2. RECALL: PERCEPTIONS OF HUMANS
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TO NATURE
A.Nature is FRAGILE
- delicate balance
- could easily be upset by
changes
!
B. Nature is DURABLE
- very sturdy
- may change without much
adverse consequence
- can restore itself back
3. RECALL: ENERGY CANNOT BE
CREATED NOR DESTROYED
The movement of
elements and
compounds that are
essential to life
Materials are transported
through organisms, the
atmosphere, water and
land in a series of
CYCLES
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4. BIOGEOCHEMICAL CYCLING
“Bio” – life, participation
of organisms
“Geo” - abiotic
environment as source
of nutrients
“Chemical” – nature of
substances being cycled
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5. BASIC TYPE OF
CYCLES
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Gaseous type – the
reservoir is the atmosphere
and/or hydrosphere (e.g. N2,
CO2, O2)
Sedimentary type – the
reservoir is the Earth’s crust
(e.g. Phosphorus)
Linkage type – the reservoir
includes major pathways in
air, water, and crust (e.g.
sulfur)
6. WHEN DO THE PROBLEMS COME
IN?
Errors in Nutrient Cycling
www.foe.co.uk
7. SOURCES OF
ERRORS
Pollution –
accumulation of a
chemical form
that is higher than
the standards
njitvector.com
9. SOURCES OF
ERRORS
Non-biodegradable
substances –
change to form
new chemical
structure where no
organism has yet
to utilize it
A to A’ to A’’ to A’’’
sarahmosko.wordpress.com
10. SOURCES OF
ERRORS
Reduction of the
concentration of
other chemical
forms – limits
growth of the
subsequent
components of
the cycle
www.conserve-energy-future.com
11. SOURCES OF
ERRORS
Eutrophication -
the channeling of
a substance to
other pathways
(greater amounts
of phosphates in
aquatic systems)
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14. PURPOSE: Mediates Nutrient
Cycle and A Major Energy
Dissipation Pathway
IMPACTS OF HUMAN INTRUSION
More consumption than supply
Pumping waters from aquifers - not a normal
part of the water cycle
Garbage and wastes pollute the water and clog
drainage systems induces flooding
Asphalting – render the ground impervious to
water blocks infiltration
18. TYPE: Gaseous
!
Major Reservoir: Atmosphere
Forms: Free and Molecular Oxygen
Sources: Photosynthesis from producer AND Photodissociation
of Water Vapor
Fate of Free O2:
Reach higher levels of trophosphere and reduced to ozone
(provides protection by filtering out the sun's UV rays)
May react with chemicals and organic compounds of the
earth’s crust
May be used up in cell respiration which release CO2 to be
used by autotrophs to produce more O2
19. IMPACTS OF HUMAN
INTRUSION
CFC’s (chlorofluorocarbons) deplete ozone
layer “ozone hole”
Eutrophication (nutrient enrichment from
agricultural and domestic wastes) leads to
depletion of oxygen in water
Combustion of fossil fuels and removal of
vegetation (deforestation) deplete the supply
of oxygen in the atmosphere
23. TYPE: Gaseous
!
Major Reservoir: Atmosphere but also
calcium carbonate in shells and limestone,
as well as fossil fuel
Significance : Major element of organic
compounds; building blocks of all
biomolecules
24. TYPE: Gaseous
!
Processes:
Photosynthesis removes CO2 while respiration
and combustion add CO2 to the atmosphere.
CO2 from air and water combine to form
bicarbonate (HCO3) – source of carbon for
aquatic producers. Carbonic acid makes
rainwater also slightly acidic
Similarly, when aquatic organisms respire,
CO2 is released and combine with water to
form HCO3. HCO3 (water) = CO2 (air)
29. TYPE: Gaseous
!
Major reservoir – ATMOSPHERE
Importance – Essential for many biological
processes, constitutes part of proteins
(amino acids), in bases of nucleic acids
that make up DNA and RNA
79% of atmosphere is made up of nitrogen
(N2) but this is INERT
It must be fixed for organisms to utilize it
31. IMPACTS OF HUMAN
INTRUSION
USE OF NITROGEN FERTILIZERS
NITROGEN OXIDES RELEASED THROUGH
COMBUSTION
Human use of nitrogen fertilizers causes
runoff, leading to eutrophication in
aquatic systems (e.g. eutrophication)
Ozone + PAN Photochemical Smog
33. IMPACTS OF HUMAN
INTRUSION
LIVESTOCK RELEASE OF LARGE AMOUNTS OF AMMONIA
(FROM WASTES)
The ammonia released from wastes of livestock can
have detrimental effects on fish and other organisms
NITRATES LEACHING INTO GROUNDWATER
Nitrogen level in drinking water rises
A large rise of nitrogen in drinking water supplies
leads to Methemoglobinemia / Blue-Baby Syndrome
There is reduction in diversity
36. TYPE: PURELY
SEDIMENTAL
Major reservoir – Earth’s crust
Importance
Phosphorous -also found in bones, in
phospholipids which are found in
biological membranes.
37. TYPE: PURELY
SEDIMENTAL
Gradual cycle - It has no gaseous phase
Phosphorous normally occurs in nature as part of
phosphate ion. Most phosphates found as salts in
ocean sediments or in rocks.
Over time : geologic processes can bring
sediments from ocean to land, and weathering
can bring it from land to ocean
Phosphorous constituent of nucleic acids in DNA,
and energy currency of cell ATP
39. IMPACTS OF HUMAN
INTRUSION
Humans mine phosphate ores for use in
fertilizer production and detergents
Human actions could lead to
eutrophication of aquatic systems which
cause algal blooms
Algal blooms cause fish kills
43. TYPE: SEDIMENTARY WITH
ATMOSPHERIC COMPONENT
Major reservoir – inorganic sulfur in rocks
and fossil fuel
Biological Importance
Sulfur is an important element in
protoplasm which is an important component
of some amino acids
Sulfur is part of proteins, vitamins and
hormones
44. ISSUE ASSOCIATED WITH SULFUR
CYCLE: ACID RAIN
www.ypte.org.uk
science.howstuffworks.com
50. BIOMAGNIFICATION
It is the increase in concentration
of an element or compound that
occurs in the food chain as a
result of food chain energetics or
degradation of substance
Accumulation of chemicals in
higher predators or in higher
trophic levels
52. BIOMAGNIFICATION
Chemical concentration is said to
be magnified thousand fold in
tissues of higher trophic level
organisms
It is important in ecology because
: it indicates that solution to
certain types of pollution is not
dilution because food chains will
concentrate the pollutant
