iv) Shortage of trained personnel to take care of the animals within the sanctuaries. This leads to death of sick animals.
(v) Shortage of funds for management of the sanctuaries.
The wildlife sanctuaries can be protected better in the following ways :
(i) Strict vigilance of the areas within the sanctuaries.
(ii) Enforcing strict measures against people encroaching the wildlife sanctuaries without proper permission.
(iii) Making laws against poaching and hunting more strict and punishing people who dare to destroy the sanctity of the wildlife sanctuaries.
(iv) Training the personnel to take proper care of animals within the wildlife sanctuary.
(v) Creating a proper, protected boundary for the wildlife sanctuaries.
(vi) Creating public awareness regarding the need of wildlife sanctuaries.