Ecosystem Ecology

1. Ecosystem Ecology Food Chains, Food Webs, Trophic Levels, nutrient Cycles...

2. Ecosystem • All the organisms in a community plus abiotic factors • Transform energy & process matter • Ecosystems are self-sustaining • what is needed? • capture energy • transfer energy • cycle nutrients

3. constant inputof energy energy flowsthrough biosphere How does energy move through the ecosystem? Ecosystem inputs nutrients cycle • inputs • energy • nutrients

4. loss of energy loss of energy sun Energy flows through ecosystems secondary consumers (carnivores) primary consumers (herbivores) producers (plants)

5. Primary Productivity • What is primary productivity? • What is GPP? • What is NPP? • How does the light/dark bottle method allow you to calculate primary productivity? 5

6. Limiting Factors • What are some limiting Factors that can effect productivity? • Light • Nitrogen • Phosphorous

7. What is learned from this data?

8. Food chains Level 4 Tertiary consumer top carnivore • Trophic levels • Why do food chains usually go up only 4 or 5 levels? • all levels connect to decomposers Level 3 Secondary consumer carnivore Level 2 Primary consumer heterotrophs herbivore Level 1 Producer autotrophs Fungi Decomposers Bacteria

9. energy lost todaily living energy lost todaily living only this energymoves on to the next level in the food chain Inefficiency of energy transfer • Loss of energy between levels of food chain • Where is the energy that is not available to the next tropic level? 17% growth 33% cellular respiration 50% waste (feces)

10. 100 1,000,000,000 100,000 1 Ecological pyramid • Loss of energy between levels of food chain • can feed fewer animals in each level

11. Food webs • Food chains are linked together into food webs • Who eats whom? • a species may weave into web at more than one level • bears • humans • eating meat? • eating plants?

12. Humans in food chains • What has more energy a pound of hamburger or a pound of peas? • What is the most efficient way for one person to eat? • What is the most efficient way for the human population to eat?

13. Biological Magnification Why do eggshells become Fragile? Where does the toxin accumulate? Let’s go to the video!

14. biosphere Matter cannot be created ordestroyed Don’t forgetthe laws of Physics! Nutrients… nutrients cycle

15. nutrientsENTER FOOD CHAIN= made availableto producers return toabioticreservoir geologicprocesse abioticreservor consumer decomposer producer Decompositionconnects all trophic levels consumers consumers decomposers nutrientsmade availableto producers abioticreservoir geologicprocesses General Nutrient Cycle

16. CO2 in atmosphere Combustion of fuels • abiotic reservoir: • CO2 in atmosphere Other reservoir • Fossil fuels • enter food chain: • photosynthesis = carbon fixation in Calvin cycle • recycle: • decomposition • return to abiotic: • respiration • combustion Industry and home Photosynthesis Diffusion Respiration Plants Animals Dissolved CO2 Bicarbonates Photosynthesis Deposition of dead material Animals Plants and algae Fossil fuels (oil, gas, coal) Deposition of dead material Carbonates in sediment Carbon cycle

17. abiotic reservoir: • N in atmosphere • Local reservoir N in soil • enter food chain: • nitrogen fixation by soil & aquatic bacteria • recycle: • decomposing & nitrifying bacteria • return to abiotic: • denitrifying bacteria Nitrogen cycle Atmospheric nitrogen Carnivores Herbivores Birds Plants Plankton with nitrogen-fixing bacteria Death, excretion, feces Nitrogen-fixing bacteria (plant roots) Fish Decomposing bacteria amino acids excretion Nitrogen-fixing bacteria (soil) Ammonifying bacteria loss to deep sediments Nitrifying bacteria Denitrifying bacteria soil nitrates

18. abiotic reservoir: • surface & atmospheric water • enter food chain: • precipitation & plant uptake • recycle: • transpiration • return to abiotic: • evaporation & runoff Water cycle Solar energy Transpiration Water vapor Evaporation Precipitation Oceans Runoff Lakes Percolation in soil Aquifer Groundwater

19. Transpiration

20. abiotic reservoir: • rocks, minerals, soil • enter food chain: • erosion releases soluble phosphate • uptake by plants • recycle: • decomposing bacteria & fungi • return to abiotic: • loss to ocean sediment Phosphorus cycle Land animals Plants Animal tissue and feces Urine Soluble soil phosphate Decomposers (bacteria and fungi) Loss in drainage Rocks and minerals Phosphates in solution Decomposers (bacteria & fungi) Animal tissue and feces Plants and algae Aquatic animals Precipitates Loss to deep sediment

21. Breaking the water cycle • Deforestation breaks the water cycle • groundwater is not transpired. Precipitation is not created. forest → desert desertification

22. 7800 acres Studying ecosystems 38 acre deforestation • Hubbard Brook Experimental Forest

23. Effects of deforestation • 60x loss in nitrogen • 10x loss in calcium • 40% increase in runoff • loss of water loss into surface water nitrate levels in runoff 80 40 loss out of ecosystem! Concentration of nitrate (mg/l ) 4 Why is nitrogen so Important? Deforestation 2 0 1965 1966 1967 1968 Year

24. Rising CO2 Would this have happened without us?

25. Ozone Depletion What did we do this time?