n utrient c ycling n itrogen c ycling t hrough e cosystems dr. jeffrey r. corney, managing director...
TRANSCRIPT
NUTRIENT CYCLINGNUTRIENT CYCLINGNITROGEN CYCLING THROUGH ECOSYSTEMS
Dr. Jeffrey R. Corney, Managing Director of the University of Minnesota’s Cedar Creek Ecosystem Science Reserve
D. Kindersley
Nitrogen Free
NUTRIENT CYCLINGENERGY FLOWNUTRIENT CYCLINGEnergy Flow, Carbon & Oxygen Cycling
J. Corney
NUTRIENT CYCLINGThe Nitrogen Cycle
McGraw-Hill
Elm
hurs
t
10% of naturally occurring available nitrogen is generated by lightning.
NUTRIENT CYCLINGENERGY FLOWNUTRIENT CYCLINGNitrogen Cycling Through an Ecosystem
PRODUCERS
DECOMPOSERS
CONSUMERS
ECOSYSTEM
1o 2o 3o
SOIL “SINK”
N-cmpds
N-cmpds
OTHERSOURCES
N
J. Corney
NO3- & NH4
+
N2
&
NOxATMO
SPHERE
NUTRIENT CYCLINGCarbon vs. Nitrogen Cycles
Nitrogen cycling is mostly soil based.
Carbon cycling is mostly atmosphere based.
NUTRIENT CYCLINGCarbon & Nitrogen Cycles Are Linked
U.S. Dept of Energy
NUTRIENT CYCLINGIn the “Top Four” Elements for Life
ASU
Pear
son
NUTRIENT CYCLINGRoles of CARBON & NITROGEN:
“Life as a House”
If Carbon comprises the framing and roofing (FORM)…
…then Nitrogen comprises the appliances (FUNCTION).E
Patr
ol
NUTRIENT CYCLINGKey Component of Life’s Molecules
Hemoglobin & Chlorophyll
Amino Acids & Proteins
DNA & RNA
UD
EL
Wikipedia
NobelPriz
e.org
NUTRIENT CYCLINGCarbon to Nitrogen (C:N) Ratios
McGraw-Hill
Plants ~ 25:1
Animals ~ 6:1
NUTRIENT CYCLING
Atmospheric N2
Nitrogen Is Abundant in Atmosphere
…but, N2 as a gas is relatively inert to life
U.S. EPA
NUTRIENT CYCLING
…but, only plants can absorb Nitrogen directly from the environment
Forms of Nitrogen Available for Life
Nitrogen Free
NUTRIENT CYCLINGThe Nitrogen Cycle
NUTRIENT CYCLINGOrganic vs. Inorganic Nitrogen
Organisms consume other organisms and excrete inorganic wastes.
Inorganic (mineral) nutrients are usable by plants, and are mobile in soil.
Organic (immobile) nutrients are stored
in soil organisms and organic matter.
Organisms take up and retain nutrients
as they grow.
USDA-NRCS
NUTRIENT CYCLINGNitrogen Cycle (zoomed in)
NUTRIENT CYCLING
N2 Nitrogen
Atmospheric Nitrogen
Ammonifying Bacteria
Nitrogen -Fixing Bacteria
Fixing Nitrogen…
NUTRIENT CYCLING
Nitrifying Bacteria
Nitrosomonas
Nitrobacter
Getting to Nitrate…
NUTRIENT CYCLINGNutrients Need Water to Move
?
DK
Clip
art
Nutrient ions are mobile while in a solution of water.
So, how do nutrients move in soil?
NUTRIENT CYCLINGComposition of Soil
PhysicalGeography.net
NUTRIENT CYCLINGInterstitial Spaces
U o
f Min
neso
ta
NUTRIENT CYCLINGGetting Nutrients to the Plants
USDA-NRCS
U of Georgia
River P
artners
NUTRIENT CYCLINGMychorrizhae: Plants & Fungi Together
90% of plant families have mychorrizhal associations.
Agro-Genesis
A symbiotic, mutualistic association between a fungus and the roots of plants.
NUTRIENT CYCLINGMychorrizhal Relationship Up Close
Plant root
Mycorrhizal structure
Fungal hyphae
USDA-NRCS
NUTRIENT CYCLING2 Types of Mychorrizhal Relationships
Nature
Plan
t a G
lobe
10% of plant families, mostly woody species (e.g. pine, oak, birch)
USD
A-N
RCS
80% of plant families, mostly herbaceous species (e.g. grasses, forbs)
USD
A-N
RCS
NUTRIENT CYCLINGPlant-Fungal Cellular Connection
Cold
Spr
ing
Har
bor
Oxf
ord
Jour
nal
Imag
e N
atur
e
RHIZOSPHEREArea of soil immediately adjacent to plant roots and mychorrizhal structures.
NUTRIENT CYCLINGFungi Help Get Nutrients into Roots
NO3-
NO3-
NO3-
NO3-
NO3-
NH4+
NH4+
NH4+
NO3-
H2O H2O
H2O
H2O
H2O
H2OH2O
H2O
H2O
H2O
H2O
M. Harrison
NUTRIENT CYCLINGNutrients Move from Roots to Shoots
Tuto
r Vis
ta
Helicon
NUTRIENT CYCLING
J. Co
rney
NUTRIENT CYCLINGNUTRIENT CYCLINGSOIL ORGANISMS & DECOMPOSITION
Dr. Jeffrey R. Corney, Managing Director of the University of Minnesota’s Cedar Creek Ecosystem Science Reserve
Organic
Garden
NUTRIENT CYCLINGFormation of Soil
Brooks-Cole
NUTRIENT CYCLINGSoil Layers
DK
Clip
art
USDA-NRCS
Surface Litter
Top Soil
Sub-Soil
Rock
NUTRIENT CYCLING
Absolute Science
Cross-Section of Soil
NUTRIENT CYCLINGSoil Ecosystem at Micro-level
USD
A-N
RCS
Rose & Elliot
NUTRIENT CYCLINGProcess of Decomposition of Animals
McG
raw
-Hill
NUTRIENT CYCLINGProcess of Decomposition of Plants
Broo
ks-C
ole
NUTRIENT CYCLINGSoil Food Chain
Landscape for Life
NUTRIENT CYCLINGSoil Food Web
Brooks-Cole
NUTRIENT CYCLINGBacteria, Fungi, & Actinomycetes
Decompose material, mineralize nutrients, fix nitrogen, help aggregate soil particles.
USD
A-N
RCS
USD
A-N
RCS
USD
A-N
RCS
USD
A-N
RCS
NUTRIENT CYCLINGAnnual Microbial Activity by Season
USDA-NRCS
NUTRIENT CYCLINGProtozoans
Consume bacteria and fungi, releasing nutrients when excrete wastes.
USD
A-N
RCS
BLM
Mau
by
NUTRIENT CYCLINGNematodes & Springtails
Roda
le
Consume bacteria, fungi, and protozoans, releasing nutrients when excrete wastes.
TAM
U
USD
A-N
RCS
USD
A-N
RCS
NUTRIENT CYCLINGMites, Sowbugs, Millipedes
Shred plant litter and consume detritus, increasing ability for microbes to decompose material.
USD
A-N
RCS
USD
A-N
RCS
EcoL
ibra
ry
NUTRIENT CYCLINGAnts, Beetles, Spiders, Centipedes
Predators that eat other consumers, controlling populations and excreting nutrients.
USD
A-N
RCS
Dis
cove
r Life
NUTRIENT CYCLINGEarthworms: “Soil Aerators”
Mix soil layers, redistributing nutrients throughout soil, and aerate the soil.
Cary
Insti
tute
Scie
nce
Dai
ly
WO
RM
NUTRIENT CYCLINGGophers & Ants: “Earth Movers”
Move nutrient poor sub-layers of soil to the surface, helping enrich soil layers.
NUTRIENT CYCLINGSoil Organisms By-the-Numbers
USDA-NRCS
1 gram of soil
NUTRIENT CYCLINGSoil Organisms By Type of Ecosystem
USDA-NRCS
NUTRIENT CYCLINGSoil Biodiversity by Ecosystem
USDA-NRCS
NUTRIENT CYCLINGFun Facts About Soil
A single spade full of rich garden soil contains more species of organisms than can be found above ground in the entire Amazon rain forest.
One cup of soil may hold as many bacteria as there are people on Earth.
The weight of all the bacteria in one acre of soil can equal the weight of a cow.
A teaspoon of soil from a coniferous forest may hold tens of miles of fungi.
The air in the upper 8 inches of a well-drained soil is completely renewed about every hour.
The plants growing in a 2-acre field can have more than 30,000 miles of roots, greater than the circumference of the Earth.
Mature trees can have as many as 5 million active root tips.
SOURCE: USDA-NRCS
NUTRIENT CYCLINGMore Fun Facts About Soil
Twenty thousand species of nematodes have been described, but it is thought that 500,000 species may exist.
Every time you take a step in a mature forest, your foot is being supported on the backs of 16,000 invertebrates held up by an average total of 120,000 legs.
There is an estimated one quadrillion individual ants on the planet; that’s approximately 150,000 ants for every one human being.
Where earthworms are active, they can turn over the entire top 6 inches of soil in 10 to 20 years.
Pocket gopher mounds can cover as much as 25% of a grassland’s ground surface, depositing on average 20 tons of soil per acre per year.
SOURCE: USDA-NRCS
NUTRIENT CYCLINGSUSTAINABILITY ISSUESTHE CONCERN:
Nitrogen Deposition & Eutrophication
“Too Much of a Good Thing”
NUTRIENT CYCLINGSUSTAINABILITY ISSUESGlobal Sources of Nitrogen Today
Vitousek & Matson
Scien
tific A
mer
ican
NUTRIENT CYCLINGSUSTAINABILITY ISSUESHaber-Bosch “Synthetic” Nitrogen
Fritz Haber Carl Bosch
Fertilizer 101
Men
lo S
choo
l
Invented process in early 1900s
NUTRIENT CYCLINGSUSTAINABILITY ISSUESNitrogen Use, Agricultural Revolution,
and Human Population Growth
Tilman
NUTRIENT CYCLINGSUSTAINABILITY ISSUESSoil Nitrogen Runoff from Fertilizer
NUTRIENT CYCLINGSUSTAINABILITY ISSUESAtmospheric Nitrogen Deposition
NUTRIENT CYCLINGSUSTAINABILITY ISSUESExcessive Nitrogen
in Mississippi Watershed
USGS
NUTRIENT CYCLINGSUSTAINABILITY ISSUESProcess of Eutrophication
NUTRIENT CYCLINGSUSTAINABILITY ISSUESEutrophication of Coastal Gulf Waters
NUTRIENT CYCLING
Dr. Jeffrey R. Corney, Managing Director University of Minnesota Cedar Creek Ecosystem Science Reserve2660 Fawn Lake Dr NEEast Bethel, MN 55005(763) 434-5131