Biodiversity and Conservation

What is Biodiversity?

The word biodiversity (biological diversity) means the total variety of living organisms in a given area — including plants, animals, fungi, and microorganisms — along with the ecosystems they form. The term was popularised by biologist Edward O. Wilson. It is a single word that captures everything from the tiniest soil bacterium to the tallest forest tree and the largest mammal in the ocean.

Life on Earth is unevenly spread. The greatest variety is found near the equator, in tropical regions where warmth, rainfall, and sunlight stay high all year. As you move towards the poles, the number of species steadily falls. This is why tropical rainforests, though they cover a small part of the land, are home to more than half of all known species.

India is one of the world’s 17 megadiverse countries. Though it has only about 2.4% of the world’s land area, it holds nearly 8% of all recorded species. This richness comes from India’s wide range of climates and landforms — snow-capped Himalayas, hot deserts, humid rainforests, long coastlines, and island groups all packed into one country. So far, scientists have named only a fraction of the species that actually exist; millions more, especially insects and microbes, are still undiscovered.

Three Levels of Biodiversity

Biodiversity is measured at three connected levels. The NDA frequently asks you to match the level with its example.

1. Genetic diversity

Variation in genes within a single species. Members of one species are not identical — their genes differ slightly, which is why some plants resist disease better or some animals survive cold better. For example, India has over 50,000 genetically different varieties of rice and many breeds of mango. The medicinal plant Rauwolfia, used to make a drug for high blood pressure, shows different chemical strengths across the country because of this genetic variation. Such diversity is the raw material of evolution; it lets a species adapt to new conditions instead of dying out.

2. Species diversity

The variety of species in a region. A region with many different kinds of plants and animals has high species diversity. For instance, the Western Ghats have a far greater amphibian (frogs and toads) species diversity than the Eastern Ghats. Species diversity is the level most people picture when they hear the word “biodiversity”.

3. Ecosystem diversity

Variety of habitats, communities, and ecological processes — deserts, rainforests, mangroves, grasslands, wetlands, and coral reefs. Each ecosystem has its own food chains and nutrient cycles. India shows great ecosystem diversity, stretching from the dry Thar Desert in the west to the wet mangrove forests of the Sundarbans in the east, and from alpine meadows in the Himalayas to coral reefs near the islands.

Why Biodiversity Matters

Biodiversity is not just about saving cute animals. It keeps ecosystems stable and supports human life directly. Scientists often divide its value into ecological, economic, and ethical reasons.

• Ecological balance: food chains and nutrient cycles depend on many interacting species. If even one important species is removed, the whole web can be disturbed.
• Economic value: crops, timber, medicines, fibres, rubber, and fisheries all come from biodiversity. Millions of people earn their living from these natural products.
• Medicinal value: a large share of modern medicines is derived from plants — for example, quinine for malaria comes from cinchona bark, and many other drugs are based on wild species we have not even studied yet.
• Ecosystem services: pollination of crops, clean air and water, soil formation, flood control, and climate regulation. These “free services” of nature would cost an enormous amount to replace.
• Ethical and aesthetic value: every species has a right to exist, and natural beauty supports tourism, culture, and mental well-being.

A stable ecosystem with high biodiversity is also more resilient — it recovers faster from droughts, floods, or disease because many species share the load of keeping it running.

Biodiversity Hotspots of India

A biodiversity hotspot is a region that is both very rich in species and seriously threatened. To qualify, a region must satisfy two conditions: it must have a high number of endemic species (species found nowhere else on Earth), and it must have already lost most of its original natural habitat. The concept was given by ecologist Norman Myers in 1988. Hotspots are conservation priorities because losing them would mean losing a huge slice of life forever.

The Western Ghats, for example, are home to species such as the lion-tailed macaque and the Malabar civet that live nowhere else. The Eastern Himalaya shelters the red panda and many rhododendron species. India has four recognised hotspots:

• The Himalaya — including the Eastern Himalaya.
• The Western Ghats and Sri Lanka.
• Indo-Burma — covering Northeast India.
• Sundaland — including the Nicobar Islands.

Endemic, Endangered, and Extinct Species

The NDA tests these IUCN categories and definitions carefully. Learn them precisely.

Key terms

• Endemic: species found only in one specific region (e.g. the lion-tailed macaque in the Western Ghats).
• Endangered: at high risk of extinction in the near future.
• Vulnerable: likely to become endangered if conditions don’t improve.
• Extinct: no living member survives anywhere (e.g. the dodo).

The IUCN Red List

The IUCN (International Union for Conservation of Nature) maintains the Red Data Book / Red List, which records the conservation status of species worldwide. It uses categories such as Least Concern, Vulnerable, Endangered, Critically Endangered, Extinct in the Wild, and Extinct. Indian species like the Bengal tiger, Asiatic lion, and one-horned rhinoceros have all appeared on threatened lists, which is why focused projects were launched to save them.

A species can also be critically endangered — the highest risk category for a living species — meaning it faces an extremely high chance of extinction in the immediate future. The great Indian bustard is one such bird.

Threats to Biodiversity

Several human-driven factors cause loss of biodiversity. A useful memory aid is “The Evil Quartet”, the four major causes:

1. Habitat loss and fragmentation — the biggest cause; e.g. clearing tropical rainforests.
2. Over-exploitation — over-hunting and over-fishing.
3. Invasive alien species — introduced species that outcompete natives (e.g. water hyacinth, Lantana).
4. Co-extinctions — when one species dies out, dependent species follow.

On top of the quartet, pollution, climate change, and poaching add further pressure. Climate change shifts rainfall and temperature patterns faster than many species can adapt, while poaching for skins, horns, ivory, and traditional medicine has pushed rhinos, tigers, and pangolins towards extinction. When habitat is broken into small isolated patches, animals cannot move freely to find food or mates, and small populations are far more likely to die out.

Conservation: In-Situ vs Ex-Situ

Conservation methods are split into two clear types. This distinction is a near-certain NDA question.

In-situ conservation (on-site)

Protecting species in their natural habitat. This is considered the better method because the species continues to live, breed, and evolve in its own surroundings along with all the other organisms it depends on. Examples include:

• National parks — strictly protected areas where no human activity like grazing or farming is allowed; e.g. Jim Corbett, Kaziranga.
• Wildlife sanctuaries — protect a particular species but allow some regulated human activity.
• Biosphere reserves — large areas that protect whole ecosystems together with human communities; e.g. Nilgiri, Sundarbans.
• Sacred groves — forest patches protected by local communities for religious reasons, especially in the Western Ghats, Meghalaya, and Rajasthan.

Ex-situ conservation (off-site)

Protecting species outside their natural habitat, in human-controlled conditions. This is used as a backup, especially for species that are very rare or whose wild habitat has been destroyed. Examples include:

• Zoological parks (zoos) and botanical gardens, which keep living animals and plants for protection, breeding, and education.
• Seed banks and gene banks, which store seeds, pollen, and tissue for the long term.
• Cryopreservation — freezing gametes (eggs and sperm) at very low temperatures so they can be used later.
• Captive breeding programmes that raise endangered animals and later release them into the wild.

Protected Areas & Conservation Projects

India runs several famous species-specific projects to save flagship animals. Protecting a large flagship species like the tiger automatically protects its whole habitat and every other species living in it. These are high-frequency NDA facts.

• Project Tiger (1973) — protects the Bengal tiger through tiger reserves.
• Project Elephant (1992) — conserves elephants and their corridors.
• Crocodile Conservation Project.
• Project Rhino / Project Snow Leopard.

Famous protected areas to memorise

• Kaziranga National Park (Assam) — one-horned rhinoceros.
• Gir National Park (Gujarat) — Asiatic lion.
• Sundarbans (West Bengal) — Royal Bengal tiger and mangroves.
• Periyar (Kerala) — elephants and tigers.

Global Conventions & Days

Because animals, birds, and pollution cross national borders, countries sign international agreements to protect biodiversity together. Know these for GK-style questions, as the NDA often mixes them with current affairs.

• Convention on Biological Diversity (CBD) — signed at the 1992 Earth Summit, Rio de Janeiro.
• CITES — controls international trade in endangered species.
• Ramsar Convention — protects wetlands of international importance.
• International Day for Biological Diversity — observed on 22 May.

Worked Example

Let’s practise classifying a conservation scenario the way the NDA frames it.

Tip: always ask “is the organism in its natural home or not?” to decide the category instantly.

Previous-Year Style Question

Quick Revision