NUTRIENT CYCLING (biogeochemical_cycles).ppt

NUTRIENT CYCLE

1. Biogeochemical
Cycles
Carbon Cycle
Nitrogen Cycle
Phosphorus Cycle

2. Earth Photo
Matteris recycled within and
between ecosystems.

3. Biogeochemical Cycles
Biogeochemical Cycles
or nutrient cycles, are how elements, chemical
compounds, and other forms ofmatterare
passed from one organism to anotherand from
one part of the biosphere to another.
Types of Biogeochemical Cycles:
1.Hydrologic-ex water cycle
2.Atmospheric-ex carbon cycleand nitrogen
cycle
3.Sedimentary–ex phosphorus cycle

4. The
Carbon
Cycle

5. The Carbon Cycle
•.
The carbon cycleis
the movement of
carbonfrom the
nonliving environment
into living things and
back.
Carbonis the
essential component of
proteins, fats, and
carbohydrates,which
make up all organisms

6. •Carbonis a key ingredient of
living tissue.
•In the atmosphere, carbonis
present as carbon dioxidegas.
CO
2

7. Carbon dioxideis released into the atmosphere by:
–volcanic activity
–respiration
–human activities
–the decomposition of
organic matter

8. Plants take in carbon dioxideand use the
carbon to build carbohydratesduring
photosynthesis.

9. The carbohydrates
are passed along
food websto
animals and other
consumers.
In the ocean, carbonis
also found in calcium
carbonatewhich is
formed by many marine
organisms.

10. The Carbon Cycle cont…
•Carbonstored asfat, oils, or other
molecules may be released into the soilor
airwhen the organisms dies.
•These molecules form
deposits ofcoal, oil,
or natural gas,which
are knownasfossil
fuels.
•Fossil fuels storecarbon.

11. •Humans burn fossil fuelsreleasing carbon
into the atmosphere.
•The carbonreturns to the atmosphere as
carbon dioxide.
How Humans Affect the Carbon Cycle

12. How Humans Affect the Carbon Cycle
•Increased levels of
carbon dioxide may
contribute to global
warming
•Global warmingis an
increase in the
temperature of the
Earth.

15. Carbon Cycle Review
1.How do plants obtain carbon?
2.How do animals obtain carbon?
3.How does carbon recycle back through the
hydrosphere, atmosphere, and lithosphere?
4.Describe the two processes of the carbon cycle.
5.Describe how the burning of fossil fuels affects the
carbon cycle.
6.Describe the role of carbon dioxide in the carbon
cycle.
7.What is one way that a person can help reduce the
level of carbon dioxide in the atmosphere? Can you
think of more than one way?

16. The Nitrogen Cycle

17. •The nitrogen cycleis
the process in which
nitrogencirculates
among the air, soil,
water, plants, and
animalsin an ecosystem.
•All organisms need
nitrogento build
proteins.
•Nitrogenmakes up 78%
of the gases in the
atmosphere.
The Nitrogen Cycle

18. The Nitrogen Cycle
•Nitrogenmust be
altered or fixedbefore
organisms can use it.
•Nitrogenmust be
converted into
compounds that can
enter food websby the
process ofNitrogen
Fixation.
•These bacteria are
known as nitrogen-fixing
bacteria.

19. Nitrogen Fixation
•How do we get the Nitrogenwe need?
Nitrogen Fixation.
•Specialized bacteriaconvert N
2from
the atmosphere to ammonia (NH
3)for
the plantsto use.
•Plantswill use to the ammoniato make
nitrogen-containing organic molecules
–Proteins, DNA, RNA
•Animals get nitrogenby eating plantsor
plant-eatinganimals

21. Denitrification
•How is nitrogenreturned to the soil?
Denitrification
•When organisms die, decomposersreturn
nitrogento the soil. Other bacteria
change nitrogen compounds called
nitrates (NO
3)back into nitrogen gas
(N
2).
•This process is called denitrification.

23. 1.How do plants obtain nitrogen?
2.How do animals obtain nitrogen?
3.How does it recycle back through the hydrosphere,
atmosphere, and lithosphere?
4.What is the role of nitrogen-fixing bacteria in the nitrogen
cycle?
5.Which of the following statements about the nitrogen cycle is
not true?
A. Animals get nitrogen by eating plants or other animals.
B. Plants generate nitrogen in their roots.
C. Nitrogen moves back and forth between the atmosphere
and living things.
D. Decomposers break down waste to yield ammonia.
6.Abandoned fields in the southwestern part of the United States
are often taken over by mesquite trees, which can grow in
nutrient-poor soil. If the land is later cleared of mesquite, the
soil is often found to be enriched with nitrogen and is more
suitable for crops. What might be the reason for this
phenomenon?
Nitrogen Cycle
Review

24. The Phosphorus Cycle

25. •Phosphorusis necessary for nucleic
acids, fats, cell membranes, bones,
teethand shells.
•There is very littlephosphorusin the
atmosphere. Most phosphorusis stored
in rocksand oceansediments.
•This phosphorusis slowlyreleasedinto
waterand soiland then used by
organisms.

26. •Phosphorusis a
key part of:
–ATP
–Phospholipids
–DNA and RNA

27. Fertilizers and the Nitrogen
and Phosphorus Cycles
•Fertilizerscontain both nitrogen and phosphorus.
•Excessive amountsof fertilizer can enterterrestrial
and aquatic ecosystems throughrunoff.
•Excess nitrogen and phosphorus
can cause rapid growth of algae
-algal bloom.
•Excess algaecan depletean
aquatic ecosystem of important
nutrientssuch as oxygen, on
which fish and other aquatic
organisms depend.

28. Acid Precipitation
•When fuel is burned, large amounts of nitric
oxideis release into the atmosphere.
•In the air, nitric oxide can
combine with oxygen and
water vapor to form
nitric acid.
•Dissolved in rain or snow,
the nitric acid falls as
acid precipitation.

29. 1.How do plants obtain phosphorus?
2.How do animals obtain phosphorus?
3.How does it recycle back through the hydrosphere, atmosphere,
and lithosphere?
4.Explain how the excess use of fertilizer affects the nitrogen cycle
and the phosphorus cycle.
5.Explain why the phosphorus cycle occurs more slowly than both
the carbon cycle and the nitrogen cycle.
6.Write a short paragraph that describes the importance of
bacteria in the carbon, nitrogen, and phosphorus cycles. What
role does bacteria play in each cycle?
7.Excessive use of fertilizer that contains nitrogen and phosphorus
A. affects the carbon cycle.
B. may cause algal blooms in waterways.
C. causes soil erosion.
D. contributes to primary succession.
8.Describe the importance of the carbon, nitrogen, and phosphorus
cycles to humans.
Review