the document provide information about the subject ESDM to b.sc. students

1. ESDM-211 [3(2+1)]
Environmental Studies and Disaster
Management
Taught by:-
Dr. Anita Sharma
(Asstt. Prof. Entomology)
To
Class- B.Sc. (Hons.) Ag. IInd Year Ist Sem.

2. Ecology
• Ecology is the science that deals with the
relationships between living organisms with their
physical environment and with each other.
• The word ecology coined by Ernst Haeckel, in
1869. First defined the ecology as the study of
total relations of the animal both to its inorganic
and organic environment, including above all.
• The two main sub-division of ecology-
Autecology – It is the study of individual
organism or spp. In relation to its environment
Synecology- It is the study of group of organisms
comprising diff. spp. in relation to their
environment.

3. Concept of level of organization
 Population includes the group of individuals of the same spp. in a
particular area is called population
 The group of individuals of diff. spp. Occupying a given area is called
community
 The community & the non-living environment interacting together
for the exchange of energy constitute an ecosystem.
 The large regional biosystem characterised by a major vegetation
type or other landscape is called biome.
 All the living organisms on earth ineracting with the physical
environment as a whole to maintain a steady state is called
biosphere.
 The environment in which a particular organism lives is called its
habitat.
 The role of an organism in a habitat is called its niche

4. • For the study of ecology it is often convenient to
divide the environment into four broad categories.
 Terrestrial environment - The terrestrial environment
is based on land and consists of biomes, such as
grasslands, one of several kinds of forests, savannas, or
deserts.
 Freshwater environment - The freshwater
environment can be further subdivided between
standing-water habitats (lakes, reservoirs) and running-
water habitats (streams, rivers).
 Oceanic marine environment - The oceanic marine
environment is characterized by saltwater and may be
divided broadly into the shallow waters of the
continental shelf composing the neritic zone
 Oceanic region - The deeper waters of the ocean that
constitute the oceanic region.

5. Ecosystem- Definition & Concept
• Definition- The living community of plants and
animals in any area together with the non-living
components of the environment such as soil, air
and water, constitute the ecosystem.
• - Any unit that includes all the organisms in a
given area interacting with the physical
environment so that a flow of energy leads to
clearly defined trophic structure, biotic diversity.
• The word ecosystem proposed by A.G.Tansley in
1935

6. Concept of ecosystem
 An ‘Ecosystem’ is a region with a specific and
recognizable landscape form such as forest, grassland,
desert, wetland or coastal area.
 The nature of the ecosystem is based on its geographical
features such as hills, mountains, plains, rivers, lakes,
coastal areas or islands. It is also controlled by climatic
conditions such as the amount of sunlight, the temperature
and the rainfall in the region. The geographical, climatic and
soil characteristics form its non-living (abiotic) component.
 Ecosystems are divided into terrestrial or landbased
ecosystems, and aquatic ecosystems in water. These form
the two major habitat conditions for the Earth’s living
organisms.

7. Structure of an Ecosystem
• An ecosystem has two components the biotic components consisting of
living things, and the abiotic portion, consisting of elements that are not
alive.
• The non living or abiotic constituents are said to include the following
category- inorganic and organic components of the environment or
habitat of the organism.
• The inorganic components of an ecosystem are carbon dioxide, water
nitrogen, calcium phosphate all of which are involved in matter cycle
(biogeochemical cycles).
• The organic components of an ecosystem are proteins, carbohydrates,
lipids and amino acids, all of which are synthesized by the biota (flora and
fauna) of an ecosystem and are reached to ecosystem as their wastes,
dead remains etc. the climate 'microclimate' temperature, light soil etc.
are abiotic components of the ecosystems.
• The living or biotic organisms may be sub divided into producers,
consumers and decomposers.

8. Functions of an Ecosystem
• There are four primary groups of ecosystem
functions
(1) Regulatory functions
(2) Habitat functions
(3) Production functions
(4) Information functions

9. (1) Regulatory functions: This group of functions relates to the capacity of
natural and semi-natural ecosystems to regulate essential ecological
processes and life support systems through bio-geochemical cycles and
other biospheric processes. These regulatory functions provide many
services that have direct and indirect benefits to humans (i.e., clean air,
water and soil, and biological control services).
(2) Habitat functions: Natural ecosystems provide refuge and a reproduction
habitat to wild plants and animals and thereby contribute to the (in situ)
conservation of biological and genetic diversity and the evolutionary
process.
(3) Production functions: Photosynthesis and nutrient uptake by autotrophs
converts energy, carbon dioxide, water and nutrients into a wide variety of
carbohydrate structures which are then used by secondary producers to
create an even larger variety of living biomass.
(4) Information functions: Most of human evolution took place within the
context of an undomesticated habitat, natural ecosystems contribute to
the maintenance of human health by providing opportunities for
reflection, spiritual enrichment, cognitive development, recreation and
aesthetic experience.

10. Components of ecosystem
1. Producers- Organism which produces its own food by
using energy from the sun
2. Consumers- Organism which doesn’t make its own food,
but gets it from eating plants or other animals
3. Decomposers - Organism which digests or breaks down
formerly living material
1. Producers- are those organisms that use photosynthesis
to capture energy by using sunlight, water and carbon
dioxide to create carbohydrates, and then use that energy
to create more complex molecules like proteins, lipids and
starches that are crucial to life processes. E.g. Mostly
green plants, are also called autotrophs

11. 2. Consumers -Consumers are organisms (including
humans) that get their energy from producers,
regarding the flow of energy through an
ecosystem. For example, producers, (such as
plants), make their own food by the process of
photosynthesis.
An organism ate this plant, than it would be a
primary consumer. The animal that eats this
animal is known as the secondary consumer.
Scientifically, all consumers are either
herbivores, carnivores, omnivores or detrivores
(decomposers and other organism that break
down organic matter). These 'orders' are known
as trophic levels.

12. 3. Decomposers -Decomposers eventually convert
all organic matter into carbon dioxide (which they
respire) and nutrients. This releases raw nutrients
(such as nitrogen, phosphorus, and magnesium)
in a form usable to plants and algae, which
incorporate the chemicals into their own cells.
This process resupplies nutrients to the
ecosystem.
By breaking down dead material, they provide
the nutrients that other organisms need to
survive. As decomposers feed on dead organisms,
they leave behind nutrients. These nutrients
become part of the soil. Therefore, more plants
can grow and thrive.

13. Ecological Pyramids
• The trophic structure and function at successive trophic
levels, i.e. producers - herbivores - carnivores, may be
shown graphically by means of ecological pyramids where
the first or producer level constitutes the base of the
pyramid and the successive levels or the tiers making the
apex.
• The graphic expression of the trophic structure and
function at successive trophic level is referred as
“Ecological Pyramids”.
• Ecological Pyramids are of three types; i) Pyramid of
numbers refers to number of individual organisms at each
level. ii) Pyramid of biomass refers to total dry weight of
total amount of living matter iii) Pyramid of energy shows
the rate of energy flow/productivity at successive energy
level.

14. • The pyramids of
numbers and biomass
may be upright or
inverted depending
upon the nature of the
food chain in the
particular ecosystem,
whereas pyramids of
energy are always
upright
Tertiary consumers
(Carnivores)
Secondary consumers
Primary consumers
(Herbivores)
Producers

15. Pyramid of numbers
• It shows the relationship between
producers, herbivores and carnivores at
successive trophic level in terms of their
numbers. In grassland ecosystem,
producers are maximum in number.
• This number then shows a decrease
towards apex as the primary
consumer/herbivore are lesser in
number than producers and tertiary
consumers are least in number. So
pyramid becomes upright.
• But in forest ecosystem, producers are
lesser in number, which forms the base
of pyramid. Herbivores - fruit/eating
birds, elephants, deers etc. are more in
number than producers. In parasitic food
chain, pyramids are always inverted.
Number of organisms gradually shows an
increase making the pyramid inverted.

17. Pyramids of Biomass
• In grassland and forest
ecosystems, the pyramid
of biomass shows an
upright position. But in
ponds and other aquatic
systems, producers are
small organisms and
biomass is also least. This
value shows an increase
towards the apex of the
pyramid and making the
pyramid inverted.

18. Pyramids of Energy
• Of the three types of ecological
pyramid, this energy of pyramid
gives the best picture of overall
nature of the system. It is a picture
of the rates of passage of food mass
through food chains. So it’s shape is
always upright. Because there is
always a gradual decrease in the
energy content at successive trophic
levels from the producers to various
consumer.
• The 10% law of Energy Flow in the
Ecosystem states that when energy
is transferred from one trophic
level to another, only 10% of it is
transferred to the next trophic
level.

19. Energy flow in the ecosystem
Energy flow is the flow of energy through living things
within an ecosystem. It is always unidirectional.
From energetics point of view it is essential to understand
for an ecosystem
(i) The efficiency of the producers in absorption and
conversion of solar energy.
(ii) The use of this converted chemical form of energy by
the consumers.
(iii) The total input of energy in form of food and its
efficiency of assimilation.
(iv) The loss through respiration heat, excretion etc.,
(v) The gross net production.

21. The energy flow takes place via the food chain and food web. During the
process of energy flow in the ecosystem, plants being the producers
absorb sunlight with the help of the chloroplasts and a part of it is
transformed into chemical energy in the process of photosynthesis.
• The chemical energy of food is the main source of energy required by all
living organisms. This energy is transmitted to different trophic levels
along the food chain. This energy flow is based on two different laws of
thermodynamics:
 First law of thermodynamics, that states that energy can neither be
created nor destroyed, it can only change from one form to another. E.g.
solar energy, can neither be created nor destroyed. It can only be
transferred from one system to another as from one form to another
form.
 Second law of thermodynamics, that states that as energy is transferred
more and more of it is wasted.
• The 10% law of Energy Flow in the Ecosystem states that when energy is
transferred from one trophic level to another, only 10% of it is
transferred to the next trophic level.

22. What Do You Understand by the Energy Flow?
• Animals can use energy in two forms: Radiant and fixed energy. Radiant energy
is the framework of electromagnetic waves, such as light. Fixed energy is
potential chemical energy tied up in different organic substances that can be
injured to discharge their energy content.
Organisms that can fix radiant energy can use inorganic substances to produce
organic molecules and are called autotrophs. Organisms that cannot obtain
energy from an abiotic source but depend on energy-rich organic molecules
synthesized by autotrophs are called heterotrophs.
Those who obtain energy from living organisms are called consumers, and
those who receive energy from dead animals are called decomposers.
• When the light energy spill on the green surfaces of plants, a part of it is
converted into chemical energy, which is kept in various organic products in the
green plants. When the herbivores eat plants as food and transform energy
into chemical energy accumulated in plant products into kinetic energy,
degradation of energy will occur through its conversion into hotness.
When herbivores are eaten up by carnivores of the foremost order (secondary
consumers), further degradation will occur. Similarly, when top carnivores feed
primary carnivores, again energy will be degraded.

23. Fig: Energy Flow in Ecosystem Diagram

24. Energy flow Models
• For a better understanding of the energy flow concept in an
ecosystem, there are two types of energy flow models:
Single-channel Energy Flow Model
 This model illustrates the uni-directional flow of energy.
 Whatever the energy captured by the green plants does not revert
back to solar input. As it moves progressively through the various
trophic levels, it is no longer applicable to the previous level.
 The system would crash if the primary source, the sun, were cut
off.
 There is a progressive decline in energy level at each trophic level.
So, the shorter the food chain, the greater would be the available
food energy.

26. Y-shaped or 2-channel Energy Flow Model
• E.P. Odum (1983) gave a generalized model of Y-shaped
or double channel energy flow
 It is applicable to both terrestrial and aquatic
ecosystems. In this energy model, one arm represents
the herbivore food chain and the other arm represents
the decomposer (detritus) food chain.
 The primary producers (green plants) are entirely
different for each arm.
• This model also indicates that two food chains are in
fact, under natural conditions, not completely isolated
from one another.
(i) It conforms to the basic stratified structure of an
ecosystem.
(ii) It separates the eating and detritus food chains in
both time and space.
(iii) Micro consumers and macro consumers differ
greatly in size and metabolic relations.

27. Y-shaped energy flow model

28. UNIVERSAL ENERGY FLOW MODEL
• E.P. Odum (1968) gave
Universal Energy Flow
Model, which represents the
basis for a general
explanation of ecosystem
trophic flows. The model can
be applied to any living
component, whether it is
plant, animal,
microorganism, individual,
population or trophic group.
Such a model may depict
food chain as already shown
in previous models or the
bioenergetics of an entire
ecosystem.

29. Food Chain and Food Web
• A food chain explains which organism eats
another organism in the environment. The food
chain is a linear sequence of organisms where
nutrients and energy is transferred from one
organism to the other.
• A food chain refers to the order of events in an
ecosystem, where one living organism eats
another organism, and later that organism is
consumed by another larger organism. The flow
of nutrients and energy from one organism to
another at different trophic levels forms a food
chain.

31. • The food chain consists of four major parts, namely:
• The Sun: The sun is the initial source of energy, which provides
energy for everything on the planet.
• Producers: The producers in a food chain include all autotrophs
such as phytoplankton, cyanobacteria, algae, and green plants. This
is the first stage in a food chain. The producers make up the first
level of a food chain. The producers utilise the energy from the sun
to make food.
• Consumers: Consumers are all organisms that are dependent on
plants or other organisms for food. This is the largest part of a food
web, as it contains almost all living organisms. It includes herbivores
which are animals that eat plants, carnivores which are animals that
eat other animals, parasites that live on other organisms by
harming them and lastly the scavengers, which are animals that eat
dead animals’.
• Decomposers: Decomposers are organisms that get energy from
dead or waste organic material. This is the last stage in a food chain.
Decomposers are an integral part of a food chain, as they convert
organic waste materials into inorganic materials, which enriches the
soil or land with nutrients.

32. Food Web
• A food web is a detailed interconnecting diagram that shows the overall
food relationships between organisms in a particular environment. It can
be described as a "who eats whom" diagram that shows the complex
feeding relationships for a particular ecosystem.
• Types of Food Chain
• There are two types of food chains, namely the detritus food chain and
the grazing food chain. Let’s look at them more closely:
• Detritus food chain: The detritus food chain includes different species of
organisms and plants like algae, bacteria, fungi, protozoa, mites, insects,
worms and so on. The detritus food chain begins with dead organic
material. The food energy passes into decomposers and detritivores,
which are further eaten by smaller organisms like carnivores. Carnivores,
like maggots, become a meal for bigger carnivores like frogs, snakes and so
on. Primary consumers like fungi, bacteria, protozoans, and so on are
detritivores which feed on detritus.
• Grazing food chain: The grazing food chain is a type of food chain that
starts with green plants, passes through herbivores and then to
carnivores. In a grazing food chain, energy in the lowest trophic level is
acquired from photosynthesis.

34. Ecological Succession
• Ecological Succession is defined as “a series of changes in an
ecological system across time.” It can be defined simply as the
sequence of species colonisation of an ecosystem from a barren or
infertile piece of land.
Ecological Succession Causes
• 1. Initial or initiating causes– These causes include both biotic and
climatic. It has factors like erosion, wind, fire, natural disasters, etc.
These causes heavily affect the population of that locality.
•
2. Ecesis causes- These causes are also known as continuing causes.
These can modify the population to adapt to several conditions of
the environment. It includes several factors like aggregation,
competition, migration, etc.
•
3. Stabilising causes- These causes bring stability to the
communities. It has several factors like the nature of the climatic
condition of the area, fertility of land and abundance of availability
of minerals, etc.

35. Fig: Ecological Succession

36. Characteristics of Ecological Succession
The ecological succession has the following
characteristics:
 It is a systematic process.
 It involves changes in species structure and also
increases the diversity of species.
 The succession takes place due to changes in the
physical environment and population of the species.
 The changes that occur are directional and take place
as a function of time.
 Succession works in a stabilised ecosystem.
 The population of decomposer components becomes
significant.
 The changes are calculable.
 The simple food chains will be replaced by complex
food chains.

37. Types of Ecological Succession
(1) Primary succession-
It starts in a barren area, never having vegetation of any type where no living
organism ever existed. Some bare primary areas are the newly exposed
seafloor, igneous rocks, sand dunes, new cooled lava sediments, newly
submerged areas, etc. It usually takes several hundred to a thousand years for
establishing a biotic community depending upon the substratum and the
climate.
(b) Secondary succession-
It starts in areas that somehow lost all the living organisms that existed there.
Since some soil or sediment is present, succession is faster. Destruction of the
previous community can occur due to forest fire, flooded lands, landslides,
earthquakes, drought, overgrazed areas, storms, etc. Following such destruction,
the process of succession will occur again from the new environmental
conditions. It takes 50−100 years to complete a grassland and 100−200 years to
develop a forest.

38. (c) Cyclic Succession-
It is a pattern that takes place in an established
community by changing the structure of the
ecosystem on a cyclic basis.
(d) Autogenic Succession-
After biotic succession has begun, the existing
vegetation is held responsible for its own
replacement by the new communities by changing
the existing environmental condition. This
succession is known as autogenic succession.
(e) Allogenic Succession-
In allogenic succession, the existing community is
replaced by other external conditions and not by
existing vegetation itself.

40. Types of Successional Communities
There are three main types of successional communities:
• Pioneer community is the one that sets first in a barren area.
Examples include lichens on rock, phytoplankton and zooplanktons in
ponds. They survive in the most hostile environment.
• Climax community is the last community in biotic succession, which
is relatively stable and is in near equilibrium with the
environment of that area called a climax community. Example:
forests.
• Transitional or seral communities are the ones that follow the
pioneer community. Examples include bryophytes, herbs, shrubs in
xerosere, submerged, floating etc., in ponds. They contribute
maximum to the formation of a stable community.
The entire series of communities occurring in biotic succession is
called sere.
Seral stages or seral communities are individual transitional
communities.

41. Seral community: It is an intermediate stage of ecological
succession that advances towards the climax community. It
consists of simple food chains and food webs.
1) Xerosere or Xerarch succession – When succession takes place
in dry areas like a rock (lithosere), sand (psammosere) and saline
conditions (halosere).
2) Hydrosere or Hydrarch succession – When succession starts on
the aquatic habitat where water is plenty and progresses from
hydric to mesic conditions.
3) Lithosere: This ecological succession develops on bare rock
surfaces.
4) Psammosere: This ecological succession originates on the sand.
5) Halosere: The plant succession that begins on salty soil and saline
water.
6) Senile: This succession takes place on a dead matter of
microorganisms.
7) Eosere: It shows the development of vegetation in an era.

42. Stages of Ecological Succession
• Clements (1916)(1916) has discussed the process of ecological succession. This process
involves the following stages, which are as follows:
1. Nudation: Development of bare area or nudation without any form of life. It may be
caused due to several factors like volcanic eruptions, landslides, floods, erosion,
earthquake, forest fire, the spread of disease, etc.
2. Invasion: It is the successful establishment of a species in a barren area. The arrival of
reproductive bodies or propagules of various species and their settlement in the new
or bare area occurs by air, water, etc., known as migration. Adjustment of establishing
species with the prevailing conditions is known as ecesis. Then the individual species
are multiplied by reproduction and increase their numbers; this is called aggregation.
3. Competition and coaction: After aggregation, the individuals of a species compete with
other organisms for food, space and other resources. The intraspecific and
interspecific competition takes place along with interaction with the
environment. New invasion by plants and animals takes place.
4. Reaction: The modification of the environment through the influence of living
organisms on it is called reaction.
5. Stabilisation (Climax): The stage at which the final or climax community becomes more
or less stabilised for a longer time in that particular environment is known
as stabilisation.

44. Examples of Ecological Succession
• The examples of ecological succession are as follows:
 The volcanic island of Surtsey is located off the coast of
Iceland. In 1963, this island formed due to the eruptions of
the volcano. After the eruption, the ground was primarily
rocking. Fungi and mould started growing on the rock.
These began to break down the rock to form soil. Then the
small grasses begin to take root and start to grow. Following
smaller shrubs begin to grow. The small burrowing animals
moved in to disturb the soil as larger plants began to grow.
After several years, trees begin to take root and grow
where there was only rock.
 Tropical forests are examples of secondary succession in
which forests were cleared for timber and agricultural
needs. In these areas, the reestablishment took place at
varying speeds, and it took several years for a community
to be fully restored.

45. Importance of Ecological Succession
 It shows the way of the sequence of biotic
succession. Ecologists can immediately recognise
the seral stage of a biotic community in an area.
 It helps in knowing information about techniques
to be used during reforestation and afforestation.
 The knowledge of biotic succession is used to
prevent the growth of superiors in an area and
control the growth of one or more species.
 Protection of dams by preventing siltation and
occurrence of biotic succession.

46. Threats to biodiversity
1. Climate change
The release of greenhouse gases, like carbon dioxide and methane, when burning fossil fuels
for energy causes climate change. Not only does climate change involve an increase in average
global temperature, but it also results in unpredictable weather patterns. Climate change
threatens biodiversity through a variety of mechanisms and can cause species range shifts,
mismatched biotic interactions, sea level rise, and ocean acidification. Climate change can also
exacerbate droughts, drying out the habitats of species like the Sonoyta mud turtle.
2. Overexploitation of species
Humans have a long history of overhunting species to the point of extinction. Overexploitation
involves removing organisms at a faster rate than they can be replenished. Examples include
the poaching of elephants, unsustainable hunting for bush meat, overfishing, and
overcollection of slow-growing plants and fungi.
3. Extinction
It is the global loss of a species. Five mass extinctions have occurred in geological history, and
extinction rates were particular high during these events. Earth is currently experiencing a
sixth mass extinction, which is driven by human activities. In the 17th and 18th century the
dodo and Steller’s sea cow were hunted out of existence and many know the story of how the
passenger pigeon went from the most abundant bird in North America to disappearing forever
in 1914 due to large-scale harvesting.

47. 3. Pollution
Pollution is the release of harmful chemicals or other materials into the environment. Some
types of air pollution results in acid deposition and climate change. Nutrient pollution of
water bodies due to fertilizer overuse results in eutrophication. A startling statistic
underscoring the wide-reaching affects of pollution is that more than 430 species at the
time of their listing under the Endangered Species Act were described as being significantly
impacted by pollution. Marine plastic pollution alone has increased tenfold since 1980,
affecting at least 267 species, including sea turtles, seabirds, and many marine mammals.
4. Habitat loss
Destruction and loss of natural habitat is the single largest cause of biodiversity loss. Billions
of hectares of forests and grasslands have been cleared over the past 10,000 years for
conversion into agriculture lands, pastures, settlement areas or development projects.
Severe damage has been caused to wetlands thinking them to be useless ecosystems. The
unique rich biodiversity of the wetlands, estuaries and mangroves are under the most
serious threat today. The wetlands are destroyed due to draining, filling and pollution
thereby causing huge biodiversity loss.
Sometimes the loss of habitat is in installments so that the habitat is divided into small
and scattered patches, a phenomenon known as habitat fragmentation.

48. 5. Invasive Species
Invasive species are non-native organisms that, when introduced to an area out of its native
range, disrupt the community they invade. Non-native (exotic) refers to species occurring
outside of their historic distribution. Invasive species have been intentionally or
unintentionally introduced by humans into an ecosystem in which they did not evolve.
Invasive species can cause ecological and economic damage. They threaten other species
through competition for resources, predation, or disease.
In the United States, invasive species like the purple loosestrife (Lythrum salicaria) and the
zebra mussel (Dreissena polymorpha) have drastically altered the ecosystems they invaded.
Some well-known invasive animals include the emerald ash borer (Agrilus planipennis) and
the European starling (Sturnus vulgaris;

49. CONSERVATION OF BIODIVERSITY
The protection and management of biodiversity in obtaining sustainable development of
resources are called Biodiversity conservation.
“Protection, restoration, and management of biodiversity in order to derive sustainable
benefits for present and future generations.”. Or, it can also be defined as, “the totality of genes,
species, and ecosystems in a defined area.”
Biodiversity Conservation Methods
1. In-situ Conservation
2. Ex-situ Conservation
1.In Situ Conservation
In Situ Conservation refers to the preservation and protection of the species in their natural
habitat. In situ conservation involves the management of biodiversity in the same area where it
is found.
In situ, biodiversity conservation has many advantages:
It preserves species as well as their natural habitat.
It ensures protection to a large number of populations.
It is economic and a convenient method of conservation
It doesn’t require species to adjust to a new habitat.

50. Different methods of In-situ conservation include biosphere reserves, national parks, wildlife
sanctuaries, biodiversity hotspots, gene sanctuary, and sacred groves.
Biosphere Reserves
These are national governments nominated sites, large areas (often up to 5000 square km) of
an ecosystem where the traditional lifestyle and natural habitat of the inhabitants of that
ecosystem are protected. They are mostly open to tourists and researchers.
Example- Sundarban, Nanda Devi, Nokrek, and Manas in India.
National Parks
These are limited reserves maintained by the government for the conservation of wildlife as
well as the environment, Human activities are prohibited in national parks and they are solely
dedicated to the protection of natural fauna of the area. They mostly occupy an area of 100-
500 square km. There are a total of 104 national parks in India, right now. The national parks
may even be within a biosphere reserve. These are small reserves that are protected and
maintained by the government. Its boundaries are well protected, where human activities
such as grazing, forestry, habitat, and cultivation are restricted.
Example- Kanha National Park, Gir National Park, Nahargarh biological Park, and so on.

51. Wildlife Sanctuaries
Wildlife Sanctuaries are protected areas meant only for the conservation of wild animals. A
few human activities such as cultivation, wood collection, and other forest product collection
are allowed here, but they must not interfere with the conservation of the animals. Tourist
visits are also allowed in these areas. There are a total of 551 wildlife sanctuaries in India.
These are the places where only wild animals can be found.
Example- Ghana Bird Sanctuary, Abohar Wildlife Sanctuary, Mudumalai Wildlife Sanctuary, etc.
Biodiversity Hotspots
A biodiversity hotspot are the areas of conservation where there is strictly a minimum of 1500
species of vascular plants and a habitat that has lost its 70% cover. These are protected areas
for various purposes where the wildlife, inhabitant lifestyle, and domesticated plants and
animals are conserved. Tourist and research activities are allowed.
Example- The Himalayas, The Western Ghats, The North East, and The Nicobar Islands.
Gene Sanctuary
Gene sanctuary is a conservation area reserved only for plants. India has its only gene
sanctuary set up in Garo Hills of Meghalaya for the conservation of wild species of Citrus. Plans
to open more such sanctuaries are underway.
Sacred Groves
Sacred Groves are conserved areas for wildlife protected by communities due to religious
beliefs. It is mostly a part of the forest where its wildlife is given complete protection. Eg. Arvali
hills.

52. 2. Ex Situ Conservation
Ex Situ Conservation means conservation of life outside their natural habitat or place of
occurrence. It is the method in which part of the population or the entire endangered
species is taken from its natural habitat which is threatened and breeding and maintaining
of these species take place in artificial ecosystems. These artificial ecosystems could be zoos,
nurseries, botanical gardens, etc. The living environments are altered in these conservation
sites, so there are fewer survival struggles like scarcity of food, water, or space. Ex-situ
conservation of biodiversity consists of breeding and maintenance of endangered species
using artificial environments like zoos, nurseries, botanical gardens, gene banks, etc. The
competition for food, water, and space among the organisms is low.
Advantages of Ex Situ Conservation Include
Essential life-sustaining conditions like climate, food availability, veterinary care can be
altered and are under human control.
Artificial breeding methods can be introduced leading to successful breeding and creating
many more offspring of the species.
The species can be protected from poaching and population management can be efficiently
done.
Gene techniques can be applied to increase the population of the species and they can
again be reintroduced into the wild.

53. (i) National Bureau of Plant Genetic Resources (NBPGR) is located in New Delhi. Here
agricultural and horticultural crops and their wild relatives are preserved by cryo-
preservation of seeds, pollen etc. by using liquid nitrogen at a temperature as low as -
196°C. Varieties of rice, pearl millet, Brassica, turnip, radish, tomato, onion, carrot,
chilli, tobacco, poppy etc. have been preserved successfully in liquid nitrogen for
several years without losing seed viability.
(ii) National Bureau of Animal Genetic Resources (NBAGR) located at Karnal, Haryana. It
preserves the semen of domesticated bovine animals.
(iii) National Facility for Plant Tissue Culture Repository (NFPTCR) for the development
of a facility of conservation of varieties of crop plants/trees by tissue culture. This
facility has been created within the NBPGR.

54. Strategies for Biodiversity Conservation
Following are some of the important strategies for biodiversity conservation:
Conservation of all food varieties, timber plants, livestock, microbes, and agricultural
animals should be done.
Identification and conservation of all the economically important organisms should be
done.
Preservation of unique ecosystems should be done.
Efficient utilization of resources should be done.
Prevention of poaching and hunting of wild animals should be done.
Development of the reserves and protected areas should be done carefully.
Reduction in the levels of pollutants should be done on the environment.
Prohibition of deforestation should be followed.
Strict environmental laws should be followed.
Conservation of useful and endangered species of plants and animals should be done.