Ecology Scientific study of interactions between organisms and their environment.

Interdependence An organisms ability to interact with their : Non-living environment Other organisms Survival depends on these interactions

Interdependence 6 owl stoat fox rat rabbit beetle

Energy Pyramid? Only about 10 % of the energy available within one trophic level is transferred to organisms at the next trophic level. 4

Where does all the energy go? Organisms use energy for body functions: growing, moving, reproducing, some non-digestable, some prey escape The rest is lost as heat!!! Discuss with period 5 5

Honors ?’s  Give at least 3 reasons for the low rate of energy transfer within ecosystems (from one level to the next) Explain why food chains usually don’t have more than 3 to 4 levels.

Honors-Draw an Energy Pyramid It must have 4 trophic levels (minimum) Label each level based on how the organisms in that level get their energy Calculate how much energy will be at each level if the bottom level starts with 6,200,000 calories (kcal)

Energy Pyramid Trophic Levels Only about 10 % of the Energy in one level is transferred to the next. 1 10 100 Most of the remaining energy is used by the animal for life process. What is left is released as heat into the environment.

Biomass Pyramid

Pyramid of Numbers

Ecological Pyramids Biomass Pyramid Biomass the total amount of living tissue within a given trophic level.

Pyramid of Numbers

Ecological Pyramids Pyramid of Numbers A pyramid of numbers shows the relative number of individual organisms at each trophic level.