Download Nutrient Cycles

Cycling of
Matter
Matter Cycling in Ecosystems
• Nutrient or Biogeochemical Cycles
– Natural processes that recycle
nutrients in various chemical forms
in a cyclic manner from the what to
what?? and back again
Matter Cycling in Ecosystems
• Nutrient or Biogeochemical Cycles
– Natural processes that recycle
nutrients in various chemical forms
in a cyclic manner from the
nonliving environment to living
organisms and back again
Nutrient Cycles (Open or Closed? System)
Energy Flow (Open or Closed? System)
• Water
• Carbon
• Nitrogen
• Phosphorus
• Sulfur
• Rock
• Soil
• Energy Flow
Nutrient Cycles (Closed System)
Energy Flow (Open System)
• Water
• Carbon
• Nitrogen
• Phosphorus
• Sulfur
• Rock
• Soil
• Energy Flow
Biogeochemical Cycle Locations
• ?????sphere
– Water in the form of ice, liquid, and vapor
– Operates local, regional, and global levels
• Atmospheric
– Large portion of a given element (i.e. which??? gas) exists
in gaseous form in the atmosphere
– Operates local, regional, and global levels
• Sedimentary
– The element does not have a gaseous phase or its gaseous
compounds don’t make up a significant portion of its
supply
– Operates local and regional basis
Biogeochemical Cycle Locations
• Hydrosphere
– Water in the form of ice, liquid, and vapor
– Operates local, regional, and global levels
• Atmospheric
– Large portion of a given element (i.e. Nitrogen gas) exists
in gaseous form in the atmosphere
– Operates local, regional, and global levels
• Sedimentary
– The element does not have a gaseous phase or its gaseous
compounds don’t make up a significant portion of its
supply
– Operates local and regional basis
Nutrient Cycling & Ecosystem
Sustainability
• Natural ecosystems tend to balance
– Nutrients are recycled with reasonable efficiency
• Humans are ???????? rates of flow of mater
– Nutrient loss from soils
– Doubling of normal flow of nitrogen in the nitrogen cycle
is a contributes to global warming, ozone depletion, air
pollution, and loss of biodiversity
• Isolated ecosystems are being influenced by human
activities
Nutrient Cycling & Ecosystem
Sustainability
• Natural ecosystems tend to balance
– Nutrients are recycled with reasonable efficiency
• Humans are accelerating rates of flow of mater
– Nutrient loss from soils
– Doubling of normal flow of nitrogen in the nitrogen cycle
is a contributes to global warming, ozone depletion, air
pollution, and loss of biodiversity
• Isolated ecosystems are being influenced by human
activities
Carbon Cycle
Carbon Cycle
Role of Carbon?
building block of organic molecules (name
these 4 polymers????) – essential to life;
currency of energy exchange – chemical
energy for life stored as bonds in organic
compounds;
Which???? greenhouse gas – traps heat near
Earth's surface & plays a key role as
"nature's thermostat".
Carbon Cycle
Role of Carbon?
building block of organic molecules
(carbohydrates, fats, proteins, & nucleic acid) –
essential to life;
currency of energy exchange – chemical energy for
life stored as bonds in organic compounds;
carbon dioxide (CO2) greenhouse gas – traps heat
near Earth's surface & plays a key role as "nature's
thermostat".
Carbon Cycle
main processes:
movement in atmosphere: atmospheric C as which gas?? (0.036%
of troposphere);
primary production: what process?? (= carbon fixation) moves C
from atmosphere to organic molecules in organisms;
movement through food web: C movement in organic form from
organism to organism;
aerobic ?????: organic molecules broken down to release CO2 back
to atmosphere;
Name this process: organic molecules broken by burning down to
release CO2 back to atmosphere;
dissolving in oceans: C enters as to form what 2 compounds???
movement to sediments: C enters sediments, primarily as calcium
carbonate (CaCO3);
Carbon Cycle
main processes:
movement in atmosphere: atmospheric C as CO2 (0.036% of
troposphere);
primary production: photosynthesis (= carbon fixation) moves C
from atmosphere to organic molecules in organisms;
movement through food web: C movement in organic form from
organism to organism;
aerobic respiration: organic molecules broken down to release CO2
back to atmosphere;
combustion: organic molecules broken by burning down to release CO2
back to atmosphere;
dissolving in oceans: C enters as to form carbonate (CO32–) &
bicarbonate (HCO3–);
movement to sediments: C enters sediments, primarily as calcium
carbonate (CaCO3);
Carbon Cycle
• Respiration—organisms breathe and
give off CO2
• Photosynthesis—plants take in CO2,
water and energy from the Sun to
produce carbohydrates
• Living things act as exchange pools for
carbon
Carbon Cycle
• Carbon locked in the plant
carbohydrates passes to other
organisms through food chain
• When organisms die, bodies
decompose through activities of fungi
and bacteria in soil, which releases
CO2.
Carbon Cycle
• Dead organisms buried and subjected
to extreme heat and pressure becomes
oil, coal and gas (fossil fuels)
• Combustion of fossil fuels releases
carbon into atmosphere
• Volcanic action also releases carbon
Carbon Cycle
• Carbon Reservoirs:
– Is where??? because CO2 is soluble
in water
– And here??? that contain carbon in
the form of calcium carbonate
(marble and limestone)
Carbon Cycle
• Carbon Reservoirs:
– Oceans because CO2 is soluble in
water
– Earth’s rocks that contain carbon in
the form of calcium carbonate
(marble and limestone)
Carbon Cycle
• Human impacts:
– Removal of what???: decreases
primary production (decreases
carbon fixation)
– Add carbon and CO2 by burning
fossil fuels, wood and other biomass
material (slash and burn in tropics)
– Increased CO2 can alter global ????
Carbon Cycle
• Human impacts:
– Removal of vegetation: decreases
primary production (decreases
carbon fixation)
– Add carbon and CO2 by burning
fossil fuels, wood and other biomass
material (slash and burn in tropics)
– Increased CO2 can alter global
climate
Water Cycle
Water Cycle
main processes:
(1)??: conversion from liquid to vapor form (surface to
atmosphere).
(2)??: evaporation from leaves of water extracted from soil by
roots & transported through the plant (surface to atmosphere).
movement in atmosphere: transport as vapor.
(3)??: conversion of vapor to liquid droplets.
precipitation: movement as rain, sleet, hail, & snow (atmosphere
to surface).
(4)???: movement into soil.
(5)?? downward flow through soil to aquifers.
flow in aquifers: belowground flow of water.
runoff: surface flow downslope to ocean or other body of water.
Water Cycle
main processes:
evaporation: conversion from liquid to vapor form (surface to
atmosphere).
transpiration: evaporation from leaves of water extracted from
soil by roots & transported through the plant (surface to
atmosphere).
movement in atmosphere: transport as vapor.
condensation: conversion of vapor to liquid droplets.
precipitation: movement as rain, sleet, hail, & snow (atmosphere
to surface).
infiltration: movement into soil.
percolation: downward flow through soil to aquifers.
flow in aquifers: belowground flow of water.
runoff: surface flow downslope to ocean or other body of water.
Water Cycle
• Human Impact:
– Withdrawing large amounts of fresh water that
is often accompanied by what ???intrusion and
this ???? depletion.
– Clearing of land for agriculture or habitation
•  runoff, flood risks, soil erosion, landslides
•  infiltration
– Augmenting pollutions by
• Nutrients through runoff
• Disturbing natural processes
• Introducing infectious agents
Water Cycle
• Human Impact:
– Withdrawing large amounts of fresh water that
is often accompanied by saltwater intrusion and
groundwater depletion.
– Clearing of land for agriculture or habitation
•  runoff, flood risks, soil erosion, landslides
•  infiltration
– Augmenting pollutions by
• Nutrients through runoff
• Disturbing natural processes
• Introducing infectious agents
Nitrogen Cycle
Nitrogen Cycle
Role of Nitrogen?
building block of various essential organic
molecules – especially what 2???;
L???????? nutrient in many ecosystems –
typically, addition of N leads to increased
productivity.
Nitrogen Cycle
Role of Nitrogen?
building block of various essential
organic molecules – especially
proteins & nucleic acids;
limiting nutrient in many ecosystems
– typically, addition of N leads to
increased productivity.
Nitrogen Cycle
• Needed to make amino acids, proteins,
DNA and RNA
• 78% of atmosphere is nitrogen
• Nitrogen stores include organic matter in
soil and oceans
• Atmospheric nitrogen is not in form that can
be ?????????????????
Nitrogen Cycle
• Needed to make amino acids, proteins,
DNA and RNA
• 78% of atmosphere is nitrogen
• Nitrogen stores include organic matter in
soil and oceans
• Atmospheric nitrogen is not in form that can
be used directly by most organisms
Nitrogen Cycle
• Plants absorb N through nitrate ions and
ammonium ions
• Animals absorb N by consuming organic
matter
• Decomposers convert ammonia to
ammonium compounds through
mineralization
Nitrogen Cycle Processes
(1)???—converts N2 to NH3
– By specialized bacteria (cyanobacteria
and actinomycetes in soil and R??????
bacteria in root systems of legumes)
– N2 + 3H2  2NH3
(2)???—ammonia converted by aerobic
bacteria to nitrite ions then to nitrate ions
NH3 by aerobic bacteria  NO2- by bacteria NO3-
Nitrogen Cycle Processes
1. Nitrogen fixation—converts N2 to NH3
– By specialized bacteria (cyanobacteria
and actinomycetes in soil and Rhizobium
bacteria in root systems of legumes)
– N2 + 3H2  2NH3
2. Nitrification—ammonia converted by
aerobic bacteria to nitrite ions then to
nitrate ions
NH3 by aerobic bacteria  NO2- by bacteria NO3-
Nitrogen Cycle Processes
3???—plants absorb ammonia, ammonium
ions and nitrate ions through their roots
which are then eaten by heterotrophs
Plant roots + NH3 + NH4+ + NO3- → DNA + amino acids + proteins
4???—decomposing bacteria convert dead
organisms and other waste to ammonia or
ammonium ions that can be reused by
plants
Organic material → NH3 + NH4+
Nitrogen Cycle Processes
3. Assimilation—plants absorb ammonia,
ammonium ions and nitrate ions through
their roots which are then eaten by
heterotrophs
Plant roots + NH3 + NH4+ + NO3- → DNA + amino acids + proteins
4. Ammonification—decomposing bacteria
convert dead organisms and other waste to
ammonia or ammonium ions that can be
reused by plants
Organic material → NH3 + NH4+
Nitrogen Cycle Processes
5???—specialized bacteria convert NH3
and NH4+ into NO2- and NO3- and then
into N2 and released into the atmosphere
NH4+ + NH3 → NO2- + NO3- → N2 + N2O
Nitrogen Cycle Processes
• 5. Denitrification—specialized bacteria
convert NH3 and NH4+ into NO2- and
NO3- and then into N2 and released into
the atmosphere
NH4+ + NH3 → NO2- + NO3- → N2 + N2O
Nitrogen Cycle
• Human Impact
– Burning fuels lead to ??????? rain
– Depleting N from ???? by over-planting
– Leaching from soil by irrigation and into
groundwater
– Agricultural runoff leads to e???? (aerobic
decomposers break down aquatic bloom,
depleting water of dissolved oxygen)
– Discharge of municipal what?????
– Which??? process: industrial way to make
N-rich fertilizer
Nitrogen Cycle
• Human Impact
– Burning fuels lead to nitric acid/acid rain
– Depleting N from soil by over-planting
– Leaching from soil by irrigation and into
groundwater
– Agricultural runoff leads to eutrophication
(aerobic decomposers break down aquatic
bloom, depleting water of dissolved oxygen)
– Discharge of municipal sewage
– Haber process: industrial way to make Nrich fertilizer
Phosphorous Cycle
Phosphorus Cycle
Role of Phosphorus?
essential nutrient for plants & animals – especially
building block for ???? And ?????), various fats in cell
membranes (??????????), & hard calcium–phosphate
compounds (found where?????);
limiting nutrient in many ecosystems – typically,
addition of P leads to increased productivity, especially
for fresh water aquatic systems.
Phosphorus Cycle
Role of Phosphorus?
essential nutrient for plants & animals – especially
building block for DNA, other nucleic acids (including
ATP; ATP stores chemical energy), various fats in cell
membranes (phospholipids), & hard calcium–
phosphate compounds (in bones, teeth, & shells);
limiting nutrient in many ecosystems – typically,
addition of P leads to increased productivity, especially
for fresh water aquatic systems.
Phosphorous Cycle
• P is found in here?????, not in the atmosphere
• Found in form of phosphate ion or hydrogen
phosphate ion
• Production not dependent on bacterial action
• P released from terrestrial rock by ????????
• Slow process
• Becomes dissolved in soil water and is then
taken up by what??????????
Phosphorous Cycle
• P is found in sedimentary rock, not in the
atmosphere
• Found in form of phosphate ion or hydrogen
phosphate ion
• Production not dependent on bacterial action
• P released from terrestrial rock by weathering
and action of acid rain
• Slow process
• Becomes dissolved in soil water and is then
taken up by plant roots
Phosphorus Cycle
NAME THESE main processes:
(1)????: P slowly released from rock or soil minerals as
phosphate (P043-), which dissolves in H20 & is readily leached;
uptake: by plants to form organic phosphates;
movement through food web: nucleic acids (including DNA &
ATP), certain fats in cell membranes (phospholipids),
bones/teeth/shells (calcium–phosphate);
break down of organic forms: to phosphate (P043-) by
decomposers;
(2)???: P043- from soil;
burial in ocean sediments: not cycled in short time scale, only
over geologic time;
Phosphorus Cycle
main processes:
weathering: P slowly released from rock or soil minerals as
phosphate (P043-), which dissolves in H20 & is readily leached;
uptake: by plants to form organic phosphates;
movement through food web: nucleic acids (including DNA &
ATP), certain fats in cell membranes (phospholipids),
bones/teeth/shells (calcium–phosphate);
break down of organic forms: to phosphate (P043-) by
decomposers;
leaching: P043- from soil;
burial in ocean sediments: not cycled in short time scale, only
over geologic time;
Phosphorous Cycle
How do Humans Impact this cycle??
– M????????, scarring land
– Clear c???? tropical areas for agriculture
– R????? of animal waste and fertilizers
and discharge of municipal sewage plants
– Stream runoff causes it to accumulate in
lakes increasing growth of bacteria and
plants, blocking sun, decrease oxygen,
killing life
Phosphorous Cycle
• Human Impact
– Mining, scarring land
– Clear cutting tropical areas for agriculture
– Runoff of animal waste and fertilizers
and discharge of municipal sewage plants
– Stream runoff causes it to accumulate in
lakes increasing growth of bacteria and
plants, blocking sun, decrease oxygen,
killing life
Sulfur Cycle
Sulfur Cycle
• Most found in underground rocks and deep
oceanic deposits
• Released through weathering, gases
released from what 2 locations????
• Most enters atmosphere through burning
fossil fuels such as what????
Sulfur Cycle
• Most found in underground rocks and deep
oceanic deposits
• Released through weathering, gases
released from sea floor vents and volcanic
eruptions and venting
• Most enters atmosphere through burning
fossil fuels such as coal and oil
Sulfur Cycle
• Makes up proteins and vitamins
• Dissolves in water that plants absorb
through roots in form of sulfates
• Animals obtain sulfur from eating plants
• Most found in rocks and salts or oceanic
sediments
• Some in atmosphere from natural and
human activities
Sulfur Cycle
main processes:
storage in rocks: much of Earth's S is in rock form (e.g., iron
disulfides or pyrites) or m?????????? (sulfates);
A????? input from volcanoes, anaerobic decay, & sea spray:
S enters atmosphere in form of hydrogen sulfide (HS) & sulfur
dioxide (SO2), & sulfates (SO42–);
c????????: sulfur compounds released to the atmosphere by oil
refining, burning of fossil fuels, smelting, & various industrial
activities;
movement through f??????: movement through this?? &
eventual release during decay;
Sulfur Cycle
main processes:
storage in rocks: much of Earth's S is in rock form (e.g., iron
disulfides or pyrites) or minerals (sulfates);
atmospheric input from volcanoes, anaerobic decay, & sea
spray: S enters atmosphere in form of hydrogen sulfide (HS) &
sulfur dioxide (SO2), & sulfates (SO42–);
combustion: sulfur compounds released to the atmosphere by oil
refining, burning of fossil fuels, smelting, & various industrial
activities;
movement through food web: movement through food web &
eventual release during decay;
Sulfur Cycle
• Natural
– Volcanic eruptions
– Certain bacterial functions
– decay
• Human
– Industrial processes producing SO2 and H2S
gases (mostly burning coal and oil)
Sulfur Cycle
2SO2 + O2  2SO3
SO3 + H2O  H2SO4 (acid rain)
NH3 + SO2  acid deposition
SO2 and sulfate aerosols create health
problems, damages crops and buildings,
reduce visibility and absorb UV
•  a??????? and produce cooling effect
•
•
•
•
Sulfur Cycle
2SO2 + O2  2SO3
SO3 + H2O  H2SO4 (acid rain)
NH3 + SO2  acid deposition
SO2 and sulfate aerosols create health
problems, damages crops and buildings,
reduce visibility and absorb UV
•  albedo and produce cooling effect
•
•
•
•
Sulfur Cycle
How do Humans Impact?
– Burning of coal and oil and petroleum refining
release 2x SO2 into troposphere as nature
– Smelting of metal o??? containing sulfur
– Using sulfuric acid in industrial processes and
manufacture
– Refining p????
Sulfur Cycle
• Human Impact
– Burning of coal and oil and petroleum refining
release 2x SO2 into troposphere as nature
– Smelting of metal ores containing sulfur
– Using sulfuric acid in industrial processes and
manufacture
– Refining petroleum
Nutrient Storehouses
Major nonliving & living storehouses of elemental nutrients.
You are prepared if you can fill in this info
Nutrient Storehouses
Major nonliving & living storehouses of elemental nutrients.
H???? Brook Experimental Forest
• Study on how deforestation affects nutrient
cycles
• Forest consisted of several watersheds
drained by single creek
• Impervious bedrock close to surface,
prevented seepage of water
Hubbard Brook Experimental Forest
• Study on how deforestation affects nutrient
cycles
• Forest consisted of several watersheds
drained by single creek
• Impervious bedrock close to surface,
prevented seepage of water
Hubbard Brook Experimental Forest Conclusions
• Undisturbed forest ecosystem in dynamic
equilibrium—nutrients leaving balanced by ones
entering
• Inflow and outflow was low compared to levels of
nutrients being recycled
• D????—water runoff and soil erosion increase or
decrease??? causing large increase or decrease??
in outflow of nutrients causing water pollution
• Nutrient loss reduced by clearing trees and
vegetation in horizontal strips, remaining increase
or decrease?? soil erosion
Hubbard Brook Experimental Forest Conclusions
• Undisturbed forest ecosystem in dynamic
equilibrium—nutrients leaving balanced by ones
entering
• Inflow and outflow was low compared to levels of
nutrients being recycled
• Deforestation—water runoff and soil erosion 
causing large  in outflow of nutrients causing
water pollution
• Nutrient loss reduced by clearing trees and
vegetation in horizontal strips, remaining  soil
erosion
Nutrient Cycling & Sustainability
Are ecosystems self–contained?
immature natural ecosystems tend to have major shifts
in energy flow & nutrient cycling;
over time ecosystems tend to reach an equilibrium with
respect to energy flow & nutrient cycling, such that
these ecosystems appear self–contained;
however, there is considerable exchange of water &
nutrients of ecosystems with adjacent ecosystems;
human disturbance (clear cutting, clearing, etc.) can
cause major loss of nutrients.
Nutrient Cycling & Sustainability
How does nutrient cycling relate to ecosystem sustainability?
the law of conservation of matter enables us to understand major
nutrient cycles, and observe that given time natural ecosystems
tend to come into a balance wherein nutrients are recycled with
relative efficiency;
modification of major nutrient cycles may lead to shift in
ecosystems, such that current ecosystems are not sustainable;
developing a better understanding of energy flow & nutrient
cycling is critical to understanding the depth of environmental
problems.
All things come from earth, and to earth they all return.
–– Menander (342–290 B.C.)