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

ENERGY IN AN ECOSYSTEM Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae 100% of energy available

Where does energy made by the producer go? CELLULAR RESPIRATION - ingested food is broken down into energy C6H12O6 + 6O2  6CO2 + 6H2O + energy

ENERGY IN AN ECOSYSTEM Primary Consumer (heterotroph) = eats producers and produces energy through cellular respiration AKA - Herbivore = PLANT EATER (Ex: zebra, cow) 10% of energy available Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae 100% of energy available

ENERGY IN AN ECOSYSTEM 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 Primary Consumer (heterotroph) = eats producers, and produces energy through cellular respiration AKA - Herbivore = PLANT EATER (Ex: zebra, cow) 10% of energy available Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae 100% 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?

ENERGY IN AN ECOSYSTEM Tertiary Consumer (heterotroph) = eats secondary consumers (Ex: owl, shark) *May be the APEX PREDATOR (top of food chain) 0.1% of energy available 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 Primary Consumer (heterotroph) = eats producers, and produces energy through cellular respiration AKA - Herbivore = PLANT EATER (Ex: rabbit, cow) 10% of energy available Producer (autotroph) = makes its own food through photosynthesis (self-feeder). Ex: grasses, trees, flowering plants, algae 100% of energy available

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.

Why does the population decrease as the trophic levels increases? 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

SECONDARY CONSUMER (heterotroph / carnivore) TERTIARY CONSUMER (heterotroph/carnivore) 0.1% of energy available SECONDARY CONSUMER (heterotroph / carnivore) 1% of energy available PRIMARY CONSUMER (heterotroph / herbivore) 10% of energy available PRODUCERS (autotroph) 100% of energy available

ENERGY IN AN ECOSYSTEM