Download 13.6 Pyramid Models

13.6 Pyramid Models
KEY CONCEPT
Pyramids model the distribution of energy and matter
in an ecosystem.
13.6 Pyramid Models
An energy pyramid shows the distribution of energy
among trophic levels.
• Energy pyramids compare energy used by producers
and other organisms on trophic levels.
• Between each tier of an energy
pyramid, up to 90 percent of the
energy is lost into the
atmosphere as heat.
• Only 10 percent of the energy at
each tier is transferred from one
trophic level to the next.
• Energy is in the form of
Proteins, carbohydrates energy
energy transferred
lost
And fats
13.6 Pyramid Models
Ninety percent of this mouse’s food energy is used to maintain its life functions.
13.6 Pyramid Models
13.6 Pyramid Models
Energy is measure in calories. A kilocalorie is 1000 calories.
Calculate the flow of energy from the producers to the owl.
The total energy at the producer level is 1,700,000 Kcals! Put it in the
First pyramid in your notes!
13.6 Pyramid Models
Other pyramid models illustrate an ecosystem’s biomass
and distribution of organisms.
• Biomass is a measure of the total dry mass of organisms in
a given area.
tertiary
consumers
75 g/m2
150g/m2
secondary
consumers
primary
consumers
producers
producers
675g/m2
2000g/m2
13.6 Pyramid Models
• A pyramid of numbers shows the numbers of individual
organisms at each trophic level in an ecosystem.
tertiary
consumers
5
secondary
consumers
5000
primary
consumers
500,000
producers
producers
5,000,000
• A vast number of producers are required to support even a
few top level consumers.
13.6 Pyramid Models
Pyramids of numbers and biomass can become inverted
or upside down if based on a single tree.
13.6 Pyramid Models
On your note paper Use one of the energy pyramids to
draw in the desert food chain introduced in section 4.