Chapter Notes

Biodiversity and Conservation

The variety of life we see on Earth, known as biodiversity, is deeply connected to the planet's physical processes. The weathering of rocks creates a "weathering mantle" or soil, which is the foundation for all vegetation. The richness of this soil and the life it supports depends on two key ingredients: solar energy and water. It's no surprise that regions with plenty of sunlight and water, like the tropics, have the most diverse range of life.

Today's biodiversity is the product of an incredible 2.5 to 3.5 billion years of evolution. Before humans appeared, the Earth supported more species than at any other time. However, since the emergence of humans, biodiversity has started to decline rapidly as species face extinction due to overuse of resources.

What is Biodiversity?

The term biodiversity is a combination of two words: Bio (meaning life) and diversity (meaning variety). In simple terms, it is the number and variety of organisms—plants, animals, and micro-organisms—found in a specific geographic area. This includes not just the different species, but also the variety of genes they contain and the different ecosystems they form. It is our planet's living wealth, built over hundreds of millions of years.

Biodiversity is not spread evenly across the globe. It is richest in the tropics. As you move towards the polar regions, you find fewer types of species, but the populations of those species can be very large.

Levels of Biodiversity

Biodiversity can be understood at three different levels:

• Genetic diversity
• Species diversity
• Ecosystem diversity

Genetic Diversity

Genes are the fundamental building blocks of all life forms. Genetic diversity refers to the variation of genes within a single species.

Species Diversity

This level refers to the variety of different species within a defined area. It can be measured by the number of species (richness), their population size (abundance), and the different types present. Areas that are particularly rich in species diversity are known as hotspots of diversity.

Ecosystem Diversity

This refers to the variety of different ecosystems, habitats, and ecological processes. An ecosystem is a community of living organisms interacting with their physical environment. The boundaries between different ecosystems are often not clearly defined, which can make studying this level of diversity complex.

Importance of Biodiversity

Biodiversity is essential to human culture and development, and in turn, human communities have significantly shaped the natural world. Its importance can be seen in three key areas: ecological, economic, and scientific.

Ecological Role of Biodiversity

Every single organism in an ecosystem plays a role. Species capture and store energy, produce and decompose organic material, help cycle water and nutrients, fix atmospheric gases, and regulate the climate. These functions are vital for the health of the ecosystem and for human survival.

A more diverse ecosystem is generally more stable and productive. It has a better chance of surviving challenges like disease or environmental changes.

Economic Role of Biodiversity

For all humans, biodiversity is a critical resource in daily life. It provides us with essential economic commodities, including:

• Food: A major part of this is 'crop diversity', also called agro-biodiversity.
• Livestock: Animals for food, labor, and other products.
• Forests: For timber and other resources.
• Fish: A vital source of food for many communities.
• Medicinal Resources: Many pharmaceuticals are derived from plants and animals.

Biodiversity is also used to manufacture cosmetic products. Viewing biodiversity solely as a collection of "biological resources" has unfortunately led to its deterioration and created conflicts over how these resources should be used and shared.

Scientific Role of Biodiversity

Each species provides clues about how life evolved and how it will continue to evolve. Studying biodiversity helps us understand how life functions and the specific role each species plays in sustaining the ecosystems we are a part of.

Furthermore, there is an ethical responsibility to protect biodiversity. Every species has an intrinsic right to exist, and it is morally wrong to cause the extinction of any species voluntarily. The level of biodiversity is a good indicator of the state of our relationship with other living things.

Loss of Biodiversity

In recent decades, the growing human population has increased the consumption of natural resources, leading to an accelerated loss of species and habitats worldwide. This is especially true in tropical regions, which hold about three-fourths of the world's human population but cover only about one-fourth of the world's land area. The tropical rainforests alone contain 50 percent of all species on Earth, so their destruction is disastrous for the entire biosphere.

Major factors causing the loss of biodiversity include:

• Over-exploitation of Resources: Deforestation and overuse of natural resources to meet the needs of a large population.
• Natural Calamities: Events like earthquakes, floods, volcanic eruptions, forest fires, and droughts damage flora and fauna.
• Pollution: Pesticides, hydrocarbons, and toxic heavy metals can destroy weak and sensitive species.
• Introduction of Exotic Species: Exotic species are those that are not native to a habitat. Their introduction can cause extensive damage to the natural community.
• Hunting and Poaching: Animals like tigers, elephants, and rhinos have been hunted mercilessly for their horns, tusks, and hides, pushing them into the endangered category.

Classifying Threatened Species

The International Union of Conservation of Nature and Natural Resources (IUCN) classifies threatened species into three categories to aid in their conservation. The IUCN publishes information on these species in the Red List of threatened species.

Endangered Species

These are species that are in immediate danger of extinction.

Vulnerable Species

This category includes species that are likely to become endangered in the near future if the factors threatening them continue. Their survival is not assured because their populations have been greatly reduced.

Rare Species

These species have very small populations in the world. They are either confined to limited geographical areas or are thinly scattered over a wider area.

Conservation of Biodiversity

All forms of life are closely interlinked. When one species becomes endangered, it can create an imbalance that affects others. This degradation of the environment can ultimately threaten human existence itself. Therefore, conserving biodiversity is crucial.

Why is Conservation Necessary?

There is an urgent need to educate people on environment-friendly practices. Sustainable development requires that our activities are harmonious with other life forms. This can only be achieved with the cooperation and involvement of local communities and individuals. The real challenge is not just conserving a species or a habitat, but ensuring the entire process of conservation continues.

Global and National Conservation Efforts

Recognizing this urgency, governments and international bodies have taken several steps.

• The Earth Summit: In June 1992, the Convention of Biodiversity was signed by India and 155 other nations at the Earth Summit held in Rio de Janeiro, Brazil.
• World Conservation Strategy: This strategy suggests key steps for conservation:
  1. Preserve endangered species.
  2. Use proper planning and management to prevent extinction.
  3. Preserve varieties of food crops, timber trees, livestock, and their wild relatives.
  4. Identify and protect the habitats of wild relatives of domesticated species.
  5. Safeguard habitats where species feed, breed, and raise their young.
  6. Regulate the international trade of wild plants and animals.
• Government of India Initiatives: India passed the Wild Life (Protection) Act, 1972. Under this act, national parks and sanctuaries were established, and biosphere reserves were declared to protect, preserve, and propagate species in their natural boundaries.

Mega Diversity Centres and Hotspots

Some countries, mostly in tropical regions, possess a huge number of the world's species. These are called mega diversity centres. There are twelve such countries: Mexico, Columbia, Ecuador, Peru, Brazil, Democratic Republic of Congo, Madagascar, China, India, Malaysia, Indonesia, and Australia.

To focus conservation efforts on the most vulnerable areas, the IUCN has identified certain areas as biodiversity hotspots. Hotspots are defined by their vegetation, as plants form the base of an ecosystem's productivity.