concept of ecosystem

1. JAIPUR NATIONAL UNIVERSITY
SEEDLING SCHOOL OF NURSING
PREPARED BY-
(Prof.) Dr. Rahul Sharma
HOD of Mental Health Nursing
Ph.D. Coordinator
Seedling School of Nursing

2. CONCEPT OF
ECOSYSTEM

3. Introduction of
ecosystem
Species
components
Stratification
Trophic
organisation—
relationship of
food between
various layers
Nutrients—
required for
living
organisms

4. Introduction of
ecosystem
Biotic componentsThis
comprises of all the living
organisms

5. The autotrophs
These are green plants and certain photosynthetic
or chemosynthetic bacteria which can convert the
light energy of sun into potential chemical energy in
the form of organic compounds needed by plants
for their own growth and development
Oxygen is produced as a by-product of
photosynthesis, needed by all living organisms for
respiration
These green plants are also known as producers
because they produce food for all the other
organisms

6. THE HETEROTROPHS
Macroconsumers

7. The
heterotrophs
Climate regime: Precipitation,
temperature, light, and other physical
factors
Inorganic substances: Elements such
as C, N, H, O, P, S, etc., involved in
material cycles
Organic Compounds: Carbohydrates,
proteins, lipids and humic substances
that link the abiotic components with
the biotic components

8. Function of
ecosystem
The function of the ecosystem is to allow flow of
energy and cycling of materials which ensures
stability of the system and continuity of life
These two ecological processes including
interaction between the abiotic environment and
the communities
For the sake of convenience, the ecosystem
dynamics may be analysed in terms of the
following

9. Producers of
ecosystem
Producers or autotrophs are organisms that
produce food for themselves and other
organisms
Algae are protists, as a particular type of single-
celled organism with a cellular structure
different from that of plants can also make their
food
Producers make food not only for their
reproduction and growth but also for nourishing
the rest of the ecosystem

10. Types of Producers
Phototrophs – Phototrophs are the
ones that use the energy from the sun
to convert carbon dioxide into
carbohydrates
Chemotrophs – Chemotrophs go
through a similar process, except that
the energy source is inorganic
oxidation and reduction reactions

11. Characteristics of Producers
Producers can make their food
They are found at the lowest trophic level in an
ecosystem and serve as the basis for the survival of
higher animals
Producers have a type of pigment in their bodies called
chlorophyll
These producers can also bind solar energy to their
bodies
They release oxygen while making food
Producers occupy a large part of the world’s biomass

12. Examples of
Producers
Plants Cyanobacteria
Phytoplankton

13. Consumers of
Ecosystem
Consumers or heterotrophs are
organisms that feed on other
organisms to obtain energy
Animals and birds are the most
commonly known consumers and the
lesser-known ones are fungi
The bacteria in the soil act as
decomposers, consuming dead organic
matter and breaking it down to be
recycled into the ecosystem

14. Types of
Consumers
Primary consumers –
Herbivores that only
eat plants,
vegetables, grass, or
other vegetation
types are the majority
of primary
consumers
Secondary
consumers –
Secondary
consumers are
organisms that eat
other consumers or
organisms
Tertiary consumers –
Tertiary consumers
are also called
omnivores
Decomposers –
Decomposers feed
on the remains of
dead plants and
animals

15. Characteristics of
Consumers
Consumers cannot prepare their food
They breathe oxygen and emit carbon dioxide into
the environment during respiration
The energy they obtain from food is used for a
variety of physiological functions
Consumers are located in the second to highest
trophic levels in the ecosystem
Consumers are only a small part of the world’s
biomass

16. Examples of
Consumers
Primary consumers: Sheep,
cows, and goats
Secondary consumers: Lion,
tiger, jaguar, and puma
Tertiary consumers: Humans
Decomposers: Bacteria and fungi

17. Energy flow in
Ecosystem
The behaviour of energy in ecosystem can be
conveniently termed as energy flow because of
unidirectional energy transformations
Total energy flow that constitutes the energy
environment has already been dealt in detail,
and now we take up the study of that portion of
the total energy flow that passes through the
biotic components of the ecosystem
According to the first law, the law of
conservation of energy, in a closed system, no
energy comes in or escapes out and not created
or destroyed but may be altered from one form
to another

18. Energy flow in
Ecosystem
The second law of thermodynamics, the
law of entropy, states that there is always
a tendency for increase in entropy or
degradation from a concentrated to a
dispersed form leading to dissipation of
heat
Energy flow is based on two different
laws of thermodynamics: The first law of
thermodynamics states that energy can
neither be created nor destroyed

19. Figure of Energy flow in Ecosystem
Ecological SuccessionEcological succession is the
phenomenon or process by which an ecological
community undergoes more or less orderly and
predictable changes following disturbance or initial
colonization of new habitat
• Soil is already present, so there is no need for pioneer
species
• Seeds, roots and underground vegetative organs of
plants may still survive in the soil

20. Food Chain
The transfer of food energy from the source in plants through
a series of organisms with repeated stages of eating and
being eaten is known as the food chain
The green plants, in the food chain, occupy the first trophic -
the producer level, the herbivores that eat the plants the
second trophic - the primary consumer level, the carnivores
that eat the herbivores the third trophic - the secondary
consumer level and perhaps even a fourth- the tertiary
consumer level
Some organisms are omnivores that eat the plant as well as
animals at their lower level in the food chain and they may
occupy more than one trophic level in the food chain

21. Grazing food chain
The consumers which utilise the living
plant parts as their food or energy source
constitute the grazing food chain
The food chain, thus begins from a green
plant base
It is common in the terrestrial and aquatic
ecosystems where most of the primary
production is edible by herbivores

22. Parasitic food chain
It also begins from a green plant
base and goes to herbivores,
which may be the host of a huge
number of lice living as
ectoparasites

23. Detritus food
chain
The food chain goes from dead organic
matters of decaying animal and plant bodies
to the microorganisms and then to detritus
feeding organisms and their predators is
known as “detritus food chain”
Soil organisms are thus less dependent on
direct solar energy and depend chiefly on the
influx of organic matter produced in another
system
Mangrove leaves, through detritus food chain
make substantial contribution to the food
chain that is upto 90% of the stored energy in
the dead organic material is consumed
through detritus food chain

24. Food Web and
Ecological Pyramid
All processes in this world, whether living or
non-living, need energy
Living organisms are capable of producing
energy or getting it through predation
It is also required for supporting voluntary and
involuntary actions of the human body and
other multiple processes within the body like
reproduction, cell division, metabolism,
digestion, circulation, excretion, and much more

25. What is Food Web?
There are unique interactions
and relationships which are
involved in the transportation
of energy
The energy, once produced
and captured, is distributed
throughout the various living
organisms
This transfer of energy is
termed as the food web

26. Ecological pyramid
It can be observed that these pyramids are in the
shape of actual pyramids, with the base being the
broadest, which is covered by the lowest trophic
level, i.e., producers
The next level is occupied by the next trophic level,
i.e., the primary consumers and so on
All the calculations for construction of these types
of ecological pyramids must take into account all
the organisms in a particular trophic level because
a sample space of a few numbers or a few species
will end up giving a huge level of errors

27. Types of
Ecological
Pyramid
The pyramid of numbers is usually upright
except for some situations like that of the
detritus food chain, where many organisms
feed on one dead plant or animal
The pyramid of biomass is also upright except
for that observed in oceans where large
numbers of zooplanktons depend on a
relatively smaller amount of phytoplankton
Pyramid of energy is the only type of
ecological pyramid, which is always upright as
the energy flow in a food chain is always
unidirectional

28. Importance of
Ecological Pyramid
•The importance of ecological
pyramid can be explained in the
following points: •They show the
feeding of different organisms in
different ecosystems

29. Limitations of
Ecological Pyramid
•More than one species may occupy
multiple trophic levels as in case of the
food web
Thus, this system does not take into
account food webs
•The saprophytes are not considered
in any of the pyramids even though
they form an important part of the
various ecosystem

30. Types of
Ecosystems
An ecosystem can be as small as an oasis in a
desert, or as big as an ocean, spanning
thousands of miles
There are two types of ecosystems: Aquatic
Ecosystem Terrestrial ecosystems are
exclusively land-based ecosystems
There are different types of terrestrial
ecosystems distributed around various
geological zones

31. Forest Ecosystem
A forest ecosystem consists of several
plants, particularly trees, animals and
microorganisms that live in
coordination with the abiotic factors of
the environment
Forests help in maintaining the
temperature of the earth and are the
major carbon sink

32. Grassland
Ecosystem
In a grassland
ecosystem, the
vegetation is dominated
by grasses and herbs
Temperate grasslands
and tropical or savanna
grasslands are examples
of grassland ecosystems

33. Tundra
Ecosystem
Tundra ecosystems are devoid of
trees and are found in cold
climates or where rainfall is scarce
These are covered with snow for
most of the year
Tundra type of ecosystem is found
in the Arctic or mountain tops

34. Desert
Ecosystem
Deserts are found throughout
the world
These are regions with little
rainfall and scarce vegetation
The days are hot, and the
nights are cold

35. Aquatic Ecosystem
Aquatic ecosystems are
ecosystems present in a body of
water
These can be further divided into
two types, namely: Freshwater
Ecosystem

36. Freshwater
Ecosystem
The freshwater ecosystem is an
aquatic ecosystem that includes
lakes, ponds, rivers, streams and
wetlands
These have no salt content in
contrast with the marine
ecosystem

37. Marine Ecosystem
The marine ecosystem includes
seas and oceans
These have a more substantial
salt content and greater
biodiversity in comparison to the
freshwater ecosystem

38. Forest
Ecosystem
Study of interdependent relations of
flora and fauna in a forest is termed as
Forest Ecosystem
In such ecosystems, the entire
interaction happens naturally between
all abiotic and biotic components
The ecological potential of any species
depends on their habitat requirements
like temperature, climate, frugality, their
lifespan and, reproducing capacity

39. Forest Biome
Forests can be divided into 5
main categories, depending on
the types of trees found in them
They are

40. 1) Coniferous
Forest
As the name suggests, the
trees found in these forests
mainly consists of cone-
bearing trees like the spruce,
pine, fir, and hemlock
These are found mostly in the
northern parts of North
America, Asia, and Europe

41. 2) Deciduous
Forest
The trees of these forests are
broadleaved and are shed between
late summer to early autumn
The leaves are usually green but later
acquires yellow, red and orange
colours gradually
These forests are found in America,
Western and Central Europe, and
Northeastern Asia where the winters
are cold and summers are warm

42. 3) Mixed Forests
Deciduous and Coniferous trees
as both types constitute mixed
forests, which are mostly found in
mountainous areas
These are found almost every
part of the world

43. 4)
Mediterranean
Forests
They are also called scrublands as
its temperature is suitable for short
oaks and pines to grow
The Mediterranean Forest
contains a wide variety of
wildflowers and insect-eating birds
This forest is also termed as
“maquis”

44. 5) Tropical
Rainforest
These forests are situated in the
areas with hot temperatures like
South America, Africa, Asia and
Australia
Thus, they are called Tropical and
due to continuous rainfall throughout
the year, they are called Rainforests
It is a habitat for various insects,
colorful birds and mammals

45. Grassland
Ecosystem
The grassland ecosystem is called the largest
biomes on earth and it covers about 10 per cent
of the earth’s surface
It is mainly found where rainfall is about 15-75
cm per year, not enough to support a forest, but
more than that of a true desert
The Grassland ecosystems are called by various
names in several regions, such as pampas in
South America, Veldt in South Africa, Steppes in
Europe and Asia, and Downs in Australia

46. Types of Grassland
ecosystems
This ecosystem contains five
types of grasslands that are:
Temperate Grasslands

47. Importance of
grassland
Ecosystem
A Grassland Ecosystem is a mixture of small
herbs, weeds, grass, trefoil, dicotyledonous,
shrubs and other leguminous species,
contributing to a high degree of preservation
The economic importance of the grassland
ecosystem is that it serves in the maintenance
of the crop of many domesticated and wild
herbivores such as cattle, sheep, goats, ass,
pigs, horses, mules, camels, deer, zebras, etc
These animals provide food, milk, wool and
transportation to man

48. Functions of Grassland Ecosystem
•Energy flow through the food chain •Nutrient cycling
•Homeostasis or feedback control mechanisms •To
reduce the leaching of minerals due to low rainfall

49. Desert
Ecosystem
Deserts are barren areas of land
characterised by extremely high or low
temperatures, with low rainfall and
scarce or no vegetation
Deserts are examples of terrestrial
ecosystems, which are found
throughout the world
Neither all deserts are flat, nor do all
deserts have cacti or oases

50. Types of deserts
Deserts are arid regions with
especially low or high
temperatures and limited
vegetation
Based on the climate condition,
deserts are classified into two
types – hot deserts and cold
deserts

51. Hot desert
The Sahara is known as the world’s largest
desert, covering over 8.54 million square
kilometres
Sahara Desert is located in tropical regions,
which are 1,000 m above sea level
It covers a huge part of North Africa, and
eleven other countries – Algeria, Tunisia,
Egypt, Mali, Chad, Niger, Western Sahara,
Sudan, Mauritania, Libya and Morocco

52. Cold desert
The cold and dry desert
of Ladakh is famously
known as the cold desert
of India
It is found in the high
altitudes of the
temperate regions, which
lie in the Great
Himalayas within the
eastern parts of Jammu
and Kashmir and located
in the western Himalayas
region, within Himachal
Pradesh in North India
The altitude in Ladakh
ranges from about 3,000
m in Kargil to 8,000 m in
Karakoram

53. Features and Desert
Habitats
The most determining feature of this
terrestrial ecosystem is the amount of
precipitation it receives, which is the
least compared to other ecosystems
A desert is an arid or bone-dry region of
the landscape where there is little
precipitation, hence living conditions are
unfavourable for both flora and fauna
This ecosystem can exist from the Arctic
to the tropics

54. Aquatic Ecosystem
An aquatic ecosystem includes a group
of interacting organisms which are
dependent on one another and their
water environment for nutrients and
shelter
Examples of aquatic ecosystem
include oceans, lakes and rivers
Different types of aquatic ecosystems
are as follows

55. Freshwater Aquatic
Ecosystem
Freshwater involves lakes, ponds,
rivers and streams, wetlands,
swamp, bog and temporary pools
Freshwater habitats are classified
into lotic and lentic habitats
Water bodies such as lakes, ponds,
pools, bogs, and other reservoirs are
standing water and known as lentic
habitats

56. Lotic Ecosystems
They mainly refer to the rapidly flowing
waters that move in a unidirectional way
including the rivers and streams
These environments harbour numerous
species of insects such as beetles,
mayflies, stoneflies and several species of
fishes including trout, eel, minnow, etc
Apart from these aquatic species, these
ecosystems also include various
mammals such as beavers, river dolphins
and otters

57. Lentic Ecosystems
Lakes and ponds are the main examples
of Lentic Ecosystem
The word lentic mainly refers to stationary
or relatively still water
These ecosystems are home to algae,
crabs, shrimps, amphibians such as frogs
and salamanders, for both rooted and
floating-leaved plants and reptiles
including alligators and other water
snakes are also found here

58. Wetlands
Wetlands are marshy areas and are
sometimes covered in water which has
a wide diversity of plants and animals
Swamps, marshes, bogs, black spruce
and water lilies are some examples in
the plant species found in the wetlands
The animal life of this ecosystem
consists of dragonflies and damselflies,
birds such as Green Heron and fishes
such as Northern Pike

59. Marine Aquatic
Ecosystem
Marine ecosystem covers the largest surface
area of the earth
Two third of earth is covered by water and they
constitute of oceans, seas, intertidal zone,
reefs, seabed, estuaries, hydrothermal vents
and rock pools
The marine ecosystem is more concentrated
with salts which make it difficult for freshwater
organisms to live in

60. Ocean
Ecosystems
Our planet earth is gifted with the five major
oceans, namely Pacific, Indian, Arctic, and the
Atlantic Ocean
These oceans serve as a home to more than
five lakh aquatic species
Few creatures of these ecosystems include
shellfish, shark, tube worms, crab small and
large ocean fishes, turtles, crustaceans, blue
whale, reptiles, marine mammals, seabirds,
plankton, corals and other ocean plants

61. Coastal Systems
The coastal ecosystems have a different
structure, and diversity
A wide variety of species of aquatic plants and
algae are found at the bottom of the coastal
ecosystem
Plants and animals in an aquatic ecosystem
show a wide variety of adaptations which may
involve life cycle, physiological, structural and
behavioural adaptations

62. Bibliography
1.http://ecoursesonline.iasri.res.i
n/mod/page/view.php?
id=89586