EVS-GE6351 UNIT 1 FULL

GE 6351 - Environmental Science and Engineering

Unit I – Environment, Ecosystem and Biodiversity
Unit II – Environmental Pollution
Unit III – Natural Resources
Unit IV – Social Issues and the Environment
Unit V – Human Population and the Environment

Unit I / Environment, Ecosystem and Biodiversity
Environment:
Definitions:
Environment – a French word “Environner” – to encircle or surround.
The sum total of water, air and land and the inter-relationships that exists among them and with the human
beings, other living organisms and materials.

Environment:
According to Boring: A person’s environment consists of the sum total of the stimulation which he
receives from his conception until his death.
According to Douglas and Holland: the term environment is used to describe in the aggregate, all the
external forces, influences and conditions, which affect the life ,nature,behaviour and the growth
,development and maturity of living organisms.
External forces: Physical,economic,political,cultural,social,moral and emotional activity
Other Definitions:
Environmental Science – Study of environment, its biotic & abiotic components and their interrelationship.
Environmental Engineering – Application of environmental principles to the protection and enhancement.
Environmental Studies – Awareness on Environmental protection.

Elements of Environment:
1)Physical 2)Biological 3)Cultural
Scope of Environment:
 Awareness and sensitivity + related problems.
 Motivate active participation.
 Identifying and solving environmental problems and skills.
 Necessity of conservation of natural resources.
 Environmental programs.

Importance of Environment:
 Global vs. Local Nature of Environment.
Global Warming Depletion of Ozone Layer Dwindling Forest & Energy Resources Loss of Global Diversity

Importance of Environment:
 Individualistic Nature of Environment.
Drinking Water Hygienic Living Fresh Air Fertile Land Healthy Food Sustainable Energy

1.Environment issues being of internal importance
2.Problems cropped in the wake of development
3.Explosively increase in pollution
4.Need for an alternative solution
5.Need to save Humanity from extinction
6.Need for Wise planning of development
Importance-significant reasons

Need for Public Awareness:
Environmental issues received International Attention on June 5, 1972 at Stockholm (Sweden)
 Pressure caused due to population increase, urbanization and poverty – Govt. and NGOs for creating
awareness.
 Environmental pollution cannot be removed by laws alone – need active participation from the public /
individuals.
Summary:
 Implementation of Environmental Protection Plans.
 Developing societies, lifestyle and attitudes – self-oriented.
 Environmental pollution awareness.

Need for Public Awareness:
Types of Public Awareness:
 Pressure Group - influence the government and also industries.
 Watch Dog - protect the interest of public against environmental hazardous activities.
 Advisory Council – as advisory committee to keep environment suitable for living.
 Enforcing Environmental Laws – service utilized to enforce the environmental laws
What’s the use of a beautiful house if you don’t have a decent planet to put it on? – Hendry D. Thoreau

General:
World Environment Day – June 5 to raise global awareness of the need to take positive environmental action. It is run by
the United Nations Environment Programme (UNEP).
Theme 2014 - The theme for this year’s World Environment Day celebrations is Rise our voice not the sea level.
According to the UN Food and Agriculture Organization (FAO), every year 1.3 billion tonnes of food is wasted. This is
equivalent to the same amount produced in the whole of sub-Saharan Africa.
One in every 7 people in the world go to bed hungry and more than 20,000 children under the age of 5 die daily from
hunger.
Think – Eat – Save: encourages you to become more aware of the environmental impact of the food choices you make and
empowers you to make informed decisions.

Hazard is the potential for harm.
A hazard is often associated with a condition
or activity that can cause undesired
consequences such as injury or illness if left
uncontrolled.
Basically, a hazard can cause harm or
adverse health effects to individuals or to
organizations as property or equipment
losses.
*What is hazard?

*1) Chemical hazards
Chemicals can affect skin by contact.
Chemicals can also enter our body either
through the inhalation or digestive system if
air is contaminated with chemicals, vapor,
mist or dust.
The accumulation of chemicals in or on our
body will cause acute (immediate) effect or
chronic (long-term) effect.
*Types of hazard

*2) Physical hazards
Physical hazard will cause injury risks on our
body.
This category includes the hazards from
working in confined spaces, being hit by
flying objects, caught in explosions, hurt by
collapsing machinery, falling from heights and
tripping on obstacles.

* 3) Biological hazards (biohazards)
Biohazards refer to biological substances
that pose a harm to the health of living
organisms.
Sources of biological hazards may include
insects, bacteria, fungi, plants, worms,
animals and viruses.
These sources can cause a variety of health
effects ranging from skin irritation and
allergies to infections, cancer and so on.

Hazard
Analysis
Analysing their
potential causes
First step
in a process
used to
assess risk
Result of a hazard
analysis is the
identification of
different type of hazards
Process of
recognizing
hazards that may
arise from a system or
its environment
*What is
Hazard
Analysis?

Job
Hazard
Analysis
Technique that
focuses on job
tasks as a way to
identify hazards
before they occur
Identify
hazards
potentially created
by a product,
process or
application
Technique to identify the
dangers of specific tasks in order to
reduce the risk of injury to workers.
Focuses on the
relationship
between the worker,
the task, the tools,
and the work
environment

Determine the
hazards and
hazardous events
of the equipment
under control and
the control system
Analyse the event
sequences leading
to the hazardous
events identified
To analyse
the risk associated
with the hazardous
events
Identify hazards
Identify causes
Determine risks
Hazard
Analysis
Objectives

Ecosystem:
Concept:
Ecosystem is a self-regulating group of biotic communities of species interacting with one
another and with their non-living environment exchanging energy and matter.
Ecology is a scientific study of interactions between living and their environment. It discovers and
understands the relationship between living things and their environment.
Ecologist is a person who studies about ecology

*
ecosystem
Natural
terrestial Aquatic
Aritificial
Marine Fresh Water

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Diagram showing ecological organization
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Ecosystem:
Structure:
ECOSYSTEM
- Living (Biotic)
- Producers
- Consumers
- Herbivores
- Carnivores
- Omnivores
- Detritivores
- Decomposers (bacteria & fungi)
- Non Living (Abiotic)
- Physical Factors Sun light, rainfall, wind, latitude, soil type, water)
- Chemical Factors Carbon, hydrogen, oxygen, sulphur)

Stepped Art
Smallest unit of a chemical element that
exhibits its chemical propertiesAtom
Molecule
Chemical combination of two or more atoms of
the same or different elements
Cell
The fundamental structural and functional unit
of life
Organism An individual living being
Population A group of individuals of the same species
living in a particular place
Community Populations of different species living in a
particular place, and potentially interacting with
each other
Ecosystem
A community of different species
interacting with one another and with their
nonliving environment of matter and energy
Parts of the earth's air, water, and soil
where life is found
Biosphere

Ecosystem:
Functional Attributes:
Primary Functions - Manufacture of starch (photosynthesis)
Secondary Functions - Distributing energy in the form of food to all consumers

Ecosystem:
Function Studies:
Energy and Material Flow - Flow of energy in an ecosystem takes place through the food chain and it is
energy flow which keeps the ecosystem going.

Food Chain - The sequence of eating and being eater in an ecosystem is known as food chain
or
Transfer of food energy from the plants through a series of organisms is referred to as food chain
.
Autotrophs Vs Heterotrophs
Food chain in Various Condition
1.Food chain in a grass land
2.Food chain in a pond
3.Food chain in a forest

.
1.Food chain in a grass land

TYPES OF FOOD CHAIN
1. Detritus food chain- It starts with dead organic material or detritus
which is consumed by the decomposers or detrivores. Smaller carnivores feed
on these detrivores. The smaller carnivores are in turn consumed by larger
carnivores and so on. The food energy passes from one trophic level to
another. Example of a detritus food chain is given below:
2. Grazing food chain- It is the most common food chain and is also
known as predator food chain. This food chain is made up of producers,
consumers and decomposers. Example of a grazing food chain in an aquatic
ecosystem is given below:

ENERGY FLOW IN GRASS LAND AND FOREST ECOSYSTEM

*
Trophic Levels - The position occupied by an organism in a food chain.

Trophic Levels - The position occupied by an organism in a food chain.
PRODUCERS
PRIMARY CONSUMERS
SECONDARY
CONSUMERS
TERTIARY
CONSUMERS

Food Web:
Food web is a network of food chains where different types of organisms are connected at different tropic
levels.
(or)
The food chain in an area forms the food web
Food chain Vs Food web- difference, importance

Ecological Pyramids: (Video Lecture)
Graphic representation of tropic structure and function of an ecosystem starting with producers at the base
and successive tropic levels forming the apex is known as ecological pyramid.
Autotrophs Vs Heterotrophs

*Types:
Pyramids of numbers - The number of individual organisms at each tropic level
Pyramids of biomass - The total biomass at each tropic level in a food chain
Pyramids of energy - The amount of energy present at each tropic level

*Ecological Pyramids
*An ecological pyramid is a diagram that shows the
relationship amounts of energy or matter contained
within each trophic level in a food web or food
chain.
*Energy Pyramid only 10% of the energy available
within one trophic level is transferred to organisms
at the next trophic level.

*Pyramids Continued
Biomass pyramids show the total amount
of living tissue available at each trophic
level. This shows the amount of tissue
available for the next trophic level.
Numbers pyramid shows the number of
species at each trophic level.
Because each trophic level harvests only
about one tenth of the energy from the
level below, it can support only about one
10th the amount of living tissue.

*Feeding Relationships
Energy flow through an ecosystem in one
direction, from the sun or inorganic compounds to
autotrophs (producers) and then to various
heterotrophs (consumers).
Food Chains are a series of steps in which
organisms transfer energy by eating or being eaten.
Food webs show the complex interactions within
an ecosystem.
Each step in a food chain or web is called a
trophic level. Producers make up the first step,
consumers make up the higher levels.

*ECOLOGICAL PYRAMIDS
*Food chains and food webs do not give any
information about the numbers of organisms
involved.
*This information can be shown through ecological
pyramids.
*Shows the number of organisms at each trophic
level per unit area of an ecosystem.

PYRAMID OF NUMBERS
Pyramid of numbers displays the number of individuals
at each level.
1 owl
25 voles
2000
grass plants

 The total amount of matter present in organisms
of an ecosystem at each trophic level is biomass.
 Biomass is preferred to the use of numbers of
organisms because individual organisms can vary
in size. It is the total mass not the size that is
important.
 Pyramid of biomass records the total dry organic
matter of organisms at each trophic level in a
given area of an ecosystem.

Biomass Pyramids
Displays the biomass at each trophic level.

Energy Pyramid
Fig. 4–19
In nature, ecological
efficiency varies from
5% to 20% energy
available between
successive trophic
levels (95% to 80%
loss). About 10%
efficiency is a general
rule.
*

Another Energy Pyramid
Annual pyramid of energy flow (in kilocalories per square
meter per year) for an aquatic ecosystem in Silver Springs,
FL.
Note: More individuals can be
supported at lower trophic
levels. Less energy is lost.

Ecosystem:
Pyramids of Numbers:
It represents the number of individual organisms at each tropical levels
Producers
Herbivores
Carnivores
Top
Carnivores
Grass
Insects
Frogs
Eagle
Carnivores
Herbivores
Producers
Top
Carnivores
Trees
Insects
Snakes
Lion
Producers
Herbivores
Parasites
Hyper Parasites Fleas
Bugs
Birds
Trees

Pyramids of Biomass:
It is based on the total biomass at each trophic level of a food chain
Producers
Herbivores
Carnivores
Grass
Squirrel
Snakes
Producers
Herbivores
Carnivores
Tertiary Carnivores Big Fish
Small Fish
Insects
Phytoplankton

Pyramids of Energy:
It is based on the amount of energy present at each trophic levels.
It gives the best representation of trophic relationship. (always upright)
Producers
Herbivores
Carnivores
Top Carnivores

Ecological Succession:
The progressive replacement of one community by another till the development of
stable community in a particular area.

Process of Succession:
Process of succession takes place in a symmetrical order of sequential steps
Nudation – Development of a bare area without any life form.
Causes:
Land Slides Volcano Drought
Glaciers
Topographical Factor Climatic Factor

 Nudation – Development of a bare area without any life form.
Causes:
Over grassing Disease Outbreak
Biotic Factor

 Invasion – Successful establishment of one or more species on a bare area through dispersal
or migration.
Process:
By Air By Water By Birds By insects

 Competition and Coaction – Competition between inter and intra species for space, water and
nutrition called coaction
 Reaction – Living organisms grow, use water from substratum and they in turn have strong
influence on the environment which is modified to a large extent. Modifications may become
unstable for existing species and favour new species which replaces them. This is called seral
communities.
 Stabilization – The succession ultimately culminates (ends) in more or less stable community
called climax which is in equilibrium with the environment. It is characterized by maximum
biomass and symbiotic linkages between organism and are maintained quite efficiently.

Ecosystem:
Types:
Forest Ecosystem – A forest ecosystem is the one in which a tall and dense
trees grow that support many animals and birds.
Classification: Depending upon the climate conditions forests can be
classified into the following types.
 Tropical rain forests
 Tropical deciduous forests
 Tropical scrub forests
 Temperate rain forests
 Temperate deciduous forests

Types:
 i)Tropical Rain Forest:
The tropical rainforest is a hot, moist biome found near Earth's
equator.
The world's largest tropical rainforests are in South America, Africa,
and Southeast Asia.
Tropical rainforests receive from 60 to 160 inches of precipitation that
is fairly evenly distributed throughout the year.
The combination of constant warmth and abundant moisture makes
the tropical rainforest a suitable environment for many plants and
animals.
Tropical rainforests contain the greatest biodiversity in the world.
Over 15 million species of plants and animals live within this biome

 ii)Tropical Deciduous Forest:
Tropical deciduous forests are also called the "Monsoon forests".
Long dry season of summer leads these forests to shed their
leaves in order to prevent evaporation.
Period of shedding the leaves varies for each species of trees.
Hence, all the trees do not shed leaves at one and the same time.
Tropical deciduous forests are grown in the areas with annual
rainfall of 70-200 cm.
Sandal wood, Shisam, Mahua, Sal, Teak and Bamboo are
important species of trees. They are famous for their economic
importance. They supply timber for use in various activities.
Shed –prevent -evaporation

 Tropical Deciduous Forest:
 Moist deciduous and the dry deciduous forests are two major categories of these
forests.
 The moist deciduous forests are found in Shiwalik foothills, Bhabar, Tarai, Chhota
Nagpur Plateau, the North-eastern Deccan Plateau and North-south strip to the east
of the Western Ghats.
 The dry deciduous forests are grown in the Central India where rainfall is
comparatively less.
Moist Forests-Teak Dry Forests-Sal

 iii)Tropical Scrub Forest:
It is one of the biomes that make up arid land.
This type of biome also consists of desert and areas of low-lying, dense
underbrush.
It is an area of little precipitation, plenty of continuous winds, poor drainage
and medium to poor soil quality.
The plants and animals of the tropical scrub forest have adapted to flourish
in this harsh environment.

Tropical Scrub Forest:
Tropical scrub forests, or chaparral as they are referred to in
California, are found across the southern United States, along
the Mediterranean coastline, in north and central Africa and
within the interior of Australia.
Average annual rainfall is only 2 to 9 inches, and the
temperature fluctuates very little, averaging near 64 degrees
Fahrenheit all year round.
Virtually all tropical scrub forest is found in the same equatorial
region, and temperatures fluctuate little regardless of season.

*iv)Temperate Rainforest
*Mid Latitudes.
*1000- 1200 mm of Rain
per year average some
receive more.
*Winter temperatures
rarely drop below
freezing.
*Summer Temperatures
rarely exceed 80
degrees.
*Mild wet winters and
cool, foggy and
clouded summers.

*Temperate Rainforest Around
the World

*
A DECIDUOUS FOREST is used to describe a type of forest trees shed their
leaves during the cold months of the year and re-grow new leaves the next
Spring.
The major characteristic is that it has 4 DISTINCT SEASONS!

*
*Eastern third of the North
America
*western Europe
*China, Korea, Japan and
Australia
*southern tip of South
America
*The only part of Texas that
has this type of forest is far
East Texas

Grassland Ecosystem:
 Grassland occupies about 20% of earth’s surface. In addition to grass species, some
trees and shrubs are also present.
Types:
Depending upon the climate conditions grassland can be classified into three types
 Tropical grasslands – savannas
 Temperate grassland – pampas, steppes, prairies
 Polar grassland

Grassland Characteristics:
 It is a plain land occupied by grasses
 Soil is very rich in nutrients and organic matter
 It is ideal place for grazing animals.
 It is characterized by low or uneven rainfall
Grassland Structure:
 Biotic
 Producers (grass, shrubs, forbs etc.)
 Consumers (cow, buffaloes, deer, etc.)
 Decomposers (fungi and bacteria)
 Abiotic
 Physical Factor (rainfall, light, temperature)
 Chemical Factor (organic and inorganic matter, nutrient)

Desert Ecosystem:
 It is regions where evaporation exceeds precipitations.
 It occupies about 35% of our world’s land area.
Types:
Depending upon the climate conditions grassland can be classified into three types
 Tropical Desert – Sahara, Thar
 Temperate Desert – Mojave
 Polar Desert - Gobi

Desert Ecosystem Characteristics:
The desert air is dry and the climate is hot.
Annual rainfall is less than 25 cm
The soil is very poor nutrients and organic matter
Vegetation is poor
Desert Ecosystem Structure:
Biotic
Producers (Shrubs, Bushes, Few Trees)
Consumers (Squirrels, Mice, Rabbits)
Decomposers (Fungi, Bacteria)
Abiotic
Physical Factor (Rainfall, Light, Temperature)
Chemical Factor (Organic and Inorganic matters)

Aquatic Ecosystem:
An aquatic ecosystem is an ecosystem in a body of water.
Communities of organisms that are dependent on each other and on their
environment live in aquatic ecosystems.
Types:
Fresh water
Pond
Lake
River
Salt water
Ocean
Estuarine

Pond Ecosystem:
 Small bodies of freshwater with shallow and still water, marsh, and aquatic plants.
 They can be further divided into four zones:
 vegetation zone
 open water
 bottom mud
 surface film.
 The size and depth of ponds often varies greatly with the time of year; many ponds are
produced by spring flooding from rivers.
 Food webs are based both on free-floating algae and upon aquatic plants.
 There is usually a diverse array of aquatic life, with a few examples including algae, snails,
fish, beetles, water bugs, frogs, turtles, otters and muskrats.
 Top predators may include large fish, herons, or alligators.
 Since fish are a major predator upon amphibian larvae, ponds that dry up each year,
thereby killing resident fish, provide important refugia for amphibian breeding
 .

1.vegetation zone
2.open water
3.bottom mud
4.surface film.

Pond Ecosystem Characteristics:
It is temporary
It is a stagnant fresh water body
It may be seasonal

Lake Ecosystem:
 Lake ecosystems can be divided into zones.
 One common system divides lakes into three zones (see figure).
 The first, the littoral zone - shallow zone near the shore, where rooted wetland plants occur.
 The offshore is divided into two further zones, an open water zone and a deep water zone.
 In the open water zone (or photic zone) sunlight supports photosynthetic algae, and the
species that feed upon them.
 In the deep water zone(or aphotic zone), sunlight is not available and the food web is based
on detritus entering from the littoral and photic zones.
 The off shore areas may be called the pelagic zone, and the aphotic zone may be called the
profundal zone.
 Inland from the littoral zone one can also frequently identify a riparian zone which has plants
still affected by the presence of the lake—this can include effects from windfalls, spring
flooding, and winter ice damage.

Lake Ecosystem Characteristics:
It is a shallow fresh water body
It is a permanent water body
It helps in irrigation and drinking
Organism : Planktons, Nektons, Neustons, Benthos, Periphytons

Types of Lakes: Oligotrophic
(Low Nutrient)
Eutrophic
(High Nutrient)
Dystrophic
(Low pH)
Endemic
(Has Fauna)
Artificial
(Due to Dams)
Desert Salt
(High Salt)
Volcanic
(Volcanic Eruption)
Meromictic
(Rich in Salt)

River Ecosystem:
 The ecosystem of a river is the river viewed as a system operating in its natural environment, and
includes biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (non-
living) physical and chemical interactions.
 River ecosystems are prime examples of lotic ecosystems.
 Lotic refers to flowing water, from the Latin lotus, washed.
River Ecosystem Characteristics:
 Flow is unidirectional.
 There is a state of continuous physical change.
 There is a high degree of spatial and temporal heterogeneity at all scales (microhabitats).
 Variability between lotic systems is quite high.
 The biota is specialized to live with flow conditions

Ocean Ecosystem:
 Marine ecosystems are among the largest of Earth's aquatic ecosystems.
 They include oceans, salt marsh and intertidal ecology, estuaries and lagoons, mangroves and
coral reefs, the deep sea and the sea floor.
 They can be contrasted with freshwater ecosystems, which have a lower salt content.
 Marine waters cover two-thirds of the surface of the Earth. Such places are considered
ecosystems because the plant life supports the animal life and vice-versa.
Ocean Ecosystem Characteristics:
 Marine ecosystems are very important for the overall health of both marine and terrestrial
environments.
 According to the World Resource Centre, coastal habitats alone account for approximately 1/3 of
all marine biological productivity, and estuarine ecosystems (i.e., salt marshes, sea-grasses,
mangrove forests) are among the most productive regions on the planet.
 Marine ecosystems such as coral reefs, provide food and shelter to the highest levels of marine
diversity in the world.
 Marine ecosystems usually have a large biodiversity and are therefore thought to have a good
resistance against invasive species.

Ocean Ecosystem Structure:
Types of Zones:
 Coastal Zone – Warm, nutrient rich shallow water
 Open Sea – Deepest
 Euphotic Zone – Receives abundant light and shows high photosynthetic activities.
 Bathyal Zone – It receives dull light
 Abyssal Zone – It is the dark zone (2 – 5km deep)

Estuarine Ecosystem:
 An estuary is a partly enclosed coastal body of brackish water with one or more rivers or
streams flowing into it, and with a free connection to the open sea.
 Estuaries form a transition zone between river environments and maritime environments and are
subject to both marine influences, such as tides, waves, and the influx of saline water.
 The inflows of both sea water and fresh water provide high levels of nutrients in both the water
column and sediment, making estuaries among the most productive natural habitats in the world.
Klamath River – North California

Estuarine Ecosystem Characteristics:
Estuaries are transition Zones
Water characteristics are periodically changed
Salinity remains highest during the summer and lowest during the winter.
It is strongly affected by tidal action.
The organisms (Eurythermal and Euryhaline) present in estuaries show a wide
range of tolerance to temperature and salinity.

Biodiversity:
Definition:
 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.
 Rapid environmental changes typically cause mass extinctions.One estimate is that <1%-3% of
the species that have existed on Earth are extant.

Biodiversity:
Definition:
 Biologists most often define biodiversity as the "totality of genes, species, and ecosystems of a
region".
 An advantage of this definition is that it seems to describe most circumstances and presents a
unified view of the traditional three levels at which biological variety has been identified:
 Species diversity
 Ecosystem diversity
 Genetic diversity

Species Diversity:
 Species diversity is the effective number of different species that are represented in a collection
of individuals (a dataset).
 The effective number of species refers to the number of equally-abundant species needed to
obtain the same mean proportional species abundance as that observed in the dataset of
interest (where all species may not be equally abundant).
 Species diversity consists of two components, species richness and species evenness.

Ecosystem Diversity:
 Ecosystem diversity refers to the diversity of a place at the level of ecosystems.
 Ecosystem diversity can also refer to the variety of ecosystems present in a biosphere, the
variety of species and ecological processes that occur in different physical settings.
2001 2002

Genetic Diversity:
 Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in
the genetic makeup of a species.
 It is distinguished from genetic variability, which describes the tendency of genetic
characteristics to vary.
 Genetic diversity serves as a way for populations to adapt to changing environments.
 With more variation, it is more likely that some individuals in a population will possess variations
of alleles that are suited for the environment.
 Those individuals are more likely to survive to produce offspring bearing that allele.
 The population will continue for more generations because of the success of these individuals.

Biogeographically Classification of India:
India has different types of climate and topography in different parts of the
country and these variations have induced enormous variability in flora and
fauna.
It occupies tenth position among the plant rich nations of the world.
Biogeography deals with the study of distribution, evolution, dispersal and
environmental relationship of plants and animals in time and space.
In our country, it has been classified into ten biogeographic zones. Each of
these zones has its own characteristic climate, soil, topography and biodiversity.

 Biogeographic classification of India is the division of India according
to biogeographic characteristics. Biogeography is the study of the distribution
of species (biology), organisms, and ecosystems in geographic space and through geological
time. The biogeographic zones of India are as follows:
 Himalayan zone
 Desert zone
 Semiarid zone
 Western Ghats zone
 Deccan plateau zone
 Gangetic plain zone
 North east zone
 Coastal zone
 Islands present near the shore line
 Trans Himalayan zone.

Value of Biodiversity:
Food Fuel Drug

Elephant Tusk Silk Wool

Tulsi Plant Sacred Flowers Snakes

Awareness

Tourism

Potential Cure

Preventing
Soil Erosion
Flood
Prevention Global
Warming
Awareness

Biodiversity Levels:
Global Biodiversity:
 Terrestrial biodiversity of earth is called as biomes.
 Biomes : the largest ecological units present in different geographic areas
and are named after the dominant vegetation
eg. Tropical rain forests, tall grass prairies, savannas, desert, tundra.
Tropical rain forests :
 Largest storehouse of biodiversity
 About 50 to 80% of global biodiversity lies in these rainforests.
 More than 1/4th of the world’s prescription drugs are extracted
 70% Cancer fighting plants.
 One of the creeping vines in rainforests at Cameroon to cure AIDS virus

National Biodiversity:
India ranks 10th among the plant rich countries of the world.
11th in terms of endemic species of higher vertebrates.
India ranks 6th among the centers of diversity and origin of agricultural crops.
India is one of the mega-biodiversity countries in world.
Out of 25 biodiversity hot-spots in the world, 2 Hotspots are in India.

Local Biodiversity:
 Point richness : number of species that can be found at a single point in a given space.
 Alpha richness : number of species found in a small homogeneous area. Alpha-richness is
strongly correlated with physical environment variables.
Eg : 100 species of tunicates in arctic waters, 400 species in temperate waters.
 Beta richness : rate of change in species composition across different habitats. Cumulative
number of species increases as more heterogeneous habitats are taken into consideration.
 Gamma richness : rate of change across large landscape gradients.

India as a Mega-diversity Nation:
 India contains about 8% of world’s biodiversity on 2% of the earth’s surface.
 India records 47,000 species of plants and 81,000 species of animals which is about 7% and
6.5% of global flora and fauna.
 India is home to 5 world heritage sites.
 33% of life forms are found in India and is one among the 12 mega diversity countries.
 33 Botanical Gardens, 89 National Parks, 275 Zoos, 504 sanctuaries and 12 biosphere reserves
in India.
 Western Ghats are site of maximum endemism (species which are restricted only to a particular
area. 62% Amphibians and 50% lizards)
 5000 species of flowering plants had their origin in India.
 Center of origin of 166 species of crop plants and 320 species of wild relatives of cultivated
crops.

India as a Mega-diversity Nation:
 Along 7500Km long coastline of our country in the mangroves, estuaries, coral reefs, back
waters etc there exists a rich biodiversity.
 340 species of corals of world are found here.
 Rich in mollusks, crustaceans, polychaetes and corals.
 Several species of Mangrove plants and sea grasses are found in our country.
 Indian forests cover 64.1 million hectares having a rich biodiversity of plants in Trans-Himalayan,
north-west, west, central and eastern Himalayan forests, western ghats, coasts, deserts,
Gangetic plains, Andaman and Nicobar, Lakshadweep islands.

Hot Spots of Biodiversity :
 Areas which exhibit high species richness as well as high species endemism (restricted to only a
particular region) are termed as hot spots of biodiversity.
 Hotspots cover less than 2% of the world’s land area are found to have about 50% of the
terrestrial biodiversity.
 According to Myer’s et al (2000) an area is designated as a hotspot when it contains at least
0.5% of the plant species as endemics.
 About 40% of the terrestrial plants and 20% of vertebrate species are endemic and found in
these hotspots.
 After the tropical rain forests, the second highest number of endemic plant species are found in
the Mediterranean. Broadly, these hot spots are in Western Amazon, Madagascar, North and
East Borneo, North Eastern Australia, W. Africa and Brazilian Atlantic forests.

 These areas have high diversity, endemism and also threatened by human activities.
 Indian hot spots are not only rich in floral wealth, endemic species of plants but also reptiles, amphibians
and some mammals.
 Eastern Himalayas:
 Ultra-varied topography that fosters species diversity and endemism.
 Numerous deep and semi-isolated valleys in Sikkim which are extremely rich in endemic plant
species.
 Forest cover of Eastern Himalayas decreased to about 1/3rd of its original cover.
 Certain species like Sapria himalayana (a rare holoparasitic flowering plant related to Rafflesia
found in the Eastern Himalayas) was seen only twice in last 70 years.

 North East India:
 Cradle of flowering plants.
 Out of the world’s recorded flora 30% are endemic to India of which 35,000 are in Himalayas
 Western Ghats:
 17,000 Km2 strip of forests in Maharashtra, Karnataka, Tamil Nadu and Kerala has 40% of total
endemic plant species, 62% amphibians and 50% lizards are endemic to Western Ghats.
 Major centers are Agastyamalai Hills and Silent Valley : the New Amambalam Reserve Basin.
 Only 6.8% of original forests are existing today.
 Common plants include Ternstroemia japonixa, Rhododendron and Hypericum while common fauns
includes laughing thrush, lizard hawk, Fairy blue bird.

Threats to Biodiversity:
 Extinction or elimination of a species is a natural process of evolution
 The process of extinction has become faster due to human civilization
 The figure of extinction is at a rate of 10,000 species per year or 27 per day.
 One third to two-third of our current biodiversity will be lost by the year 2050
 Causes:
 Loss of Habitat or Habitat Degradation
 Poaching
 Invasion of Non-native Species
 Pollution
 Over-exploitation of Resources
 Global Environmental Change

Man-Wildlife Conflicts:
 Wildlife causing damage and danger to humans and properties – crops/houses
 In Samalpur (Orissa) 195 humans were killed in the last 5 years by elephants.
 Humans responded by killing 98 elephants and injuring 30 elephants.
 In Nepal, 17 peoples were killed in the Royal Chitwan National Park by a man-eating tiger.
 Electrical fencing, explosives were some of the methods adopted by villages to kill wild animals.
 Causes:
 Human encroachment into forest areas
 Animals suffering from illness, weak and injured take humans
 Lack of alternate cultivation practices (paddy, sugarcane) by forest department for animals
like elephants when bamboo leaves are not available.
 Electric fencing causes injury to animals, which in return turn violent
 Poor cash compensation by govt. to farmers for crop damages, turn farmer to take revenge
on wild animals

Endangered Species of India:
 Extinct species - When it is not seen in the wild for 50 years at a stretch. Eg., Dodo, passenger
pigeon.
 Endangered species - When its number has been reduced to a critical level or whose habitats
are drastically reduced and if such a species is not protected and conserved, its in immediate
danger of extinction.
 Vulnerable species - If a population of a species is facing continuous decline due to
overexploitation or habitual destruction.
 Rare species - Species which are not endangered or vulnerable at present but at a risk.
 International Union for Conservation of Nature and Natural Resources (IUCN) publishes Red
Data Book (list of endangered species of plants and animals.
 Nearly 450 plant species have been identified as categories of endangered, threatened or rare.

Endemic Species of India:
 Species which are restricted only to a particular area are known as endemic
 Out of 47,000 species of plants in our country 7,000 are endemic.
 Indian subcontinent has about 62% endemic flora, restricted namely to Himalayas, Khasi Hills
and Western Ghats.
 Endemic Flora : Sapria Himalayana, Pitcher plants and Orchids
 Out of 81,000 animal species – large number of species are described to be endemic
 Western Ghats: 62% amphibians, 50% Lizards are endemic
 Endemic species : reticulated python, Indian Salamander and Viviparous toad.

Conservation of Biodiversity:
 In Situ Conservation (within habitat) - achieved by protection of wild flora and fauna in nature
itself.
 Eg. Biosphere reserves, National Parks, Sanctuaries, Reserve forests etc.
 Ex Situ Conservation (outside habitat) - done by establishment of gene banks, seed banks,
zoos, botanical gardens, culture collections.

 In Situ Conservation:
 7 major biosphere reserves, 80 national parks, 420 wild-life sanctuaries, 120 Botanical gardens in our
country covering 4% of geographic area.
 Biosphere reserves - conserve some representative ecosystems as a whole for long-term in situ
conservation.
 In India, we have Nanda Devi(U.P.),Nokrek (Meghalaya), Manas (Assam), Sunderbans (West
Bengal), Gulf of Mannar (T.N.),Nilgiri (Karnataka, Kerala,T.N.),Great Nicobars, Similipal (Orissa)
biosphere reserves.
 National Park - area dedicated for the conservation of wildlife along with its environment. Its meant
for enjoyment through tourism.
 Grazing of domestic animals, all private rights, forestry activities are prohibited within a National
Park

 Wildlife Sanctuaries - Protected areas where killing, hunting, shooting or capturing of
wildlife are prohibited except under the control of highest authority.
 Project Tiger, Gir Lion Project, Crocodile Breeding Project, Project Elephant, Snow
Leopard Project.

 Ex Suit Conservation:
 Conservation of crop varieties, wild relatives of crops and all local varieties (conserve total
genetic variability of crop species for future crop improvement).
 Important Gene bank/Seed bank facilities :
 National Bureau of Plant Genetic Resources (NBPGR) : located in New Delhi.
 Agricultural, horticultural crops, their wild relatives are preserved by cryo-preservation of
seeds, pollen etc by using liquid nitrogen at a temp as low as -196 0c.

Ex Suit Conservation:
Varieties of rice, pearl millet, Brassica, turnip, radish, tomato, onion, carrot,
chilli, tobacco, poppy etc : preserved in liquid nitrogen for several years
without losing seed viability.
National Bureau of Animal Genetic Resources (NBAGR) located at Karnal,
Haryana. Preserves semen of domesticated bovine animals.
National Facility for plant tissue culture repository (NFPTCR) : development
of facility of conservation of varieties of crop plants/trees by tissue culture.

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