Roles of Organisms in Roles of Organisms in EcosystemsEcosystems
Essential Questions• What are the energy roles of organisms in
an ecosystem?
Energy Roles
• An organism’s energy role is determined by how it obtains or gets energy and interacts with other organisms within an ecosystem.
• Each organisms in an ecosystem fills the energy role of producer consumer, or decomposer – this is it’s niche.
Producers and their Niche
• An organism that can make its own food is a producer.
• Energy enters most ecosystems as sunlight, which plants, algae and some bacteria use to make their own food (photosynthesis).
• Producers are the source of all food in an ecosystem.
• Think about it – have you ever had to give a plant half of your lunch because it was starving?
Consumers and their Niche
• Consumers cannot make their own food and therefore get food by feeding off of other organisms.
• Compare and Contrast: How are producers and consumers similar and different?
• Consumers are classified by what they eat. They can be herbivores, carnivores or omnivores.
Herbivores
• Herbivores are consumers that get their energy from eating only plants.
• Can you think of some herbivores?
Omnivores
• Omnivores are consumers that get energy from eating both plants and animals.
• Bears, humans and ____________ are omnivores.
Carnivores
• Carnivores are consumers that eat only animals.
• Lions and spiders are some examples of carnivores.
Decomposers and their Niche
• Decomposers break down wastes and dead organisms and return nutrients to the ecosystem.
• Earthworms, mushrooms and bacteria are decomposers.
• Is the niche of a decomposer important?
Paparazzi!!
• Looking for producers, consumers and decomposers in our ecosystem!
• Grab your science notebooks, your pencils and I’ll grab my camera as we go on a hunt for organisms in our ecosystem.
Energy Flows Through Ecosystems
• The Sun’s energy can flow through an ecosystem.
• As the Sun’s energy enters most ecosystems it is converted into food by producers.
• This energy is transferred to each organism that eats a producer and then to other organisms that feed on these consumers.
Food Chain and Webs• The movement of energy through an
ecosystem can be shown in diagrams called food chains and food webs.
• A food chain is a series of events in which one organism (predator) eats another (prey) and obtains energy.
• It shows one possible path that energy can flow.
Levels in a Food Chain
• All food chains have different levels of consumers.
Producer First level Second
consumer consumer
A Food Web• Do you eat the same thing every day?• A Food Web is a combination of many food
chains.• Consumers and producers belong to many
different food chains.
Red arrows showenergy moving fromsecond-level consumersto third-level consumers.
Yellow arrows showenergy moving fromfirst-level consumers tosecond-level consumers.
Blue arrows show themovement of energyfrom producers tofirst-level consumers.
Producers form the baseof the food web.
Decomposers consumethe wastes and remainsof other organisms.Bacteria
Energy Pyramid• A diagram called an energy pyramid
shows the amount of energy that moves from one feeding level to another in a food web.
• The most energy is available at the producer level of the pyramid. As you move up the pyramid, each level has less energy available than the level below.
• Why do you think this happens?
Producers (1,000 kcal)
First-Level Consumers (100 kcal)
Second-Level Consumers (10 kcal)
Third-Level Consumers (1 kcal)
Energy Pyramids
• When an organism in an ecosystem eats, it obtains energy. The organism uses some of this energy to move, grow, reproduce, and carry out other life activities.
• This means that only some of the energy it obtains will be available to the next organism in the food web.
What Eats What?
• In your groups research a food chain that exist within each type of ecosystem below:
• Ocean• Forest• Desert• Wetland
• Use a flow chart to show your work.• There are books and computers for you to
use!
