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
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.
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….
water
We will look at several images depicting this cycle:
condensation
precipitation
percolation
runoff
evaporation
transpiration
Do you know
each of these?
http://www.carillionplc.com/sustain/images/water-cycle.gif
note
http://wetlab.coralhead.com/wp-content/uploads/2008/04/water_cycle.png
water (cont.)
- evapotranspiration?
- sublimation?
- groundwater
water (cont.)
also called aquifer→
Biospheric water?
(The water in living
things on Earth.) →
Water
Equivalent
depth (meters)
Residence
Time
Oceans/Seas
2500
~4000 years
Lakes/Reservoir
s
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-10000
years
Ice
caps/Glaciers
60
10-1000 years
Atmospheric
water
0.025
~10 days
Biospheric water 0.001
~ 1 week
http://www.spokaneaquifer.org/aq.htm
How long does
water sit around
in the stages of
the
hydrologic cycle?
(This is called its
residence time.)
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?→
http://www.bcscience.com/bc8/images/0_quiz_water_cycle.jpg
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…
http://www.lbl.gov/Science-Articles/Archive/images2/sea-carbon-cycle.jpg
carbon (cont.)
This shows the
relative amounts
of carbon in
different places:
-Most in sediments
-Lots of exchange
with seas.
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
http://oceanworld.tamu.edu/students/forams/images/arctic_marine_food_web_90.jpg
Carbon Footprint
Homework: Do research to find out - What is meant by carbon footprint?
- What are the implications?
i.e., why might we care?
- List 10 things that could be done individually
to reduce your footprint.
- List 5 things that would have a positive impact,
but require large scale coordination.
- 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.
nitrogen
Nitrogen is in all proteins (amino acids)
and nucleic acids (nitrogenous bases)
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 recycling organic N.
-Bacteria also do
denitrification
(sending nitrogen
back into the
atmosphere).
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
nitrogen (cont.)
-Lightning can
also fix nitrogen
-Artificial fertilizers
upset the nitrogen
balance…
http://www.h2ou.com/h2images/NitrogenCycle-lgr-F.jpg
-Industry adds nitrogen compounds to air
nitrogen (cont.)
(contributing to acid rain)
-Agriculture adds excess N and P to waterways
(eutrophication; kills lakes)
Phosphorus cycle
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) ↑
www.geneticengineering.org/.../DNA.htm
What do we need phosphorus for?
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
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
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…?
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?
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?
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