CHAPTER 5 : Natural Vegetation NCERT SOLUTION CLASS 11TH Indian Physical Environment | EDUGROWN NOTES

SHORT ANSWER TYPE QUESTION:

Q1.What is natural vegetation? Under what climatic conditions are tropical evergreen forests develop?

Answer

Natural vegetation refers to a plant community that has been left undisturbed over a long time, so as to allow its individual species to adjust themselves to climate and soil conditions as fully as possible.
Tropical evergreen forests develop in warm and humid areas with an annual precipitation of over 200 cm and mean annual temperature above 22°C.

Q2. What do you understand by social forestry?

Answer

Social forestry means the management and protection of forests and afforestation on barren lands with the purpose of helping in the environmental, social and rural development.

Q3. Define Biosphere reserves?

Answer

A Biosphere Reserve is a unique and representative ecosystem of terrestrial and coastal areas which are internationally recognised within the framework of UNESCO’s Man and Biosphere (MAB) Programme.

Q4. What is the difference between forest area and forest cover?

Answer

The forest area and forest cover are not the same.

• The forest area is the area notified and recorded as the forest land irrespective of the existence of trees, while the actual forest cover is the area occupied by forests with canopy.

• The forest area is based on the records of the State Revenue Department, while the forest cover is based on aerial photographs and satellite imageries.

• According to state records, the forest area covers 23.28 per cent of the total land area of the country while the actual forest cover in India is only 21.05 percent.

Q5.What steps have been taken up to conserve forests?

Answer

There are various steps taken based on the forest conservation policy. These are:

• Social forestry: It means the management and protection of forests and afforestation on barren lands with the purpose of helping in the environmental, social and rural development. The National Commission on Agriculture (1976) has classified social forestry into three categories. These are Urban forestry, Rural forestry and Farm forestry.

→ Urban forestry: It pertains to the raising and management of trees on public and privately owned lands in and around urban centres such as green belts, parks, roadside avenues, industrial and commercial green belts, etc.–

→ Rural forestry: It lays emphasis on promotion of agro-forestry and community-forestry.

→ Agro-forestry: It is the raising of trees and agriculture crops on the same land inclusive of the waste patches.

• Community forestry: It involves the raising of trees on public or community land such as the village pasture and temple land, roadside, canal bank, strips along railway lines, and schools etc.

• Farm forestry is a term applied to the process under which farmers grow trees for commercial and non-commercial purposes on their farm lands.

Q6.How can people’s participation be effective in conserving forests and wildlife?

Answer

The government can make policies on the conservation of forests and wildlife but it is on the people who take part in this and make them successful. It is mostly the local people who take part in the illegal activities by damaging the environment for their benefits knowingly or unknowingly. The government need the cooperation of common people for ensuring the protection against the deforestation, poaching, hunting etc. This can effective in many ways:

• Holding a regular meeting of local people and make them aware of the advantages of conservation of forests and wildlife.
→ The government officials can inform them about the various policies of the government about the conservation and how they can be part of it.

• Incentives for the good work: The government can provide the incentives to the local people for their good work in protecting the local trees or wildlife which will encourage others to do the same work. Gradually, it will spread to mass scale.

• Various NGOs can also help in doing this activity by providing the skills to the people in conserving forests and wildlife through their experts.

Long Answer Type Questions:

Q1.“Natural vegetation is an outcome of climate.” Substantiate the statement by taking example of Indian vegetation.
Answer:
India is a land of great variety of natural vegetation. Himalayan heights are marked with temperate vegetation; the Western Ghats and the Andaman Nicobar Islands have tropical rain forests.

• Tropical evergreen forests are found in warm and humid areas with an annual precipitation of over 200 cm and mean annual temperature above 22°C. In these forests, trees reach at great heights up to 60 m or above. The semi¬evergreen forests are found in the less rainy parts of these regions.
• Tropical deciduous forests are spread over regions which receive rainfall between 70-200 cm.
• The moist deciduous forests are more pronounced in the regions which record rainfall between 100-200 cm. Dry deciduous forest covers vast areas of the country, where rainfall ranges between 70-100 cm.
• Tropical thorn forests occur in the areas which receive rainfall less than 50 cm. In mountainous areas, the decrease in temperature with increasing altitude leads to a corresponding change in natural vegetation.
• The Himalayan ranges show a succession of vegetation from the tropical to the tundra, with change in the altitude. Deciduous forests are found in the foothills of the Himalayas. It is succeeded by the wet temperate type of forests between an altitude of 1,000-2,000 m. In the higher hill ranges of north-eastern India, hilly areas of West Bengal and Uttarakhand, evergreen broad leaf trees such as oak and chestnut are predominant. Between 1,500-1,750 m, pine forests are also well-developed in this zone, with Chir Pine as a very useful commercial tree.

Q2.Mention the reasons for the decline of wildlife in India?
Answer:
Important reasons for the decline of Wildlife in India are-

• Industrial and technological advancement brought about a rapid increase in the exploitation of forest resources.
• More and more lands were closed for agriculture, human settlement, roads, mining, resources, etc.
• Pressure on forests maintained due to looping for fodder and fuel, wood and removal of small timber by the local people.
• Grazing by domestic cattle caused an adverse effect on wildlife and its habitat.
• Hunting was taken up as a sport by the elite and hundreds of wild animals were killed in a single hunt. Now commercial poaching is rampant.
• Incidence of forest fire.

Q3.According to the statistics received from state records, there are differences in forest area and actual forest cover. Explain.
Answer:
According to state records, the forest area covers 23.28 percent of the total land area of the country. It is important to note that the forest area and the actual forest cover are not the same. The forest area is the area notified and recorded as the forest land irrespective of the existence of trees, while the actual forest cover is the area occupied by forests with canopy.
Forest area is based on the records of the State Revenue Department, while the actual forest cover is based on aerial photographs and satellite imageries.

According to India State of Forest Report 2011, the actual forest cover in India is only 21.05 percent. Of the forest cover, the share of dense and open forests is 12.29 and 8.75 percent respectively. Both forest area and forest cover vary from state to state. Lakshadweep has zero percent forest area; Andaman and Nicobar Islands have 86.93 percent. Most of the states with less than 10 percent of the forest area lie in the north and northwestern part of the country. These are Rajasthan, Gujarat, Punjab, Haryana and Delhi.

States with 10-20 percent forest area are Tamil Nadu and West Bengal. In Peninsular India, excluding Tamil Nadu, Dadra and Nagar Haveli and Goa, the area under forest cover is 20-30 percent. The northeastern states have more than 30 percent of the land under forest. Hilly topography and heavy rainfall are good for forest growth. There is a lot of variation in actual forest cover, which ranges from 9.56 percent in Jammu and Kashmir to 84.01 percent in Andaman and Nicobar Islands.

Q4.On the basis of actual forest cover, in how many categories have Indian states been divided?
Answer:
On the basis of the percentage of the actual forest cover, the states have been grouped into four regions:

• The region of high concentration > 40: It includes Andaman and Nicobar islands, Mizoram, Nagaland, Arunachal Pradesh which have 80% of their total area under forests. Manipur, Tripura, Meghalaya, Sikkim and Dadar and Haveli have forest cover between 40-80%.
• The region of medium concentration 20-40: It includes Madhya Pradesh, Odisha, Goa, Kerala, Assam and Himachal Pradesh. In Goa, actual forest cover is 33.27% which is highest in this range. Thereafter, comes Assam and Orissa. In other states 30% of their area is covered with forests.
• The region of low concentration 10-20: It includes states of Maharashtra, Andhra Pradesh, Karnataka, Tamil Nadu, Bihar and Uttar Pradesh.
• The region of very low concentration < 10: It includes states of Rajasthan, Punjab, Haryana, and Gujarat. It also includes union territories of Delhi and Chandigarh. It also includes West Bengal.

Q5.Explain in short about four important Biospheres of India.
Answer:
Four Biosphere Reserves have been recognised by the UNESCO on World Network of Biosphere Reserves. These are as follows:

1. Nilgiri Biosphere Reserve: The Nilgiri Biosphere Reserve (NBR) is the first of the fourteen biosphere reserves of
India. It was established in September 1986. It embraces the sanctuary complex of Wyanad, Nagarhole, Bandipur and Mudumalai, the entire forested hill slopes of Nilambur, the Upper Nilgiri plateau, Silent Valley and the Siruvani hills. The total area of the biosphere reserve is around 5,520 sq. km. The largest south Indian population of elephant, tiger, gaur, sambar and chital as well as a good number of endemic and endangered plants are also found in this reserve. The topography of the NBR is extremely varied, ranging from an altitude of250 m to 2,650 m. About 80 percent of the flowering plants reported from the Western Ghats occur in the Nilgiri Biosphere Reserve.

2. Nanda Devi Biosphere Reserve: The Nanda Devi Biosphere Reserve is situated in Uttarakhand. It includes parts of Chamoli, Almora, Pithoragarh and Ba’geshwar districts. The major forest types of the reserve are temperate. A few important species are silver weed and orchids like latifolie and rhododendron. The biosphere reserve has a rich fauna like the snow leopard, black bear, brown bear, musk deer, snow- cock, golden eagle and black eagle.

3. Sunderbans Biosphere Reserve: It is located in the swampy delta of the river Ganga in West Bengal. It extends over a vast area of 9,630 sq. km and consists of mangrove forests, swamps and forested islands. Sunderbans is the home of nearly 200 Royal Bengal tigers. More than 170 birds species are known to inhabit these mangrove forests. In the Sunderbans, the mangrove forests are characterised by Heritiera fomes, a species valued for its timber.

4. Gulf of Mannar Biosphere Reserve: The Gulf of Mannar Biosphere Reserve covers an area of 105,000 hectares on the south-east coast of India. It is one of the world’s richest regions from a marine biodiversity perspective. The biosphere reserve comprises 21 islands with estuaries, beaches, forests of the nearshore environment, sea grasses, coral reefs, salt marshes and mangroves.