Food Chains and Food Webs Energy Flow in Nature

Energy Roles An organism’s energy role in an ecosystem may be that of a producer, consumer, or decomposer.

Producers An organism that can make its own food is a producer. Autotroph Source of all food in an ecosystem. Capture energy from sunlight and stores it as food energy.

Consumers Consumers are heterotrophs, or living things that cannot make food for themselves. A food chain contains several kinds of consumers, each of which occupies a different trophic level. Herbivore, carnivores, omnivores

Niche-A niche is an organism’s way of making a living that includes choices of habitat, food and behavior. No two species within a community may share the same niche. This eliminates competition.

Example of Ecological Niche:basically how an animal/plant lives day to day. Oak Tree:Oak trees: absorb sunlight by photosynthesis; absorb water and mineral salts from the soil; provide shelter for many animals and other plants; act as a support for creeping plants; serve as a source of food for animals; cover the ground with their dead leaves in the autumn.

Hedgehogs Hedgehogs in a garden also have an ecological niche. They rummage about in the flowerbeds eating a variety of insects and other invertebrates which live underneath the dead leaves and twigs in the flowerbeds. That is their profession. They are covered in sharp spines which protect them from predators, so being caught and eaten is not a part of their job description. However, hedgehogs cannot groom themselves properly. All those spines on their backs make a superb environment or microhabitat for fleas and ticks. Hedgehogs put nitrogen back into the soil when they urinate! They eat slugs, so that reduces the effect which slugs have on the flowers.

Consumer Tropic Levels Primary consumers eat producers (herbivores) Secondary consumers eat primary consumers (carnivores) Tertiary consumers eat secondary consumers (carnivores) Scavengers are carnivores that feed on the bodies of dead organisms.

Decomposers Help break down wastes and dead organisms and return the raw materials to the environment Bacteria and fungi

Food Chains Series of events where one organism eats another and obtains energy. First organism in chain is the producer. The second organism is the consumer that eats the producer.

Plankton—Crab—Seal—Orca This is only one possible chain in a marine ecosystem.

Come up with an example to fill in the blocks of a food chain in two different ecosytems.

Food Webs Consists of many overlapping food chains in an ecosystem. Some organisms may play more than one role by changing consumer levels.

What happens in a food web if one or more of the organisms disappear?

Which animals are carnivores and herbivores?

Energy Pyramids A diagram that shows the amount of energy that moves from one feeding level to another in a food web. Represented in a triangle with the most energy at the producer level.

Energy Loss and Use 10% of energy transferred to next higher level. 90% of energy is used by organisms’ life processes. Due to energy loss, ecosystem cannot support many feeding levels.

Energy Pyramid