Energy Flows thru Ecosystems

• LIVING THINGS CAPTURE & RELEASE ENERGY

• MODELS HELP EXPLAIN FEEDING RELATIONSHIPS

• AVAILABLE ENERGY DECREASES AS IT MOVES THROUGH AN ECOSYSTEM.

Living Things Capture & Release Energy

• Everything you do requires energy. You use chemical energy (in food) which is released to environment as heat, as you sweat.

• All living things need energy. Most comes from Sun originally. First, living things must capture Sun’s energy and store it in a usable form (food).

• Producers, Consumers and Decomposers all need energy and transfer it in some way.

PRODUCERS• Producer: organism that captures energy & stores it in food as

chemical energy.• Producers package energy for other living parts of an

ecosystem. • Most energy enters thru photosynthesis (CO2 + H2O sugar +O2)

• Plants are most common producers on land, photosynthetic bacteria & algae help make food in water.

• Chemosynthesis: produce food from chemicals (special bacteria in deep ocean water volcanic vents)

CONSUMERS• Consumer: can’t produce

own food, must get it by eating/consuming other organisms.

• Primary consumer (caterpillar) are first link between producers & other consumers; Secondary consumer (bird) eat primaries; tertiary (cat) eats secondaries.

• Scavengers are special consumers (like vulture, that feeds on dead animals)

DECOMPOSERS• Decomposer: break down

dead plant & animal matter into simpler compounds.

• A type of clean-up crew of an ecosystem.

• Fungi & bacteria break down dead leaves, roots, branches, & dead animals into soil again. A pinch of soil may have ½ million fungi & billions of bacteria.

• Decomposers release the last bit of energy from once-living matter back into to environment & recycle matter at the same time.

HELPFUL FOOD MODELS• FOOD CHAIN:

Feeding relationship between a producer & single chain of consumers in ecosystem.

• 1oCattail2ocaterpillar3ofrog4oheron

• Energy is captured & released at each link in the chain. Arrows show flow of energy from organism to organism.

• FOOD WEB: Feeding relationship between many different consumers & producers in an ecosystem.

• A web can show how one consumer can play several roles in an ecosystem.

• If one organism is removed from chain or web, it may affect many other organisms in the ecosystem.

Energy Decreases as Moves Thru Ecosystem• Energy Pyramid = shows

amount of energy available at each feeding level of an ecosystem.

• First level = producers, 2nd level are primary consumers and so on.

• Usable energy decreases as it moves from producer to consumers (gets smaller, the farther up the pyramid you go).

• Plants capture Sun’s Energyinsects eat plant & use some energyshrew eats insect & uses someowl eats shrew