An ecosystem consists of biotic and abiotic components that interact. Energy from the sun is absorbed by producers like plants through photosynthesis and transfers through consumers to decomposers. Organisms fill different roles as producers, primary consumers, secondary consumers, decomposers and form complex food webs. Nutrient cycles like carbon and nitrogen allow recycling of essential elements. Limiting factors shape ecosystem structure and function.

1. ECOSYSTEMS

2. What is an Ecosystem
• An ecosystem is made up of
biotic (Living) as well as
abiotic (Non-living) factors.
• The interactions of living
organisms with their physical
environment builds up the
ecosystem and is designated as
the bioshphere or ecosphere
• Examples: a pond, a forest, an estuary, a grassland

3. Biotic Factors

4. Abiotic Factors

5. ECOLOGY
• ECOLOGY IS A
SCIENTIFIC
STUDY OF THE
INTERACTION
THAT
DETERMINE
THE
DISTRIBUTION
AND
ABUNDANCE OF
ORGANISMS

6. Ecology: The scientific study of interactions
between different organisms and their
environment or surroundings

7. The term Ecosystem was proposed by
Sir Arthur George Tansley FLS, FRS in
1935 .
He was an English botanist and a
pioneer in the science of ecology.
He is Educated at High gate School,
University College London and Trinity
College, Cambridge,
Born: August 15, 1871, London, United
Kingdom
Died: November 25, 1955,
The ecosystem as the
system resulting from
integration of all living and
nonliving factors of the
environment.
He concluded that
ecosystem includes not only
the organism complex but
also a whole complex of
physical factors forming the
environment

8. TYPE OF ECO SYSTEM
• NATURAL ECO SYSTEM
• ARTIFICIAL ECOSYSTEM

9. NATURAL
1.Terrestrial ecosystems (grasslands, forests, desert ecosystems)
2.Aquatic ecosystem
a.Lentic (Stagnant water) like lake, ponds etc.
b.Lotic (Flowing water) like river, ocean, sea, etc.
•Freshwater Ecosystem (Stream, Spring, River, Lakes, Ponds, Pools,
Swamps, Ditches)
•Marine Ecosysem (sea, Estury,Ocean)
ARTIFICIAL
1.Some ecosystems managed by man are called Artificial ecosystem
( The crop land, garden, aquarium, park, kitchen garden.)

10. STRUCTURE & FUNCTION OF ECOSYSTEM
• Two important aspects of the ecosystem are
Architectural (Structural) and Working process
(Functional)
• 1.The composition of biological community including
species numbers, biomass, life history and distribution
in space
• 2.The quantity and distribution of nonliving materials
like nutrients, water.
• 3.The condition of existence such as temperature, light
etc.

11. STRUCTURE AND FUNCTION OF
ECOSYSTEM
• Two important aspects of the ecosystem are working
process (Functional)
• 1.The rate of energy flow ie., production and respiration
rates of the community
• 2.The rate of material (nutrient) cycles
• 3.Biological regulation including both regulations of
organisms by environment (Photoperiodism) and
regulation of environment by the organisms (Nitrogen
fixing organisms)

12. An ecosystem consists of two main components
Abiotic or Non-living components.
1. Inorganic substances
2. Organic compounds
3. Climatic factors
Biotic or Living components.
1. Autotrophs or Producers
2. Heterotrophs or Consumers
3. Decomposers or Saprotrophs

13. Structural aspects of ecosystem
ABIOTIC
• light
• Moisture
• Water
• Salinity
• Oxygen supply
• Soil
BIOTIC
• Trees
• Flowers
• Cats
• Dogs
• you

14. Sunlight
Sunlight is one of the principle energy
source for life on earth.
Use light or chemical energy to make food
1. Plants
2. plant-like protists (algae)
3. Bacteria
Photosynthesis-use light energy to
convert carbon dioxide and water into
oxygen and carbohydrates
( 6CO2 + 6H2O 6O2 + C6H12O6)
Chemosynthesis—performed by
bacteria, use chemical energy to
produce carbohydrates

15. Most energy comes
from the sun
• Plants, also called producers, convert energy from
the sun into food through a process called
photosynthesis.
• Photosynthesis is a process which uses water,
carbon dioxide, and sunlight energy to make
sugars. Plants do this in special cells called
chloroplasts. These are usually green because of
a pigment called chlorophyll. Most
photosynthesis happens in a plant's leaves, which
is why they are green.
• When an animal eats a plant, some of the energy
gets passed from the plant to the animal. A food
web shows this passage of energy, by showing
what animals can eat what, and who gets eaten by
who

16. MOISTURE
• The amount of moisture in environment varies
from desert areas to lakes and oceans.
•
• All forms of life on earth requires water to live
and the abundance and the quality of water are
the main factor to determine what kind of
communities will develop in the environment
• In land environment the amount of available
moisture is a function of precipitation, humidity
and the evaporation rate
• In water environment the types of communities
depends of the availability of water

17. Water
• Three form of Water Solid, Liquid or gas.
• Large amount of heat is needed to change
the phases for this reasons temperature
changes in water tend to occur slowly and
changes in air temperature

18. Salinity
(Salt water)
• Ocean contains 3.5% of salts.
• The salt content is the major factor to
determine what organisms will be found
there.

19. Fresh water organisms
both plants and animals
have a salt concentration
in their body fluids and
inside their cells higher
than that of the water in
which they live.
Some salt water
organisms have salt
concentration in their
bodies or cells almost
identical to that of ocean
water

20. Oceans
The ocean has many kinds of ecosystems. The
oceans are so large that the conditions in one
part of the ocean are very different from the
conditions in another part of the ocean.
Some ocean ecosystems are close to land and
receive more sunlight. In the deep sea, sunlight
cannot reach the ocean floor and the
ecosystems are quite different.
The deep-sea anglerfish has a body
that glows in the dark. It has a rod
that glows and dangles in front of
its mouth which attracts prey.

21. Estuaries
Intermediate salt
concentration.
Salt and fresh
water meet
Estuaries are places
where rivers flow into
the ocean. Estuaries
have water that is
saltier than a river, but
not as salty as the
ocean.

22. Salt Marshes
Salt marshes are grassy
wetlands at the edges of
estuaries. South Carolina
has many estuaries and salt
marshes and is home to
many living things such as
fish, blue crabs, shrimp, and
oysters.

23. Dissolved gases: Oxygen
• Condition:
– Marine animals need
oxygen to survive
– Plants and animals
need oxygen for
respiration
• Respiration is a
series of complex
biochemical reaction.
• Glucose broken down by
biological catalyst called enzymes
The energy released is utilized by
the cells.
If oxygen is available the
material is fully broken
down to CO2,H20 and
Energy

24. Soil
Soil is not an entirely abiotic component of
an ecosystem but rather is a mixture of living
and non living materials.

25. Soil
HUMUS

26. PRODUCERS CONSUMERS AND
DECOMPOSERS
Energy flows through an ecosystem in one
direction—from the sun or inorganic compounds
to autotrophs (producers) and then to
heterotrophs (consumers) Finally to
decomposers

27. How do organisms interact and depend
on one another in an ecosystem?
A food chain shows how organisms get
their food. The first organism in a food
chain is a producer; consumers or
decomposers follow
Producer consumer decomposer

28. Consumers
Organisms that rely on other organisms for their
energy and food supply.
There are several classes of consumers depending
upon their food sources
1.Herbivores- are primary consumers they feed directly on producers
and obtain energy by eating only plants
2.Carnivores – Secondary consumers feed only on secondary
consumers
3. Omnivores: Tertiary consumers eat both plants and animals

29. Predator - Prey
• Lions and zebras, for example
• One hunts and kills, the other gets killed and eaten

30. Predation—one organism captures and feeds on
another organism
1. Predator—one that does the killing
2. Prey—one that is the food

31. Scavengers
• Scavengers are animals that do not
kill for a meal, but pick on “leftovers”
from other animals
• Hyenas, vultures, crows, racoons,
and some bears are scavengers

32. Decomposers
• Decomposers or detritivores are organisms that
degrade or decompose dead or organic material
in simpler molecules
• Fungi and bacteria are decomposers

33. Decomposers
Detritus feeder
such as crabs,
carpenter ants,
termites,
earthworms and
wood beetles,
extracts nutrients
from partly
decomposed
organic matter
End products
• Methane gas
• Ethyl alcohol
• Acetic Acid
• Hydrogen sulphide

34. Food Chain—series of steps in which organisms
transfer energy by eating and being eaten
1. Arrows go in the direction of how energy is
transferred
2. Start with producer and end with top consumer
or carnivore
Ex: grass cricket frog
raccoon

35. C. Food Web-network of food chains within an
ecosystem
Hawks
Weasels Raccoons
Mice
Grass

36. Trophic Levels—each step in a food chain or food web
1. Level 1—Producers (autotrophs)
2. Level 2—Primary Consumers (herbivores)
3. Level 3—Secondary Consumers
(carnivores or omnivores)
4. Level 4—Tertiary Consumers
(carnivore—usually top carnivore)

37. Ecological Pyramids
Diagram that shows the relative amount of energy or organisms
contained within each trophic level of a food chain or food web

38. Energy
Pyramid
Biomass
Pyramid
100%
10%
1%
0.1%

39. Represents amount of energy
available at each level as well
as amount of living tissue—
both decrease with each
increasing trophic level
Energy and Biomass Pyramid (together)

40. Pyramid of Biomass or Numbers
Just like energy, biomass decreases at each level, because there is only
enough energy at that level to support the biomass found there.

41. The first level always
has autotrophs
The second level has
primary consumers –
heterotrophs, herbivores.
The last level contains secondary,
tertiary consumers – heterotrophs,
carnivores, omnivores
10% of the energy from the 1st
trophic level is available to the
2nd trophic level
90% of the energy at any given trophic level is used for growth
and reproduction, and is eventually lost as heat.
Energy is eventually lost as heat on the top of the pyramid

42. Heavy metals
Ex: mercury
Pesticides
Ex: DDT
(dichlorodiphenyltri
chloroethane)
Organochlorides:
Ex: PCBs

43. V. Ecological Interactions between organisms
A. Competition—when two organisms of the same
or different species attempt to use an ecological
resource in the same place at the same time.
Ex: food, water, shelter

44. Monkeys compete
with each other and
other animals for
food.
Rams compete with
each other for
mates.

45. Until Americans introduced gray squirrels into parts of
England in the early 20th century, red squirrels had been the
only species of squirrel in the country. The gray squirrels were
larger and bred faster and successfully competed for
resources. Within a couple years of overlap in an area, the red
squirrels disappeared.

46. B. Niche-the ecological niche involves both the
place where an organism lives and the roles that an
organism has in its habitat.
Example: The ecological niche of a sunflower growing in the
backyard includes absorbing light, water and
nutrients (for photosynthesis), providing shelter and
food for other organisms (e.g. bees, ants, etc.), and
giving off oxygen into the atmosphere.

47. The ecological niche of an organism depends not
only on where it lives but also on what it does. By
analogy, it may be said that the habitat is the
organism’s “address”, and the niche is its
“profession”, biologically speaking.
Worm’s
Niche
“Address”—Soil, Ground,
etc.
“Profession”– Mix-up
soil

49. D. Symbiosis—any relationship in which two
species live closely together
1. Mutualism—both species benefit (WIN-WIN)
a. Ex: insects and flowers

50. 2. Commensalism-one member of the association
benefits and the other is neither
helped nor harmed.
(WIN-0)
Example: barnacles on a whale

51. Commensalism
The Remora fish attaches
to the shark and gets a free
ride.
Birds build nests in trees.

52. 3. Parasitism-one organisms lives on or
inside another organism (host) and harms
it.
The parasite obtains all or part of its
nutritional needs from the host. (WIN-
LOSE)
Example: fleas on a dog

53. Parasitism
Wasp eggs on back
of caterpillar.
Mosquito biting a
human.
Sea lampreys feed
on fluids of other
fish.

54. Mutualism, Commensalism or Parasitism

55. Food
Chain
• A food chain describes
a single pathway that
energy and nutrients
may follow in an
ecosystem. There is one
organism per trophic
level, and trophic levels
are therefore easily
defined. They usually
start with a primary
producer and end with a
top predator.
• Here is an example of a
food chain:
phytoplankton →
zooplankton → fish →
squid → seal → Orca
(Killer whale)

56. Secondary, tertiary, quaternary
consumers
• Secondary consumers are those that eat primary consumers, tertiary
consumer secondary and so on…
• These consumers are either carnivores (sometimes insectivores or egg
eaters), or ominvores
The extinct oviraptor (egg thief)

57. FOOD
WEB
A combination of
different food chains is
called a food web.
Can you identify
all the different
organisms and
their levels?

58. Matter Cycles

59. Parasite - Host
• Fleas and dogs for example
• The parasite harms the host
and benefits from the
relationship. The host is
harmed, but not usually
killed

60. Pathogen - Host
• A pathogen is a disease-causing agent, like a
bacterium or a virus
E.coli H.I.V.

61. Mutualism
• A symbiotic relationship where
two organisms are in a
mutually beneficial relationship
• Examples: Lichens are not one
organism but two – an algae
and a fungus living as one.
The algae provides the fungus
with glucose in return for
moisture from the fungus.
Clown Fish are protected from predator
fish by the stinging tentacles of the
anemone. The anemone receives
protection from polyp-eating fish, like
Butterfly Fish, which the Clown Fish
chases away. The anemone also gets
fertilizer from the feces of the Clown Fish.

62. Commensalism
• In this relationship, one organism benefits but
the other is neither harmed nor benefited
• Examples: Shark and remora,

63. More unusual examples of animal symbiosis

64. How nutrients cycle
• Nitrogen cycle
• Carbon cycle
• Water Cycle
These are some of the various nutrient
cycles on Earth.

66. Nitrogen Cycle

67. Carbon cycle

68. Limiting Factors
• Any abiotic factor that
limits the survivability of
organisms in a particular
ecosystem is called a
limiting factor
• Examples: Water in a
desert, light in the deepest
parts of the ocean (abyssal
and benthic zones), etc.

69. Food Webs

70. Food Chains

71. In this picture, how does
the coyote depend on the
sun?

72. Life Depends on the Sun
• Photosynthesis is the process by which
plants, algae, and some bacteria use
sunlight, carbon dioxide, and water to
produce carbohydrates and oxygen.

73. B. Energy Pyramid shows relative amount of energy available at
each trophic level
1. Organisms in a trophic level use the available
energy for life processes (such as growth,
photosynthesis, cellular respiration, metabolism,
etc.)and release some energy as heat
Remember: Every chemical process that happens in
your body releases heat as a byproduct (ex: burning
calories).
2. Rule of 10—only about 10% of the available energy
within a trophic level is transferred to the next
higher trophic level
C. Biomass Pyramid—represents the amount of living organic
matter at each trophic level