Natural Vegetation And Wildlife - CBSE Class 7 Geography

Understanding Natural Vegetation and Wildlife

Natural vegetation refers to plant communities that have grown naturally without any human aid or interference for a long period. These are the untouched, wild plants, from towering trees to tiny mosses, that form the green cover of our Earth. The type and density of natural vegetation primarily depend on factors like temperature and moisture. Areas with heavy rainfall and high temperatures often support dense forests, while regions with moderate rainfall might have grasslands, and dry areas are home to thorny bushes and shrubs. "Wildlife," on the other hand, includes all the non-domesticated animal species, from insects to mammals, that live in their natural habitats. Just like vegetation, wildlife is also heavily influenced by the climate and the type of vegetation available, as it provides food, shelter, and breeding grounds. Together, natural vegetation and wildlife form complex ecosystems, where each component depends on the others for survival, creating a delicate balance in nature. Understanding this interconnectedness helps us appreciate biodiversity and the importance of its preservation.

Major Types of Natural Vegetation

The world's natural vegetation can be broadly classified into three main categories: forests, grasslands, and shrubs. Each type is characterized by specific climatic conditions, particularly temperature and rainfall.

1. Forests: These grow where temperature and rainfall are abundant to support a tree cover. Forests are further categorized:

• Tropical Evergreen Forests (Rainforests): Found in hot, wet regions near the equator. Trees shed leaves at different times, so they always appear green. Example: Amazon rainforest, home to rich biodiversity like monkeys, sloths, and various birds.
• Tropical Deciduous Forests (Monsoon Forests): Found in large parts of India, northern Australia, and Central America. Trees shed their leaves in the dry season to conserve water. Example: Teak and Sal trees, with animals like tigers, lions, elephants, and langurs.
• Temperate Evergreen Forests: Found along the eastern margins of continents (e.g., SE USA, South China). They have both hard and soft wood trees. Example: Oak, Pine, Eucalyptus.
• Temperate Deciduous Forests: Found in higher latitudes (e.g., NE USA, China, New Zealand). Trees shed leaves in autumn. Example: Oak, Ash, Beech, home to deer, foxes, wolves.
• Mediterranean Vegetation: Found around the Mediterranean Sea, California, Chile, Australia. Adapted to hot dry summers and mild rainy winters. Citrus fruits are common. Example: Olives, grapes.
• Coniferous Forests (Taiga): Found in higher latitudes (50°-70° N) and high altitudes. Characterized by tall, evergreen, soft-wood trees like pine, cedar, spruce. Animals include silver fox, mink, polar bear.

2. Grasslands: These grow in regions of moderate rainfall.

• Tropical Grasslands: Found on either side of the equator, extending to the interior of continents. Example: Savanna in Africa, home to elephants, zebras, giraffes, leopards.
• Temperate Grasslands: Found in mid-latitudinal zones and the interior parts of continents. Grass is short and nutritious. Example: Prairies in North America, Steppes in Eurasia, home to bison, antelopes.

3. Shrubs: Thorny shrubs and scrubs grow in dry desert-like regions. Their plants have deep roots and waxy leaves to reduce moisture loss. Example: Deserts of Sahara, Gobi, with animals like camels, desert foxes, and snakes.

4. Tundra Vegetation: Found in polar regions. Characterized by mosses, lichens, and very small shrubs, due to extremely cold climate. Animals include seal, walruses, musk-oxen, polar bears.

How Climate Shapes Vegetation and Wildlife

1. Step 1: Temperature and Moisture — The fundamental drivers of vegetation type are temperature and moisture (rainfall). Higher temperatures and abundant rainfall support lush, dense vegetation, like tropical rainforests. As temperature decreases and rainfall becomes scarce, vegetation becomes sparser and changes its form.
2. Step 2: Formation of Vegetation Zones — These varying climatic conditions create distinct vegetation zones. For instance, consistently high temperatures and rainfall lead to evergreen forests, while seasonal rainfall and high temperatures result in deciduous forests. Moderate rainfall fosters grasslands, and very low rainfall leads to thorny shrubs and desert vegetation. Extreme cold conditions result in tundra vegetation.
3. Step 3: Habitat for Wildlife — Each type of vegetation provides a specific habitat and food source for different animal species. Dense forests offer shelter and food for animals like monkeys, elephants, and big cats. Grasslands support grazing animals like deer, zebras, and their predators. Deserts are home to animals adapted to arid conditions, such as camels and reptiles.
4. Step 4: Adaptation and Interdependence — Wildlife adapts to the vegetation and climate of their region. For example, animals in cold regions develop thick fur or blubber. This creates an intricate web of interdependence: plants provide food and shelter for animals, and animals, in turn, help in pollination and seed dispersal, maintaining the health of the ecosystem.

Conservation of Natural Vegetation and Wildlife

• Deforestation: Large-scale cutting down of forests for agriculture, housing, and industry leads to loss of habitat for countless species and contributes to climate change.
• Soil Erosion: Removal of vegetation cover exposes soil to wind and water, leading to loss of fertile topsoil.
• Forest Fires: Natural or human-caused fires destroy vast areas of forests, harming both plants and animals.
• Poaching: Illegal hunting of animals for their skin, tusks, horns, or other body parts severely threatens species like tigers, elephants, and rhinos.
• Conservation Measures: Establishing national parks, wildlife sanctuaries, and biosphere reserves protects natural habitats. Awareness programs and strict laws against poaching and deforestation are crucial.
• Balance: Maintaining the balance of nature is vital. Disturbing one component, like clearing a forest, can have a ripple effect, impacting all other parts of the ecosystem and ultimately human well-being.

Practice Questions with Solutions

• Q: What is natural vegetation and how is it different from cultivated crops?
  A: Step 1: Define natural vegetation as plant communities growing naturally without human interference for a long time.
  Step 2: Define cultivated crops as plants grown by humans for specific purposes like food or commercial use, requiring human intervention (sowing, watering, harvesting).
  Final answer: Natural vegetation refers to plant life that grows on its own without human intervention, adapting to the natural environment. Cultivated crops are plants that are intentionally grown and managed by humans for agriculture, requiring farming practices.

• Q: Name two major types of grasslands and give one example of each.
  A: Step 1: Identify the two major types of grasslands: Tropical Grasslands and Temperate Grasslands.
  Step 2: Provide an example for Tropical Grasslands, such as the Savanna in Africa.
  Step 3: Provide an example for Temperate Grasslands, such as the Prairies in North America or Steppes in Eurasia.
  Final answer: The two major types of grasslands are Tropical Grasslands (e.g., Savanna in Africa) and Temperate Grasslands (e.g., Prairies in North America).

• Q: Why do tropical deciduous trees shed their leaves in the dry season?
  A: Step 1: Recall the characteristic of tropical deciduous forests being found in regions with seasonal rainfall.
  Step 2: Understand that shedding leaves is a mechanism to conserve water during periods of drought or dry season.
  Step 3: Explain that without shedding leaves, the trees would lose too much water through transpiration, leading to dehydration and death.
  Final answer: Tropical deciduous trees shed their leaves in the dry season to conserve water. By losing their leaves, they reduce the surface area through which water can evaporate (transpire) during periods when water is scarce, helping them survive until the rainy season returns.

• Q: List two threats to natural vegetation and wildlife, and suggest one way to mitigate each threat.
  A: Step 1: Identify a threat to natural vegetation, such as deforestation. Suggest mitigation like promoting afforestation and sustainable logging practices.
  Step 2: Identify a threat to wildlife, such as poaching. Suggest mitigation like enforcing stricter anti-poaching laws and establishing protected areas.
  Final answer: Two threats are:

  1. Deforestation: Clearing forests for agriculture, urbanization, or timber. Mitigation: Promote afforestation (planting new trees), implement sustainable forestry practices, and educate communities on the importance of forests.
  2. Poaching: Illegal hunting of animals for their body parts. Mitigation: Enforce strict anti-poaching laws, establish national parks and wildlife sanctuaries, and raise public awareness about wildlife conservation.

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