Class 11 Geography Notes Chapter 5 (Natural vegetation) – Geographia me Amli Kamm (Urdu) Book

Alright students, let's focus on Chapter 5, 'Qudrati Nabataat' or Natural Vegetation, from your Class 11 Geography textbook. This is a crucial chapter, not just for understanding India's geography but also frequently tested in various government exams. Pay close attention to the details.

Chapter 5: Natural Vegetation (Qudrati Nabataat) - Detailed Notes

1. Introduction

• Natural Vegetation: Refers to a plant community that has grown naturally without human aid and has been left undisturbed by humans for a long time. This is also termed virgin vegetation.
• Flora vs. Vegetation: Flora refers to plant species of a particular region or period. Vegetation refers to the assemblage of plant species living in association with each other in a given environmental frame (forests, grasslands etc.).
• India's Biodiversity: India is one of the 12 mega bio-diversity countries of the world. It has about 47,000 plant species (about 15,000 flowering species which account for 6% of the world's total). It also has many non-flowering plants like ferns, algae, and fungi.
• Endemic Species: Plant species that are purely Indian in origin.
• Exotic Species: Plant species that have come from outside India.

2. Factors Influencing Natural Vegetation

The variation in flora is mainly due to the following factors:

• (A) Relief:

  • Land: The nature of land influences the type of vegetation. Fertile, level land is generally devoted to agriculture. Undulating and rough terrains are areas where grassland and woodlands develop and give shelter to a variety of wildlife.
  • Soil: Different types of soils provide basis for different types of vegetation. Sandy soils of the desert support cactus and thorny bushes, while wet, marshy, deltaic soils support mangroves and deltaic vegetation. Hill slopes with some depth of soil have conical trees.

• (B) Climate:

  • Temperature: The character and extent of vegetation are mainly determined by temperature along with humidity in the air, precipitation and soil. On the slopes of the Himalayas and the hills of the Peninsula above the height of 915 metres, the fall in temperature affects the types of vegetation and its growth, and changes it from tropical to subtropical temperate and alpine vegetation.
  • Photoperiod (Sunlight): The variation in duration of sunlight at different places is due to differences in latitude, altitude, season and duration of the day. Longer duration of sunlight allows trees to grow faster (e.g., in summer).
  • Precipitation (Rainfall): In India, almost the entire rainfall is brought in by the advancing southwest monsoon (June to September) and retreating northeast monsoons. Areas of heavy rainfall have more dense vegetation as compared to areas of less rainfall. This is the most crucial factor determining vegetation type in India.

3. Ecosystem

• Plants occur in distinct groups of communities in areas having similar climatic conditions.
• The nature of the plants in an area determines the animal life in that area.
• All the plants and animals in an area are interdependent and interrelated to each other in their physical environment, thus, forming an ecosystem.
• A very large ecosystem on land having distinct types of vegetation and animal life is called a biome. Biomes are identified on the basis of plants.

4. Types of Vegetation in India

Based primarily on climatic factors (especially rainfall), Indian forests are broadly classified into the following types:

• (i) Tropical Evergreen Forests (Istawai Sada Bahar Janglaat)

  • Rainfall: Heavy rainfall areas (> 200 cm) with a short dry season.
  • Temperature: Warm and wet climate throughout the year (average annual temp > 22°C).
  • Regions: Western slopes of the Western Ghats, hills of the northeastern region (Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura), Andaman and Nicobar Islands, Lakshadweep.
  • Characteristics: Very dense, multi-layered structure. Trees reach great heights (up to 60 m or even above). No definite time for trees to shed their leaves, so forests appear green all year round ('Evergreen'). Rich biodiversity.
  • Important Trees: Ebony, Mahogany, Rosewood, Rubber, Cinchona.
  • Common Animals: Elephant, monkey, lemur, deer, one-horned rhinoceros (in Assam/West Bengal jungles), birds, bats, sloth, scorpions, snails.

• (ii) Tropical Deciduous Forests (Istawai Patjhad Janglaat)

  • Also known as: Monsoon Forests.
  • Most widespread forests in India.
  • Rainfall: Between 70 cm and 200 cm.
  • Characteristics: Trees shed their leaves for about six to eight weeks in the dry summer ('Deciduous').
  • Sub-types (based on water availability):
    • (a) Moist Deciduous:
      • Rainfall: 100 cm to 200 cm.
      • Regions: Eastern parts of the country – northeastern states, along the foothills of the Himalayas, Jharkhand, West Odisha, Chhattisgarh, and on the eastern slopes of the Western Ghats.
      • Dominant Species: Teak.
      • Other Trees: Bamboos, Sal, Shisham, Sandalwood, Khair, Kusum, Arjun, Mulberry.
    • (b) Dry Deciduous:
      • Rainfall: 70 cm to 100 cm.
      • Regions: Rainier parts of the Peninsular plateau and the plains of Bihar and Uttar Pradesh. Large parts of these forests have been cleared for cultivation or used for grazing.
      • Trees: Teak, Sal, Peepal, Neem.
      • Common Animals (in Deciduous forests): Lion, tiger, pig, deer, elephant, variety of birds, lizards, snakes, tortoises.

• (iii) Tropical Thorn Forests and Scrubs (Khaar Daar Janglaat aur Jhaariyan)

  • Rainfall: Less than 70 cm.
  • Regions: North-western part of the country including semi-arid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and Haryana. Also found in interior, drier parts of Deccan plateau.
  • Characteristics: Vegetation consists of thorny trees and bushes. Plants are scattered and have long roots penetrating deep into the soil to get moisture. Leaves are mostly thick and small to minimize evaporation. Stems are succulent to conserve water.
  • Important Plants: Acacias (Kikar, Babool), Palms, Euphorbias, Cacti.
  • Common Animals: Rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses, camels.

• (iv) Montane Forests (Pahadi Janglaat)

  • Vegetation type changes with increasing altitude due to decrease in temperature.
  • Wet Temperate Type (1000-2000 m): Evergreen broad-leaf trees like Oaks and Chestnuts predominate. Found in higher hills of NE India and Southern India (Nilgiris, Anaimalai, Palani hills - called 'Sholas' here).
  • Temperate Forests (1500-3000 m): Coniferous trees like Pine, Deodar, Silver fir, Spruce and Cedar. Found mainly on the southern slopes of the Himalayas, and higher elevations in southern and north-east India. These forests cover mostly the southern slopes of the Himalayas, places having high altitude in southern and north-east India.
  • Alpine Vegetation (> 3600 m): Temperate forests and grasslands give way to Alpine vegetation. Silver fir, junipers, pines and birches are common. As they approach the snow-line, they become progressively stunted, eventually merging into Alpine grasslands (used extensively for grazing by nomadic tribes like Gujjars and Bakarwals). At higher altitudes, mosses and lichens form part of tundra vegetation.
  • Common Animals: Kashmir stag, spotted deer, wild sheep, jackrabbit, Tibetan antelope, yak, snow leopard, squirrels, shaggy horn wild ibex, bear, rare red panda, sheep and goats with thick hair.

• (v) Mangrove Forests (Mangrove Janglaat)

  • Regions: Found in coastal areas influenced by tides. Mud and silt get accumulated on such coasts. Also known as Tidal Forests.
  • Location: Deltas of the Ganga, Mahanadi, Krishna, Godavari and Kaveri. Ganga-Brahmaputra delta has the largest extent (Sundarbans).
  • Characteristics: Dense mangroves are common varieties with roots submerged under water. Trees are adapted to survive in saline conditions and tidal variations. Roots are often stilt-like and help the plant breathe (pneumatophores).
  • Important Trees: Sundari tree (provides durable hard timber) is famous in the Ganga-Brahmaputra delta, giving it the name 'Sundarbans'. Palm, coconut, keora, agar also grow in some parts.
  • Wildlife: Royal Bengal Tiger is the famous animal here. Turtles, crocodiles, gharials and snakes are also found.

5. Importance of Forests

• Ecological Balance: Maintain climate, control soil erosion, regulate stream flow.
• Resources: Provide timber, fuel wood, fodder, medicinal plants, herbs, lac, honey, gum, etc.
• Habitat: Support a variety of wildlife.
• Livelihood: Provide livelihood for many communities.
• Oxygen: Major producers of oxygen.
• Soil Formation: Contribute to soil formation and maintain soil fertility.
• Climate Moderation: Influence local climate and atmospheric humidity.

6. Forest Cover in India

• According to the India State of Forest Report (ISFR) - Note: The exact percentage varies slightly with each report, usually released every two years by the Forest Survey of India (FSI). For exams, know the approximate figure and the trend. Currently, the actual forest cover in India is significantly less than the desired 33% outlined in the National Forest Policy (1952, revised 1988).
• Forest cover is not uniform across states. Lakshadweep has zero forest cover (as per administrative definition), while states like Mizoram, Arunachal Pradesh have very high percentages. Punjab and Haryana have very low forest cover due to extensive agriculture.

7. Conservation of Flora and Fauna

• Threats: Deforestation (for agriculture, industry, infrastructure), overgrazing, poaching, forest fires, shifting cultivation (Jhum).
• Government Steps:
  • Biosphere Reserves: 18 biosphere reserves have been set up (e.g., Nilgiris, Nanda Devi, Sundarbans, Gulf of Mannar). These aim to conserve biodiversity, promote sustainable development, and facilitate research/education.
  • National Parks: Areas set aside strictly to preserve natural environment and wildlife (e.g., Jim Corbett, Kaziranga, Gir, Kanha).
  • Wildlife Sanctuaries: Areas where protection is given mainly to fauna; some human activities may be allowed (e.g., Periyar, Sariska).
  • Project Tiger, Project Rhino, Project Elephant: Specific projects for conserving endangered species.
  • Wildlife Protection Act, 1972: Provides legal framework for protection.
  • Forest Conservation Act, 1980: Regulates diversion of forest land for non-forest purposes.

Multiple Choice Questions (MCQs) for Practice:

1. Which factor is MOST dominant in determining the type of natural vegetation in India?
   a) Temperature
   b) Soil
   c) Rainfall
   d) Photoperiod

2. Ebony, Mahogany, and Rosewood are commercially important trees typically found in which type of forest?
   a) Tropical Deciduous Forests
   b) Montane Forests
   c) Tropical Evergreen Forests
   d) Mangrove Forests

3. The most widespread forests in India are:
   a) Tropical Evergreen Forests
   b) Mangrove Forests
   c) Montane Forests
   d) Tropical Deciduous Forests

4. Sundari trees are characteristic features of which type of vegetation?
   a) Tropical Thorn Forests
   b) Mangrove Forests
   c) Alpine Vegetation
   d) Tropical Dry Deciduous Forests

5. In which type of forest do trees shed their leaves for about six to eight weeks during the dry season?
   a) Tropical Evergreen Forests
   b) Tropical Deciduous Forests
   c) Montane Forests
   d) Mangrove Forests

6. Which of the following regions in India has the lowest forest cover percentage primarily due to extensive agriculture?
   a) Arunachal Pradesh
   b) Andaman & Nicobar Islands
   c) Punjab & Haryana
   d) Western Ghats

7. Alpine vegetation in the Himalayas is found typically above which altitude?
   a) 1000 metres
   b) 1500 metres
   c) 2500 metres
   d) 3600 metres

8. Teak is the dominant species in which type of forest?
   a) Tropical Evergreen Forests
   b) Tropical Moist Deciduous Forests
   c) Tropical Thorn Forests
   d) Alpine Forests

9. 'Sholas' are temperate forests found in:
   a) The Himalayas
   b) The Sundarbans Delta
   c) The Thar Desert
   d) The Nilgiris and Anaimalai Hills

10. The National Forest Policy of India aims to achieve what percentage of geographical area under forest cover?
    a) 20%
    b) 25%
    c) 33%
    d) 50%

Answer Key for MCQs:

1. c) Rainfall
2. c) Tropical Evergreen Forests
3. d) Tropical Deciduous Forests
4. b) Mangrove Forests
5. b) Tropical Deciduous Forests
6. c) Punjab & Haryana
7. d) 3600 metres
8. b) Tropical Moist Deciduous Forests
9. d) The Nilgiris and Anaimalai Hills
10. c) 33%

Make sure you revise these notes thoroughly. Understand the characteristics, distribution, and key species of each forest type, along with the factors influencing them and the conservation measures. This will be very helpful for your exams. Good luck!