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What is a Biodiversity?
- Foram Mehta
180 million years ago, India was a small part of the
earth’s single super continent. Gradually this continent
splits over and over due to immense physical forces within
the earth, isolating their plants and animals. These plants
and animals evolved independently. As India split away from
the cost of Africa and began to northwards, evolution on this
island began to process. A great period of adaptation,
migration, survival and extinction followed, resulting in
changes in the ecology. Eventually, climatic stabilization
and the development of the monsoon pattern produced
ecosystems with their typical present day flora and fauna.
Life has continued to evolve on this earth and only those
species have survived that have adapted to the changing
environment. This change could be due to natural causes like
earthquakes, eruption of volcanoes, cyclones or due to
climate change. These natural causes of extinctions proved
blessings as same opened up the gates for the evolution of
new species. For an example, the extinction of Dinosaurs gave
way to the evolution on higher forms of mammalians. The large
number of species in India can thus be attributed to this
great mixture of species, which migrated to India from
different regions in which they had evolved.
Our Earth is the only spaceship having life on it. All living
beings-animals, plants and microbes-living in soil, water, on
trees, in and on other animals; useful and/or harmful;
cultivated, domesticated, or wild; their genes and the
ecosystems in which they live make up the biodiversity of the
earth.
The term Biodiversity has been derived from two words, “Bio”
meaning life and “diversity” indicating variety so, the term
biodiversity stands for different varieties of life forms
present
on
the
Earth
including
terrestrial,
aquatic
ecosystems and the ecological complexes of which they are
part. This includes diversity within species, between species
and of ecosystems. Hence, all plants, animals, micro
organisms as well as genetic material are components of
biodiversity.
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EO Wilson is thought to have coined the term ‘biodiversity’
as a contraction of "biological diversity" in 1985. He
stresses upon the fact that many of the species are still
unknown to science and could play a key role in maintaining
an ecosystem. They would also include micro-organisms, fungi
and insect life. Quite simply it can be defined as “variety,
variability, between genes, species and ecosystems.”
Biodiversity forms the web of life of which we are an
integral part and fully dependent. An environment rich in
biological diversity offers the broadest array of options for
sustainable economic activity.
Levels
Drawing lines between where one type of diversity starts
and where another type begins is not always possible as there
is usually a large amount of overlap.
Biodiversity can be expressed in different ways. Breaking
diversity
down
into
different
levels
of
biological
organization is a useful way of looking at the variation.
These levels are intimately linked, interact and affect one
another. "If any one type is removed from the system, the
cycle can break down, and the community becomes dominated by
a single one. While many of the elements may be difficult to
define rigorously, and in some cases may have no strict
biological reality, they remain useful and important tools
for studying biodiversity.
Biodiversity is usually described in terms of three
intimately connected levels which help to simplify a complex
system.
• Genetic diversity
• Species diversity
• Ecological diversity
Genetic diversity
In a population of moths, some individuals camouflaged
against a tree with lichen on the bark and some against a
tree with pollution damaged black bark. If pollution
increases and more trees get black bark, the moths
camouflaged against this and increase in the numbers. The
environment affects the genes which affect the diversity
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within the
diversity.
species
and
this
could
affect
the
ecological
The genetic variation within a population of species is
called as a genetic diversity. This is the diversity of the
basic units of hereditary information (genes) within a
species, which are passed down to the generations. Genetic
diversity results in variations. It can give rise to 50,000
varieties of rice, 1000 varieties of mangoes and 27 varieties
of cattle. For e.g. Basmati rice is distinct from Jirasar
rice. Some variations are easy to see, such as size, colour,
taste or flavor, susceptibility to diseases etc.
A 2007 study conducted by the National Science Foundation,
India found that genetic diversity and biodiversity are
dependent upon each other.
Species Diversity
Horses and donkeys are distinct species, so are lions
and tigers. Species diversity is a crucial to the existence
of life on earth. The most species rich groups are flowering
plants and insects. Live forms are classified into Kingdom,
Phylum, Class, Order, Family, Genus and species. Each life
form is given a name that consists of its genus and species.
For e.g. Human is referred as Homo sapiens sapiens. Species
is the unit which is used to classify the millions of life
forms on earth. Each species is distinct from every other
species. The more abundant the species, the more diverse an
ecosystem is considered to be.
Ecosystem Diversity
Plants, animals and microbes are directly – indirectly
connected to one another and with the non living elements of
the environment. These all together create ecosystem of that
region. It can refer to the variety of species within
different ecosystems and variety of ecosystems found within a
biogeography. Ecosystems turned by humans into agricultural
and rural landscapes. They vary from traditional farming to
intensively use agricultural areas under modern irrigation
systems. This is in turn, leads to an overgrowth of weeds or
algae, and the use of pesticides or insecticides lead to the
serious hazardous effect and formation of resistant species.
All these lead to the loss of biodiversity as well as
productivity in the long term. If they are overused or
misused, their productivity decreases and ecosystem is
eventually degraded.
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If we need to preserve our environment, we shall need to
understand the interdependence of the species on each other
and the importance of natural resources for living beings.
Individual species and ecosystems form a highly complex web
of interdependence like the interlocking pieces of Jigsaw
puzzle. If we remove enough of the key species on which the
ecosystem is sustaining, then the whole ecosystem may be in
danger of collapsing.
Distribution of diversity
India is rated as one of the 12 mega-diversity nations
of the world. Over 46000 species of plants and 81000 species
of animals have been documented here. India is an acknowledge
centre of crop diversity, and harbors many wild relatives of
crops and various indigenous breeds of domesticated animals.
Among the plant species, 18% are endemic to the country and
found nowhere else in the world.
India has a 1200 bird species accounts for 14% of the world’s
avifauna, ranks 8th in the world, while its 453 reptile
species places it fifth.
India has ten biogeographic regions,
•
The Trans- Himalayan
•
The Himalayan
•
The Indian desert
•
The Semi-arid zone(s)
•
The Western Ghats
•
The Deccan Peninsula
•
The Gangetic Plain
•
The Northeast India
•
The Islands
•
The Coasts NE Himalayas
Its rich and varied biodiversity encompassing a wide Spectrum
of ecosystems from Tropical rain forest to alpine vegetation,
Temperate forest to coastal, Marine to freshwater wetlands
,Rivers, Lakes, Ponds, Mangroves, Corals etc., Semi-arid to
Arid, Plains to Himalaya, to Islands. India has also a rich
variety of wetland habitats, may be manmade or natural where
the soil remains waterlogged or submerged for whole or part
of year upon which the wetland biota depends. Great physical
variations, from the lofty mountainous regions in the
Himalayas, to the hill ranges in the peninsula and low laying
plains, form multiple watersheds are responsible for local
variations in species diversity.
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The view of Indian forests ranges from evergreen tropical
rain forests in the Andaman and Nicobar Islands, the Western
Ghats, and the northeastern states, to dry alpine scrub high
in the Himalaya to the north. Between the two extremes, the
country has semi-evergreen rain forests, deciduous monsoon
forests, thorn forests, subtropical pine forests in the lower
mountain zone and temperate mountain forests. Within each of
these terrestrial zones there are diverse aquatic ecosystems,
which include ponds, lakes, wetlands, streams, rivers and
deltas, each with its own distinctive web of life.
Role of Biodiversity
Biodiversity touches almost every aspect of our life. It
has direct consumptive value in food, agriculture, medicine,
industry. It also has aesthetic and recreational value. The
joy of watching a peacock, listening to the song of a cuckoo,
spending time in a park is some aesthetic pleasure that we
get from the biodiversity. In India various plants and animal
species are considered sacred on account of their association
with different deities in the Hindu religion. E.g. Hibiscus
to Kali and datura to Shiva offered to deities.
It maintains ecological balance and continues evolutionary
process. The indirect ecosystem services provided through
biodiversity are photosynthesis, pollination, transpiration,
chemical cycling, nutrient cycling, soil maintenance, climate
regulation, air, water system management, and waste treatment
and pest control. It composes ecosystems that maintain oxygen
in the air, enrich the soil, purify the water, protect
against flood and storm damage and regulate climate.
Biodiversity makes up the structure of the ecosystems and
habitats that support essential living resources, including
wildlife, fisheries and forests. Stabilization and moderation
of the Earth’s climate by moderating floods, droughts and
temperature extremes and creation of drainage systems is the
key role of the biodiversity. It also helps to generate and
renew soil fertility, soil prevention and cycling nutrients
in the system.
The most important value of biodiversity, particularly
in a country like India, is that it meets the basic survival
needs of a vast number of people. Even today large number of
communities depends partially or completely for their daily
needs of food, medicine, shelter, clothing, household goods,
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medicines etc. For e.g. fishing community depends on the rich
diversity of marine life for its livelihood.
Aspirin from the plant Filipendula ulmaria or quinine from
the bark of several species of the Cinchona tree, just not
traditional
medicines
but
nearly
one-forth
of
all
prescription drugs are derived from plants, microbes and some
from animals. About 90% of the world’s food comes from 20
plant species. Crop breeders need a diversity of crop
varieties in order to breed new varieties that resist pests
and diseases.
Extinction/threats
Valmiki begins the Ramayana with the story of the
killing of a sarus crane. The hunter is admonishing for
having killed a crane, leaving its partner dies in
loneliness. Though this understanding of the behavior of
cranes and values ascribed to life has been passed down from
one generation to other in India, the population of our
beautiful cranes, once seen in thousands, is rapidly
shrinking. In spite of this, the species is under serious
threat. The crane population has declined due to loss of its
wetland habitat and the effects of pesticides and chemicals
on the water quality of its residual habitat.
India’s folklore and mythology are replete with stories of
her beautiful mountains, lakes, rivers and forests. Our great
ancient’s philosophers, writers and rulers studied and
documented the great diversity of flora and fauna. The
growing
human
population
and
the
rapid
increase
of
agriculture and industry share the responsibility for the
destruction of what is left of the Biodiversity.
Society's growing consumption of resources and increasing
populations have led to a rapid loss of biodiversity. Human
activities have raised the rate of extinction to 1,000 times
its usual rate. If this continues, Earth will experience the
sixth great wave of extinctions in billions of years of
history. Already, an estimated two of every three bird
species are in decline worldwide, one in every eight plant
species is endangered or threatened, and one-quarter of
mammals, one-quarter of amphibians and one-fifth of reptiles
are endangered or vulnerable. Over fishing, destructive
fishing techniques and other human activities have also
severely put in danger to marine species and ecosystems.
We the higher up in the ladder of evolution, by controlling
and changing the environment to suit its needs and for
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development are posing a great threat to the earth system as
a whole. The species are being destroyed at faster rate now
than they were earlier. This fact has been further supported
by the studies done on fossils. Presently more than 30%
species of all amphibian species; 23% of all mammals, and 12%
of all birds are facing the problem of survival. The natural
scavengers such as vultures are already at the verge of
extinction. We rely on this diversity of life to provide you
with the food, fuel, medicine and other essentials, you
simply cannot live without. Yet this rich diversity is being
lost at a greatly accelerated rate because of human
activities.
Large-scale habitat and biodiversity losses mean that species
with potentially great economic importance may become extinct
forever before they are even discovered. The vast, largely
untapped resource of medicinal plants and useful chemicals
contained in wild species may also disappear with them. Same
is true to marine species; especially those defend themselves
chemically and could be a rich potential source of new
medicines. Additionally, if the wild relatives of our
cultivated crops, which are a valuable reservoir of genetic
material, are lost, then our crop plants will also become
more vulnerable to extinction. This will pose a serious
problem to our food security.
The loss of biodiversity often reduces the productivity of
ecosystems, thereby shrinking nature’s basket of goods and
services, from which we constantly draw. It destabilizes
ecosystems, and weakens their ability to deal with natural
disasters such as floods, droughts, and hurricanes, and with
human –caused stresses, such as pollution and climate change.
This impoverishes us all and weakens the ability of the
living systems, on which we depend, to resist growing threats
such as climate change.
Many farmers these days grow a single crop usually a cash
crops, in order to earn the maximum from their agricultural
activity. This is leading to decrease in the diversity of
agricultural crops. Diversity in agriculture is crucial. It
provides a variety of foods to eat and meet divergent needs
(cereals, pulses and oil seeds). It assists in soil fertility
because if one crop draws nutrients, the other outs it back
reducing dependence of costly fertilizers. Diversity means
insurance against crop failure. If one crop fails, there are
still the others to fall back up on. It ensures food
security, nutritional balance and provides a range of fodder
for the cattle.
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International Year of Biodiversity 2010
Biodiversity, the variety of life on Earth, is essential
to sustaining the living networks and systems that provide us
all with health, wealth, food, fuel and the vital services
our lives depend on.
Human activity is causing the diversity of life on Earth to
be lost at a greatly accelerated rate. These losses are
irreversible, impoverish us all and damage the life support
systems we rely on everyday. But we can prevent them. 2010 is
the International Year of Biodiversity. Let’s reflect on our
achievements to safeguard biodiversity and focus on the
urgency of our challenge for the future. Now is the time to
act.
To draw the attention of the world to the importance of
biodiversity, the United Nations (UN) has declared the year
2010 as “The Year of the Biodiversity”. A host of activities
and programmes are being organized all over the world for
this purpose. It is hoped that with the cooperation of all,
we shall be able to save the biodiversity and the life on
this earth.
We do not know which species may prove to be value in the
future. This is known as its’ Option value’. Future
generations have the right to the use of biodiversity, and
our generation has no right to destroy this invaluable
resources.
When we say we want to save the planet, we use the word
“biodiversity" to encompass this entire concept - which,
granted, is a big one…
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