CBSE Class 12 Biology Notes Chapter 15 Biodiversity and Conservation

The term biodiversity refers to the variety and variability among living organisms and the ecological complexes in which they occur.

• The plant and animal life may range from a small herb to a large tree or from a tiny insect to a large mammal.
• Apart from plants and animals, various microbes, which cannot be seen with normal eyes also occur in nature.
• This shows the biological diversity or biodiversity of a forest patch.
• Thus biodiversity can be defined as the totality of genes, species, and ecosystem of a region.

Conservation of biodiversity is essential for maintaining healthy ecosystems and the food chains that depend on them. This includes preserving the genetic variation within plant and animal populations, which allows them to adapt to changing environments and ensures the continued functioning of Earth's life support systems. CBSE Class 12 Biology Notes for Chapter 15 Biodiversity and Conservation are given in the article below for easy preparation and understanding of the concepts involved.

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Class 12 Biology Chapter 15 Notes –Biodiversity and Conservation

Biodiversity

Biodiversity refers to the variety of living things on Earth, including those found on land (terrestrial), in oceans (marine), and even in deserts.

• The term biodiversity was coined in 1985.
• It describes the number of various organisms and their relative frequencies in an ecosystem. 
• It also represents the arrangement of organisms on different levels.
• It provides us with nourishment, housing, fuel, clothing, and several other resources.

Biodiversity

Types of Biodiversity

There are three main types of biodiversity:

• Genetic diversity: This refers to the variety of genes within a single species.
• Species diversity: This focuses on the number of different species found in a specific area.
• Ecological diversity: This refers to the variety of ecosystems within a particular region.

Types of biodiversity

Patterns of Biodiversity

The following are the patterns of biodiversity

• Latitudinal gradients: Species diversity decreases towards the poles.
• Species-area relationship: The graph between species richness and area for a variety of taxa is a rectangular hyperbola.

On a logarithmic scale, the relationship is a straight line described by the equation

log S = log C + Z log A

Where,

• S is species richness
• A is the area
• Z is the slope of the line (regression coefficient)
• C is the Y-intercept

Species-area relationship

Biodiversity Loss

Loss of biodiversity in a region can lead to several negative consequences, including:

• Decrease in plant production
• Decreased resistance to environmental challenges such as drought, global warming, and others.
• High fluctuations in ecosystem processes, impact plant productivity, water use, and pest and disease cycles.

Causes of Biodiversity Loss

The following are the causes of biodiversity loss

• Over-exploitation
• Habitat loss and fragmentation
• Co-extinctions
• Alien species invasions

Biodiversity Conservation

• Biodiversity conservation refers to the protection, management, and responsible use of Earth's variety of life.
• This ensures that present and future generations can continue to benefit from this natural wealth.
• There are two main methods for achieving biodiversity conservation:
• In-situ conservation: This method focuses on protecting a variety of animal and plant species within their natural habitats. 

Examples include biosphere reserves, biodiversity hotspots, national parks, sanctuaries, and wild forests.

• Ex-situ conservation: This method involves protecting rare species outside their natural habitats. 

Zoos, aquariums, botanical gardens, and gene banks are all examples of ex-situ conservation efforts

Biodiversity Conservation

Reasons for Biodiversity Conservation

Biodiversity conservation is essential for several reasons:

• Economic benefits: Nature provides us with a wealth of resources, including firewood, food, construction materials, fibers, and medicines.
• Environmental benefits: Forests like the Amazon play a vital role in regulating Earth's atmosphere, producing a significant portion of the oxygen we breathe.

Ethical responsibility: Biodiversity represents our biological heritage and should be preserved for future generations.

There are Some important List Of Top Biology Questions On Biodiversity and Conservation Asked In CBSE CLASS XII