1. Hey APES
 Any more lab reports?
 Ch. 3, continued.
 Color?

2. Ecosystems: What are they
and how do they work?
Ch. 3
Miller and Spoolman, 16th ed.

3. Big Idea # 1
 Ecology is the study of how organisms
interact with each other and with their
environment.

4. Organization of
Life
All living things
are made of 1 or
more cells

5. Organization of
Life
 A population is members
of the same species, that
live in a particular place
at a particular time
 Who, where, when
 The variation among
members of a population
is due to its genetic
diversity (DNA)

6. Organization of
Life
 A community is all
the populations in an
area
 Populations in a
community interact
with each other
 Feeding
relationships,
competition, nutrient
cycles, etc

7. Organization of
Life
 An ecosystem is the
community plus all
the abiotic factors in
the area
 Biotic - living or
recently living
 Abiotic - nonliving

8. Organization of
Life
 The biosphere is all
the ecosystems…
our whole world…
where we all live

9. Cells
 All living things are
made of one or more
cells…
 You should know the
basics about cell
types

10. Cell types
 There are 2 basic cell types:
prokaryotic & eukaryotic

11. Prokaryotic Cells
 Most simple
 BACTERIA & Archaea
Protein construction and energy
conversion occur without specialized
internal structures
DNA (no nucleus)
 No nucleus
 No organelles
 DNA, ribosomes,
cell wall, cell
membrane
 VERY DIVERSE &
SUCCESSFUL
 FOUND
EVERYWHERE

12. Eukaryotic Cells
 Larger
 More complex
 Nucleus for DNA
Nucleus
(DNA)
Protein
construction
Energy
conversion
 Specialized organelles
 Plants, animals, fungi,
protists
 Animals and some
protists do not have cell
walls

13. Summary Check
 What are the biological levels of
organization? (say it)
 Venn diagram: prokaryotic vs.
eukaryotic cells (put it in your notes)

14. Big Idea # 2
 Life is sustained
by 3 things:
 The flow of
energy from the
sun through the
biosphere
 The cycling of
nutrients within
the biosphere
 gravity

15. 4 Spheres of
Life
 All 4 spheres
interact with
each other
 We need all
four to keep us
alive
1.
3.
4.
2.

16. Sphere 1 - the atmosphere
 Atmosphere = Thin
layer surrounding the
earth’s surface
 Closest to land is the
troposphere (ground
level to 4-11 miles
up)
 Has most of our air
 Air is:
 78% N2
 21% O2
 1% methane, CO2,
H2O - greenhouse

17. The Atmosphere, cont’d
 Next layer up is
the stratosphere
(11-31 miles)
 Has ozone
layer - filters
out most UV
radiation

18. Sphere 2 - the hydrosphere
 Hydrosphere = all the
water on earth
 Liquid (on surface and
underground)
 Solid (ice)
 Water vapor (in
atmosphere)
 Most in oceans - covers
~ 71% of the planet

19. Sphere 3 - the geosphere
 Geosphere =
super hot core,
thick, fluid mantle,
thin outer crust
 Contains our fossil
fuels and minerals
(nonrenewable)
and soil nutrients
(renewable)

20. Sphere 4 - the biosphere
 All the living things on earth
 Life exists from ~ 6 miles above the
earth’s surface to the bottom of the
ocean

21. Biomes
 Large regions of
land that have
characteristic
climate and
species adapted
to them

22. Terrestrial Biomes
 Tropical forest
 Savanna
 Desert
 Chaparral
 Temperate
grassland
 Temperate
broadleaf forest
 Coniferous forest
 Tundra
 Taiga
 High mountains
 Polar ice

23. Terrestrial Biomes
 Vertical stratification important
 Plants provide the stratification
 Canopy
 Low trees
 Shrubs
 Litter layer (forest floor)
 Many organisms
adapted to a particular
layer

24. Terrestrial Biomes
 Don’t have clear, defined boundaries
 Ecotone - area where one biome
grades into another
 Find different organisms here

25. Summary Check
 What is a biome?
 What biome do you live in?

26. Biomes
 Also aquatic life zones
 Freshwater - lakes, rivers, streams
 Marine - oceans, coral reefs, estuaries

27. The environment limits the
distribution of species
– or – not everyone can live everywhere
 Dispersal – movement
out of a high density area
 Natural range expansions
 Species transplants –
intentional or accidental
introduction of a species to
a new area
 Actual range vs. potential
range

28. Climate
 Major components:
 Temperature
 Water
 Sunlight
 Wind
 Macroclimate – global/regional
 Microclimate – very small
(like under a fallen log)

29. Macroclimate
 Affected by
 Water
 Large bodies
of water
have a
moderating
effect
 Currents
carry warm
or cold air

30. Climate
 Affected by
 Mountains
 Windward vs. leeward sides

31. Climate
 Affected by
 Seasonality
 Due to changing angle of sun
 Causes turnover in lakes that mixes water - essential for
life

32. Summary Check
 How might climate affect the evolution
of species over time?

33. The Flow of Energy
 It all starts with
the sun
 Ozone layer
absorbs 95% of
incoming solar
radiation

34. The Flow of Energy
 Sunlight that
does reach
the surface
warms the
planet, drives
the water
cycle,
generates
wind

35. The Flow of Energy
 Less than 0.1% of
incoming solar
radiation used by
plants and protists
for photosynthesis

36. The Greenhouse Effect
 Heat radiated up off
the surface of the
earth makes the
greenhouse effect
 Yay! Makes life
possible on earth
 The heat increases
the kinetic energy of
the greenhouse
gases, thus raising
their temperature

37. Big Idea # 3
 Ecosystems are
made up of both
biotic and abiotic
components
including producers,
consumers, and
decomposers

38. Populations thrive under
different conditions
 Every
population has
a range of
tolerance -
variations within
the preferred
chemical and
physical
environment

39. Populations are affected by
limiting factors
 Limiting factors affect the number of
organisms in a population
 Too much or too little of any abiotic
factor can be a limiting factor
1.1. What are some abiotic factors?What are some abiotic factors?
2.2. Use one abiotic factor to explain aUse one abiotic factor to explain a
situation in which too much or too littlesituation in which too much or too little
of it limits population growth, even if allof it limits population growth, even if all
other factors are in the range ofother factors are in the range of
tolerancetolerance

40. Density-Dependent Factors
• Competition for resources
• Predation
• Parasitism
• Disease
• Poisoning

41. Density-Independent Factors
• Natural disasters
• Global warming ?
• Ozone depletion ?

42. Density Controls

43. Summary Check
 What are some limiting factors
that would affect a population
of:
 Polar bears?
 Butterflies?
 Humans?

44. Trophic Levels
 Trophic level =
feeding level
 3 main types:
 Producers
 Consumers
 Decomposers

45. Producers
 Producers - aka autotrophs
 Self- feeders
 Mostly plants
 Also algae (protists) and plankton
in water
 Make their own food through
photosynthesis (use CO2 and
sunlight)
 Some do chemosynthesis -
bacteria in deep ocean (use H2S
& heat)
 START ALL FOOD WEBS
6CO2 + 6H2O + light energy  C6H12O6 + 6O2

46. Consumers
 Consumers -
aka
heterotrophs
 Consume
producers or
other organisms
for energy
 Several levels

47. Levels of Consumers
 Primary Consumers
(herbivores) - the
first consumers in a
food web - they eat
producers
 Examples: rabbits,
cows, horses, some
birds, grasshoppers,
etc

48. Levels of Consumers
 Secondary
Consumers -
omnivores (eat
both plants and
animals) and
carnivores (only
eat other animals
 They eat the
primary
consumers

49. Levels of Consumers
 Tertiary (and
beyond)
consumers -
omnivores and
carnivores
 They eat the
secondary
consumers

50. Levels of
Consumers
 Decomposers - 99% are
bacteria and fungi
 Consumer dead organisms
to get their energy
 Feed by secreting enzymes
 RETURN NUTRIENTS IN
THE ORGANISMS TO THE
EARTH!

51. Levels of Consumers
 Detritivores - aka detritus feeders or
scavengers
 Feed on wastes or dead organisms

52. Summary Check
 So what’s the difference between
decomposers and detritivores?

53. Levels of Consumers
 Organisms can occupy more than one
level

54. How we harvest that energy
 Both producers and consumers go
through respiration to harvest the
energy from their food
 Aerobic - uses oxygen, needs
mitochondria
 Anaerobic - does not need oxygen
or mitochondria
 We store the energy from our food
as ATP molecules

55. Summary Check
 What does a food web diagram show?
 What is the ultimate source of energy
for most ecosystems?
 What is the exception to the second
question?

56. Big Idea # 4
 Energy flows through ecosystems in
food webs
 Energy is lost as it flows from one
tropic level to the next

57. Plants, animals, and
decomposers make up food
chains
 A food chain is a pathway that tells us
what eats what
 Food chains are over-simplified models of
nature

58. Food webs
 A food web
is more
realistic
 It shows us
how several
food chains
overlap and
connect to
each other

59. Limits on Food Webs
 A food web can
only go so far
 It usually does
not go beyond
the level of
tertiary or
quaternary
consumer

60. Energy
Why?
 It’s all about energy!
 Every time energy is
passed from one
organism to another,
some of that energy is
lost
 The amount of energy
transferred from one
level to the next is
called ecological
efficiency

61.  Ecological efficiency
varies, but a good rule of
thumb is 10%
 This means 90% of the
energy is lost and only
10% makes it to the next
level

62. Why only 10%?
 1. Not everything gets eaten
 There may be 1000 pounds of clover in a
field, but the rabbit does not eat it all
 Good thing, too, or else there would be no
clover left to make new clover

63.  2. Not everything
that is eaten gets
digested
 In other words,
some of what you
eat is lost as waste
(poo).
 Some animals
actually eat their
own poo to get
some more
nutrition out of it!
Ew.

64.  3. The most important reason: energy is always
being lost as HEAT
 Whenever something does WORK, it creates
HEAT
 Your body is always working (heart beat,
breathing, etc)

65. New energy must
constantly enter the
system
 Since energy is always being lost,
new energy is always needed.
 This energy comes from the sun
(which feeds the grass, which feeds
the cow, which feeds the person,
etc.)

66. Energy Pyramids
 We can show
how energy is
lost at each
stage of a
food web in
an energy
pyramid.

67.  In an energy
pyramid:
 Producers
are at the
bottom,
because
they have
the most
available
energy.
(They got it
right from
the source)

68.  The next level is the primary consumers.
They got 10% of the energy in the plants.

69.  Since only 10% of the energy moves
on, it takes a lot of producers to
support the primary consumers.

70.  The next level is the secondary
consumers. They got 10% of the energy
in the primary consumers.

71.  It takes a lot of primary consumers
to support a secondary consumer

72. Energy Pyramid Practice
 If there is 10,000
kcal of energy
available in the
plants at the bottom
of the pyramid, how
much energy will
make it to the
zebras, and how
much will make it to
the lion?
10,000
1000
100

73. An energy Pyramid
Gets smaller as it
goes up since there
is less and less
energy as you go up

74. Pyramid ofPyramid of
numbersnumbers
How many
organisms are at
each level
Usually mostly
producers, then
primary
consumers, then
secondary and
so on
100,000 plants
1000
voles
1 owl

75. Pyramid ofPyramid of
numbersnumbers
Could look like
this:
1 oak tree
supports lots of
primary
consumers,
which support
fewer secondary
consumers, then
even fewer
tertiary, etc.
1 oak tree
1000
caterpillars
50 bluetits
1 sparrow
hawk

76. Pyramid ofPyramid of
biomassbiomass
How much
everything
weighs at
each level
Always
pyramid
shaped

77. Interdependence
 All living things are
connected to other
living things, both
directly and indirectly.
 Living things eat and/or
get eaten
 Living things obtain
chemicals that came from
other living things
 The actions of living
things affect other
organisms

78. GPP and NPP
 Gross Primary Productivity – all the
light energy that is converted to
chemical energy in an ecosystem
 Not all of this is available to
consumers though, because the
plants need some for themselves
 Net Primary Productivity – the
chemical energy available to
consumers

79. NPP
 Expressed as:
 Energy per unit area
per unit time (J/m2
/yr)
 Biomass of
vegetation added to
the ecosystem per
unit area per unit
time (g/m2
/yr)
 Not the total biomass
– the amount added
 Total biomass called
standing crop
 Forests have high
total biomass, but
relatively low NPP

80. Ecosystems with high NPP
 Tropical rain forests
 Estuaries
 Coral reefs
 Open ocean (just because so much of the
planet is covered in it)

81. Aquatic Ecosystems and NPP
 Light is important but…
 Nutrients are more important
 Nitrogen and phosphorus
 Tend to be low in photic zones and high
in aphotic zones
 Upwelling brings
these nutrients up
and increases NPP

82.  Fertilizers and sewage runoff bring
nutrients in to aquatic ecosystems
 Too much nitrogen and phosphorus
leads to algal blooms and high
numbers of cyanobacteria
 This leads to eutrophication
 Depletes water of oxygen and thus most
life

83. Summary Check
 Choose 1 word to represent what this
chapter is about.
 Explain why you chose that word. Be
thorough in your explanation.