Biodiversity refers to the totality of

genes, species and ecosystems of a region.

The term Biodiversity was popularised

by the the sociobiologist Edward Wilson.

It is the assemblage of different life

forms.

It is also be defined as the number of

different organisms and their relative

frequency in an ecological system.

Biodiversity differs from place to place

SIGNIFICANCE OF BIODIVERSITY

Biodiversity, besides its ecological significance provides a socio-

economic and monetary asset to the Nation.

Human society depends on biological resources.

It provide essential goods and services for mankind.

Values related to biodiversity can be grouped into three categories;

a) Productive Use

b) Consumptive Use

c) Indirect Use

PRODUCTIVE USE

This is assigned to products that are

commercialy harvested for exchange

in formal markets.

Here the only value of biological

resources is that is concerned in

National income.

Biodiversity provides us many

products such as fuel, timber, fish,

fodder, skin, fruits, cerals and

medicinal plants.

CONSUMPTIVE USE

Consumption value is

related to natural products that

are consumed directly that is

the goods donot come under

normal circulation of trade.

Non –timber forest products

as soft broom grass and cane

under this category.

INDIRECT USE

They may provide us indirect

benefits as non-consumptive

values such as maintenance of

ecological balance,

conservation of natural

resources, and preservation of

soil erosion may be considered

as the examples of indirect use

of biodiversity.

TYPES OF BIODIVERSITY

Biodiversity includes three hierarchial

levels. They are;

a) Genetic diversity

b) Spcies diversity

c) Ecosystem diversity

These levels of biodiversity are

interrelated. Their interconnections

support the life form earth.

Genetic diversity refers to the

variation of genes within the species

and the variation occures at the levels

of alleles or entire genes of

chromosomes. The genetic diversity

helps a population to adapt to its

environment. If a species has more

genetic diversity it can adapt better to

the changed environmental condition.

Genetic variation results in the

species variation.

Species diversity diversity means the

variety of species within a region. Species

are distinct unit of diversity. Loss of

species leads to serious consequences

affecting the total ecosystem. Simplest

measure of species diversity is species

richness, which is the number of species

per unit area.

Ecosystem diversity deals with the number of niches, trophic

levels and various ecological processes that sustain energy flow,

food webs and the recycling of nutrients. The number ecosystems

varies within a geographical area.

HOT SPOTS OF DIVERSITY

Areas that are rich in species diversity are

called hot spots. There are over a

thousand major “ecoregions” in the world.

Contries which have a large area of

biodiversity hot spots are refered as

‘Mega-diversity nations’. Our globally

accepted national hotspots are in the forest

of Western Ghats, Himalaya, which are

included in the world’s most bio-rich

areas. The Andaman and Nicobar Islands

are extremly rich in species diversity.

THREATS OF BIODIVERSITY

Natural calamities such as flood,

drought, storms, forest fire,

volcanic eruptions, epidemics etc

are all threats to biodiversity

Artificial causes such as habitat

loss, over exploitation, pollution,

introduction of exotic species,

poaching of wild life & man and

wildlife conflict.

HABITAT LOSS: Distruction of is the primary reason for the

loss of biodiversity. The natural habitat of some species is

distroyed by cutting down trees, burning forest filling of wet

lands. These activities can kill many plants, animals and micro

organisms etc.

OVER EXPLOITATION: It is an another

cause for extinction. Over exploitation of

particular species reduces the size of its

population to an extent that it become

vulnerable to extinction. Ex: Indian cheetah,

Mauritian bird Dodo.

POLLUTION: Environmental pollution

may reduce and eliminate population of

sensitive species.

INTRODUCTION OF EXOTIC SPECIES:

New species entering a geographical area

are called exotic species. Introduction of

exotic species causes changes in biotic

interactions leading to disappearence of

native species. Intoduction of such invasive

species are considered second only to

habitat destruction as a major cause of

extinction of species

POACHING OF WILD LIFE : Specific threat to certain

animals are related to large economic benefits. The skin of bones

from tiger, ivory from Elephants, perfumes from musk deer are

extensively used abroad. Bears are killed for their gall bladder.

Corals and shells are also collected for export.

MAN-WILDLIFE CONFLICT:

Man and wildlife conflict is another reason for depletion

of biodiversity. Co-existence of man and wildlife exists in

certain areas and that will enhance biodiversity

METHODS OF CONSERVATION OF BIODIVERSITY

The concept of conservation of

biodiversty encomposes protection and

sustained use of all genetic resources

whether it is wild or domestic.

There are two methods of conservation

of biodiversity;

a) In-situ conservation (on site)

b) Ex-situ conservation (off site)

In-situ conservation

It means the conservation of

ecosystem and natural habitat,

and the maintenance and

recovery of vulnerable

populations or species in their

natural surroundings.

Protected areas such as

National parks, Wild life

sanctuaries, biosphere reserve

are the important needs of in-situ

conservation.

NATIONAL PARKS

It is an area which is strictly preserved for

the betterment of the wildlife where

activities such as foresting, grazing or

cultivation not permitted.

No private ownership right is allowed.

Yellow stone national park is the first

national park in the world (1872).

Northest greenland national park (1974) is

the largest national park in the world.

Ex:Jim Corbet National Park – Tiger - UP

Eravikulam National Park- NilgiriTahr-kerala

WILDLIFE SANCTUARIES

It is an area where protection of certain

species get much emphasis.

Sanctuaries provide protection and

optimum living condition to wild animals.

A sanctuary is created by order of a

competent authority

Ex: PeparaWildlife sanctuary

Neyyar

Parambikulam

BIOSPHERE RESERVES

They are protected areas where all biological species, including

wild population native tribals, cultivated plants and domesticated

animals are given in protection and multiple land use is permitted.

Biosphere are the larger protected areas of natural habitat.

They include one or more national park and wildlife sanctuaries.

In India there are 15 Biosphere reserves.

Ex: Nilgiri biosphere reserve – Kerala, TamilNadu, Karnataka

Nanda Devi Biosphere Reserve – UP

Uttarkhand Biosphere Reserve – North-West Himalayas

Ex-situ Conservation

It means the conservation of components of

biological diversity outside their natural

habitats.

Endangered species and those are at the

verge of extinction are protected here.

Ex: Botanical gardens

Zoological park (ZOO)

Gene bank Gene plasm bank

Breeding program