Ec o l o g y Energy Pyramids

Walnut High School

P r e s e n t s

EQ:EQ:What is the rule of 10%

and how does that affect the amount of food the next energy

level must consume?

ZUMA

2nd Order CARNIVORES

The Laws of Thermodynamics andFOOD CHAINS !

The10 %

RULE !

The maximum amount of ENERGY that passes from one trophic level to the

next is 10%.

90% of the ENERGY at eachtrophic level is used to keep

theorganisms alive and is

converted to HEAT.

Always startwith the SUN.

PHYTOPLANKTONThe 10% RULE !

90% of theENERGY capturedby PRODUCERSis used to keep

themselvesalive (converted

to heat).

Max. 10 % toHERBIVORES

HEAT

PRODUCERS

HERBIVORES

1st OrderCARNIVORES

2nd OrderCARNIVORES

3rd OrderCARNIVORES

Producers are the BASEof the pyramid of biomass because

their ENERGY comes directfrom the SUNSUN.

ZOOPLANKTONPHYTOPLANKTONThe 10% RULE !

10%

HEATMax. 10 % toCARNIVORES

90%

90% was usedto keep the

HERBIVORESalive.

PRODUCERS

HERBIVORES

1st OrderCARNIVORES

2nd OrderCARNIVORES

3rd OrderCARNIVORES

HERBIVORESexist on only 10%

of the ENERGYfrom PRODUCERS.

ZOOPLANKTONPHYTOPLANKTON

1st O

rder

CARNIV

ORES

The 10% RULE !

90%

HEAT

Max. 10 % to2nd O. CARNIVORES

10%

10%

10%

PRODUCERS

HERBIVORES

1st OrderCARNIVORES

2nd OrderCARNIVORES

3rd OrderCARNIVORES1st O. Carnivores are max.10%

of HERBIVORES.

ZOOPLANKTONPHYTOPLANKTON

1st O

rder

CARNIV

ORES

2nd Order CARNIVORES

The 10% RULE !

10%

10%

10%

PRODUCERS

HERBIVORES

1st OrderCARNIVORES

2nd OrderCARNIVORES

3rd OrderCARNIVORESThere isn’t much

ENERGY left near the top.

PRODUCERS

HERBIVORES

1st OrderCARNIVORES

2nd OrderCARNIVORES

3rd OrderCARNIVORES

The 10% RULE . . .

...resultsin this

ECOLOGICALPYRAMID

PRODUCERS - 1000HERBIVORES - 100

1st OrderCARNIVORES - 10

2nd OrderCARNIVORES - 1

3rd OrderCARNIVORES

0.1

The 10% RULE . . .

...is usedto helppredict

NUMBERS.

1000

100

10

1

0.1

The 10% RULE . . .

...is usedto helppredict

BIOMASS.

The ecologicalpyramid at

ZUMA.

ZOOPLANKTONPHYTOPLANKTON

2nd Order CARNIVORES

1st O

rder

CARNIV

ORES10

%

10%

10%

Population sizeratios atZUMA.

10%

10%

10%

1,0001,000

100100

1010

11

individuals

individuals

individ

uals

individ

uals

individ

uals

individ

uals

indiv

idual

indiv

idual

For every 1 lb. ofFor every 1 lb. ofhalibut, how manyhalibut, how many

lbs. of lbs. of sea lionsea lioncan be supported ?can be supported ?

??

1 lb.1 lb.

For every 1 lb. ofFor every 1 lb. ofhalibut, 0.1 lbs.halibut, 0.1 lbs.

of of sea lionsea lioncan be supported !can be supported !

0.1 lbs0.1 lbs

1 lb.1 lb.

ZOOPLANKTONPHYTOPLANKTON

1st O

rder

CARNIV

ORES

2nd Order CARNIVORES

For a 30 lb.For a 30 lb.halibut, halibut, 30,000 lbs.30,000 lbs. of of phytoplanktonphytoplanktonare necessary !are necessary !

30 lbs.30 lbs.300 lbs.300 lbs.

3,000 lbs.3,000 lbs.

30,000 lbs.30,000 lbs.

REVIEW QUESTIONS:

1. What is the 10% rule ?

2. Where does most of the ENERGY go at each trophic level ?