1. Ecosystems: components, energy flow, and matter cycling Chapter 3

2. Ecosystems Ecosystems include living and nonliving components

3. Ecosystems Living components of the ecosystem: Producers (autotrophs)- chemo- and photosynthesizers Consumers(heterotrophs)- herbivores, carnivores, omnivores, detritivores, decomposers

4. EcosystemsNonliving components of the ecosystem Physical-sunlight, shade, temperature change Chemical- level of water or oxygen in the soil, salinity in soil or water

5. Tolerance Levels Range of levels of physical or chemical factors in which an organism can survive Can be increased if exposed gradually – *This is acclimation (not passed to offspring like adaptation)

6. Threshold Effect The limit of tolerance is exceeded Example: After years of exposure to pollutants, an entire forest dies.

7. Limiting Factor One factor is limiting growth – either too much or too little Example: temperature, nutrient, salinity

8. Food Chain general sequence in which animals feed -Each organism is assigned a trophic level Primary producer  1st consumer  2 nd consumer plant herbivore1 st level carnivore

9. Energy Flow Pyramids Show useable energy at each trophic level. 80-95% of original energy is lost at each level. – What should we feed starving nations?

10. Matter and Energy Cycling Life on earth depends on: One way flow of useable energy to low quality, dispersed energy high quality ___ low quality Energy (usable) Energy (dispersed) usually solar heat

11. Matter and Energy Cycling Cycling of matter is required by living things Sun and gravity drive all cycles Light, warmth, energy to grow plants which feed other organisms, weather patterns.

12. Solar Energy drives Earth’s Cycles 34% of solar energy reflected into space 66 % degraded to heat (unusable) Only 0.023% of sunlight entering our atmosphere is used by green plants and some bacteria for photosynthesis (storing the energy from the sun as carbohydrates)

14. Nutrient Cycles Nutrients- elements needed by organisms to live and reproduce. “Macro” means it is needed in large amounts Ex. Oxygen, N,H,P,D,Ca “Micro” means it is needed in small amounts Ex. Zn, I, Fe *All nutrients cycle through living and nonliving systems and are converted to useable forms *We are using the same atoms as those from when life began!

15. Carbon Cycle Needed for carbohydrates (food/energy) We intervene Green House Effect- add more CO 2 to atmosphere than is being removed, by burning fossil fuels and trees.

16. Nitrogen Cycle Needed to make proteins We intervene: Add NO (burning fossil fuel) or excess NH 3 (ammonia fertilizer) and NO 2 (bacteria and fertilizers.)

17. Phosphorus Cycle needed for DNA, ATP, bones, teeth, some fats moves slowly (not a gas) limiting factor in many soil and aquatic systems

18. Phosphorus Cycle We intervene: -Mining PO 4 for fertilization and detergents (decrease in one area means an increase in another) -Untreated sewage dumped into ocean -Runoff of animal waste and fertilizer

19. Sulfur Cycle Needed in proteins We intervene -Burn fossil fuels -Refining petroleum -Use smelting to convert sulfur compounds of metallic mineral into free metals such as copper, lead, and zinc.

20. Water Cycle Needed for major component of cells and for all life processes Temp is very important Increase temp= increase evaporation Decrease temp= condensation

21. Water Cycle We intervene: -Drawing large amts. Of ground H 2 O -Intrusion of salt H 2 O in underground supplies -Cutting forests and paving roads.