1. Ecosystems

2. Ecosystem inputs nutrients cycle inputs energy nutrients biosphere
energy flows through
constant input of energy
nutrients cycle
nutrients can only cycle
inputs
energy
nutrients

3. Biogeochemical Cycles
Matter is recycled and reused between the living and nonliving worlds through biogeochemical cycles
Water
Carbon
Nitrogen
Phosphorus

4. Water cycle Solar energy Transpiration Evaporation Precipitation
Water vapor
Evaporation
Precipitation
Oceans
Runoff
Lakes
Percolation in soil
Aquifer
Groundwater

5. Nitrogen cycle Atmospheric nitrogen Carnivores Herbivores Birds Plants
Plankton with
nitrogen-fixing
bacteria
Plants
Death, excretion, feces
Fish
Nitrogen-fixing
bacteria
(plant roots)
Decomposing bacteria
amino acids
excretion
Ammonifying bacteria
Nitrogen-fixing
bacteria
(soil)
loss to deep sediments
Nitrifying bacteria
Denitrifying
bacteria
soil nitrates

6. Nitrogen Cycle
All organisms need nitrogen to make proteins and nucleic acids
Nitrogen gas makes up 78% of the Earths atmosphere
Most plants only use nitrates (NO3)

7. Nitrogen fixation
The process bacteria use to convert nitrogen gas (N2) to ammonia (NH3)
The bacteria are known as nitrogen-fixing bacteria
They live in the soil and inside swellings on the roots of some plants (beans, clover, etc)
The plants supply the carbohydrates for the bacteria and the bacteria provide usable nitrogen

8. Recycling Nitrogen
The bodies of dead organisms contain nitrogen (proteins & nucleic acids)
Urine and dung also contain nitrogen
Decomposers break down these materials and release the nitrogen as ammonia (NH3), which becomes ammonium (NH4 +) in the soil
Processes known as ammonification, and makes nitrogen available to other organisms again.

9. Recycling Nitrogen
Soil bacteria take up NH4 + and oxidize it into nitrites (NO2 -) and nitrates (NO3 -) through the nitrification process
Plants use nitrates to form amino acids

10. Denitrification
When anaerobic bacteria break down nitrates and release nitrogen gas into the atmosphere
How nitrogen gas returns to the atmosphere
Animals must obtain nitrogen by eating plants and other organisms

11. Phosphorus cycle Land Plants animals 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
Aquatic
animals
Plants and
algae
Precipitates
Loss to deep sediment

12. Phosphorous Cycle
The movement of phosphorous from the environment to the organisms and back again
Phosphorous is essential to animals for bones, teeth, and DNA/RNA
Plants get it from the soil; Animals get it from other organisms
Extremely slow cycle and doesn’t normally occur in atmosphere

13. Phosphorous Cycle
When rocks erode, small amounts of phosphorous dissolve as phosphate (PO3 -)
Plants absorb phosphates through their roots
Also added when wastes and organisms decompose
Some comes from fertilizer

14. Carbon cycle CO2 in atmosphere Diffusion Respiration Photosynthesis
Plants and algae
Plants
Animals
Industry and home
Combustion of fuels
Carbonates in sediment
Bicarbonates
Deposition of
dead material
Deposition
of dead
material
Fossil fuels
(oil, gas, coal)
Dissolved CO2

15. Carbon Cycle
Photosynthesis and cellular respiration form the basis of this cycle
In photosynthesis, plants and other autotrophs use CO2, water, and solar energy to make carbohydrates
Autotrophs and heterotrophs break down carbohydrates during cellular respiration

16. Carbon Cycle
The byproducts of cellular respiration are carbon dioxide and water
Decomposers also release CO2 into the atmosphere when they break down organic molecules

17. Human Influences on the Carbon Cycle
The concentration of atmospheric carbon has risen more than 30% in the last 150 years
Humans contribute by burning fossil fuels and organic matter to produce energy

18. Fossil Fuels
The remains of organisms that have been transformed by decay, heat, and pressure into energy rich molecules
Burning releases the energy and CO2
When large areas of land are burned, more CO2 is produced, and less plants are there to absorb it

19. The Greenhouse Effect and Carbon Dioxide
The mean global temperature has increased about 1 °C since 1900, possibly because of trace gases like methane and CFC’s.
The atmospheric level of methane has more than doubled since What could have caused this?
Methane is the product of the bacterial decomposition of organic matter in the absence of oxygen. Mainly occurs in rice paddies and digestive tracts of termites (now in greater number because of the forests being destroyed).

20. GREENHOUSE EFFECT

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

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

23. T or F: The process that returns nitrogen to the atmosphere is called ammonification.
FALSE!
Denitrification!!

24. How could humans affect the nitrogen cycle at the bacterial level?
The addition of toxic chemicals to the soils; construction and deforestation can cause soil erosion

25. Pick 2 and write me an essay about each. 1
Pick 2 and write me an essay about each. 1. The role of bacteria in the carbon, nitrogen, and phosphorous cycles. 2. Explain the statement that nutrients cycle , but energy flows. 3. How do plants influence the various biogeochemical cycles? 4. How do humans influence the various biogeochemical cycles?