1. Keystone Ecology Review

2. Levels of Organization Ecosystem—biotic & abiotic Community—all biotic factors Pollution—only one group (species) of organisms

3. Comparing Biotic and Abiotic Factors Biotic—all living or once living organisms Abiotic—all non living factors

4. Food Chain in an Antarctic Ecosystem A food chain shows ONE possible feeding pathway. The arrow always goes into the mouth of the eater

5. Food Web in an Antarctic Ecosystem A food web shows all possible feeding relationships in a ecosystem

6. Energy Transfer Through Trophic Levels Only 10% of energy from each level is available to be passed on to the next level. Most of it gets used or lost as heat. That’s why more organisms on bottom than top

7. Energy Pyramid

8. Symbiosis—close, long term relationship b/w to organisms (at least one benefits Parasitism, mutualism, commensalism

9. Parasitism The parasite benefits while the host is hurt

10. Mutualism Both organisms benefit

11. Commensalism One benefits while the other is neither hurt nor helped

12. Recycling Matter through the Ecosystem

13. Water Cycle Key processes are – Evaporation – Transpiration – Precipitation

14. Carbon Cycle Photosynthesis & Respiration are the two main steps

16. Nitrogen Cycle Nitrogen fixing bacteria change nitrogen gas into a useable form for nitrogen for plants (& then animals) Denitrification puts nitrogen gas back into the atmosphere

17. Phosphorus Cycle Phosphorous moves from phosphate deposited in rocks, to the soil, to living organisms and finally to the ocean

18. Succession—gradual sequential regrowth of a community of a species in a area Two Types: Primary Secondary

19. Primary Succession Occurs where the land has not supported any prior life, bare rock, newly formed islands (soil lacks nutrients or any life left behind)

20. Secondary Succession Occurs where soil has previously existed and some life is still left behind.

21. Ecological Succession at Glacier Bay

22. Carrying capacity— number of individuals the environment can sustain Limiting factor— any factor the restrains the growth of a population (space, sunlight, food, water, mates)

23. Carrying Capacity of Reindeer in Pribilof Islands