Sunday, 9 October 2011
NATURAL RESOURCES
RESOURCE:
Anything useful or can be made useful to humans to meet their needs and wants
NATURAL
RESOURCE:
·
A resource available directly /indirectly
from nature in raw form
·
Goods and services supplied by nature or
environment
Examples:
Fresh air, water, soil, land, forest etc.
·
Natural resources are differentiated from
manufactured goods. For example, trees, fish are natural resources, but
furniture and prepared meals are not natural resources.
·
Solar energy, coal, wind and water are natural
resources while electricity is not a natural resource
.
TYPES
OF NATURAL RESOURCES:
·
Living
and Nonliving
·
Renewable:
Solar
energy, winds, tides
·
Non-renewable:
Minerals
(metallic and non-metallic) and fossil fuels (oil, coal, gas)
NATURAL
RESOURCES DEPLETION:
Resources are utilized at a faster rate than they are replaced
NATURAL
REPLACEMENT RATE/ SUSTAINABLE YIELD (SY)
·
Sustainable yield or natural replacement rate
is the highest rate at which a renewable resource can be used without
decreasing its potential for natural replacement.
·
If sustainable yield is more than the base
supply of natural resources that resource starts declining and gradually it
leads to degradation of resource.
BIODIVERSITY
Concept
Biodiversity is essential for human survival and economic well being. It
plays prominent role in modulating in ecosystem function, stability and
resilience. Biodiversity refers to the
totality of genes, species and ecosystems of a region. The term ‘biological
diversity’ was first defined as including two related concepts, genetic
diversity (the amount of genetic variability within species) and ecological
diversity (the number of species in a community of organisms) by Norse and
McManus (1980). The term biodiversity was coined by Walter Rosen for the
National Forum organized by the National Research Council under the title
‘Biodiversity’ (Wilson 1988).
Definition
Variability among living organisms from all sources, including, inter
alia, terrestrial, marine and other aquatic ecosystems and the ecological
complexes of which they are part; this includes diversity within species,
between species and of ecosystems.
(United Nations Environment Programme 1992)
Value of Biodiversity
Value of Biodiversity
Human derive many
direct and indirect benefits from the living world. The uses of the
biodiversity have been described below:
(a) Direct Values:
· Consumptive
use values
It refers to value of
natural products consumed directly, without passing through market, e.g.
hunting, firewood.
· Productive
use values
It is the value of commercially harvested products.
This type
of value of biodiversity is basically economic Value. These include:
·
Source of Food: Biodiversity is the source of food (grains, fat,
oils, fibres, etc.),
· Drugs and medicines: Biodiversity is a rich source of substances with
therapeutic purposes.
·
Industrial products: Industrial products like timber, oil, lubricants,
food flavours, industrial enzymes, cosmetics, perfumes, fragrances, dyes,
paper, waxes, rubber, latexes, resins, poisons, cork are obtained from plants.
Wool, silk, fur, leather, lubricants, waxes are derived from animals.
Biodiversity provides feed for livestock. It also provides biomass and biofuels
as source of energy.
(b) Indirect Values:
Non-consumptive use value
is the value provided by biological resources without being consumed. These
values include:
· Recreational: Sport, tourism and other recreations (Parks, sanctuary,
biosphere reserve, safari, bird watching, angling)
· Religious: Many of the plants and animals are considered sacred
e.g. Ocimum sanctum (Tulsi), Ficus
religiosa (Pipal), Prosopis cinererie (Khejri).
· Ethical: All species have an ethical values associated with
them as all species have an inherent right to co-exist.
·
Aesthetic: Value of beauty borne by nature
·
Emotive: emotional attachment with plants and animals
·
Ecological: Ecosystem services
ECOSYSTEM
· An ecosystem is a natural system consisting of all plants, animals and
microorganisms (biotic factors) in an area functioning together with all the
non-living physical (abiotic) factors of the environment.
· In any ecosystem communities or living
organisms interact with their physical environment in such a way that there is
a well defined flow of energy forming clear trophic levels and material cycles
within the system.
· Term ‘Ecosystem’
was first of all given by British ecologist Arthur Tansley (1935). He described it as the interactive system established
between biocoenosis (a group of living creatures) and their biotope (the
environment in which they live). Thus,
he defined Ecosystem as “System arising out of interactions between living and
non-living components of environment.”
· "Ecosystem"
means a dynamic complex of plant, animal and micro-organism communities and
their non-living environment interacting as a functional unit" (Convention
on the Biological Diversity, 1992).
TYPES OF ECOSYSTEM
It
is mainly of two types:
·
Natural Ecosystems
·
Artificial Ecosystems
STRUCTURE AND FUNCTION OF ECOSYSTEM
a. Structure of Ecosystem includes:
·
Abiotic Components
·
Biotic Components
·
Climatic Conditions
b. Function of Ecosystem includes
·
Energy Flow
·
Material cycles or biogeochemical cycles
ENVIRONMENT
Environment is
the sum total of all biotic (living) and abiotic (non-living) factors that
surround and potentially influence an organism.
The
word ‘Environment’ has been derived from the French word ‘environner’.
Environment
is defined as sum total of all the external conditions and factors that
surround and influence the organisms and are responsible for their wellbeing
and development.
Environment Science is
defined as that branch of science which deals with the study of environment and
various aspects related to environment.
Environmental Sciences in
its broadest sense is the science of the complex interactions that occur among
the terrestrial, atmospheric, aquatic, living and anthropogenic environments.
It includes all the disciplines, such as chemistry, biology, ecology,
sociology, and environment that affect or describe these interactions.
Environmental Chemistry: It
may be defined as the study of the sources, reactions, transport, effects and
the fates of chemical species in water, soil, air and living environments, and
the effects of technology thereon.
Ecology:
(Oikologie, made of two Greek words, i.e.,
Oikos- house or dwelling+ Logos-
study). Thus literary meaning of ecology is, study of organisms at their home,
Ecology
can be defined as the branch which deals with inter-relationship between
environment and organisms.
The term ‘Ecology’ was first coined by
Ernest Haeckel in 1868.
Ecological Factors: Any
external thing, substance or condition which has effect on living organisms is
called ecological factors or factor and totality of all these factors
constitute environmental complex or environment.
There
are four major types of factors:
A.
Climatic Factors
·
Light
·
Temperature
·
Humidity
·
Precipitation
·
Wind
·
Fire
B.
Topographic Factors
These are related with physical geography of earth and
are also called ‘physiographic factors’
Altitude
Direction of mountains and valleys
C.
Edaphic Factors
·
Soil type and properties
D.
Biotic Factors
·
Positive Interactions: Mutualism,
Proto-corporation, Commensalism
·
Negative interactions: Parasitism, Predation,
Competition, Amensalism
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