Biogeochemical%20Cycles:

1
Biogeochemical Cycles
2
Biotic vs. Abiotic

• Biotic factors all the living parts of an
  ecosystem like plants, animals, and decomposers.
• Abiotic factors all of the non-living things
  that affect the ecosystem like rainfall, rocks,
  clouds, water, wind, and minerals.

3
The Water Cycle

• Water is crucial to every living thing on the
  planet. It covers 75 of earth and composes
  about 75 of our body mass.

4
(No Transcript)
5
The Carbon Cycle

• All living things on this planet are
  carbon-based.
• Photosynthesis and cellular respiration is the
  basis for the carbon cycle.
• Plants use CO2 for photosynthesis to make
  carbohydrates
• Many organisms use oxygen to break down
  carbohydrates for energy during cellular
  respiration
• Humans have increased the concentration of CO2 in
  the atmosphere by 30

6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
The Nitrogen Cycle

• All organisms need nitrogen to make proteins and
  nucleic acids.
• Consumers get that nitrogen by eating plants or
  other consumers.
• Plants must get the nitrogen from the
  environment. They cannot absorb it through the
  air, it must be absorbed as nitrate in the soil.
• Nitrogen-fixing bacteria convert the gas to
  nitrate the plants can use called nitrogen
  fixation
• Urine and dung also contain nitrogen that can be
  used.

11
Nitrogen Fixation

• Bacteria convert the gas to ammonia then to
  nitrite then to nitrate
• Ammonification decomposers convert urine, dung,
  and dead things into ammonia which can be reused
  by the ecosystem
• Nitrification bacteria taking ammonia and
  turning into nitrites then nitrates
• Denitrification anaerobic bacteria returning
  nitrogen gas to the atmosphere

12
(No Transcript)
13
The Phosphorus Cycle

• Phosphorus is needed by organisms for DNA,
  phospholipids (cell membranes), and bones, teeth
  and shells of animals.
• Most phosphorus comes from phosphate salts from
  rocks and deposited into water
• Humans add lots more phosphate to water by
  fertilizer runoff and surface mining and reduce
  phosphate by cutting forests.

14
(No Transcript)