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Natural Vegetation – Class 11 Geography notes, important questions and MCQs

NCERT Class 11 Geography, chapter 19. Notes, key terms, important questions with answers and MCQs.

Chapter overview

Natural vegetation is the plant community that has grown naturally without human help. India's vegetation varies with rainfall, temperature, soil and relief. Major forest types are tropical evergreen and semi-evergreen, tropical deciduous, tropical thorn, montane and littoral or swamp forests. Forests provide many resources and ecological services, and India has policies, protected areas and programmes for conservation.

Types of forests

Tropical evergreen forests grow in areas with over 200 cm of rainfall, such as the Western Ghats, the north-east and the Andaman and Nicobar Islands; trees such as rosewood, ebony and mahogany grow tall and dense.
Tropical deciduous forests (monsoon forests) are the most widespread; moist deciduous forests (100–200 cm rain) have teak and sal, and dry deciduous forests (70–100 cm) have tendu, palas and amaltas.
Tropical thorn forests grow where rainfall is below 50 cm, such as in Rajasthan and Gujarat; montane forests change with altitude, from deciduous to coniferous and alpine vegetation; littoral and swamp forests, including mangroves of the Sundarbans and Bhitarkanika, grow in deltas and coasts.

Forest cover and conservation

The National Forest Policy aims for one-third of the geographical area under forest; actual forest cover is about 21–22% according to Forest Survey of India reports.
Conservation measures include social forestry and farm forestry, joint forest management, protected areas such as national parks and wildlife sanctuaries, and biosphere reserves such as the Nilgiri, Gulf of Mannar, Sundarbans and Similipal.
Wildlife is protected under the Wildlife (Protection) Act 1972 and programmes such as Project Tiger and Project Elephant.

Key terms

Natural vegetation: plant community that grows without human help
Tropical evergreen forest: dense forest in areas with very high rainfall where trees do not shed leaves together
Deciduous forest: forest whose trees shed leaves in the dry season
Mangroves: salt-tolerant trees growing in tidal coastal swamps
Social forestry: management of forests by communities for environmental and social benefits

Important questions with answers

What are mangrove forests?2 marks

Mangrove forests are salt-tolerant trees and shrubs that grow in tidal swamps along coasts and in deltas, such as the Sundarbans and Bhitarkanika. They have stilt roots and breathing roots, protect coasts from erosion and cyclones and provide breeding grounds for fish.

Why is it necessary to conserve forests?3 marks

Forests provide timber, fuel, fodder and medicines, support tribal livelihoods, maintain rainfall and climate, prevent soil erosion and floods, absorb carbon dioxide and provide habitat for wildlife. Their loss leads to environmental degradation, so conservation is essential.

Describe the major types of forests in India.5 marks

India's forests vary with rainfall and temperature. Tropical evergreen and semi-evergreen forests grow in areas with more than 200 cm of annual rainfall and a short dry season, such as the western slopes of the Western Ghats, the north-eastern states and the Andaman and Nicobar Islands; they are dense and multi-layered, with tall trees such as rosewood, mahogany and ebony that do not shed their leaves at one time. Tropical deciduous forests, the most widespread type, grow where rainfall is between 70 and 200 cm; the moist deciduous type, with teak, sal, sandalwood and bamboo, is found in the north-east, the Himalayan foothills, Odisha, Jharkhand and the Western Ghats' eastern slopes, while the dry deciduous type, with tendu, palas, amaltas and bel, occurs in drier parts of the peninsula and plains. Tropical thorn forests grow in areas with less than 50 cm of rainfall, such as Rajasthan, Gujarat and parts of the Deccan, with acacia, babool, cacti and euphorbias. Montane forests vary with altitude in the Himalayas and southern hills: wet temperate forests with oak and chestnut, coniferous forests with pine, deodar and fir, and alpine vegetation of shrubs and meadows near the snowline; in the south, shola forests grow in the Nilgiris. Littoral and swamp forests, including mangroves, grow along coasts and deltas such as the Sundarbans, Mahanadi and Godavari deltas.

Quick revision

Tropical evergreen: over 200 cm rain.
Deciduous: moist and dry; teak, sal.
Thorn, montane, littoral and swamp forests.
Forest policy; conservation; biosphere reserves.

Exam tips

Map the forest types with rainfall zones.
List four biosphere reserves including one from Odisha.

Practice MCQs

The most widespread forests of India are
1. tropical evergreen
2. thorn
3. tropical deciduous
4. alpine
Show answer
Answer: (c) tropical deciduous. They are also called monsoon forests.
Mangrove forests are found in the
1. Thar desert
2. Ladakh
3. Aravallis
4. Sundarbans
Show answer
Answer: (d) Sundarbans. They grow in tidal swamps.
Tropical evergreen forests grow where rainfall is
1. below 50 cm
2. about 70 cm
3. over 200 cm
4. zero
Show answer
Answer: (c) over 200 cm. The Western Ghats are an example.
Teak and sal are typical of
1. thorn forests
2. mangroves
3. alpine forests
4. moist deciduous forests
Show answer
Answer: (d) moist deciduous forests. They need 100–200 cm rain.
The National Forest Policy aims to keep about what part of the area under forests
1. one-tenth
2. half
3. one-third
4. two-thirds
Show answer
Answer: (c) one-third. It aims for 33%.
Similipal biosphere reserve is in
1. Gujarat
2. Kerala
3. Assam
4. Odisha
Show answer
Answer: (d) Odisha. It is also a tiger reserve.
Why do montane forests change with altitude
1. soil colour changes
2. animals plant them
3. rainfall is zero at heights
4. temperature falls with height, so vegetation changes as with latitude
Show answer
Answer: (d) temperature falls with height, so vegetation changes as with latitude. Coniferous and alpine plants appear higher up.
Thorn forests with acacia and cacti are typical of areas with
1. very high rainfall
2. less than 50 cm rainfall
3. tidal swamps
4. high mountains only
Show answer
Answer: (b) less than 50 cm rainfall. Plants adapt to conserve water.

All chapters of Class 11 Geography

Written by Kundali IQ from standard, well-established facts to help with revision. This is not an official NCERT publication; always read your textbook too.