1. Principles of Ecology

2. Learning Targets Describe the different niches organisms occupy in food chains and diagram a model of a food web that includes several food chains. Compare and contrast how matter and energy move through ecosystems and explain how each process relates to the laws of conservation of mass and energy. Discuss the potential ecological, environmental, and social impacts of a primary plant-based or primary meat-based diet in a human society. Identify how living organisms influence global and local cycles of matter (ex. Carbon, nitrogen, phosphorus, and water cycles)

3. Energy flows through an ecosystem from producers to consumers. Energy flows from one trophic level to the next. (troph = feeding) Nutrients (matter) cycle in an ecosystem. The processes of photosynthesis and aerobic respiration are important in nutrient cycling and energy flow.

4. Primary Producers – plants, algae, photosynthetic bacteria, some archaea cells. Most are photoautotrophs. Some are chemoautotrophs (use chemicals in the environment instead of sunlight to produce food)

5. Food Chains – show the trophic relationship between organisms in an ecosystem. A single food chain is just one link in a food web Primary Producer Primary Consumer Secondary Consumer Tertiary Consumer Quaternary Consumer

6. Food Webs show all the interacting food chains in an ecosystem.

7. You are locked in a large, steel room with a lot of corn (100kg), 3 cows, 6 chickens, and 3 other people. There is a water source and a light source, but no way to grow the corn on the hard steel floor. You can not escape. Your only option is to survive as long as possible until you starve to death. Talk with your table group and try to find a strategy that would allow you to survive the longest.

8. Energy flow in an ecosystem is not efficient between trophic levels, which can be seen in an energy pyramid. The 10% rule Biomass pyramids also decline as the trophic level increases. Why? Energy lost in the form of heat. Energy used for metabolic purposes. Indigestible material Only about 10% of all energy is passed from one trophic level to the next

9. The dynamics of energy flow through ecosystems have important implications for the human population. Consider the resources needed to grow, feed, process, and transport beef.

10. Discussion Question: As human populations continue to grow, will humans be able to sustain a diet that relies on animals for protein? Trophic level Secondary consumers Primary consumers Primary producers

11. Decomposers and Detritivores play an important role in recycling nutrients in an ecosystem.

12. The chemical cycling in an ecosystem is an essential component of ecosystem function. Also called Biogeochemical Cycles CO 2 in atmosphere Photosynthesis Cellular respiration Burning of fossil fuels and wood Higher-level consumers Primary consumers Detritus Carbon compounds in water Decomposition THE CARBON CYCLE N 2 in atmosphere Denitrifying bacteria Nitrifying bacteria Nitrifying bacteria Nitrification Nitrogen-fixing soil bacteria Nitrogen-fixing bacteria in root nodules of legumes Decomposers Ammonification Assimilation NH 3 NH 4 + NO 3  NO 2  Rain Plants Consumption Decomposition Geologic uplift Weathering of rocks Runoff Sedimentation Plant uptake of PO 4 3  Soil Leaching THE NITROGEN CYCLE THE PHOSPHORUS CYCLE

13. The Carbon Cycle is a global biogeochemical cycle What are some living and non-living reservoirs of carbon? What are some of the processes that occur that change carbon from one form to another? In what form(s) is carbon utilized by living things?

14. The nitrogen cycle is a global biogeochemical cycle What sort of organisms convert nitrogen from one form to another? Why are each of these processes essential for an ecosystem foodweb?