Ecosystems

1. Ecosystems

2. Studying organisms in their environment biosphere ecosystem community population organism

3. Essential questions • What limits the production in ecosystems? • How do nutrients move in the ecosystem? • How does energy move through the ecosystem?

4. Ecosystem • All the organisms in a community plus abiotic factors • ecosystems are transformers of energy& processors of matter • Ecosystems are self-sustaining • what is needed? • capture energy • transfer energy • cycle nutrients

5. Ecosystem inputs biosphere constant inputof energy energy flowsthrough nutrients cycle Don’t forgetthe laws of Physics! Matter cannot be created ordestroyed nutrients can only cycle inputs • energy • nutrients

6. Participants in an Ecosystem • Primary producers-autotrophs that make up the first trophic level of any ecosystem • Ex-plants, phytoplankton, & some bacteria • Consumers-heterotrophs that feed on the tissues, products, and remains of other organisms • Ex=herbivores, carnivores, omnivores, parasites, detritivores, decomposers

7. Decomposers vs Detritivores • Detritivores eat particles of decomposing matter(detritus) • Types- • Scavengers-animals that feed on carrion, dead plant matter, or refuse. Ex-buzzards, ants, & vultures • Decomposersbreak down organic remains and wastes off all organisms and return nutrients to earth • Ex-bacteria, protists, and fungi

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

9. sun energy lost todaily living energy lost todaily living Inefficiency of energy transfer • Loss of energy between levels of food chain(only 10% is transferred b/t trophic levels) • To where is the energy lost? The cost of living! 17% growth only this energymoves on to the next level in the food chain 33% cellular respiration 50% waste (feces)

10. sun Level 4 Tertiary consumer Food chains • Trophic levels • feeding relationships • start with energy from the sun • captured byplants • 1st level of all food chains • food chains usually go up only 4 or 5 levels • inefficiency of energy transfer • all levels connect to decomposers top carnivore Level 3 Secondary consumer carnivore Level 2 Primary consumer heterotrophs herbivore Level 1 Producer autotrophs Fungi Decomposers Bacteria

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. Types of Food Webs • Grazing food web-energy flows mostly into herbivores, carnivores, then decomposers • Detrital food web-energy from producers flows mainly into detritivores and decomposers.

13. Biological Magnification in Food Webs • In biological magnification, some chemical substance is passed from organisms at one trophic level to those above and becomes increasingly concentrated in body tissues. • By 1995, people in the US were spreading more than 1.25 billion pounds of toxins per year! (insecticides, herbicides, fungicides…) • Example- The peregrine falcon almost became extinct as a result of biomagnification of DDT (a pesticide). DDT has been banned since the 70’s.

14. sun Ecological pyramid • Loss of energy between levels of food chain 1 100 100,000 1,000,000,000

15. Types of ecological pyramids • Biomass pyramid-depicts the dry weight of all of an ecosystem’s organisms at each tier • Energy pyramid-illustrates how the amount of usable energy diminishes as it is transferred through an ecosystem • Pyramid of numbers-shows how population size decreases as you go from producer to consumer

17. Decompositionconnects all trophic levels Generalized Nutrient cycling consumers consumers producers consumers decomposers decomposers nutrientsENTER FOOD CHAIN= made availableto producers nutrientsmade availableto producers return toabioticreservoir abioticreservoir abioticreservoir geologicprocesses geologicprocesses

18. In a biogeochemical cycle , an essential element moves from the environment, through ecosystems, then back to the environment. • Ex: O2,H,C,N, & P

19. CO2 in atmosphere Combustion of fuels 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 • abiotic reservoir: • CO2 in atmosphere • enter food chain: • photosynthesis = carbon fixation in Calvin cycle • recycle: • return to abiotic: • respiration • combustion Carbon cycle

20. abiotic reservoir: • N in atmosphere • 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

21. Nitrogen fixation-bacteria convert gaseous nitrogen to ammonia • Denitrification-conversion of nitrate or nitrite to gaseous nitrogen or nitrogen oxide by certain bacteria in the soil • Human activities add nitrogen to ecosystems. Use of fertilizer and fossil fuel burning are examples

23. 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

24. 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

25. Transpiration Remembertranspiration?

26. Breaking the water cycle • Deforestation breaks the water cycle • groundwater is not transpired to the atmosphere, so precipitation is not created forest  desert desertification

27. WangariMaathai Repairing the damage • The Greenbelt Movement • planting trees in Kenya • restoring a sustainable ecosystem • establishing democracy • empowering women Nobel Peace prize 2004

28. 7800 acres Studying ecosystems 38 acre deforestation Hubbard Brook Experimental Forest

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

30. A Global Water Crisis • Most water on Earth is too salty to drink (around 75%) • 2/3 of fresh water is used to irrigate fields • About ½ of the US population taps into groundwater for drinking water that can be contaminated. • If the US population and water depletion continues, our freshwater supply will be in danger. • Important terms: • Salinization-a build up of salt in soil that stunts crop plants and decreases yields. • Desalination-removal of salt from sea water

31. Greenhouse Gases, Global Warming • The greenhouse effect occurs when greenhouse gases trap heat in the lower atmosphere. • This makes Earth’s surface warm enough to support life. • Natural processes and human activities are adding more greenhouse gases to the atmosphere. • Examples: carbon dioxide, CFCs, methane, & nitrous oxide • This results in a result in global warming and climate change.