1. Biogeochemical Cycles
What is a biogeochemical cycle?
What things cycle?
(Which will you
be responsible for?)
What does NOT cycle?
Chapter 13.5 in text

2. What is a biogeochemical cycle?
Minerals
(including the things you are made of)
exist in set quantities on Earth,
and are repeatedly recycled.
The ones we will look at
travel through food webs (bio),
and have significant non- bio forms (geo).
All your atoms have been parts of other organisms before you,
many (many) times over.

3. ALL of the atoms in living systems cycle.
What things cycle?
(Which will you be responsible for?)
ALL of the atoms in living systems cycle.
Some spend a lot of time out of the cycle
(in a sink… reserve).
We will look at water, carbon, nitrogen, and phosphorus,
but there are cycles for potassium, vanadium,
oxygen, sodium, chlorine, iron,
calcium, hydrogen,
etc….

4. water We will look at several images depicting this cycle: note
condensation
precipitation
percolation
runoff
evaporation
transpiration
Do you know
each of these?

5. evapotranspiration? sublimation? groundwater water (cont.)

6. Equivalent depth (meters)
water (cont.)
How long does
water sit around
in the stages of
the
hydrologic cycle?
(This is called its
residence time.)
also called aquifer→
Water
Equivalent depth (meters)
Residence Time
Oceans/Seas
2500
~4000 years
Lakes/Reservoirs
0.25
~10 years
Swamps
0.007
~1-10 years
Rivers
0.003
~2 weeks
Soil moisture
0.13
~2 weeks-1 year
Groundwater
120
~2 weeks years
Ice caps/Glaciers 60
years
Atmospheric water
0.025
~10 days
Biospheric water
0.001
~ 1 week
Biospheric water?
(The water in living
things on Earth.) →

7. Water is not actually a mineral… it is a compound;
water (cont.)
note
Water is not actually a mineral… it is a compound;
but it is very important to living systems.
Things live in water, as well as having water in them:
freshwater, marine, and terrestrial ecosystems
are all defined by water.
The cycle includes three phases:
gas, liquid, and solid
Not much of this cycle is
in living things!
It enters via roots/drinking
and leaves via
evapotranspiration.
What do the letters
represent?→

8. Carbon There is carbon in the air, in rock, in water, and you are made
largely of it.
note
photosynthesis
respiration
combustion
phytoplankton
lithosphere
Carbon reservoirs:
Less CO2 dissolves
as water temp rises…

9. This shows the relative amounts of carbon in different places:
carbon (cont.)
This shows the
relative amounts
of carbon in
different places:
Most in sediments
Lots of exchange
with seas.

10. -Carbon enters the food chain through photosynthesis.
carbon (cont.)
-Carbon enters the food
chain through
photosynthesis.
It leaves via respiration
and decomposition.
Increasing levels of CO2
add to global warming
although the greenhouse
effect itself is vital to life.
zooplankton

11. Homework: Do research to find out -
Carbon Footprint
Homework: Do research to find out -
- What is meant by carbon footprint?
- What are the implications?
i.e., why might we care?
- Give some things that could be done individually
to reduce your footprint.
- What are some things you are doing well?
↓ Find an on-line resource to calculate yours.
- Evaluate your confidence in said resource.
- Cite your sources, making sure they are
authoritative.
This is the scoring rubric.
 site for carbon footprint calculator

12. nitrogen Nitrogen is in all proteins (amino acids)
and nucleic acids (nitrogenous bases)
nitrogen
note
Atmospheric N2
must be fixed, as
by bacteria, to enter
food chain…
It then is assimilated
through plant roots.
Decomposers play
a key role in re-
cycling organic N.
Bacteria also do
denitrification
(sending nitrogen
back into the
atmosphere).

13. Artificial fertilizers upset the nitrogen balance…
nitrogen (cont.)
Lightning can
also fix nitrogen
Artificial fertilizers
upset the nitrogen
balance…

14. Industry adds nitrogen compounds to air (contributing to acid rain)
Agriculture adds excess N and P to waterways
(eutrophication; kills lakes)
nitrogen (cont.)

15. What do we need phosphorus for?
Phosphorus cycle
What do we need phosphorus for?
It is part of every
nucleotide in your body →
The energy for most of your
body functions is carried in
the last phosphate bond in
adenosine triphosphate (ATP) ↑

16. uplifting weathering detritus detritivores Any obvious differences
Phosphorus cycle
the natural scheme
uplifting
weathering
detritus
detritivores
Any obvious
differences
between this and
the other cycles?
(hint: look up)
bioh.wikispaces.com/More+Elemental+Cycles?f=print

17. note: - no “volatile” form - “suspended particulates”
Phosphorus cycle
agriculture added
note:
- no “volatile” form
- “suspended
particulates”
- loss due to harvest
- this is also often a
limiting nutrient:
fertilizers applied
leaching
erosion
big problems in
rain forests
nutrients.ifas.ufl.edu/.../Phosphoruscycle.htm

18. RECAP
Matter is recycled through the ecosystem in
biogeochemical cycles.
- Water, carbon and nitrogen enter the food chain
in different ways.
- They spend different amounts of time in various reservoirs.
All components of an ecosystem must remain in balance.
However, energy…?

19. How are water and these 3 nutrients
used in living systems?
Which cycles have which phases:
solid, liquid, gas?
How does each enter the food web?
How does each leave the food web?
How are we dependant on other organisms
in each cycle?

20. through biological systems impact you?
Enduring Understandings
All biological life is
interconnected and
[inter]dependent.
Essential Questions
How does the movement
of matter and energy
through biological systems
impact you?

21. biogeochemical cycle
residence time
nitrogen
food webs
aquifer
fixation
sink
biospheric
assimilate
water
carbon
denitrification
condensation
photosynthesis
acid rain
precipitation
respiration
eutrophication
percolation
combustion
phosphorus
runoff
phytoplankton
uplifting
evaporation
lithosphere
weathering
transpiration
decomposition
detritus
evapotranspiration
global warming
detritivore
sublimation
greenhouse effect
limiting nutrient
groundwater
zooplankton
leaching
hydrologic cycle
carbon footprint
erosion
carbon cycle
nitrogen cycle
phosphorus cycle
biogeochemical cycle
carbon footprint
limiting nutrients