An ecosystem consists of biotic and abiotic components that interact with each other. Biotic factors include living organisms like plants, animals, and microbes, while abiotic factors refer to non-living physical and chemical elements like water, soil, sunlight, temperature, and minerals. Organisms depend on each other through food webs, with energy transferring between trophic levels from producers to primary, secondary and tertiary consumers. Ecosystems also cycle nutrients through the actions of decomposers which break down organic matter. Examples of ecosystems include forests, grasslands, freshwater and marine environments.

1. What is an Ecosystem
• An ecosystem is made up of
biotic as well as abiotic
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

2. Biotic Factors

3. Abiotic Factors

4. Abiotic factors affect living organisms in an ecosystem
Fires destroy forests, but can sometimes help a forest community by allowing
new organisms to thrive
Early or unexpected
frost can kill plants and
an entire food chain.
Wind can affect
the way an
organism grows

5. Biotic factors affect the abiotic
factors in an ecosystem
Lichens on rocks help break them
down into soil. Lichens are made
up of algae and fungi.
Dead organisms and animal
waste contribute to soil nutrients
(with the help of decomposers,
of course)

6. ECOLOGY
• ECOLOGY IS AN
SCIENTIFIC STUDY OF
THE INTERACTION
THAT DETERMINE THE
DISTRIBUTION AND
ABUNDANCE OF
ORGANISMS

7. Ecology—the scientific study of interactions
between different organisms and between
organisms and their environment or
surroundings

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.
ARTIFICIAL
1.A crop land, garden, aquarium, park, kitchen garden.

10. STRUCTURE AND FUNCTION OFSTRUCTURE AND FUNCTION OF
ECOSYSTEMECOSYSTEM
• Two important aspects of the ecosystem are ArchitecturalTwo important aspects of the ecosystem are Architectural
(Structural)(Structural)
• 1.The composition of biological community including1.The composition of biological community including
species numbers, biomass, life history and distribution inspecies numbers, biomass, life history and distribution in
spacespace
• 2.The quantity and distribution of nonliving materials like2.The quantity and distribution of nonliving materials like
nutrients, water.nutrients, water.
• 3.The condition of existence such as temperature, light3.The condition of existence such as temperature, light
etc.etc.

11. STRUCTURE AND FUNCTION OFSTRUCTURE AND FUNCTION OF
ECOSYSTEMECOSYSTEM
• Two important aspects of the ecosystem are workingTwo important aspects of the ecosystem are working
processprocess
• 1.The production and respiration rates of the community1.The production and respiration rates of the community
• 2.The rate of material (nutrient) cycles2.The rate of material (nutrient) cycles
• 3.Biological regulation including both regulations of3.Biological regulation including both regulations of
organisms by environment (Photoperiodism) andorganisms by environment (Photoperiodism) and
regulation of environment by the organisms (Nitrogenregulation of environment by the organisms (Nitrogen
fixing organisms)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. Biotic-living factors that influence an
ecosystem
Abiotic -non-living factors that influence an
ecosystem

15. Sunlight
Sunlight is the main energy source for life on
earth. Also called autotrophs
Use light or chemical
energy to make food
1. Plants
2. plant-like protists (algae)
3. Bacteria

16. Photosynthesis-use light energy to convert carbon
dioxide and water into oxygen and carbohydrates
(Remember: 6CO2 + 6H2O 6O2 + C6H12O6)
Chemosynthesis—performed by bacteria, use
chemical energy to produce carbohydrates
Light
Energy

17. 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

18. 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 .
• 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 water

19. Water
• Three form of Water Solid, Liquid or gas.
• Large amount of heat is needed to change
the phases

20. Salinity• Ocean contains
3.5% of salts.
• The salt content
is the major
factor to
determine what
organisms will
be found there
Figure 12-1

21. 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

22. 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.

23. Estuaries and Salt Marshes
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.
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.

24. Estuaries
Intermediate salt
concentration.
Salt and fresh
water meet

25. Dissolved gases: Oxygen
• Condition:
– Marine animals need
oxygen to survive
– Plants and animals
need oxygen for
respiration
• Respiration is a
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

26. soil

27. Soil
HUMUS

28. Relationship to soil quality?

29. Deciduous Forests
• Deciduous forest ecosystems have trees such as oaks,
elms, and maples. These forests grow in moderately
warm places where there is a lot of rain.
• The trees lose their leaves in the fall. Food and shelter
are hard to find in the winter so, some animals hibernate.

30. Coniferous Forests
Coniferous forests are made up of mostly conifers,
trees that have cones. These forests are found
mostly in the northern part of the Northern
Hemisphere.
Trees include spruces, hemlocks, pines, and firs.
Animals include moose, deer, caribou, wolves,
bears, and elk.

31. Rainforests
Rain forests get large amounts of rain. Tropical
rain forests are warm all year. These conditions
enable large populations of many kinds of
organisms to live there. Hawaii is the only state
with tropical rain forests.

32. Grasslands
Grasslands are ecosystems in which grasses
are the main plant life. Grasslands have
fertile soil and have few trees. These
ecosystems do not receive much rain during
the year, so trees do not grow well.

33. 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

34. Consumers
A.Organisms that rely on other
organisms for their energy and food
supply
B. Also called heterotrophs

35. Herbivores-obtain energy
by eating only plants
Carnivores-eat only
animals

36. Omnivores-eat both plants and
animals
Decomposers—breaks down dead organic
matter

37. Feeding Interactions
A. Energy flows through an ecosystem in one
direction—from the sun or inorganic compounds to
autotrophs (producers) and then to heterotrophs
(consumers)

38. B. 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

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

40. D. 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)

41. Hawks
Weasels Raccoons
Mice
Grass
Food Webs

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

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

44. 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)

45. Heavy metals
Ex: mercury
Pesticides
Ex: DDT
(dichlorodiphenyltrichloro
ethane)
Organochlorides:
Ex: PCBs

46. 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

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

48. 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.

49. 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.

50. 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

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

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

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

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

56. 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

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

58. Mutualism, Commensalism or Parasitism

59. 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)

60. 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)

61. 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

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

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

64. 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

65. Matter Cycles

66. 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.

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

68. 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

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

70. 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.

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

72. More unusual examples of animal symbiosis

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

75. Nitrogen Cycle

76. Carbon cycle

77. 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.

78. Food Webs

79. Food Chains

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

81. 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.

82. 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