Biodiversity is
the degree of variation of life forms within a given species, ecosystem, biome, or planet. Terrestrial
biodiversity tends to be highest at low latitudes near the equator, which seems to
be the result of the warm climate and high primary productivity. Marine
biodiversity tends to be highest along coasts in the Western Pacific, where sea
surface temperature is highest and in mid-latitudinal band in all oceans. Biodiversity
generally tends to cluster in hotspots, and has been increasing through time but will
be likely to slow in the future. The great variety
of life on earth has provided for man’s needs over thousands of years. This diversity
of living creatures forms a support system which has been used by each
civilization for its growth and development. Those that used this “bounty of
nature” carefully and sustainably survived. Those that overused or misused it
disintegrated. Science has attempted to classify and categorize the variability
in nature for over a century. This has led to an understanding of its
organization into communities of plants and animals. This information has
helped in utilizing the earth’s biological wealth for the benefit of humanity
and has been integral to the process of ‘development’. This includes better
health care, better crops and the use of these life forms as raw material for
industrial growth which has led to a higher standard of living for the
developed world. However this has also produced the modern consumerist society,
which has had a negative effect on the diversity of biological resources upon
which it is based. The diversity of life on earth is so great that if we use it
sustainably we can go on developing new products from biodiversity for many
generations. This can only happen if we manage biodiversity as a precious
resource and prevent the extinction of species.
What is the
actual definition=>>‘Biological diversity’ or biodiversity is that part of
nature which includes the differences in genes among the individuals of a
species, the variety and richness of all the plant and animal species at
different scales in space, locally, in a region, in the country and the world,
and various types of ecosystems, both terrestrial and aquatic, within a defined
area. and its deals with the degree of nature’s variety in the biosphere. This
variety can be observed at three levels; the genetic variability within a
species, the variety of species within a community, and the organization of
species in an area into distinctive plant and animal communities constitutes
ecosystem diversity.
Genetic diversity: Each member of any animal or plant species differs widely from other
individuals in its genetic makeup because of the large number of combinations
possible in the genes that give every individual specific characteristic. Thus,
for example, each human being is very different from all others. This genetic
variability is essential for a healthy breeding population of a species. If the
number of breeding individuals is reduced, the dissimilarity of genetic makeup
is reduced and in-breeding occurs. Eventually this can lead to the extinction
of the species. The diversity in wild species forms the ‘gene pool’ from which our
crops and domestic animals have been developed over thousands of years. Today
the variety of nature’s bounty is being further harnessed by using wild
relatives of crop plants to create new varieties of more productive crops and
to breed better domestic animals. Modern biotechnology manipulates genes for
developing better types of medicines and a variety of industrial products.
Species diversity: The number of species of plants and animals that are present in a region
constitutes its species diversity. This diversity is seen both in natural
ecosystems and in agricultural ecosystems. Some areas are richer in species
than others. Natural undisturbed tropical forests have much greater species
richness than plantations developed by the Forest Department for timber production. 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. In the long-term the
economic sustainable returns from non-wood forest products is said to be
greater than the returns from felling a forest for its timber. Thus the value
of a natural forest, with all its species richness is much greater than a
plantation. Modern intensive agricultural ecosystems have a relatively lower
diversity of crops than traditional agro-pastoral farming systems where
multiple crops were planted. At present conservation scientists have been able to
identify and categorize about 1.8 million species on earth. However, many new
species are being identified, especially in the flowering plants and insects.
Areas that are rich in species diversity are called ‘hotspots’ of diversity.
India is among the world’s 15 nations that are exceptionally rich in species
diversity.
Ecosystem diversity: There are a large variety of different ecosystems on earth, which have
their own complement of distinctive inter linked species based on the
differences in the habitat. Ecosystem diversity can be described for a specific
geographical region, or a political entity such as a country, a State or a
taluka. Distinctive ecosystems include landscapes such as forests, grasslands,
deserts, mountains, etc., as well as aquatic ecosystems such as rivers, lakes, and
the sea. Each region also has man-modified areas such as farmland or grazing
pastures.An ecosystem is
referred to as ‘natural’ when it is relatively undisturbed by human activities
or ‘modified’ when it is changed to other types of uses, such as farmland or
urban areas. Ecosystems are most natural in wilderness areas. If natural
ecosystems are overused or misused their productivity eventually decreases and
they are then said to be degraded. India is exceptionally rich in its ecosystem
diversity.
