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Let's build the energy pyramid.
Go to the
Primary Productivity Table and find the table that shows the Primary Productivity per
Square Meter per Year for your biome. Find my biome and see
how many Kilocalories each square meter can produce in a year.
Build Your Pyramid Diagram
The plants use
energy from the sun to combine the carbon in carbon dioxide with oxygen,
hydrogen, and other atoms. It makes organic molecules (sugars) and
turns them into plant tissues, stems, seeds, flowers, leaves, fruits and
roots. Plants are the Primary Producers.
They are at the bottom of the food chain because the
other life forms depend on them and eat them. Without plants, algae,
and phytoplankton there would be no complex life forms. This
is why primary productivity is so important.
The level of
the primary producers is called the First Trophic Level.
Trophic Level One -- Carbohydrates Are
Produced by Plants
This is where you use the number that you just found. I'm
using the Polar Tundra. Summer is short, only six to ten
weeks, and temperatures are below freezing for six to ten months
of the year. This makes for a very short growing season. I am
hoping that the plants can produce 600 Kilocalories of food per
square meter. This is not even 2 KiloCalories a day, but most
days the plants are paralyzed by the cold, so they are doing
the best that they can.
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600 Kilocalories per Square Meter Per Year available
for herbivores to eat
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Trophic Level Two -- Edible Carbohydrates are
turned into Proteins by Herbivores
Herbivores use about 90% of the Kilocalories that they
eat for breathing, digesting, warming their bodies, running around, and
reproducing. This leaves about 10% of the Kilocalories that they eat for
building their bodies, which are mostly edible protein.
On my Energy Pyramid I show that only about 10% of the
carbohydrates are turned into animal bodies, which are mostly protein.
On this level of the pyramid =
10% of 600 Kilocalories = 0.10 * 600 = 60 Kilocalories
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600 Kilocalories per Square Meter Per Year available
for herbivores to eat
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Herbivores produce 60 Kilocalories of animal body per
square meter per year
Trophotic Level Three -- Edible Calories
Produced by Carnivores Eating Herbivores
Carnivores really have to work to eat meat.
They can capture 60 Kilocalories per square meter
of ground by eating the herbivores, but they can only transfer
about 10% of the Kilocalories that they eat into the structures
of their own bodies.
10% of 60 Kilocalories = 0.10 * 60 = 6 Kilocalories
Herbivores produce
60 Kilocalories
per square meter per year |
Predators
(carnivores ) produce six Kilocalories of biomass (their
actual bodies) per year per square meter.
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600 Kilocalories per Square Meter Per Year available
for herbivores to eat
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In rich biomes with high primary
productivity and old, well-developed ecosystems, there may be
one or two more layers of predators who eat predators.
This condition is rare, however.
Make this into a graphic:
or
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