*Read the entire board! *Note change to homework!!!! Please have your homework on your desk for a stamp Yo!*
Comparative Niches Share with your neighbor! Find the strongest comparison in the group. Statement: Even though ecosystems are different, they need to have the same niches. Agree or disagree? Defend your choice!
Energy flow in ecosystems
Energy Pyramid Fig. 4–16 ecological efficiency 5% to 20% 10% efficiency general rule © Brooks/Cole Publishing Company / ITP Graphic representation of energy available at each trophic level. 90% energy is lost in transfer between trophic levels: motion, body heat, metabolism, growth 10% Rule: Only 10% of energy is available to next trophic level.
Energy pyramids – key understandings Fig. 4–17 © Brooks/Cole Publishing Company / ITP Explain why there are no more than 5 or 6 links in a food chain. Give us our language “lower/higher” on the food chain. Can NEVER be “upside” down Explain why top predators like wolves need lots of land to find enough food to survive.
Prairie Ecosystem Hawks Snakes Mice Grasses
Our food chain – which would provide more total calories for 7 billion people? human animals plants human plants
Biomass Pyramids measure mass Fig. 4–18 © Brooks/Cole Publishing Company / ITP
Pyramids of Numbers Fig. 4–19 © Brooks/Cole Publishing Company / ITP
A measure of the rate at which autotrophs store biomass. Net primary productivity = photosynthetic rate of plants – respiration rate of plants. Primary Productivity determines the shape of the pyramids’ base (and then the next levels up) Net Primary Productivity
Primary Productivity (per area) Fig. 4–21 © Brooks/Cole Publishing Company / ITP
Check for understanding! Key understandings of energy pyramids Where does 90% of the energy go? How to calculate energy at each level (units?) Exceptions to numbers and biomass pyramids