1. Biogeochemical Cycles
The movement of materials through the biotic (living) and abiotic (non-living) parts of an ecosystem

2. Nutrient Cycles
Biogeochemical Cycles are also known as Nutrient Cycles
-They are the pathways that 4 materials vital to life follow through an ecosystem Carbon
- Nitrogen
- Phosphorus
- Water
These materials cycle through both biotic and abiotic reservoirs in an ecosystem
-biotic reservoirs are the living things that these materials move through
-abiotic reservoirs are the non-living things that these materials move through

3. Carbon Cycle:

4. Carbon Cycle
Carbon is the backbone for many of the most important molecules used by living things.
carbohydrates, fats, protein, nucleic acid
Carbon exists as CO2 in the atmosphere
- CO2 in the atmosphere cannot be used by living things – it must be converted into a usable form
- How does CO2 get converted? –
Photosynthesis in plants
- CO2 is used to make glucose – the carbon in glucose can be used by living things

5. Coal Oil CO2 in atmosphere Photosynthesis Limestone Fossil Fuels
Combustion
Cellular Respiration
CO2 is absorbed in water
Death & Decomposition
Coal
Limestone
Fossil Fuels
Oil

6. CARBON CYCLE *2

7. Carbon Cycle Carbon returns to the atmosphere - cellular respiration
- combustion
All living things are biotic reservoirs
The atmosphere and water are abiotic reservoirs
Carbon Sink – A sink is a part of the cycle which removes a nutrient from the cycle for long periods of time
- Limestone
- Fossil Fuels

8. Carbon Cycle
The carbon in fossil fuels has been stored in the earth for millions of years- Burning them for energy releases the CO2 back to the atmosphere
- causing a rapid increase in CO2 in the atmosphere
- CO2 is a greenhouse gas which traps heat, warming the Earth
- Increasing CO2 is leading to Global Climate Change

9. CARBON CYCLE RESPIRATION / PHOTOSYNTHESIS LONG TERM VS SHORT TERM
WHY IS IT IMPORTANT?
RESPIRATION / PHOTOSYNTHESIS
LONG TERM VS SHORT TERM
LIMESTONE DEPOSITS
CONNECTION TO FOSSIL FUELS
GREENHOUSE GAS
CARBON SINKS

11. Nitrogen Cycle
Nitrogen is used by living things to make proteins and nucleic acids (DNA & RNA)
Nitrogen exists in the atmosphere as N2
- the N2 molecule will not react and so must be converted to be used by living things
- Large amounts of energy are needed to split the N2 molecule – lightning will split Nitrogen

12. Nitrogen Cycle
- Certain bacteria contain the enzymes necessary to convert N2 into useable forms of nitrogen called nitrates -NO2 or NO3
- these nitrogen fixing bacteria are found in the soil and in symbiotic relationships with certain plants called legumes – beans, peas etc….
The nitrates enter the food chain when plants assimilate them – take them up and use them

13. Nitrogen Cycle Legumes Assimlation N2 in the atmosphere Plant Protein
Ammonification
Nitrogen fixing
Bacteria convert N2 into nitrates
Denitrification
Bacteria convert ammonia back to N2 and release it back to the atmosphere
Nitrification – Bacteria convert ammonia into nitrate
Nitrogen Assimilation = plants taking up nitrates from the soil
Ammonification = bacteria convert Nitrogen in waste into ammonia

14. NITROGEN CYCLE *2

15. NITROGEN CYCLE LIMITING NUTRIENT NITROGEN FIXING
NITRAFICATION / NITRIFICATION
EUTROPHICATION
ACID RAIN COMPONENT

16. NUTRIENT CYCLING FIXATION: CONVERTING N2(GAS) INTO AMMONIUM
THE NITROGEN CYCLE - TRANSITIONS
FIXATION: CONVERTING N2(GAS) INTO
AMMONIUM
NITRIFICATION: CONVERTING NH4
INTO NO3 (NITRITE)
-DENITRIFICATION: CONVERTING
NITRITE BACK INTO N2

17. Phosphorus Cycle

18. The Phosphorus Cycle
Phosphorus in needed to make Nucleic Acids – DNA and RNA
It is scarce in the biosphere – most is locked away in rocks and ocean sediment
- The phosphorus enters an ecosystem when rocks are weathered (eroded)
- some of the phosphorus is retained in soil and some finds its way into water
- The phosphorus enters the food chain when it is assimilated by plants

19. Phosphorus Cycle Weathering of Rock Rock Phosphorus locked up
in the rock
Phosphorus Cycle
Uplifting
of Rock
Assimilation by
Plants
Weathering
of Rock
Death and
Decomposition
Dissolved
Phosphates
Phosphates
in Soil
Precipitated
Phosphates
Rock

20. Water Cycle

21. Water Cycle The water cycle is powered by the sun
- water evaporates and moves into the atmosphere to begin the cycle.
- transpiration: the evaporation of water from plants – accounts for large amounts of water moving into the atmosphere
-the moisture cools and condenses to become clouds
-the moisture falls back to earth as precipitation – rain, snow, sleet, hail etc…
-some of the water percolates back into the ground and becomes ground water
-some of the water runs off and finds its way through rivers to lakes and the ocean

22. Plant leaves have openings on the bottom called stomata
Transpiration
Plant leaves have openings on the bottom called stomata
- the stomata open during photosynthesis to allow CO2 into the leaf
- water evaporates from the leaf while the stomata are open

23. Condensation
Transpiration
Precipitation
Evaporation
Run-off
Surface Water
Infiltration / Percolation
Ground Water

24. WATER CYCLE *

25. Limiting Nutrient
Nutrients like nitrogen and phosphorus are typically in limited supply in an ecosystem.
- the limited supply of nutrients limits the overall productivity of a given ecosystem
- If additional quantities of the limited nutrient are added to an ecosystem, productivity increases.

26. Limiting Nutrient
- people have learned how to use chemical processes to fix nitrogen, and mine phosphorus
- the use of fertilizer has led to a boom in food production called the Green Revolution.

27. IMPORTANCE OF OXYGEN
EUTROPHICATION *7

28. Eutrophication
In aquatic ecosystems, additional quantities of a limiting nutrient cause algae to multiply out of control
- when the algae die, they sink to the bottom and are decomposed- unfortunately the decomposers remove oxygen from the water creating dead zones area without enough oxygen to support life
- this process is called Eutrophication

29. Eutrophication This map shows the dead zone in the Gulf of Mexico,
Red = least oxygen Blue = most
This map shows the dead zone in the Gulf of Mexico,
which is the result of eutrophication caused by nitrogen and phosphorus carried by the Mississippi River

30. Vocabulary Biogeochemical/Nutrient Cycles
Biotic and abiotic reservoirs
Carbon Sink- Definition and examples
Assimilation
Nitrification
Denitrification
transpiration
Infiltration / Percolation
limiting nutrient
eutrophication