Transcript Energy Flow Pyramids and Trophic Levels

Energy Flow Pyramids and
Trophic Levels
Does all the energy this caterpillar eats get
passed to the bird who eats him?
Plant material eaten by
caterpillar
100 kilocalories (kcal)
35 kcal
50 kcal
Feces
15 kcal
Growth
Cellular
respiration
TROPHIC LEVELS
 Determined by the organism’s source of energy
 Organisms are identified by their trophic level
according to their name.
1.
2.
3.
Autotrophs
Heterotrophs
Decomposers
Decomposers are a specific type of heterotroph.
1. AUTOTROPHS:
• Capture energy from the sun (photosynthetic) or
inorganic molecules = chemicals
(chemosynthetic) and converts it into usable
energy.
• Also known as PRODUCERS
– produces food (make energy storing molecules),
• Eg. Plants, algae and some kinds of bacteria
2.
HETEROTROPHS-
• Obtains the energy to build their molecules
by consuming plants or other organisms
• Also known as CONSUMERS
– Includes not only primary, secondary, tertiary (etc.)
consumers, but also include:
decomposers and detritivores
3. DECOMPOSERS
• A specific type of heterotroph
• Can be one of two types:
-Scavenger/Detritivore: Eats dead organisms
(carcasses) or detritus (dead organic matter)
Eg. Bear, Dog, Vulture, Crab, Worm, Bacteria
-Saprotroph: Digests matter, extracellularly
(outside the cell) by spitting enzymes out and
then absorbing the digested material.
Eg. Fungi such as mushrooms
Pyramid Models:
graphs which
illustrate the
trophic levels in
a community.
Energy Pyramid Model
• Organisms convert
food (glucose) into
energy.
• This energy is given
off as heat which is
lost to space.
• Energy is a one way
path. It is not a
cycle.
Energy Pyramid Model
• An energy pyramid is a
diagram that compares
energy used by producers,
primary consumers, and
other trophic levels.
• As a rule each trophic level
receives only 10% from the
trophic level below.
• In other words each
trophic level loses 90%
heat to the atmosphere.
Energy Pyramid Model
Tertiary
Consumers:
123 KJ
Secondary Consumers:
1,230 KJ
Primary Consumers:
12,300 KJ
Producers:
123,000 KJ
Biomass Pyramid
• Biomass is the mass
of organisms minus
water.
• Biomass refers to the
amount of carbon
and other trace
elements in an
organism’s body
contains.
Numbers Pyramid
Illustration of the number of
organisms at each level
How can more people be supported on
Earth when there is a limited supply of
resources?
It depends on what they are eating.