1. Energy flows through an ecosystem

2. Representing energy moving through ecosystems
Food chains
Food webs
Food pyramids
(c) McGraw Hill Ryerson 2007

3. Examples of terrestrial and aquatic food chains
4th trophic level 3rd trophic level 2nd trophic level 1st trophic level
(c) McGraw Hill Ryerson 2007

4. Food Webs
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5. Energy Flow and Energy Loss
(c) McGraw Hill Ryerson 2007

6. Food Pyramids
A food pyramid shows the loss of energy from one trophic level to another. This is represented by the decreasing size of the block at each level. Producers such as plants store the most energy. Carnivores such as great horned owls store the least.
Eats carnivore
Eats herbivore
Eats plants
Plants
90% of energy is lost between trophic levels

7. Consumers in a food chain can be classified as:
Detrivores –obtain energy from dead organisms and waste matter
Ex. earthworms, bacteria, fungi
feed at every trophic level
have own, separate food chains and are very numerous
Herbivores – primary consumers
eat plants (producers) only
Carnivores – secondary or tertiary consumers
Secondary consumers - eat non-producers, such as herbivores
Tertiary consumers - eat secondary consumers
Omnivores – eat both plants and animals
Ex. Humans, bears
(c) McGraw Hill Ryerson 2007