Natural Resources
Intended
Learning Outcomes
At the end of this session, students will be able to
• Explain natural resources
Contents
• Natural resources
Natural Resources
• Our environment provides
us with a
variety of goods
and services necessary for our
day to day lives
• These natural resources include, air, water, soil,
minerals along with the climate and solar energy, which form the non-living or
‘abiotic’ part of nature
• The ‘biotic’ or living parts of nature consists of plants
and animals, including microbes
• Thus, forests, grasslands, deserts, mountains, rivers,
lakes and marine environment all form habitats for specialised communities of
plants and animals to live in
• Interactions between the abiotic aspects of nature and
specific living organisms together form ecosystems of various types
• Many of these living organisms are used as our food
resources
• Others are linked
to our food
less directly, such
as pollinators and dispersers of plants, soil animals like
worms, which recycle nutrients for plant growth and fungi and termites that break
up dead plant material so that micro-organisms can act on the detritus to
reform soil nutrients
• History of our
global environment
• About ten thousand years ago, when mankind changed from a
hunter-gatherer, living in wilderness areas such as forests and grasslands into
an agriculturalist, we began to change the environment to suit our own
requirements
• Natural ecosystems were developed into agricultural land
• Most traditional agriculturists depended extensively on
rain, streams and rivers for water
• Later they began to use wells to tap underground water
sources and to impound water and created irrigated land by building dams
• Recently we began to use fertilizers and pesticides to
further boost the production of food from the same amount of land, all this has
led to several undesirable changes in our environment
• Mankind has been overusing and depleting natural resources
• Over-intensive use of land has been found to exhaust the
capability of the ecosystem to support the growing demands of more and more
people, all requiring more intensive use of resources
• Industrial growth, urbanisation, population growth and
increase in the use of consumer goods, have all put further stresses on the
environment
• Pollution of air, water and soil have begun to seriously
affect human health
• Changes in land and
resource use
• During the last 100 years, a better health care delivery
system and improved nutritional status has led to rapid population growth, This
phenomena aids to a great demands on the earth’s natural resources
• Large stretches of land such as forests, grasslands and
wetlands have been converted into intensive agriculture
• Land has taken for industry and urban sectors
• These changes have brought about dramatic alterations in
land use patterns and rapid disappearance of valuable natural ecosystems
• Need for more water, food, energy, consumer goods is not
only the result of a greater population, but also result of over utilization of
resources by people from the more affluent societies and the affluent sections
of our own
• Industrial development is aimed at meeting growing demands
for all consumer items
• Growth of industrial complexes has led to a shift of
people from their traditional, sustainable, rural way of life to urban centres
• Last few decades, several small urban centres have become
large cities, some have even become giant mega-cities
• Urban centres cannot exist without resources such as water
from rivers and lakes, food from agricultural areas, domestic animals from
pasture lands and timber, fuel wood, construction material and other resources
from forests
• Rural agricultural systems are dependent on forests,
wetlands, grasslands, rivers and lakes
• The result
is a serious
inequality in the
distribution of resources among human beings, which is both
unfair and unsustainable
• Earth’s Resources and
Man
• Resources on which mankind is dependent are provided by
various sources or ‘spheres’
Atmosphere
• Oxygen for human respiration
• Oxygen for wild fauna in natural ecosystems and domestic
animals used by man as food
• Oxygen as a part of carbon dioxide, used for the growth of
plants (in turn are used by man)
• Atmosphere forms a protective shell over the earth
• Lowest layer, troposphere is the only part warm enough for
us to survive, is only 12 kilometers thick
• Stratosphere is 50 kilometers thick and contains a layer
of sulphates which is important for the formation of rain
• Also contains a layer of ozone, which absorbs ultra-violet
light known to cause cancer and without which, no life could exist on earth
• If its nature is disrupted it affects all mankind
• Most air pollutants have both global and regional effects
• Living creatures cannot survive without air even for a
span of a few minutes, hence air must be kept clean
• Major pollutants of air are created by industrial units
such as carbon dioxide, carbon monoxide and toxic fumes into the air
• Air is also polluted by burning fossil fuels
• Buildup of carbon dioxide which is known as ‘greenhouse
effect’ in the atmosphere is leading to current global warming
• Growing number of
scooters, motorcycles, cars,
buses and trucks which run on fossil fuel (petrol and
diesel) is a major cause of air pollution
• Air pollution leads to acute and chronic respiratory
diseases
Hydrosphere
• Clean water for drinking (a metabolic requirement for
living processes)
• Water for washing and cooking
• Water used in agriculture and industry
• Food resources from the sea, including fish, crustacea,
sea weed, etc.
• Food from fresh water sources and aquatic plants
• Water flowing down from mountain ranges harnessed to
generate electricity in hydroelectric projects
• Hydrosphere covers three quarters of the earth’s surface
• A major part of the hydrosphere is the marine ecosystem in
the ocean, while only a small part occurs in fresh water
• Fresh water in rivers, lakes and glaciers is perpetually
being renewed by a process of evaporation and rainfall
• Some of this fresh water lies in underground aquifers
• Human activities such as deforestation create serious
changes in the hydrosphere
• Water pollution threatens the health of communities as all
our lives depend on the availability of clean water
Lithosphere
• Soil, the basis for agriculture to provide us with food
• Stone, sand and gravel used for construction
• Micronutrients in soil, essential for plant growth
• Microscopic
flora, small soil
fauna and fungi
in soil, important
living organisms of the lithosphere, which break down plant litter as
well as animal wastes to provide nutrients for plants
• A large number of minerals on which our industries are
based
• Oil, coal and gas extracted from underground sources
(provides power for vehicles, agricultural machinery, and industry and for our
homes)
• Lithosphere began as a hot ball of matter which formed the
earth about 4.6 billion years ago
• Of the 92 elements in lithosphere only eight are common
constituents of crustal rocks
• Of these constituents, 47% is oxygen, 28% is silicon, 8%
is aluminium, 5% iron, while sodium, magnesium, potassium and calcium
constitute 4% each
• Together, these elements form about 200 common mineral
compounds
• Rocks, when broken down form soil on which man is
dependent for his agriculture
Biosphere
• Food from crops and domestic animals, providing human
metabolic requirements
• Food for all forms of life which live as interdependent
species in a community and form food chains in nature on which man is dependent
• Energy needs: Biomass fuel wood collected from forests and
plantations, along with other forms of organic matter, used as a source of
energy
• Timber and other construction materials
• This is the relatively thin layer on the earth in which
life can exist
• Within it the air, water, rocks and soil and the living
creatures, form structural and functional ecological units, which together can
be considered as one giant global living system, that of our Earth itself
• Within these, smaller biogeographical units can be
identified on the basis of structural differences and functional aspects into distinctive
recognizable ecosystems, which give a distinctive character to a landscape or
waterscape
• Simplest of these ecosystems to understand is a pond
Natural
cycles between the spheres
• All four spheres are closely inter linked systems and are
dependent on the integrity of each other
• Disturbing one of these spheres in our environment affects
all the others
• Linkages between them are mainly in the form of cycles
• For instance, atmosphere, hydrosphere and lithosphere are
all connected through the hydrological cycle
• Water evaporated from the hydrosphere, forms clouds in the
atmosphere
• This becomes rain, which provides moisture for the
lithosphere, on which life depends
• Rain also acts on rocks as an agent of erosion and over
millions of years has created soil, on which plant life grows
• Atmospheric movements in the form of wind, break down
rocks into soil
• All living organisms which exist on earth live only in the
relatively thin layer of the lithosphere and hydrosphere that is present on the
surface of land and in water
• Biosphere which they form has countless associations with
different parts of the three other ‘spheres’
• It is therefore essential to understand the
interrelationships of the separate entities soil, water, air and living
organisms etc
Summary
Various natural resources
• Plant
• Animal
• Land & soils
• Water
• Air
• Mineral