Energy Flow in a Ecosystem

The ultimate source of energy is the Sun!

How does energy from the Sun enter the ecosystem?

• PHOTOSYNTHESIS - Plants use the Sun’s energy to make sugars.

6CO2 + 6H2O + sunlight C6H12O6 + 6O2

•Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae

•100% of energy available

ENERGY IN

AN ECOSYSTEM

Where does energy made by the producer go?

• CELLULAR RESPIRATION - ingested food

is broken down into energy

C6H12O6 + 6O2 6CO2 + 6H2O + energy

Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae

•100% of energy available

eats producers and produces energy through cellular respiration

AKA - Herbivore = PLANT EATER (Ex: zebra, cow)•10% of energy available

ENERGY IN

AN ECOSYSTEM

Primary Consumer

(heterotroph) =

Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae

•100% of energy available

eats producers, and produces energy through cellular respirationAKA - Herbivore = PLANT EATER (Ex: zebra, cow)

•10% of energy available

ENERGY IN

AN ECOSYSTEM

Primary Consumer (heterotroph) =

Secondary Consumer (heterotroph) = eats primary consumers (cellular respiration)

AKA: Carnivore=MEAT EATER (Ex: tiger, wolf ) Omnivore = PLANT & MEAT EATER (Ex:human, bear)

•1% of energy available

• Which teeth do you think are meat-eaters?

• Which teeth do you think are plant-eaters?

• What type of diet do the human teeth indicate?

Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae

•100% of energy available

eats producers, and produces energy through cellular respirationAKA - Herbivore = PLANT EATER (Ex: rabbit, cow)

•10% of energy available

ENERGY IN AN ECOSYSTEM

Primary Consumer (heterotroph) =

Secondary Consumer (heterotroph) = eats primary consumers (cellular respiration)

AKA: Carnivore = MEAT EATER (Ex: snake, wolf ) OR Omnivore = PLANT & MEAT EATER (Ex: human, bear)

•1% of energy available

•0.1% of energy available

Tertiary Consumer (heterotroph) = eats secondary

consumers (Ex: owl, shark)

*May be the APEX PREDATOR (top of food chain)

Food Chains vs. Food Webs

• Food Chain = a sequence of energy transfer as each organism eats another organism.

Food Chains vs. Food Webs An ecosystem is more complex than a simple food

chain. Most organisms eat more than one type of food.

Food Web = a complex sequence of

energy transfer showing multiple

feeding relationships.

Energy pyramids show how each trophic level (step in a food chain) is supported by the previous level.

Why does the population decrease as the trophic

levels increases?

What about the dead stuff?

• Decomposers- Break down dead organisms in an ecosystem and return nutrients to the soil, water, and air Ex: mushroom, shrimp, bacteria

PRODUCERS (autotroph)

PRIMARY CONSUMER (heterotroph / herbivore)

SECONDARY CONSUMER (heterotroph / carnivore)

TERTIARY CONSUMER (heterotroph/carnivore)

100% of energy available

10% of energy available

1% of energy available

0.1% of energy available

ENERGY IN

AN ECOSYSTEM