- Biodiversity maintains ecological balance and ecosystem stability.
- It provides food, fuel, fibre, and raw materials.
- It is a major source of medicines and pharmaceuticals.
- It supports agriculture, pollination, and pest control.
- Biodiversity has ethical, cultural, and aesthetic value and supports human survival.
Definitions [23]
Definition: Biodiversity
The diversity of life forms present on Earth, including plants, animals, and microorganisms, is called biodiversity.
Define Biodiversity.
Biodiversity is defined as the variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable
The sum total of species richness, i.e., the number of species of plants, animals and micro-organisms inhabiting in a given habitat, is known as biodiversity.
Define dichotomous key.
It is a tool used to classify organisms based on their similarities and differences.
Define Hotspots.
Hotspot is a biodegradable region that is both a significant reservoir of biodiversity and is threatened with destruction.
Define Eutrophication.
Eutrophication: The process by which a body of water enriched in dissolved nutrients (such as phosphates) that stimulates the growth of aquatic algae usually resulting in the depletion of dissolved oxygen.
Define Ramsar Sites.
Ramsar Sites: It is a wetland site designed of international importance under the Ramsar convention. It is an inter-governmental environmental treaty established in 1971 by UNESCO and coming into force in 1975.
Give definitions of Extinct species.
Species that completely disappear from the planet are referred to as extinct.
Give definitions of Invasive species.
Species that are not native to a region or locality but are unintentionally or purposefully introduced and cause harm to the native species already present are referred to as invasive species.
Give definitions of Endangered species.
When a species possesses a very high risk of extinction as a result of rapid population decline of 50 to more than 70 per cent over the previous 10 years, it is said to be an endangered species.
Define the term fauna.
The animals occurring in a area form the fauna of that area. Fauna deals with animals.
Flora and fauna of an area is the plants and animals found in that area.
Define the term flora
Plants occurring in a particular is called flora of that area i.e. vegetative growth forms flora. Flora deals with plants.
Definition: Biodiversity Hotspots
Regions of the Earth that are extremely rich in species, especially endemic species, and are under severe threat of habitat loss are called biodiversity hotspots.
Definition: Red Data Book
The official document that records and provides information on rare, endangered, and threatened species of plants, animals, fungi, and local sub-species within a country or state is called the Red Data Book.
Definition: Gene Pool
he total set of genes and alleles present in a population is known as gene pool.
Definition: Genetic Erosion
The gradual or rapid loss of genetic diversity within a species, including loss of populations, genes, or gene combinations, is called genetic erosion.
Definition: National Park
A protected area strictly reserved for the conservation of wildlife, where activities like grazing, forestry, hunting, and cultivation are prohibited.
Definition: Wildlife Sanctuary
A protected area where special protection is given to animals, and activities like timber harvesting and collection of minor forest products are allowed as long as they do not harm wildlife.
Definition: Sacred Groves
The forest conserved in the name of god and considered to be sacred is called as sacred grove.
or
The sacred groves are tracts of forest that have been completely immune from human interference on the basis of religious beliefs.
Definition: Botanical Gardens
A botanical garden is a well-tended area displaying a wide range of plants labelled with their botanical names.
Definition: Wildlife Safari
A protected or designated area where wild animals roam freely in conditions similar to their natural habitat and visitors observe them safely is called a wildlife safari.
Definition: Seed Bank
A facility where seeds are stored under controlled conditions to preserve plant genetic diversity for future use is called a seed bank.
Definition: Cryopreservation
The preservation of cells, tissues, or germplasm by cooling them to very low sub-zero temperatures, usually –196 °C, to stop all biological activity is called cryopreservation.
Definition: Gene Bank (Germplasm Bank)
An institution where valuable plant genetic material is preserved in a viable condition to prevent its loss or extinction is called a gene bank.
Key Points
Key Points: Types of Biodiversity
- Biodiversity refers to the total variety of life forms and was coined by Walter G. Rosen (1985) and popularised by E. O. Wilson.
- Biodiversity is broadly classified into genetic, species, and ecosystem diversity.
- Genetic diversity is the variation of genes within a species, resulting in different populations and varieties (e.g., many rice and mango varieties in India).
- Species diversity refers to the number and variety of species present in a particular region or habitat (e.g., higher amphibian diversity in Western Ghats).
- Ecosystem diversity is the variety of ecosystems such as forests, deserts, wetlands, mangroves, and coral reefs within a region.
- According to IUCN (2004), about 1.5 million species have been described so far, but many more remain undiscovered.
- Animals constitute over 70% of recorded species, with insects forming about 61%, while microbial diversity may run into millions.
Key Points: Biodiversity in India
- India is a mega-diverse country, ranking among the top 12 globally and possessing about 60–70% of the world’s biodiversity due to its wide range of climates and habitats.
- India has eight major floristic regions and supports rich vegetation ranging from alpine forests to tropical rainforests, mangroves, and coral ecosystems.
- India is rich in plant diversity, with about 47,000 plant species, over 35% endemic, and is a centre of origin for many important cultivated crops.
- India also has high faunal and marine biodiversity, with about 89,000 animal species, diverse mammals and birds, and rich marine ecosystems along its long coastline.
Key Points: Importance of Biodiversity
Key Points: Loss of Biodiversity
- Habitat loss and fragmentation due to agriculture, deforestation, urbanisation, and industrialisation is the major cause of biodiversity loss.
- Over-exploitation of plants and animals for food, trade, medicine, and luxury items leads to rapid decline and extinction of species.
- Alien species invasion disturbs native ecosystems by competition, predation, and disease (e.g., water hyacinth, Nile perch).
- Pet trade and illegal wildlife trade result in large-scale removal and death of species from their natural habitats.
- Co-extinctions occur when the extinction of one species leads to the loss of other dependent species.
Key Points: Threatened Species
| Category | Status | Examples |
|---|---|---|
| Extinct (EX) | Species no longer existing in the wild | Cheetah (India), Lesser Indian Rhinoceros |
| Endangered (EN) | Species with very low population; facing high risk of extinction | Indian Rhinoceros, Asiatic Lion |
| Vulnerable (VU) | Species likely to become endangered in near future | Many declining wildlife species |
| Rare (R) | Species with small population and restricted distribution | Localised endemic species |
| Threatened (T) | Species that may be endangered, vulnerable or rare, but data is insufficient | Data-deficient species |
| Intermediate(I) | Species suspected to be threatened but lack adequate information | Poorly studied species |
| Out of Danger (O) | Species recovered due to conservation efforts | Recovered protected species |
| Critically Endangered (CR) | Species facing extremely high risk of extinction (added in 2012) | Several modern Red List species |
Key Points: Wildlife Conservation Strategy in India
- India has enacted Wildlife (Protection) Act, 1972 to protect endangered species and ban hunting and trade in wildlife.
- A network of national parks, wildlife sanctuaries, and biosphere reserves has been established for in-situ conservation.
- Project Tiger, Project Elephant, and Rhino Conservation Programme were launched to protect flagship species and their habitats.
- Central Zoo Authority manages zoological parks and supports captive breeding of endangered species.
- India is a signatory to CITES (1976) to regulate international trade in endangered flora and fauna.
- Habitat protection, anti-poaching measures, and eco-development programmes are promoted with central and state cooperation.
- Public awareness, legislation, pollution control, recycling, and scientific research form important components of conservation strategy.
Key Points: Biosphere Reserves
| Aspect | Key Points |
|---|---|
| Meaning | Multi-purpose protected areas meant to conserve genetic diversity and representative ecosystems |
| Programme | Launched by UNESCO (1971) under Man and Biosphere (MAB) programme |
| Objectives | Conservation of biodiversity, research, education, sustainable use, and international cooperation |
| Characteristics | Represent a biome, rich genetic diversity, habitat of endangered species, suitable size, scope for research |
| Importance / Advantages | Ecological balance, protection from poaching, scientific study, watershed protection, aesthetic & recreational value |
Key Points: Conventions on Biological Diversity
- Growing concern over rapid loss of biodiversity led UNEP (1988) to initiate efforts for an international biodiversity convention.
- The efforts resulted in the Convention on Biological Diversity (CBD), finalized on 22 May 1992 and adopted at the Earth Summit, Rio de Janeiro.
- The CBD is a legally binding global agreement signed by 193 countries to promote sustainable development.
- The three main objectives of CBD are conservation of biodiversity, sustainable use of biological resources, and fair sharing of benefits from genetic resources.
Key Points: Earth Summit
- The Earth Summit (UNCED) was held at Rio de Janeiro, Brazil, from 3–14 June 1992, with participation from 172 countries to link environment and development.
- Major issues discussed included climate change, pollution, energy alternatives, water resources, and sustainable development.
- Important outcomes included Agenda 21, the Rio Declaration, the Statement of Forest Principles, and opening of the Convention on Biological Diversity (CBD) for signature.
- The summit led to global environmental actions, including formation of the Commission on Sustainable Development (CSD) and later agreements like the Kyoto Protocol and Paris Agreement.
Important Questions [10]
- The table given below shows the Area, Y-intercept and regression coefficient of the continents namely, Africa and Europe. Study the table carefully and answer the questions that follow:
- Give One Significant Contribution of the Given Scientist E. Wilson
- Define Hotspots.
- Define Ramsar Sites.
- Define Biodiversity.
- Define Eutrophication.
- Explain the rivet Popper hypothesis.
- Explain Chemiosmotic Hypothesis for Atp Synthesis.
- What is Red Data Book?
- List any three major causes of loss of biodiversity.
Concepts [34]
- Biodiversity
- Types of Biodiversity
- Patterns of Biodiversity
- Biodiversity In India
- Measuring Biodiversity
- Importance of Biodiversity
- Rivet-Popper Hypothesis
- Loss of Biodiversity
- Need for Biodiversity Conservation
- Threatened Species
- Endangered Flora and Fauna
- Hotspots of Biodiversity
- Red Data Book
- Genetic Conservation
- Gene Pool
- Genetic Erosion
- Conservation Strategies
- Wildlife Conservation Strategy in India
- Wildlife Acts/Projects of India for Wildlife Conservation
- Protected Areas in India
- Biosphere Reserve
- National Parks
- Wildlife Sanctuary
- Biosphere Reserves Vs National Parks Vs Sanctuary
- Sacred Groves
- Botanical Gardens
- Wildlife Safari
- Seed Bank
- Cryopreservation
- Gene (Germplasm) Banks
- Ramsar Sites
- Conventions on Biological Diversity
- Earth Summit
- World Summit on Sustainable Development (WSSD)
