Spring 2012

ENERGY FLOW THROUGH

ECOSYSTEMS

All organisms MUST obtain and use

energy…

ENERGY FLOW THROUGH ECOSYSTEMS

ENERGY ROLES (JOBS) IN ECOSYSTEMS

Each organism in an ecosystem has a role or niche.

Producer’s Role – make their own food through photosynthesis, convert the Sun’s energy to make glucose, provide food for 1st and 3rd level consumers.

Examples: Any plant… Grasses, shrubs, trees, algae… etc.

ENERGY ROLES (JOBS) IN ECOSYSTEMS

1st Level Consumer (Herbivores) Role-must consume another organism to obtain energy, ONLY CONSUME PLANTS, provide food for 2nd and 3rd level consumers.

Examples: Deer, rabbits, rodents (mice, rats, squirrels), insects, herbivorous birds, etc.

ENERGY ROLES (JOBS) IN ECOSYSTEMS

2nd Level Consumer (Carnivores) Role-must consume another organism to obtain energy, ONLY CONSUME OTHER CONSUMERS, provide food for 3rd level consumers.

Examples: snakes, foxes, predatory birds, jellyfish etc.

ENERGY ROLES (JOBS) IN ECOSYSTEMS

3rd Level Consumer (Omnivores and Large Carnivores) Role-must consume another organism to obtain energy, CONSUMES OTHER CONSUMERS and/or PRODUCERS, provide food for scavengers.

Examples: Humans, lions, bears,sharks, whales.

ENERGY ROLES (JOBS) IN ECOSYSTEMS

Scavenger’s Role-must consume another organism to obtain energy, CONSUMES DEAD ANIMAL REMAINS, provide food for other scavengers.

Examples: Hyenas, buzzards, flies, snails.

ENERGY ROLES (JOBS) IN ECOSYSTEMS

Decomposer’s Role-must consume another organism to obtain energy, BREAK DOWN DEAD PLANT AND ANIMAL REMAINS, provide food other organisms.

Examples: fungi, bacteria, earthworms,.

ENERGY ROLES (JOBS) IN ECOSYSTEMS

Bacteria: are decomposers that break down animal remains.

Fungus: are decomposers that break down plant remains.

Role for BOTH: returns materials to the soil, clean up the environment

ENERGY FLOW

Food Chains: shows ONE possible path for the flow of energy for a particular organism in an ecosystem.

Rules: A.Must start with producers to 1st level consumer to 2nd, and so on.

B.Must use arrows to show the direction of energy flow.

Organism that is eaten

Organism that is eating

FOOD CHAIN EXAMPLES

Food Web: Many overlapping food chains in an ecosystem. Shows relationships & dependencies to others.

Rules: A.Must start with producers to 1st level consumer to 2nd, and so on.

B.Must use arrows to show the direction of energy flow (arrows may overlap).

ENERGY FLOW

FOOD WEB EXAMPLE

Energy Pyramids: Shows the flow of energy in a food chain with LESS energy as each level goes up.

Rules: A.Producers go on the bottom, 3rd level consumer on top.B.Must have more producers than 1st level consumers, more 1st than 2nd , more 2nd than 3rd, etc.

ENERGY FLOW

ENERGY PYRAMID

Autotrophs: Organisms that can make their own food. (Producers)

Heterotrophs: Organisms that cannot make their own food, they must consume. (Consumers, Scavengers, Decomposers)

TWO TYPES OF ORGANISMS