Conservation of Plants and Animals — NCERT Solutions, AI Tutor & Practice

Understand: Deforestation means the clearing or removal of forests and using the land for other purposes.

Analyze — Causes:

Natural causes:

1. Forest fires caused by lightning or extreme heat.
2. Severe droughts that dry up and destroy vegetation.

Human-made causes:

1. Cutting trees for agriculture, houses, and factories.
2. Using wood for fuel, furniture, and paper industries.

Conclude: While nature causes some deforestation, human activities are the major reason for the rapid loss of forests today.

Understand: Trees absorb carbon dioxide ($CO_2$) during photosynthesis and release oxygen.

Analyze:

• When forests are cut, fewer trees remain to absorb $CO_2$, so its level in the atmosphere rises.
• $CO_2$ is a greenhouse gas that traps heat, increasing Earth's temperature (global warming).
• Fewer trees also means less oxygen and less filtering of pollutants, raising pollution levels.

Conclude: Deforestation disturbs the balance of gases, causing higher temperatures and increased air pollution.

(a) Biodiversity: The variety of all living organisms — plants, animals and microorganisms — found in a particular area, along with their interrelationships.

(b) Endemic species: Species of plants and animals that are found exclusively in a particular area and nowhere else naturally. Example: the sal tree and wild mango in Pachmarhi Biosphere Reserve.

(c) Endangered species: Species whose numbers are decreasing so much that they are at risk of becoming extinct. Example: the tiger.

Understand: All three are protected areas for conservation, but they differ in scope.

Analyze:

| Feature | Wildlife Sanctuary | National Park | Biosphere Reserve | |---|---|---|---| | Protects | Wild animals | Flora, fauna and landscape | Whole ecosystem + culture | | Human activity | Some allowed (grazing, etc.) | Restricted | May include human settlements | | Size | Small to medium | Larger | Very large |

Conclude: A biosphere reserve is the largest and may contain within it national parks and sanctuaries, protecting biodiversity along with traditional ways of life.

Understand: The Red Data Book is a source book that keeps a record of all endangered species.

Analyze — Importance:

1. It maintains lists of endangered plants, animals and other organisms.
2. It helps scientists and governments identify which species need urgent protection.
3. Separate Red Data Books exist for plants, animals and other categories.

Conclude: The Red Data Book is important because it guides conservation efforts by highlighting species at risk of extinction.

Understand: Migration is the movement of a species from its own habitat to another habitat during a particular time of the year for a specific purpose.

Analyze — Reasons birds migrate:

1. To escape the harsh cold conditions of their home region.
2. To find better breeding grounds and food.

Conclude: Migratory birds travel long distances every year to survive climatic changes and to reproduce, returning when conditions improve.

Understand: Reforestation is the restocking of destroyed forests by planting new trees, ideally of the same species that were originally present.

Analyze — Reasons:

1. To restore the balance of oxygen and carbon dioxide in the atmosphere.
2. To provide habitat for wildlife and prevent soil erosion and floods.

Conclude: Reforestation, whether done by humans or naturally, helps repair the damage caused by deforestation and maintain ecological balance.

Understand: Trees play a key role in the water cycle by releasing water vapour and holding soil in place.

Analyze:

• Fewer trees mean less transpiration, so less water vapour goes into the air, reducing rainfall.
• Without tree roots to hold soil and absorb water, rainwater flows over the surface quickly, causing floods.
• Reduced rainfall and lowered ground-water levels can lead to droughts.

Conclude: Deforestation disturbs the water cycle, causing both floods (excess surface runoff) and droughts (reduced rainfall), harming agriculture and life.

Understand: An ecosystem consists of all the plants, animals and microorganisms in an area along with the non-living components like soil, water and air, and their interactions.

Analyze:

• Every organism depends on others through food chains and food webs.
• If forests (producers and habitats) are destroyed, herbivores lose food and shelter.
• This affects carnivores that feed on herbivores, disturbing the whole chain.

Conclude: Because all parts of an ecosystem are interconnected, harming one part upsets the balance of the entire ecosystem.

Understand: Paper is made from wood pulp obtained from trees; making paper uses up many trees.

Analyze:

• It is estimated that saving one tonne of paper can save about $17$ full-grown trees.
• We can save paper by using both sides of a sheet, reusing paper, and recycling old paper.
• Recycling paper also saves energy and water and reduces pollution.

Conclude: By recycling, reusing and saving paper, we cut down the demand for wood, thereby protecting forests and the animals living in them.

Understand: Protected areas are divided into zones to balance conservation with human needs.

Analyze:

• Core zone: The central, most protected area where no human activity is allowed; it preserves the natural ecosystem undisturbed.
• Buffer zone: The area surrounding the core where limited human activities like research, education and some resource use are permitted.

Conclude: The core zone strictly protects biodiversity, while the buffer zone acts as a protective layer that reduces human pressure on the core, together helping conserve the ecosystem.

Understand: The tiger is a top predator in the forest food web.

Analyze:

• Tigers control the population of herbivores like deer and wild boar.
• If tigers disappear, herbivore numbers increase uncontrolled, over-grazing plants and destroying vegetation.
• This damages the forest habitat and affects all other species.

Conclude: Protecting the tiger keeps the food web balanced, so Project Tiger helps conserve not just tigers but the entire forest ecosystem.