Energy Flow

Energy Flow

Objectives:

Describe how energy flows through ecosystems.

Explain how food chains and webs model feeding relationships.

Identify trophic levels in a food chain or web.

Producers

Organisms that produce food for themselves and other organisms

A producer gets its energy by making it!

Producers use energy from sunlight to make food by photosynthesis.

Examples: include plants, algae, and certain bacteria

Lupine, buckwheat, lomatiums, and other wildflowers carpet the trail to Ben Lomond Peak on the Wasatch-Cache National Forest, Utah.

Consumers

Consumers

Consumers get energy from eating producers and other animals.

Consumers cannot make their own food.

Organisms that depend on other organisms for food

Herbivores = Consumers

consume producers such as plants or algae

They are a necessary link between producers and other consumers.

Examples include deer, rabbits, and mice

Carnivores = Consumers

eats only other animals (consumers)

Examples: lions, polar bears, hawks, frogs, salmon, and spiders

Omnivores = Consumers

eats both plants (producers) and animals(consumers)

Examples: humans, black bears, gulls, crows, and some species of fish.

Decomposers

When organisms die, they leave behind ENERGY and MATTER in their remains.

Decomposers:

Break down these remains and other wastes and release simple inorganic molecules back to the environment.

Get their energy by eating dead stuff!

Examples: Bacteria & Fungi

Banana Slugs Unpeeled

Millcreek Canyon

Scavengers = Decomposers

Consume the soft tissues of dead animals

Examples: vultures, raccoons, blowflies.

Detritivores = Decomposers

consume detritus—the dead leaves, animal feces, and other organic debris that collects on the soil or at the bottom of a body of water.

On land examples: earthworms, millipedes, and dung beetles

In water examples: “bottom feeders” such as sea cucumbers and catfish.

Food Chains

A food chain represents a single pathway through which energy and matter flow through an ecosystem.

Most organisms consume—and are consumed by—more than one species.

Producer

• Dunaliella salina

• Makes own food

• Usually a plant

• Photo-synthesis

Primary Consumer

•Brine shrimp

•Usually an herbivore

•Primary must eat plants

•Consumer can eat more than plants

Secondary Consumer

• Wilson’s phalarope

• Eats primary consumer

• Can be omnivore or carnivore

Tertiary Consumer

• Marsh Hawk

• Eats secoary consumer

• Typically a carnivore

A cloud of Wilson's phalaropes fly above Farmington Bay, Utah Life in the Great Salt Lake

Producer

• Rice Grass

• Makes own food

• Usually a plant

• Photo-synthesis

Primary Consumer

•Utah Prairie Dog

•Usually an herbivore

•Primary must eat plants

•Consumer can eat more than plants

Secondary Consumer

• Black-footed ferret

• Eats primary consumer

• Can be omnivore or carnivore

Producer

• Black brush

• Makes own food

• Usually a plant

• Photo-synthesis

Primary Consumer

• Bighorn Sheep

• Usually an herbivore

• Primary must eat plants

• Consumer can eat more than plants

Secondary Consumer

• Cougars

• Eats primary consumer

• Can be omnivore or carnivore

Food Chain: Models how matter and energy flow through an ecosystem

Solar Energy

• Sun

Chemical Energy

• Glucose Molecules

Mechanical Energy

•Animal eats and uses it to live

Heat Energy

• Back into space

Food Chain: Models how matter and energy flow through an ecosystem

Food Webs

A food web represents multiple pathways through which energy and matter flow through an ecosystem.

It includes many intersecting food chains.

Most organisms eat, and are eaten, by more than one species.

Food Webs: A model that shows several connected food chains.

Trophic Levels: the feeding positions in a food chain or web

Trophic Level

Type of Organism

Where It Gets Food

Example

1st Producer Makes its own food

Plants make food

2nd Primary

Consumer

Consumes producers

Mice eat plant seeds

3rd Secondary Consumer

Consumes primary

consumers

Snakes eat mice

4th Tertiary

Consumer

Consumes secondary consumers

Hawks eat Snakes

Energy Pyramid

Shows the amount of energy available at each step of a food chain

Trophic Levels and Energy

Energy is passed up a food chain or web from lower to higher trophic levels.

Only about 10 percent of the energy at one level is available to the next level.

What happens to the other 90 percent of energy?

Trophic Levels and Energy

What happens to the other 90 percent of energy?

Used for metabolic processes

Given off to the environment as heat

Trophic Levels and Biomass

Less energy is available at higher trophic levels

there are usually fewer organisms at higher trophic levels

Organisms tend to be larger in size at higher trophic levels

Numbers of organisms tend to be smaller at higher trophic levels

Biomass is the total mass of organisms at a trophic level

Less biomass at higher trophic levels

Energy Pyramid: Shows the amount of energy available at each step of a food chain

Energy Pyramid

Shows the amount of energy available at each step of a food chain

Top Level

Carnivore

Carnivores; Omnivores

Herbivores

Producers

Energy Pyramid

Shows the amount of energy available at each step of a food chain

Energy Of Tertiary Consumers

Energy of Secondary Consumers

Energy of Consumers

Energy of Producers

Energy Pyramid

Shows the amount of energy available at each step of a food chain

.1%

Energy

1% Energy

10% Energy

100% Energy