FOOD CHAINS & WEBS Introduction to ENERGY FLOW

the ultimate energy source

Energy Flow in Ecosystems Energy flows from where into the biological world?

Energy Flow How does the sun’s energy enter the biological world? What is photosynthesis?

Energy Flow The sun’s energy flows into organisms that can change the sunlight into food then into organisms that eat them. This flow is: sunlight producer consumer 1 consumer 2

Word to Know consumer producer omnivore detritivore herbivore decomposer carnivore autotroph heterotroph

PRODUCERS What are producers? Autotrophs that trap solar energy into organic molecules during photosynthesis; can produce their own food Ex. Plants, algae and some bacteria sunlight producer consumer 1 consumer 2 ``

CONSUMERS What are consumers? Heterotrophs that eat other organisms to obtain energy Examples: deer, rabbits, cows, mice, lions, humans, hawks, snakes sunlight producer consumer 1 consumer 2

HERBIVORES What are herbivores? Organisms that eat plants Primary Consumers Ex. Cows, caterpillars, bunnies sunlight producer consumer 1 consumer 2

CARNIVORES What are carnivores? Organisms that eat meat (other animals/consumers) Secondary Consumers Ex. tigers, wolves, snakes, hawks sunlight producer consumer 1 consumer 2

TOP CARNIVORES What is a top-level carnivore? Top-level carnivores eat secondary consumers; usually nothing feeds on them consumer 3 Ex. killer whale eating a sea lion or hawk eating a snake. sunlight producer consumer 1 consumer 2

OMNIVORES What are omnivores? Consumers that eat both plants and animals Primary and Secondary Consumers Ex. bears and humans

Where do all the dead things go? They are eaten. YUMMMM! They decay. SMELLY! detritivore decomposer

Detritivore vs Decomposers Detritivores and decomposers both feed on the remains of dead plants and animals and other dead matter (detritus) They rely on dead tissues for nutrients. detritivore decomposer

Detritivore vs Decomposers Decomposers breakdown (decay) organic matter and feed on it Detritivores eat the remains of dead plants and animals Crabs, mites, earthworms, snails Bacteria & fungi

Detritivore vs Decomposers What is a scavenger? A scavengers is a type of detritivore that feeds on carrion (dead animal remains). Ex. vultures, sharks, maggots, hyenas Detritivores and Decomposers When is a detritivore called a scavenger? Detritivores are scavengers when they feed mainly on carrion (dead animals). Ex. vultures, sharks, maggots, hyenas Planetware.com, photo by Jim Steinhart http://www.planetware.com/photos/IND/IND203.HTM

Detritivore vs Decomposers Why would they be called the environmental “recyclers”? They decompose excrement, dead bodies and leaf litter, returning nutrients to the physical environment. sunlight producer consumer 1 consumer 2 decomposer consumer 3

Energy Flow The series of steps in which organisms transfer energy by eating and being eaten is called a Food Chain sunlight producer consumer 1 consumer 2

Food Chains & Food Webs The steps in the transfer of energy from organism to organism in feeding relationships are called Trophic Levels. How does a food chain describe this path of energy? (arrows) producer consumer 1 consumer 2 consumer 3

Food Chains & Food Webs Name the number of the trophic levels in the food chain below. How do the trophic level numbers correspond with the “eating terms”? producer consumer 1 consumer 2 consumer 3 Trophic Level 1 2 3 4

Food Chains & Food Webs What important energy transfer is not shown in a food chain? Why is it that some energy is lost from one level to the next level? How much energy is actually passed on to the next level? (rule of thumb) producer consumer 1 consumer 2 consumer 3

Food Chains & Food Webs What vital “recycler” is not shown in this food chain? Upon which organism(s) would it feed? decomposer producer consumer 1 consumer 2 consumer 3

Food Chains & Food Webs If all of the snakes in this chain died, what would happen to the hawk? To the decomposers? decomposer producer consumer 1 consumer 3 consumer 2

Food Chains & Food Webs Most organisms feed on more than one trophic level and feed on several different species at each trophic level. This is a food web. Food Chains & Food Webs Most organisms feed on more than one trophic level and feed on several different species at each trophic level.

Antarctic Food Web

Making a Food Web Use these organisms for Food Chains and Food Web Practice worksheet.