I. Energy Flow A. Producers Make their own food through photosynthesis Examples: Plants, algae
B. Consumers Feed on other organisms, cannot make their own food Example: humans, bear, insects
C. Decomposers Break down dead organisms, recycle chemicals to soil, water, & air Example: fungi & bacteria
D. Energy enters ecosystems as LIGHT is converted to CHEMICAL ENERGY by producers and exits the ecosystem as HEAT.
II. Food Chain A. Trophic levels Feeding level Represents position in food chain/food web
B. Food Chain pathway of food transfer from one trophic level to another You always start with PRODUCERS on the left/bottom of a food chain.
C. Producer --> Primary Consumer--> Secondary Consumer--> Tertiary Consumer D. Decomposers are found at EACH trophic level.
III. Food Web A. Definition: interconnected branching food chains- more realistic representation of feeding relationships
IV. Three Kinds of Ecological Pyramids A. Energy pyramid Description: diagram representing energy loss from one trophic level to the next
10% Rule An average of 10% of the available energy at a trophic level is converted to biomass in the next higher trophic level.
B. Biomass Pyramid Description: represents the dry mass of organisms at each trophic level
C. Pyramid of Numbers Description: the number of individual organisms in each trophic level of an ecosystem
Why do you think all 3 pyramids look similar?