1. Choose the right answer from the four alternatives given below:
(i) To which one of the following types of vegetation does rubber belong to?
(a) Tundra (c) Himalayan (b) Tidal (d) Tropical Evergreen
(ii) Cinchona trees are found in the areas of rainfall more than
(a) 100 cm (c) 70 cm (b) 50 cm (d) less than 50 cm
(iii) In which of the following state is the Simlipal bio-reserve located?
(a) Punjab (b) Delhi (c) Orissa (d) West Bengal
(iv) Which one of the following bio-reserves of India is not included in the world network of bioreserve?
(a) Manas (c) Gulf of Mannar (b) Dihang-Dibang (d) Nanda devi
2. Answer the following questions briefly.
(i) Define an ecosystem.
Ans. Ecosystem is an environment where plants and animal are interdependent and interrelated to each other as well as with the physical environment.
(ii) What factors are responsible for the distribution of plants and animals in India?
Ans. Factors responsible for the distribution of plants and animals in India are:- land, soil, temperature, humidity and precipitation.
(iii) What is a bio-reserve? Give two examples.
Ans. Biosphere Reserves are large areas where vegetation, wildlife and environment are conserved to preserve the biological diversity. In total there are 14 Biosphere Reserves in India and two of the examples are:- Sundarban biosphere reserve in West Bengal and Nanda Devi biosphere reserve in Uttaranchal.
(iv) Name two animals having habitat in tropical and montane type of vegetation.
Ans. Tropical animals:- Tiger, elephant
Montane animals:- snow leopard, spotted deer
3. Distinguish between
(i) Flora and Fauna
Ans. Flora:- The plant species of a particular region or period are called Flora.
Fauna:- The animal species of a particular region or period are called Fauna.
(ii) Tropical Evergreen and Deciduous forests
Ans. Tropical Evergreen Forests:-
- These are also called Tropical rain forest.
- These forests are found in the equatorial region and since this region is warm and wet throughout the year there is no definite time for the trees to shed their leaves.
- Some of the commercially important trees of this forest are ebony, mahogany, rosewood, rubber and cinchona.
- They are at their best in areas having more than 200 cm of rainfall with a short dry season.
- These forests are found in areas of the Western Ghats and the island groups of Lakshadweep, Andaman and Nicobar, upper parts of Assam and Tamil Nadu coast.
Tropical Deciduous Forests:-
- They are also called the monsoon forests.
- Trees of this forest-type shed their leaves for about six to eight weeks in dry summer.
- Teak is the most dominant species of this forest. Bamboos, sal, shisham, sandalwood, khair, kusum, arjun, mulberry are other commercially important species.
- These forests are found in areas receiving rainfall between 200 and 100 cm.
- These forests exist mostly in the eastern part of the country – north-eastern states, along the foothills of the Himalayas, Jharkhand, West Orissa and Chhattisgarh, and on the eastern slopes of the Western Ghats.
4. Name different types of Vegetation found in India and describe the vegetation of high altitudes.
Ans. The following major types of vegetation may be identified in our country:-
- Tropical Rain Forests
- Tropical Deciduous Forests
- Tropical Thorn Forests and Scrubs
- Montane Forests
- Mangrove Forests
The vegetation of high altitude is also known as montane forests. Since these places are mountainous areas, the decrease in temperature with increasing altitude leads to the corresponding change in natural vegetation. Its features are as follows:-
- Evergreen type of vegetation is prevalent in montane forest. Commonly pine, deodar, cidar trees are found.
- Grasslands form about 80 per cent of such forests.
- They are very affected by the existing climatic conditions. With increase in elevation, the temperature falls down gradually. So, it is more cold at the top. So, a corresponding change in natural vegetation is also observed at each level
- Generally, they are conical in shape so that it is easy for the snow to slide down.
- Fauna includes wild boar, spotted deer, stag, sloth bear, etc.
- Some e.g. The Alps, Carpathians in Europe, the Cascade Range in North America, the Himalayas in India.
5. Quite a few species of plants and animals are endangered in India. Why?
Ans. The main causes for this major threat to nature are hunting by greedy hunters for commercial purposes, pollution due to chemical and industrial waste, acid deposits, introduction of alien species and reckless cutting of the forests to bring land under cultivation and inhabitation.
6. Why India has a rich heritage of flora and fauna?
Ans. India has a rich heritage of flora and fauna due to the following reasons:-
- India is a diverse country with different relief features i.e. mountains, plateaus, plains etc. Different types of vegetation are found in these regions and the vegetation support different type of animal.
- Availability of different types of soil providing base for different types of vegetation.
- Variation in the climatic conditions like temperature humidity climate of India differs from north to south and east to west the supporting large variety of flora and fauna.
- India has a monsoon type of climate and the rainfall varies from 20 cm to 300 cm and is distributed throughout the year supporting large amount of flora and fauna.
- Variation in the duration of Sunlight at different places due to differences in latitude and altitude is also a reason behind the diverse distribution of flora and fauna.