Nutrient%20Cycles:

1
Nutrient Cycles

• How Nature Recycles Matter

2
Matter in EcosystemsThe Carbon, Nitrogen and
Water Cycles
3
Matter Recycled

• The atoms and molecules available to make up
  organisms on earth is limited
• The total amount of matter is fixed (unchanging)
• All the atoms MUST be recycled in order for new
  organisms to form.
• It is very likely that at least one of the
  carbon atoms in your body was also in a 70
  million year old dinosaur!

4
The Water Cycle
5
The Water Cycle

• Water can be found in the atmosphere, on land, in
  the ocean, and even underground.
• It is recycled over and over through the water
  cycle.
• In the cycle, water changes state between liquid
  (water), solid (ice), and gas (water vapor or
  steam).

6
The Water Cycle
Sun

• - The sun causes water from the oceans, lakes and
  other areas to heat up and evaporate.
• -Most water vapour gets
• into the atmosphere by
• this process

Evaporate
7
The Water Cycle
Sun
Clouds
As the water goes into the atmosphere it
condenses to form water droplets. -These
droplets form clouds. If they combine with each
other they grow larger
Evaporate
8
The Water Cycle

• Tiny water droplets form clouds
• Once they become too heavy to stay in the air,
  the water from the clouds falls back to the
  ground as precipitation (rain or snow)

9
The Water Cycle
The water returns to the ocean through the
ground and rivers picking up materials along the
way. What things would be picked up?
10
The Water Cycle
Sun

• Once the water returns to the oceans, rivers or
  lakes, it is evaporated by the sun to make clouds
  again.

Evaporate
11
(No Transcript)
12
The Carbon Cycle
13

• Carbon is the building block of ALL living things
• Carbon is recycled in the carbon cycle through
  several processes, but mostly through
  photosynthesis and respiration.

14
(No Transcript)
15

• Carbon moves from the atmosphere to plants
• It moves in the form of Carbon dioxide.
• Through the process of PHOTOSYNTHESIS, plants
  use the sun and carbon dioxide to make their own
  food

16

• 2. Carbon moves from plants to animals
• Through the food chain, any carbon in the plants
  will move to the animals that eat them.
• Carbon moves from the
• animals to the ground
• When plants and animals die,
• their bodies decay bringing
• carbon back into the ground.
• 4. Carbon moves from the atmosphere to the
  oceans.

17

• How does carbon get produced in the
• atmosphere?
• Animals and plants undergo CELLULAR RESPIRATION,
  where they release carbon dioxide as they exhale
• When humans burn FOSSIL FUELS to power factories,
  cars and trucks, most of the carbon enters the
  atmosphere as carbon dioxide
• DECAY of Organisms- decomposers return Carbon
  left in detritus (decaying matter) back to the
  soil in a usable form.

18
Disrupting the Carbon Cycle

• RECALL Burning fossil fuels (combustion) returns
  CO2 to the environment
• Whats the problem with this?
• Too many fossil fuels will increase the amount of
  carbon in the environment.
• - Producers wont be able to use it fast enough
• - Creates an unbalanced cycle
• Also too much carbon dioxide (which absorbs heat)
• Increases the green house effect/global warming.

19
CARBON CYCLE RECAP!
Photosynthesis (uses CO2)
CO2 in atmosphere
Respiration- CO2 released
Combustion (CO2 from cars, factories)
Decomposition organic carbon decay
FOSSIL FUELS
20
Nitrogen cycle

• N2 gas composes 79 of atmosphere
• It is Fixed into the soil by bacteria and in the
  air by lightning
• for use in organisms, nitrogen must be bonded to
  other elements i.e. fixed
• E.g. to react in cells and body, N is supplied as
  the nitrate ion (NO3-1) ammonium ion (NH4)
• plants use this to make DNA and convert sugars
  into proteins
• plants are consumed by animals proteins and DNA
  (and Nitrogen) become part of the animals
  proteins.
• animals can only obtain nitrogen by eating plants
  or other animals

21
Variations in Cycling RATES

• Depends on
• 1) Biotic factors
• soil warmth moisture, diverse number of
  decomposers
• 2) Abiotic factors
• external temperature O2 level
• also, soil chemistry frequency of fires
• tropical forests few months
• cooler forest 4-6 years
• tundra up to 50 years