Page 116 - SST Class 07
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BIODIVERSITY that compose them. Removing just one species
Biodiversity is the sum of all the different species from an ecosystem can prevent the ecosystem
of animals, plants, fungi and microbial organisms from operating optimally.
living on the earth and the variety of habitats in Benefits of Biodiversity
which they live. Scientists estimate that more Biodiversity plays an important role in the way
than 10 million different species inhabit on the ecosystems function and in the services they
earth. provide. The following is a list of some of the
Biodiversity underlies everything from food benefits or services of biodiversity :
production to medical research. Humans use at g Provisioning services such as food, clean
least 40,000 species of plants and animals on a water, timber, fiber and genetic resources.
daily basis. Many people around the world still
g Regulating services such as climate, floods,
depend on wild species for some or all of their
disease, water quality and pollination.
food, shelter and clothing. All our domesticated
g Cultural services such as recreational,
plants and animals came from wild living ances-
aesthetic and spiritual benefits.
tral species. In addition, almost 40 percent of the
pharmaceuticals used in the United States either g Supporting services such as soil formation
and nutrient cycling.
are based on or are synthesised from natural
compounds found in plants, animals or microor- ECOSYSTEM
ganisms. All organisms, whether belonging to the plant or
animal kingdoms, interact with one another and
are interdependent on one another. They also
interact with their physical environment. The
complex system of interactions between the
organisms and their physical environment in a
particular area is referred to as an ecosystem.
The size of the ecosystem varies greatly. It can be
as large as the rainforests, grasslands, deserts,
lakes, rivers or as small as a pond.
Natural Environment A typical pond ecosystem contains fish, frogs,
The array of living organisms found in a particu- algae, water lilies and other species that live in
lar environment combined with the physical and and around the pond. Most of the ecosystems
environmental factors that affect them is an are complex and contain thousands of interacting
ecosystem. Healthy ecosystems are vital to life; species. These species interact with one another
they regulate many of the chemical and climatic and also with the abiotic environment.
systems that make available clean air, clean Natural and Man-made Environment
water and plentiful oxygen. For example, forests These are two chief components of our environ-
regulate the amount of carbon dioxide in the air, ment. The natural environment is all around us.
produce oxygen as a byproduct of photosynthe- It includes all types of landforms, oceans, rivers,
sis and control rainfall and soil erosion. lakes, plants, animals, processes like soil forma-
Ecosystems, in turn, depend on the continued tion, climate, weather conditions, happenings like
health and vitality of the individual organisms day and night, waterfalls, etc. Man is also a part
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