Introduction to ENERGY FLOW

ECOSYSTEMS and

FOOD CHAINS

Habitat – place where an organism lives.

Population – group of organisms from the same species.

Community – group of organisms from several species.

Ecosystem – a community and all of the physical aspects of a habitat.

What is an ecosystem?

Organism

Community

Population

Ecosystem

Ecology

The scientific study of interactions between organisms and their environments.

Biotic Factors

All living organisms that inhabit an environment.

Ex: animals, plants, protists…

Abiotic Factors

All nonliving factors in the environment.

Ex: air currents, temperature, moisture, light, and soil

sun eclipse with palm

the ultimate energy source is the SUN!!!

Energy FlowHow does the sun’s energy

enter the biological world?

PHOTOSYNTHESIS

Energy FlowThe 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

PRODUCERS

Producers make their own food. They can also be called autotrophs.

Ex. Plants, algae and some bacteria

sunlight producer consumer 1 consumer 2

CONSUMERS

Consumers eat something else. They also are called

heterotrophs. Examples: deer, rabbits, cows,

mice, lions, humans, hawks, snakes

sunlight producer consumer 1 consumer 2

HERBIVORES

Herbivores eat plants.

They can be called primary consumers

Ex. Cows, caterpillars, bunnies

sunlight producer consumer 1Or primary consumer

consumer 2Or secondary consumer

CARNIVORES

Carnivores eat meat and can be called secondary consumers.

Ex. tigers, wolves, snakes, hawks

sunlight producer consumer 1 consumer 2

TOP CARNIVORES A “top” carnivore is a tertiary

consumer. They are at the top of the food chain.

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

sunlight producer consumer 1 consumer 2

consumer 3

OMNIVORES Omnivores eat meat and

plants. They are considered

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

DETRIVORES: feed on the remains of dead

plants and animals and other dead matter (detritus)

Crabs, mites, earthworms, snails

Detritivore vs Decomposers

DECOMPOSERS:break down dead organic matter

Bacteria & fungi

“RECYCLERS”They break down and release nutrients from dead matter back into the environment

Detritivores and Decomposers

Why would they be called the environmental “recyclers”?

sunlight producer consumer 1 consumer 2

consumer 3

decomposer

Food Chains & Food Webs Organisms in ecosystems transfer

energy from organism to organism in a graphic organizer known as trophic levels.

producer consumer 1 consumer 2 consumer 3

1 2 3 4

The Path of Energy

ARROWS on a food chain describe this path of energy.

Notice that the arrows point from the organism being eaten to the organism that is eating it.

producer consumer 1 consumer 2 consumer 3

Food Chains & Food Webs Energy is “lost” at each trophic

level as a result of the activities of the organisms such as metabolism.

Only 10% of the energy is actually passed on to the next level.

producer consumer 1 consumer 2 consumer 3

Food Chains & Food Webs What vital “recycler” is not shown

in this food chain?

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?

producer consumer 1 consumer 2 consumer 3

decomposer