BIO 124

EcologicalPyramidsVirtualLab

http://glencoe.mcgraw-hill.com/sites/dl/free/0078802849/383926/BL_02.html

Place the organisms in the correct trophiclevels to complete the pyramids for the 5 different ecosystems in the table.  After you have correctly placed all the organisms fill in the data inthe tables for the pyramids ofnumbers and energy.

1. Data for Pyramid of Energy

Now you can ask yourself, “how well does the energy transfer fromone trophic level to the next?” What you want to know is how much energy is left over fromone trophic level to the next.  To do this you will complete a “conversion efficiency” between eachtropic level.To do this you divide the energy at the higher energy level by the energy at the lower trophic level.This gives you a ratio that you can use for comparison, write your answer as a decimal.  Completethis for all three of your ecosystems.

EXAMPLE

1stOrder Heterotrophs (amount ofenergy)

Producers(amountof energy)

744 units of energy

7,500 units of energy

=0.992

2. Energy conversion efficiency table

3. If you round-off your numbers above which of the following decimal numbersmost closely matches ALL

your numbers?

A. 0.23              B. 0.10             C. 0.30             D. 0.01

This exercise shows you that

% ofenergy fromthe lower level isavailable to the next level up.

With this information complete the flow chart below that shows how much energy will be found at each level for the generalize ecosystem,

(one has been done for you).

TopCarnivore (4thconsumers)

                    unit(s) of energy

Herbivores(1stconsumers)

Omnivores(2ndconsumers)

unitsof energy

Carnivores(3rdconsumers)

                    unitsof energy

Producers

1000

units ofenergy

                    unitsof energy

4. This exercise shows you that _____% of energy from the lower level is available to the next level up.

Producers units of energy =

Omnivores units of energy =

Carnivores units of energy =

Top carnivores units of energy =