Food Chains and Food Webs

Food Chains and Food Webs Honors Biology

Ecosystem • All of the living (biotic) and nonliving (abiotic) things (factors) in a large community.

Abiotic vs. Biotic • Which is abiotic and which is biotic? • A rock • A mouse • A tree • A waterfall

Organisms • Plants – called producers and autotrophs • Animals – called consumers and heterotrophs • Auto means “self”. Hetero means “different” or “other”.

Different types of consumers • Herbivore – eats producers only • Omnivore – eats both producers and other consumers • Carnivore – eats consumers only • Detritivore – breaks down all organisms

Food Chains/Webs • Illustrates the flow of energy in an ecosystem and how organisms interact with each other. • Also shows feeding relationships.

Food chains • One direction only. • Arrows show direction of energy flow. • Producers always listed first. • Consumers are primary, secondary, tertiary, quaternary

Food Webs • Energy flows in more than one direction. Producers toward the bottom, primary consumers next, secondary consumers near top. • Made up of more than one food chain.

Food Webs How many food chains do you see?

Energy • Is lost as you move from one level (trophic level) to another. 90% is lost while 10% is available for next level = 10% rule. • How is the energy lost?

Disturbances • How do disturbances in one part of a food web affect the rest of the web or ecosystem?

Food Chains and Food Webs