Introduction to ENERGY FLOW

FOOD CHAINS& WEBS

sun eclipse with palmthe ultimate energy source

Energy Flow in Ecosystems

Energy flows from where into the biological world?

Energy FlowHow 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

Do you get more energy from the baked potato or

the steak?

producer

detritivore

omnivore

carnivore

herbivore

consumer

decomposer

autotrophheterotroph

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

Ex. killer whale eating a sea lion or hawk eating a snake.

sunlight producer consumer 1 consumer 2

consumer 3

OMNIVORES What are omnivores? Consumers that eat both plants

and animals Primary and Secondary

Consumers Ex. bears and humans

Where do allthe dead things go?

They are eaten. YUMMMM!

They decay. SMELLY!

What’s the difference?Is it just a matter of taste?

decomposerdetri

tivore

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.

detritiv

oredeco

mposer

Detritivore vs Decomposers

Detritivores eat the remains of dead plants and animals

Decomposers breakdown (decay) organic matter and feed on it

Crabs, mites, earthworms, snails

Bacteria & fungi

Detritivores and 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

On what do detritivores and decomposers feed?

Detritivores and Decomposers

Why would they be called the environmental “recyclers”?

They decompose excrement, dead bodies and leaf litter, returning

nutrients to the physical environment. consumer 3

sunlight producer consumer 1 consumer 2

decomposer

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

TrophicLevel 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?

producer consumer 1 consumer 2 consumer 3

decomposer

Food Chains & Food Webs If all of the snakes in this chain died,

what would happen to the hawk? To the decomposers?

producer consumer 1 consumer 2 consumer 3

decomposer

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.

Arctic Food Web

http://www.arctic.noaa.gov/essay_krembsdeming.html

Rangeland Prairie Food Web

Works Cited

“Ring of Fire” Solar Eclipse with Palm, Online Image, http://antwrp.gsfc.nasa.gov/apod/ap030530.html, Dennis Mammana, Skyscapes

Grizzly Bear Eating Salmon – Mineral Management courtesy of GeekPhilosopher.com http://geekphilosopher.com/bkg/anGrizzlyBearFish.htm

Dead Armadillo – National Biological Information Infrastructure, images.nbii.gov/guyra.php

Artic Food Web – National Oceanic and Atmospheric Administration http://www.arctic.noaa.gov/essay_krembsdeming.htm

Scavenger Condors – US Fish & Wildlife Service Pacific Region. http://www.fws.gov/hoppermountain/cacondor/condorprehistory.htmll

Works Cited Dung Beetle – Wikipedia, http://en.wikipedia.org/wiki/Dung_beetle

Rangeland Soil Food Web – National Science & Technology Center http://www.blm.gov/nstc/soil/foodweb/

Ofelia the cow –Bush Crawford Ranch– courtesy of GeekPhilosopher.com http://geekphilosopher.com/bkg/cowOfeliaCrawford.htm

Sunset over Africa – US Fish and Wildlife photo courtesy of GeekPhlosopher.com http://geekphilosopher.com/bkg/skySunsetAfrica.htm

Sun Through Trees – USDA photo courtesy of Geek Philosopher.com http://geekphilosopher.com/bkg/skySunriseTrees.htm

Biology Curriculum Writing Team, Plano Independent School District