Energy in the Environment

Energy Roles and Energy Flow

NGSS Standard

• MS-LS2-e. Conduct an investigation of the cycling of matter among living and nonliving parts of ecosystems to support the explanation of the flow of energy and conservation of matter.

Energy

• Think back to our discussion of predator-prey relationships.

• What is the main benefit for the predator in the organism relationship?

Energy

• The main benefit from a predator-prey relationship for the predator, is that the predator gains food from it’s prey.

• This food will eventually will be broken down by the predator and use for energy.

• What is the process that takes food and gives an organism energy?

Energy

• Energy usage is a need of living things and as a result plays a large role in the environment.

• All organisms fill out a specific energy role in an ecosystem.

• The organism’s energy role is determined by how the animal obtains energy and interacts with other organisms.

Energy Roles

• Producers

• Consumers

• Decomposers

Producers

• Most energy enters ecosystems through sunlight. This energy is then captured by certain consumers and stored as food energy, through photosynthesis.

• All organisms that produce their own food are called producers.– This includes plants, algae, and some

bacteria.

Consumers

• Obtain their food by feeding on other organisms.

• Consumers are classified by what they eat.– Herbivores– Carnivores– Omnivores– Scavenger

Decomposers

• Break down wastes and dead organisms and return the raw materials found in these organisms to the ecosystem.

• If we did not have decomposers the raw materials of life would stay locked up in organisms and would never be re-circulated in the environment.

• Serves as the “recyclers” of the ecosystem.

Energy

• How do you think energy is transferred between organisms?

Food Chains and Food Webs

• Energy is transferred to from organism to organism.

• Consumers eat producers, other consumers eat the first consumers and so on…

• The flow of this energy can be diagramed by food chains and food webs.

Food Chain

• A series of energy transfer in which one organism eats another and obtains energy.

• Food chains are not very realistic.

• Think back to our lion example last week how many food sources did it have?

Food Webs

• Are multiple overlapping food chains.

• These are more realistic because organisms can serve as food for many organisms.

Energy

• After looking at energy transfers do you think energy is available in equal amounts?

• Think about how energy comes into the ecosystem.

Energy

• Energy availability is not equal at every level.

• Organisms will use 90% of the energy they obtain for life functions or lost as heat to the environment.

• About 10% of the energy stored in an organism will be passed onto the next organism.

Energy

• Since only 10% of energy is transferred from organism to organism, ecosystems are limited to the number of consumers they can support.

• Note: just because top level consumers receive less energy when they feed, that does not mean they require less energy.

• In most cases they require more energy than other consumers.

Review

• How are consumers classed?

• How is energy transferred between organisms?

• What does an energy pyramid represent?

• How does energy enter an ecosystem?

• What are food chains and food webs?

• Which level of the energy pyramid contains the most energy?