Powerpoint presentation in teaching biogeochemical cycle

Presentation

1. Biogeochemical Cycles
Water
Nitrogen
Carbon Dioxide
Phosphorus
Sulfur
Oxygen

2. What does biogeochemical
mean?
Bio
Geo
Chemical

3. ‘Fundamentals’ of biogeochemical
cycles
All matter cycles...it is neither created nor
destroyed...
As the Earth is essentially a closed system with
respect to matter, we can say that all matter on
Earth cycles .
Biogeochemical cycles: the movement (or
cycling) of matter through a system

4. Matter = elements (carbon, nitrogen, oxygen) or molecules
(water)
so the movement of matter (for example carbon)
between these parts of the system is, practically
speaking, a biogeochemical cycle
The Cycling Elements:
macronutrients : required in relatively large amounts
carbon , hydrogen , oxygen , nitrogen , phosphorous
sulfur

5. other macronutrients:
potassium , calcium , iron , magnesium
micronutrients : required in very small amounts, (but still
necessary)
boron (green plants)
copper (some enzymes)
molybdenum (nitrogen-fixing bacteria)

6. Biogeochemical Cycle :
chemical elements are required by life from the
living and nonliving parts of the environment.
These elements cycle in either a gas cycle or a
sedimentary cycle
In a gas cycle elements move through the
atmosphere.
Main reservoirs are the atmosphere and the
ocean.
Sedimentary cycle elements move from land to
water to sediment.

7. HYDROLOGIC CYCLE
Slide 34Slide 34Slide 34
Figure 4-28
Page 76
Precipitation to
land
Transpiration
from plants
Runoff
Surface runoff
(rapid)
Evaporation
from land
Evaporation
from ocean Precipitation to
ocean
Ocean storage
Surface
runoff
(rapid)
Groundwater movement (slow)
Rain clouds
Condensation
Transpiration
Evaporation
Precipitation
Precipitation
Infiltration and
Percolation

8. Water Cycle
Evaporation-Water changes from liquid to gas
Transpiration-Water evaporates from the leaves into
the atmosphere.
Condensation- Water vapor (gas) turns into liquid
water forming clouds.
Precipitation-Water droplets become large
enough to fall to Earth
-Rain, snow, sleet, or hail
Surface Runoff - Rain, snow, that flows
into streams, rivers, or canals.

9. Effects of Human Activities
on Water Cycle
We alter the water cycle by:
Withdrawing large amounts of freshwater.
Clearing vegetation and eroding soils.
Polluting surface and underground water.
Contributing to climate change.

10. Water Quality Degradation

11. Carbon
Cycle
What are the
2 main processes
in the carbon
cycle?

12. Carbon Cycle
Carbon (C) enters the biosphere during
photosynthesis:
 CO
2
+ H
2
O (carbon dioxide+ water)--->
C
6H
12O
6 + O
2 + H
2O(sugar+oxygen+water)
Carbon is returned to the biosphere in cellular
respiration:
O
2 +H
2O + C
6H
12O
6 ---> CO
2 +H
2O + energy

13. Carbon Facts
Every year there is a measurable difference
in the concentration of atmospheric CO
2
with
changes in the seasons.
For example, in winter there is almost
no photosynthesis ( higher CO
2
)
During the growing season there is a
measurable difference in the
concentration of atmospheric CO
2
over parts of each day.

14. Where does carbon come
from?
Natural Sources
of
Carbon
Sources of Carbon from
Human Activity
•Death of plants and animals
•Animal waste
•Atmospheric CO2
•Weathering
•Methane gas from cows (and
other ruminants)
•Aerobic respiration from
terrestrial and aquatic life
•Burning wood or forests
•Cars, trucks, planes
•Burning fossil fuels such
as coal, oil and natural
gas to produce heat and
energy.

15. Carbon in Oceans
Additional carbon is stored in the ocean.
Many animals pull carbon from water to use in
shells, etc.
Animals die and carbon substances are
deposited at the bottom of the ocean.
Oceans contain earth’s largest store of carbon.

16. Fig. 3-27, pp. 72-73

18. MARINE CARBON CYCLE
Slide 35Slide 35Slide 35
Diffusion between
atmosphere and ocean
Carbon dioxide
dissolved in
ocean water
Marine food webs
Producers, consumers,
decomposers, detritivores
Marine sediments, including
formations with fossil fuels
Combustion of fossil fuels
incorporation
into sediments
death,
sedimentation
uplifting over
geologic time
sedimentation
photosynthesis aerobic
respiration
Figure 4-29a
Page 78

19. TERRESTRIAL CARBON
CYCLE
Slide 36Slide 36Slide 36
photosynthesisaerobic
respiration
Terrestrial
rocks
Soil water
(dissolved
carbon)
Land food webs
producers,
consumers,
decomposers,
detritivores
Atmosphere
(most carbon is in carbon dioxide)
Peat,
fossil fuels
combustion of wood (for
clearing land; or for fuel
sedimentation
volcanic action
death, burial, compaction
over geologic time
leaching
runoff
weathering
Figure 4-29b
Page 79
Combustion
of fossil
fuels

20. Effects of Human Activities
on Carbon Cycle
We alter the
carbon cycle by
adding excess CO
2
to the atmosphere
through:
Burning fossil
fuels.
Clearing
vegetation faster
than it is replaced.
Figure 3-28Figure 3-28

21. Nitrogen cycle

22. Nitrogen Facts
Nitrogen (N) is an essential constituent
of protein, DNA, RNA, and chlorophyll.
Nitrogen is the most abundant gas in
the atmosphere.
Nitrogen must be fixed or converted into
a usable form.

23. Sources of Nitrogen
Inorganic fertilizers
Nitrogen Fixation
Animal Residues
Crop residues
Organic fertilizers

24. Forms of Nitrogen
Urea  CO(NH2)2
Ammonia  NH3 (gaseous)
Ammonium  NH4
Nitrate  NO3
Nitrite  NO2
Atmospheric Dinitrogen N2
Organic N

25. Roles of Nitrogen
Plants and bacteria use nitrogen in
the form of NH
4
+
or NO
3
-
It serves as an electron acceptor in
anaerobic environment
Nitrogen is often the most limiting
nutrient in soil and water.

26. Nitrogen is a key element
for
 amino acids
 nucleic acids (purine, pyrimidine)
cell wall components of bacteria
(NAM).

29. Effects of Human Activities
on the Nitrogen Cycle
We alter the nitrogen cycle by:
Adding gases that contribute to acid rain.
Adding nitrous oxide to the atmosphere through
farming practices which can warm the
atmosphere and deplete ozone.
Contaminating ground water from nitrate ions in
inorganic fertilizers.
Releasing nitrogen into the troposphere through
deforestation.

30. Effects of Human Activities
on the Nitrogen Cycle
Human activities
such as
production of
fertilizers now fix
more nitrogen
than all natural
sources
combined.
Figure 3-30Figure 3-30

31. Oxygen Cycle (Photosynthesis)

32. Sources of Oxygen:

Photosynthesis and respiration
Photo disassociation of H
2O vapor
CO
2
and O
2
circulates freely throughout the biosphere.
Some CO
2 combines with Ca to form carbonates.
O
2
combines with nitrogen compounds to form nitrates.
O
2 combines with iron compounds to form ferric oxides.
O
2
in the troposphere is reduced to O3 (ozone).
Ground level O
3 (ozone) is a pollutant which damages lungs.

33. The Oxygen cycle

34. PHOTOSYNTHESIS
Photosynthesis: occurs within the chloroplasts of green plants.
The photosynthetic membranes are arranged in flattened sacs
called the thylakoids.
6CO
2
+ 12H
2
O C
6
H
12
O
6
+ 6O
2
+ 6H
2
O

light

(reactants) (products)
Function: Chemical energy
Storage for cell use

35. CELLULAR RESPIRATION
Cellular Respiration occurs
in light simultaneously with
photosynthesis. It occurs in
the cytoplasm and
mitochondria.
It is the reverse reaction of
photosynthesis.
Function = chemical energy
release
C
6H
12O
6 + 6O
2 + 6H
2O 6CO
2 + 12H
2O+
chemical energy
(reactants) (products)

36. Phosphoru
s (P) Cycle

37. Phosphorus (P) Cycle
Component of DNA, RNA, ATP, proteins and enzymes
- Cycles in a sedimentary cycle
- A good example of how a mineral element becomes part of an
organism.
- The source of Phosphorus (P) is rock.
- Phosphorus is released into the cycle through erosion or mining.
- Phosphorus is soluble in H2O as phosphate (PO4)
-Phosphorus is taken up by plant roots, then travels through food
chains.
- It is returned to sediment

39. IMPORTANCE OF
PHOSPHOROUS CYCLE
1.Phosphorous is an essential nutrient of both plants
and animals.
2. It is part of DNA molecules which carry genetic
information.
3. It is part of ATP and ADP) that store chemical
energy for use by organisms in cellular respiration.
4. Forms phospholipids in cell membranes of plants
and animal cells.
5. Forms bones, teeth, and shells of animals as
calcium phosphate compounds.

40. PHOSPHOROUS CYCLE
Slide 41Slide 41Slide 41
GUANO
FERTILIZER
ROCKS
LAND
FOOD
WEBS
DISSOLVED
IN OCEAN
WATER
MARINE
FOOD
WEBS
MARINE SEDIMENTS
weathering
agriculture
uptake by
autotrophs
death,
decomposition
sedimentation settling out weathering
leaching, runoff DISSOLVED IN
SOIL WATER,
LAKES, RIVERS
uptake by
autotrophs
death,
decomposition
miningmining
excretionexcretion
Figure 4-33
Page 82
uplifting over
geologic time

41. HUMAN IMPACTS TO
PHOSPHOROUS CYCLE
1.Humans mine LARGE quantities of phosphate rock to use in
commercial fertilizers and detergents. Phosphorous is NOT
found as a gas, only as a solid in the earth’s crust. It takes
millions to hundreds of millions of years to replenish.
2.Phosphorous is held in the tissue of the trees and vegetation,
not in the soil and as we deforest the land, we remove the
ability for phosphorous to replenish globally in ecosystems.
3.Cultural eutrophication – ad excess phosphate to aquatic
ecosystems in runoff of animal wastes from livestock feedlots,
runoff of commercial phosphate fertilizers fro cropland, and
discharge of municipal sewage.

42. Effects of Human Activities
on the Phosphorous Cycle
We remove large amounts of phosphate from
the earth to make fertilizer.
We reduce phosphorous in tropical soils by
clearing forests.
We add excess phosphates to aquatic
systems from runoff of animal wastes and
fertilizers.

43. Sulfur (s) Cycle
Component of protein
Cycles in both a gas and sedimentary cycle.
The source of Sulfur is the lithosphere (earth's crust)
Sulfur (S) enters the atmosphere as  hydrogen
sulfide (H2S) during fossil fuel combustion, volcanic
eruptions, gas exchange at ocean surfaces, and decomposition.
SO
2 and water vapor makes H
2SO
4 ( a weak sulfuric acid),
 which is then carried to Earth in rainfall.
Sulfur in soluble form is taken up by plant roots and
incorporated into amino acids such as cysteine. It then travels through the
food chain and is eventually released through decomposition.
 

44. IMPORTANCE OF SULFUR
CYCLE
1.Sulfur is a component of most proteins and some vitamins.
2.Sulfate ions (SO
4

2-
) dissolved in water are common in
plant tissue. They are part of sulfur-containing amino
acids that are the building blocks for proteins.
3.Sulfur bonds give the three dimensional structure of amino
acids.
4.Many animals, including humans, depend on plants for
sulfur-containing amino acids.

45. SULFUR CYCLE
Slide 42Slide 42Slide 42
Figure 4-34
Page 83
Sulfur
Hydrogen
sulfide
Sulfate salts
Plants
Acidic fog and
precipitation
Ammonium
sulfate
Animals
Decaying
matter
Metallic
sulfide
deposits
Ocean
Dimethyl
sulfide
Sulfur dioxide Hydrogen
sulfide
Sulfur trioxide Sulfuric acid
Water
Ammonia
Oxygen
Volcano
Industries

46. Effects of Human Activities
on the Sulfur Cycle
We add sulfur dioxide to the atmosphere by:
Burning coal and oil
Refining sulfur containing petroleum.
Convert sulfur-containing metallic ores into free
metals such as copper, lead, and zinc releasing
sulfur dioxide into the environment.

47. Summary
The building blocks of life :Water ,Nitrogen,Oxygen
Carbon Dioxide, Phosphorus, Sulfur
Continually cycle through Earth's systems, the
atmosphere, hydrosphere, biosphere, and
lithosphere, on time scales that range from a few
days to millions of years.
These cycles are called biogeochemical cycles,
because they include a variety of biological,
geological, and chemical processes.

48. Works Cited
1.http://science.pppst.com/carboncycle.html
2.westernreservepublicmedia.org/earthmotion3/
images/Carbon_Cycle.ppt
3.clima-dods.ictp.it/d3/annalisa/ocean_sv/lecture1.ppt
4.www.geology.wmich.edu/Koretsky/envs2150/
Pcycle_1.ppt