ECOSYSTEMS Energy Flow in Ecosystems SC STANDARD B3

ECOSYSTEMS: Energy Flow in Ecosystems SC STANDARD B-3. 6: Illustrate the flow of energy through ecosystems

�CN: Page 140 �Topic: Energy �EQ: Why is there a limited # of levels possible in an energy pyramid?

Energy Flow in Ecosystems �Primary source of energy for any ecosystem is the Sun. �Everything an organism does requires energy.

Energy Flow in Ecosystems �Producers: any photosynthetic or chemosynthetic autotroph that serve as the basic food source in an ecosystem

Energy Flow in Ecosystems �Consumers: an organism that eats other organisms or organic matter instead of producing its own nutrients or obtaining nutrients from inorganic sources

Energy Flow in Ecosystems �Decomposers: an organism that feeds by breaking down organic matter from dead organisms

Energy Flow in Ecosystems �Energy flows from SUN PRODUCERS CONSUMERS DECOMPOSERS

Energy Flow in Ecosystems �trophic level: one of the steps in a food chain or food pyramid

Energy Flow in Ecosystems �Food Chains: 1 st trophic level = producers 2 nd trophic level = primary consumers (herbivores) 3 rd trophic level = secondary consumers (carnivores that eat herbivores) 4 th trophic level = carnivores that eat other carnivores

Energy Flow in Ecosystems

Energy Flow in Ecosystems �Food Web: interconnected group of food chains found in ecosystems �Example: rabbits (herbivores) are not just eaten by fox. In same ecosystem they will also be eaten by hawks, coyote, panthers, or feral cats

Energy Flow in Ecosystems �Energy is transferred at each trophic level in a food chain but it is not 100% efficient. Some energy is lost as heat at each link in a food web. �The 10% Rule: (an approximate value) says that with each step in a food chain only 10% of the energy is stored in the consumer. The rest is lost as heat.

Energy Flow in Ecosystems

Energy Flow in Ecosystems �An energy pyramid is a triangular diagram that shows an ecosystem’s loss of energy which results as energy passes through the ecosystem’s food chain. �Each layer of the pyramid represents one trophic level �Producers are at the base �Each level contains about 90% less energy than the level below it

Energy Pyramids

Energy Pyramids

Biomass Pyramids �biomass: total amount of living tissue w/in a given trophic level (g/unit area) �biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem �includes all matter: waste, body mass, parts of prey not eaten by predator

Biomass Pyramids

Pyramid of Numbers �ecological pyramids can also be based on the #s of individual organisms at each trophic level