1. Chapter 3 The Biosphere

2. 3.1 What is ecology? Ecology: scientific study of interactions among & betwn org & env’t –Ernst Haeckel (1866)-oikos: “house” –Largest “house”: Biosphere: Life Layer: land, water, & atmo, supports life 8 Km atm to 11Km below ocean

3. Levels of Organization 1 organism Grp of same organism (species) in 1 area Diff pop in same area All org in area w/ env’t Biome: eco w/ same climate & dominate community

4. Ecological Research Observation: 1 st step in designing experiment/model Experimentation: test hypo –artificial env’t in lab or natural env’t Model: use computer/formula to study –for studies over time or large spacial scale global warming global warming –for ethical reasons Ex: use of mice

5. 3.2 Energy Flow Sunlight: main NRG source for life Autotrophs: (producers) produce food using E from env’t Photosynthesis: plants/algae convert sunlight E into food NRG (Carbs) 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2

6. Autotroph (cont) Chemosynthesis: bacteria convert chemical NRG into carb NRG

7. Heterotroph-Consumer: eat food for NRG Herbivore: plant eaters Carnivore: animal eaters Omnivore: eat plants & animals

8. Heterotrophs (cont) Detrivore: feed on remains/dead matter Decomposer: breakdown organic matter

9. Food Chain One-way stepwise flow of NRG

10. Food Web More complex feeding relationships (many food chains)

11. Trophic Levels NRG steps from sun, producers = 1 st level l

12. Energy Pyramid Rule of 10%-decrease amt of NRG at each trophic level

13. Biomass Pyramid Amount of living organic tissue/level

14. Pyramid of Numbers # of indiv org at each level

15. 3.3 Cycles of Matter (within/betwn ecosystems) Biogeochemical cycles: forms of matter –connects biology, geological and chemical aspects of the biosphere Continuous Cycle  Never stops

16. Water Cycle Precipitation/condensation (dew) Evaportation/transpiration (plant evap) Transpiration (evap from plants) Condensation Precip- rain

17. Carbon Cycle CO 2 to producer w/photosyn (sugar) Consumer eats prod w/C (carbs) Cellular respir breaks down food –C released back into eco as CO 2

18. Nitrogen Cycle Org require N for Amino Acid for proteins N 2 (gas) abundant in atmo N-fixing-bacteria (on legume root) turn N 2 into ammonia (useable by plants) Decomposers return N 2 to atmo

19. Limiting Nutrient Scarce nutrient, cycles slowly thru sys –Ex: Algae Bloom: growth removes O 2 causing other org to die

20. 4.2 What shapes an Ecosystem? Biotic Factors: living (plants/anmls) Abiotic Factors: physical (temp, precip) –Both influence survival, growth, & productivity in habitat (area where org lives)

21. Niche Role in community, “occupation” –Depends on abiotic & biotic factors –One species/niche (competitive exclusion principle) –Includes: food it eats, how it eats, when & how it reproduces

22. Community Interactions 1. Competition: Struggle btw org for limited resources (food, water)

23. Community Interaction 2. Predation: 1 org hunts/kills for food –Predator/Prey

24. Community Interaction 3. Symbiosis: 2 species close together –Mutualism: Both benefit (win-win) –Commensalism: 1 benefits/ other not helped/harmed

25. –Parasitism: 1 (helped) lives in/on another (harmed) –Ex: Aphids & tapeworm

26. Ecological Succession Predicatable changes in ecosystem Primary Succession: w/no soil Pioneer species (1 st species): Lichens & mosses break rock to soil

27. 2.Secondary Succession: disturbance w/o removing soil Ex: Fire, tornado, hurricanes