Biodiversity : Types and Values

  Biodiversity : Definition

¨Bio means “life” and diversity means “variety”. Hence biodiversity refers wide variety of life on the earth

¨Biodiversity (BD) is defined as the variety and variability among all groups of living organisms and the ecosystem in which they live

¨Degree of nature’s variety in the biosphere

¨The term biodiversity was coined as a contraction of biological diversity by E.O. Wilson in 1985


  Significance of Biodiversity

  • ¨Tangible and intangible benefits of BD
  • ¨Gives better health care, better crops and the use of these life forms as raw material for industrial growth
  • ¨Biological diversity is essential for preserving ecological processes, such as fixing and recycling of nutrients,
  • ¨Circulation and cleansing of air and water,
  • ¨global life support (plants absorb CO2, give out O2),
  • ¨maintaining the water balance within ecosystems,
  • ¨Watershed protection, maintaining stream and river flows throughout the year,
  • ¨erosion control and
  • ¨local flood reduction

  Biodiversity levels / types

Genetic diversity

It describes the variation in the number and types of genes as well as chromosomes present in different species

Variation of genes within the species

Two cause of variation

  • Variation in genetic makeup
    • Mutation, DNA base sequence change, hybridisation
  • Variation due to environmental parameters
    • Geographical isolation, habitat fragmentation

Genetic erosion 

Genetic erosion refers to the process in which a plant or animal species faces a gradual or drastic diminishing or complete loss of its unique gene pool

Species diversity

The number of species of plants and animals that are present in a region constitutes its species diversity

Species is basic currency of biological science

Warm and humid/wet area rich in species diversity than cold areas. Example tropical forests

A natural forest ecosystem provides a large number of non-wood products that local people depend on such as fruit, fuel wood, fodder, fiber, gum, resin and medicines. Timber plantations do not provide the large variety of goods that are essential for local consumption


gene pool is a complete set of unique pair of genes that occur in the genetic matter of all members of a particular species


Species Endemism

Endemic species are plants and animals that exist only in one geographic region. Species can be endemic to large or small areas of the earth: some are endemic to a particular continent, some to part of a continent, and others to a single island

Keystone species : if lost many species lost

Ecosystem diversity

Species richness in a particular ecosystem

Distinctive ecosystems include landscapes such as forests, grasslands, desserts, mountains, etc., as well as aquatic ecosystems such as rivers, lakes, and the sea

Ecological Hotspots

Areas very rich in biodiversity are called Hotspots. To qualify as a hot spot, a region must meet two strict criteria:

Species endemism: the region must contain at least 1,500 species of vascular plants (> 0.5% of the world’s total) as endemics, and

Degree of threat: the region has to have lost at least 70% of its original habitat

Indian Biodiversity Hot Spots

There are 3 biodiversity hot spots present in India

The Eastern Himalayas [Arunachal Pradesh, Bhutan, Eastern Nepal]

Indo-Burma/Andaman Nicobar Islands and [Purvanchal Hills, Arakan Yoma, Eastern Bangladesh]

The Western Ghats and Sri Lanka

  Value of Biodiversity

Consumptive use value

  • The direct utilisation of timber, food, fuelwood, fodder by local communities
  • Forest dwellers with all their daily needs, food, building material, fodder, medicines and a variety of other products
  • Construction material or medicines
  • Fisherfolk are highly dependent on fish


Productive use value

  • Marketable goods from the biodiversity
  • Productive value are marketable with a price however consumptive are consumed by forest dweller and stake holder without any price

Biological prospecting

The preservation of biodiversity has now become essential for industrial growth and economic development

Social Value

These are the values associated with the social life, customs, religion and psycho-spiritual aspects of the people. Many of the plants are considered holy and sacred in our country like Tulsi (holy basil), Peepal, Mango, Lotus, Bael etc. The leaves, fruits or flowers of these plants are used in worship

Many animals like cow, snake, bull, peacock, owl etc. also have significant place


Ethical and moral values

It is also sometimes known as existence value. It involves ethical issues like “all life must be preserved”. It is based on the concept of “Live and Let Live”

If we want our human race to survive, then we must protect all biodiversity, because biodiversity is valuable

This has been an important part of the ancient philosophy of many of our cultures. We have in our country a large number of sacred groves or ‘deorais’ preserved by tribal people in several States. These sacred groves around ancient sacred sites and temples act as gene banks of wild plants.

Aesthetic value

  • Pleasant view
  • No one of us would like to visit vast stretches of barren lands with no signs of visible life
  • Tourism and eco-tourism
  • The “willingness to pay” concept of such eco- tourism gives us even a monetary benefit for aesthetic value of biodiversity

Option value

These values include the potentials of biodiversity that are presently unknown and need to be explored

Possibility that we may have some potential cure of AIDS or cancer existing within the depths of marine ecosystem, or a tropical rainforests

Option value of biodiversity suggests that any species may prove to be a miracle species some day

Ecosystem Service Value

Non-consumptive use value related to self maintenance of the ecosystem and various important ecosystem services

It refers to the services provided by ecosystems like prevention of soil erosion, prevention of floods, maintenance of soil fertility, cycling of nutrients, fixation of nitrogen, cycling of water, their role as carbon sinks, pollutant absorption and reduction of the threat of global warming etc.



  Biodiversity at Global, National and Local levels

International agreements such as the World Heritage Convention attempt to protect and support such areas. India is a signatory to the convention and has included several protected Areas as World Heritage sites. These include Manas on the border between Bhutan and India, Kaziranga in Assam, Bharatpur in U.P., Nandadevi in the Himalayas, and the Sunderbans in the Ganges delta in West Bengal.

India has also signed the Convention in the Trade of Endangered Species (CITES) which is intended to reduce the utilization of endangered plants and animals by controlling trade in their products and in the pet trade

India as a Mega Diversity Region

A mega diversity region or country is one that harbors majority of the Earth’s species and is therefore considered extremely bio-diverse

India is one among the top 10 countries with rich biodiversity and one among the 12 Mega biodiversity regions in the world. Around 18 biosphere reserves have been set up in India

Apart of noticeable diversity in Indian wild plants and animals, there is also a great diversity of cultivated crops and breeds of domestic livestock.

The highest diversity of cultivars is found concentrated in the high rainfall areas of Western Ghats, Eastern Ghats, Northern Himalayas. and North-Eastern hills