Class IX - Natural Vegetation and Wildife

A. NCERT TEXTBOOK QUESTIONS

Questions Within The Lesson

Q.1. Find out why are the southern slopes in Himalayan region covered with thick vegetation cover as compared to northern slopes of the same hills.

Ans. The northern slopes of the hills in Himalayan region are at high altitude and have low temperature or are snow covered. This does not allow much vegetation. In the southern part of the hills there are plains and valleys watered by rivers and with fertile soil and pleasant temperature levels all required for dense growth of vegetation.

Q.2. Find out why have the western slopes of the Western Ghats covered with thick forests and not the eastern slopes.

Ans. The westward facing slopes receive much more rain than the eastward facing slopes and the Western Ghats are considerably wetter than the dry Deccan to the east.

Questions in the Exercise

Q.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 (b) Himalayan (c) Tidal (d) Tropical Evergreen

Ans. Tropical Evergreen

(ii) Cinchona  trees are found in the areas of rainfall more than :

(a) 100 cm (b) 70 cm (c) 50 cm (d) Less than 50 cm

Ans. more than 100 cm

(iii) In which of the following states is the Simplipal bioreserve located?

(a) Punjab (b) Delhi (c) Orissa (d) West Bengal

Ans. Orissa

(iv) Which one of the following bio-reserves of India is not included in the world network of bioreserve?

(a) Manas (b) Gulf of Mannar   (c) Sunderbans      (d) Nanda Devi

Ans. Manas

Q.2. Answer the following questions briefly.

(i) Define an ecosystem.

Ans. An ecosystem comprises plants and animals existing interdependently and inter-related to each other in their physical environment.

(ii) What  factors are responsible for the distribution of plants and animals in India?

Ans. The distribution of plant and animal life in India is determined by the following :

(a) Temperature along with humidity in the air, precipitation and the nature of the soil.

(b) Variation in sunlight due to  variations in latitude, height above sea level, season and duration of the day in any specific region.

(c) Amount of rainfall.

(d) Soil conditions

(e) Relief — mountains, plateaus or plains.

(iii) What is  a bio-reserve? Give two examples.

Ans. Bio-reserves are intended to protect and conserve the diverse flora and fauna found within the country. In these reserves every plant and animal species is protected in its natural form. The first bio-reserve came up at the trijunction of the state of Kerala, Tamil Nadu and Karnataka in 1986. Two years later another bioreserve was set up at Nanda Devi.

(iv) Name two animals having habitat in different types of vegetation.

Ans. Type of vegetation                               Plants                       Animals

        Tropical Rainforests                             Rosewood,Ebony    Elephants, Monkeys

        Tropical Deciduous Forests                 Teak, Sal                  Lion, Tiger

        Thorn Forests                                     Palms,Acacia            Rats, Rabbits

        Temperate Forests                              Oak, Chestnut          Yak, Wild sheep

        Alpine and Tundra Vegetation              Pines, Silver fir          Snow Leopard, Yak

Q.3. Distinguish between:

(i) Flora and Fauna

(ii) Tropical Evergreen and Deciduous Forests

Ans. (i) Fauna refers to species of animals found in an region. Flora denotes plants of a particular region.

(ii) Tropical evergreen forests abound in areas with rainfall exceeding 200 cm in a year. Trees reach heights up to 60 m in these forests. The vegetation is luxuriant. There is no definite time for the trees to shed leaves. A large number of species exist together in such forests. Important trees are ebony, mahogany, rosewood, rubber and cinchona. Deciduous forests are spread over the region where the rainfall ranges between 70-200 cm annually. In dry summer, the trees shed their leaves for six to eight weeks. Commercially important wood is found in these forests. Important trees are teak, sal, shisham. etc.

Q.4. Name different types of vegetation found in India and describe the vegetation of high altitudes.

Ans. The different types of vegetation found in India are:

Tropical rainforests, Tropical Deciduous forests, Thorn forests, Temperate forests, Alpine and Tundra vegetation.

Alpine vegetation is found at places over 3,600 m in height. The trees common to these are silver fir, junipers, pines and birches. The trees get stunted as they reach the snow line. There are shrubs and scrubs that ultimately merge into Alpine grasslands. Tundra vegetation is limited to lichens and mosses.

Q.5. Quite a few species of plants and animals are endangered. Why?

Ans. The main reason for extinction of certain species of plants is excessive commercialization. Plant species are endangered as more lands are being cleared for factories, housing colonies and roads. Pollution of air, water and soil adds to the danger to natural vegetation. Animal species are getting extinct due to hunting and poaching. Commercial exploitation of forestlands has also reduced space for animal habitats.

Q.6. Why has India a rich heritage of flora and fauna?

Ans. India has a rich heritage of fauna and flora as geographically the country has a very wide range of physical, climatic and soil conditions. Our tradition of respecting all forms of life has also contributed to the preservation of plant and animal species over the centuries.