1. Chapter 3 (II) Biogeochemical Cycles
CHOPS

2. DO NOW
Why is carbon important? Hydrogen? Oxygen? Phosphorus? Sulfur?

4. Biosphere, Arizona

5. What are the differences??
Eutrophic lake Healthy lake
(high primary productivity
due to excessive nutrients)
What are the differences??

6. Biogeochemical Cycles
“Bio” -Biology
“Geo” -Geology
“Chemical” -Chemistry
Elements, chemical, compounds,& other forms of matter passed from one organism to another.
How is this different from energy flow?

7. Matter cycles through the biosphere
Biosphere- The combination of all ecosystems on Earth.
Biogeochemical cycles- The movement of matter within and between ecosystems involving biological, geologic and chemical processes.

8. The Hydrologic Cycle
The movement of water through the biosphere.

10. The Hydrologic Cycle Evaporation- Water changes from liquid to gas
Transpiration- The process where plants release water from their leaves into the atmosphere.
Evapotranspiration- The combined amount of evaporation and transpiration.
Condensation- Water vapor (gas) turns into liquid water forming clouds
Runoff- When water moves across the land surface into streams and rivers, eventually reaching the ocean.

11. Figure 3.16: Natural capital.
Condensation
Condensation
Ice and snow
Transpiration
from plants
Precipitation to land
Evaporation of
surface water
Evaporation
from ocean
Runoff
Lakes and
reservoirs
Precipitation to ocean
Runoff
Increased runoff on land covered with crops, buildings and pavement
Infiltration and percolation into aquifer
Increased runoff from cutting forests and filling wetlands
Runoff
Figure 3.16: Natural capital.
This diagram is a simplified model of the water cycle, or hydrologic cycle, in which water circulates in various physical forms within the biosphere. Major harmful impacts of human activities are shown by the red arrows and boxes. Question: What are three ways in which your lifestyle directly or indirectly affects the hydrologic cycle?
Groundwater in aquifers
Overpumping of aquifers
Water pollution
Runoff
Ocean
Natural process
Natural reservoir
Human impacts
Natural pathway
Pathway affected by human activities
Fig. 3-16, p. 67

12. Carbon Cycle 4 main processes move Carbon through the cycle
1. Biological- photosynthesis, respiration, decomposition
2. Geochemical – Erosion & volcanic activity
3. Mixed biogeochemical- burial & decompostion
4. Human Activities-mining, cutting & burning forest, burning fossil fuels

14. The Carbon Cycle

15. Carbon Sequestration (Capture & Storage)
Carbon sequestration is the long-term storage of carbon in oceans, soils, vegetation (especially forests), and geologic formations.
Although oceans store most of the Earth's carbon, soils contain approximately 75% of the carbon pool on land --three times more than the amount stored in living plants and animals.

16. Benefits of Soil Sequestration of Carbon
Conservation tillage minimizes or eliminates manipulation of the coil for crop production.
Cover cropping is the use of crops such as clover and small grains for protection and soil improvement between periods of regular crop production.
Crop rotation is a sequence of crops grown in regularly recurring succession on the same area of land. It mimics the diversity of natural ecosystems more closely than intensive monocropping practices.

17. Potential Costs Growing plants on semiarid lands
-regions contain high concentrations of dissolved calcium, and bicarbonate ions. As these are deposited in the soil they release CO2 into the atmosphere.
Management for carbon sequestration affects other gases that influence climate such as atmospheric concentrations of nitrous oxide and methane.

18. Nitrogen cycle
All organisms require Nitrogen to make amino acids (which are used to make proteins)
N2 makes up 78% of Earth’s atmosphere
Humans add Nitrogen thru Nitrate (fertilizers)
Found in waste –
-Ammonia (NH3), nitrate ions (NO3-),
& nitrite ions(NO2-)

21. The Nitrogen Cycle

22. More on Nitrogen Cycle
Only certain types of bacteria can use nitrogen gas directly
They are found in soil and on roots of plants called legumes (“magical fruit”)
They convert it to ammonia through Nitrogen Fixation
Other bacteria convert ammonia into nitrates & nitrites
Producers use it to make proteins
Consumers eat producers and reuse
nitrogen to make proteins

23. DEATH!!!
When organism die, decomposers return nitrogen to soil as ammonia
Ammonia taken up by producers (again)
Denitrification -other soil bacteria convert nitrates into nitrogen gas. Releases nitrogen into atmosphere.

24. Nitrogen Cycles through the Biosphere: Bacteria in Action (1)
Human intervention in the nitrogen cycle
Additional NO and N2O in atmosphere from burning fossil fuels; also causes acid rain
N2O to atmosphere from bacteria acting on fertilizers and manure
Destruction of forest, grasslands, and wetlands
Add excess nitrates to bodies of water
Remove nitrogen from topsoil

25. Nitrogen Cycles through the Biosphere: Bacteria in Action (1)
Nitrogen fixed by lightning
Nitrogen fixed by bacteria and cyanobacteria
Combine gaseous nitrogen with hydrogen to make ammonia (NH3) and ammonium ions (NH4+)
Nitrification
Soil bacteria change ammonia and ammonium ions to nitrate ions (NO3-)
Denitrification
Nitrate ions back to nitrogen gas

26. Human Input of Nitrogen into the Environment
Figure 16 Global trends in the annual inputs of nitrogen
into the environment from human activities, with
projections to 2050, are shown in this graph. (Data
from 2005 Millennium Ecosystem Assessmentt)
Supplement 9, Fig 16

27. (Phosphorus is required for the manufacture of ATP and all nucleic acids)
Phosphorus cycle
1. Reservoir – erosion transfers phosphorus to water and soil; sediments and rocks that accumulate on ocean floors return to the surface as a result of uplifting by geological processes 2. Assimilation – plants absorb inorganic PO43- (phosphate) from soils; animals obtain organic phosphorus when they plants and other animals 3. Release – plants and animals release phosphorus when they decompose; animals excrete phosphorus in their waste products

28. The Phosphorus Cycle

29. Phosphorus Cycles through the Biosphere
Cycles through water, the earth’s crust, and living organisms
Limiting factor for plant growth
Impact of human activities
Clearing forests
Removing large amounts of phosphate from the earth to make fertilizers
Erosion leaches phosphates into streams

30. Human Impacts
Phosphorus in runoff causes algal blooms and eutrophication (oxygen depletion in water) Humans contribute to this by over fertilizing, mining, and the use of sewage treatment plants.

31. Sulfur dioxide in atmosphere
Sulfuric acid and Sulfate deposited
as acid rain
Burning coal
Refining fossil fuels
Smelting
Sulfur in animals (consumers)
Dimethyl sulfide a bacteria byproduct
Sulfur in plants (producers)
Mining and extraction
Uptake
by plants
Figure 3.22: Natural capital.
This is a simplified model of the circulation of various chemical forms of sulfur in the sulfur cycle, with major harmful impacts of human activities shown by the red arrows. Question: What are three ways in which your lifestyle directly or indirectly affects the sulfur cycle?
Sulfur
in ocean sediments
Decay
Decay
Process
Sulfur
in soil, rock
and fossil fuels
Reservoir
Pathway affected by humans
Natural pathway
Fig. 3-22, p. 74

32. Sulfur Cycles through the Biosphere
Sulfur found in organisms, ocean sediments, soil, rocks, and fossil fuels
SO2 in the atmosphere
H2SO4 and SO4-
Human activities affect the sulfur cycle
Burn sulfur-containing coal and oil
Refine sulfur-containing petroleum
Convert sulfur-containing metallic mineral ores

33. Community Interaction in Oak Forest
Oak Forest Community Relationships
Possible to link Lyme disease to bumper acorn crops

34. Ecosystems respond to disturbance
Disturbance- An event caused by physical, chemical or biological agents that results in changes in population size or community composition.

36. Natural Capital Degradation: Satellite Image of the Loss of Tropical Rain Forest
Figure 3.1: Natural capital degradation.
This satellite image shows the loss of topical rain forest, cleared for farming, cattle grazing, and settlements, near the Bolivian city of Santa Cruz between June 1975 (left) and May 2003 (right).
Fig. 3-1a, p. 54

37. Watershed Studies
Watershed- All of the land in a given landscape that drains into a particular stream, river, lake or wetland.

39. Resistance versus Resilience
Resistance- A measure of how much a disturbance can affect its flows of energy and matter.
Resilience- The rate at which an ecosystem returns to its original state after a disturbance.
Restoration ecology- A new scientific discipline that is interested in restoring damaged ecosystems.

40. The Intermediate Disturbance Hypothesis
The intermediate disturbance hypothesis- states that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels.

42. Ecosystems Provide Valuable Services
Pollination of crops
Flood control
Filtering and purifying air and water
Cycling of nutrients
Seed dispersal
Maintain biodiversity
Regulate climate
Moderates water cycle
Pest control

44. Instrumental Values of Ecosystems
Provisions- Goods that humans can use directly.
Regulating services- The service provided by natural systems that helps regulate environmental conditions.
Support systems- The support services that natural ecosystems provide such as pollination, natural filters and pest control.
Resilience- Resilience of an ecosystem ensures that it will continue to provide benefits to humans. This greatly depends on species diversity.
Cultural services- Ecosystems provide cultural or aesthetic benefits to many people.

45. Three Big Ideas
Life is sustained by the flow of energy from the sun through the biosphere, the cycling of nutrients within the biosphere, and gravity.
Some organisms produce the nutrients they need, others survive by consuming other organisms, and some recycle nutrients back to producer organisms.
Human activities are altering the flow of energy through food chains and webs and the cycling of nutrients within ecosystems and the biosphere.