Class 7 Notes

Class 7 Social Science Notes Chapter 6 (Natural Vegetation and Wildlife) – Our Environment Book

Philoid

Philoid

— 5 min read

Our Environment
Alright class, let's delve into Chapter 6, 'Natural Vegetation and Wildlife'. This is a fascinating chapter that helps us understand the diverse plant and animal life on our planet and the factors that shape it. Understanding these concepts is crucial, not just for your exams, but also for appreciating the delicate balance of our environment.

Here are the detailed notes focusing on key aspects relevant for competitive examinations:

Natural Vegetation and Wildlife - Chapter 6 Detailed Notes

1. Introduction:

  • Natural Vegetation: Refers to the plant life (like trees, bushes, grasses) that grows naturally in an area without human interference.
  • Wildlife: Refers to all non-domesticated animals living in their natural habitats.
  • Interdependence: Natural vegetation and wildlife are closely linked and exist within specific environments called Biomes.
  • Key Factors Influencing Vegetation: The type and thickness of natural vegetation vary primarily due to variations in:
    • Temperature: Affects the growing season and type of plants that can survive.
    • Moisture (Rainfall): Crucial for plant growth. Areas with heavy rainfall support dense forests, while dry areas have shrubs or grasslands.
    • Slope and Thickness of Soil: Affects drainage, water retention, and nutrient availability, influencing the type of vegetation cover.

2. Classification of Natural Vegetation:

Natural vegetation is broadly classified into three categories:

  • Forests: Grow where temperature and rainfall are plentiful to support dense tree cover.
  • Grasslands: Grow in regions of moderate rainfall.
  • Shrubs (Thorny Scrubs & Tundra): Grow in dry regions (Thorny Scrubs/Deserts) or extremely cold regions (Tundra).

3. Forests:

  • a) Tropical Evergreen Forests (Tropical Rainforests):

    • Location: Near the equator and close to the tropics (e.g., Amazon basin in South America, Congo basin in Africa, parts of Southeast Asia).
    • Climate: Hot and wet throughout the year (heavy rainfall). No distinct dry season.
    • Characteristics: Trees form a dense canopy, preventing sunlight from reaching the ground. Trees do not shed their leaves altogether (hence 'evergreen'). Rich biodiversity.
    • Flora (Plants): Hardwood trees like Rosewood, Ebony, Mahogany.
    • Fauna (Animals): Monkeys, Apes, Sloth, Anaconda (Amazon), Lemurs (Madagascar), various birds, bats, insects.

  • b) Tropical Deciduous Forests (Monsoon Forests):

    • Location: Large parts of India, Northern Australia, Central America.
    • Climate: Experience seasonal changes with distinct wet and dry seasons. Moderate rainfall.
    • Characteristics: Trees shed their leaves during the dry season to conserve water (hence 'deciduous'). Less dense than evergreen forests.
    • Flora: Hardwood trees useful for furniture and construction like Sal, Teak, Neem, Shisham.
    • Fauna: Tigers, Lions, Elephants, Langurs, Monkeys, Deer.

  • c) Temperate Evergreen Forests:

    • Location: Mid-latitudinal coastal regions (e.g., South-eastern USA, South China, South-eastern Brazil).
    • Climate: Warm temperate climate with rainfall throughout the year.
    • Characteristics: Contain both hardwood and softwood trees.
    • Flora: Oak, Pine, Eucalyptus.
    • Fauna: Deer, Foxes, Wolves, various birds.

  • d) Temperate Deciduous Forests:

    • Location: Higher latitudes (e.g., North-eastern USA, China, New Zealand, Chile, Western Europe).
    • Climate: Cool temperatures with distinct seasons, moderate rainfall. Experience snowfall in winter.
    • Characteristics: Trees shed their leaves in autumn/winter. Less dense than tropical deciduous forests.
    • Flora: Oak, Ash, Beech, Maple.
    • Fauna: Deer, Foxes, Wolves, Bears, Pheasants, Monals.

  • e) Mediterranean Vegetation:

    • Location: Areas around the Mediterranean Sea (Europe, Africa, Asia), California (USA), South-west Africa, South-western South America, South-west Australia.
    • Climate: Hot, dry summers and mild, rainy winters.
    • Characteristics: Plants adapted to dry summers (thick barks, wax-coated leaves, long roots). Known as 'Orchards of the world' due to fruit cultivation.
    • Flora: Citrus fruits (Oranges, Figs, Olives, Grapes), Cork Oak. Wildlife is limited.
    • Fauna: Limited wildlife, adapted to the climate.

  • f) Coniferous Forests (Taiga):

    • Location: Higher latitudes (50°-70°) of the Northern Hemisphere (e.g., Canada, Scandinavia, Russia). Also found at high altitudes in mountains.
    • Climate: Long, severe winters; short, cool summers. Moderate precipitation, mostly as snow.
    • Characteristics: Tall, softwood evergreen trees. Trees are often conical in shape with needle-like leaves to help shed snow and reduce water loss. Wood is useful for pulp (paper, newsprint) and packing boxes. 'Taiga' means pure or untouched in Russian.
    • Flora: Chir, Pine, Cedar (softwood trees).
    • Fauna: Silver fox, Mink, Polar bear, Reindeer, Moose.

4. Grasslands:

  • a) Tropical Grasslands (Savannas):

    • Location: Either side of the equator, extending to the tropics (e.g., East Africa, Brazil, Venezuela).
    • Climate: Moderate to low rainfall, distinct wet and dry seasons.
    • Characteristics: Tall grasses (up to 3-4 meters) with scattered trees. Supports a large number of herbivores and carnivores.
    • Flora: Tall coarse grass, scattered Acacia trees.
    • Fauna: Elephants, Zebras, Giraffes, Deer, Leopards, Hyenas, Lions.

  • b) Temperate Grasslands:

    • Location: Mid-latitudes and interior parts of continents. Known by different names: Prairies (North America), Pampas (South America), Veld (South Africa), Steppes (Central Asia), Downs (Australia).
    • Climate: Moderate rainfall, cold winters, warm summers.
    • Characteristics: Short, nutritious grasses. Often used for large-scale farming (wheat) and ranching. Trees are generally absent except along river banks.
    • Flora: Short grasses, wildflowers.
    • Fauna: Bison (Prairies), Antelopes, Wild Buffaloes, Dingos (Downs), various rodents and birds.

5. Shrubs:

  • a) Thorny Bushes (Desert Vegetation):

    • Location: Dry desert regions, typically on the western margins of continents in sub-tropics. (e.g., Sahara, Kalahari, Atacama, Thar).
    • Climate: Very low rainfall (scanty rain) and extreme temperatures (very hot days, potentially cold nights).
    • Characteristics: Vegetation is sparse. Plants adapted to conserve water (deep roots, thorny/spiny leaves, thick stems, waxy surface).
    • Flora: Cactus, Acacia, Date Palms (near oases).
    • Fauna: Camels, Snakes, Lizards, Scorpions, Desert Fox, various insects adapted to arid conditions.

  • b) Tundra Vegetation:

    • Location: Polar regions (Arctic Circle regions of North America, Europe, Asia). Also found at very high altitudes above the tree line (Alpine Tundra).
    • Climate: Extremely cold, long winters with frozen ground (permafrost). Very short, cool summer growing season.
    • Characteristics: Treeless plains. Vegetation growth is limited to the short summer.
    • Flora: Mosses, Lichens, very small shrubs.
    • Fauna: Seal, Walruses, Musk-oxen, Arctic owl, Polar bears, Snow foxes. Animals have thick fur and skin to protect against cold.

6. Conservation:

  • Human activities like deforestation, agriculture, construction, and poaching have led to the depletion of natural vegetation and wildlife.
  • Conservation efforts like establishing National Parks, Wildlife Sanctuaries, and Biosphere Reserves are crucial to protect this natural heritage. Awareness and sustainable practices are essential.

Multiple Choice Questions (MCQs):

  1. Which type of forest is characterized by hardwood trees like Rosewood, Ebony, and Mahogany?
    a) Temperate Deciduous Forests
    b) Coniferous Forests
    c) Tropical Evergreen Forests
    d) Mediterranean Vegetation

  2. In which season do Tropical Deciduous Forests shed their leaves?
    a) Wet season
    b) Dry season
    c) Winter season
    d) Spring season

  3. Coniferous Forests are also known by which name?
    a) Savanna
    b) Pampas
    c) Taiga
    d) Tundra

  4. Which type of vegetation is commonly found in hot, dry desert regions?
    a) Tundra Vegetation
    b) Temperate Grasslands
    c) Thorny Bushes
    d) Tropical Evergreen Forests

  5. 'Prairies' are temperate grasslands found in which continent?
    a) South America
    b) Africa
    c) Australia
    d) North America

  6. Which climatic region is known as the 'Orchards of the world' due to its fruit cultivation?
    a) Tropical Monsoon Region
    b) Mediterranean Region
    c) Equatorial Region
    d) Temperate Maritime Region

  7. Mosses and Lichens are typical vegetation found in:
    a) Tropical Grasslands
    b) Desert Regions
    c) Tundra Regions
    d) Temperate Deciduous Forests

  8. Sal and Teak are important trees found in which type of forests?
    a) Tropical Evergreen Forests
    b) Coniferous Forests
    c) Tropical Deciduous Forests
    d) Mediterranean Vegetation

  9. Which of the following animals is commonly associated with Tropical Grasslands (Savannas)?
    a) Polar Bear
    b) Zebra
    c) Bison
    d) Musk-oxen

  10. The primary factors influencing the type and distribution of natural vegetation are:
    a) Longitude and Altitude
    b) Temperature and Moisture
    c) Soil type and Human interference
    d) Wind patterns and Ocean currents

Answer Key for MCQs:

  1. c) Tropical Evergreen Forests
  2. b) Dry season
  3. c) Taiga
  4. c) Thorny Bushes
  5. d) North America
  6. b) Mediterranean Region
  7. c) Tundra Regions
  8. c) Tropical Deciduous Forests
  9. b) Zebra
  10. b) Temperature and Moisture

Make sure you revise these notes thoroughly. Understanding the link between climate, vegetation, and wildlife is key. Pay attention to the specific names of plants, animals, and regional names for grasslands – these are often asked in exams. Keep studying!

Read more