SEV012
Plant Litter Decomposition
Carl
S.
White
Sevilleta LTER
167 Castetter Hall
University of New Mexico
Albuquerque
NM
87131
United States of America
505-277-8689
505-277-5355
cswhite@sevilleta.unm.edu
Sevilleta Long Term Ecological Research
Department of Biology
167 Castetter Hall
MSC03 2020
1 University of New Mexico
Albuquerque
New Mexico
87131-0001
USA
505-277-5355
vanderbi@sevilleta.unm.edu
http://sevilleta.unm.edu
Field Crew
Olivia
Hopkins
Lab Crew
John
Craig
Department of Biology
MSC03 2020
University of New Mexico
Albuquerque
NM
87131
United States of America
505-277-2715
505-277-5355
jcraig@sevilleta.unm.edu
Lab Crew
english
document the effects of climate variation on decomposition of major
plant litter-types. the prject began in 1989 and has undergone
changes of locations and litter types. The long-term litter types
include black grama, Indian rice grass, juniper, and creosote. Mass
loss of the litter types can be compared to precipitation and other
meteorological factors obtained at nearby locations.
Sevilleta National Wildlife Refuge, Sevilleta LTER
litter bags
decomposition
vegetation
litter
el Nino
La Nina
nitrogen
phosphorus
precipitation
solar radiation
grassland, shrubland, pinyon-juniper woodland
vegetation
ecology
decomposition
DATA USE POLICY
Any Sevilleta LTER data set and accompanying metadata can be used for academic, research, and other professional purposes. Permission to use the data is granted to the Data User subject to the following terms: Data User will:
Notify the designated contact (e.g., Principle Investigator or Data Set Contact) when any derivative work based on or derived from the data and documentation is distributed;
Notify users that such derivative work is a modified version and not the original data and documentation distributed by the Sevilleta LTER;
Not redistribute original data and documentation
Acknowledge the support of the Sevilleta LTER and appropriate NSF Grant numbers in any publications using these data and documentation. (e.g. Data sets were provided by the Sevilleta LTER Data Bank. Funding for these data was provided by the National Science Foundation Long-Term Ecological Research program (NSF Grant numbers BSR 88-11906, DEB9411976, DEB0080529, DEB0217774)
Send two reprints of any publications resulting from use of the data and documentation to the following address: Sevilleta LTER Program Attn: Information Manager, Department of Biology, MSC03 2020, University of New Mexico, Albuquerque, NM 87131
http://sevilleta.unm.edu/data/
7] Where the Data were collected:
Site Name:: Location 1, Black Butte
Site Location: SW of gate on east side of black butte (north border of east side)
Site Coordinates: 34.40667735, -106.68647480, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1560.2 m
Site Geology:
Site Soil: sandy
Site Vegetation:
Site History:
:
:
Site Name:: Location 2, Deep Well
Site Location: deep well, east side
Site Coordinates: 34.35277814, -106.69230409, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1605.07 m
Site Geology:
Site Soil:
Site Vegetation: black and blue grama
Site History:
:
:
Site Name:: Location 3, Old 5 points
Site Location: 1 mile east-southeast of 5 points
Site Coordinates: 34.27395094, -106.67859413, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 16.92.34 m
Site Geology:
Site Soil:
Site Vegetation:
Site History:
:
:
Site Name:: Location 4, Larrea
Site Location: between location 3 and the south boundary
Site Coordinates: 34.24100599, -106.74927778, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1617.05 m
Site Geology:
Site Soil:
Site Vegetation: Creosote
Site History:
:
:
Site Name:: Location 5, Ocotillo
Site Location: Near south boundary
Site Coordinates: 34.22190529, -106.70410020, NAD83
Site Size: 5 x 5 m
Site Landform: south facing slope
Site Elevation: 1723.05 m
Site Geology:
Site Soil:
Site Vegetation: Ocotillo
Site History:
:
:
Site Name:: Location 6, Sepultura Canyon
Site Location: Sepultura Canyon
Site Coordinates: 34.30220417, -106.62011595, NAD83
Site Size: 5 x 5 m
Site Landform: foothills of the Los Pinos
Site Elevation: 1872.44 m
Site Geology:
Site Soil:
Site Vegetation: grass-juniper savannah
Site History:
:
:
Site Name:: Location 7, Cerro Montoso
Site Location: Cerro Montoso
Site Coordinates: 34.36851996, -106.53503075, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1970.74 m
Site Geology:
Site Soil:
Site Vegetation:
Site History:
:
:
Site Name:: Location 8, Bosque del Apache
Site Location: Bosque del Apache NWR, east side of Rio Grande
Site Coordinates:
Site Size: 5 x 5 m
Site Landform:
Site Elevation:
Site Geology:
Site Soil:
Site Vegetation: riparian forest
Site History:
:
:
Site Name:: Location 9F, Magdelena Mountains Forest
Site Location: Magdelena Mountains, west of Socorro
Site Coordinates: 33.98152914, -107.18597909, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 3187.6 m
Site Geology:
Site Soil:
Site Vegetation: High elevation forest-meadow
Site History:
:
:
Site Name:: Location 9M, Magdelena Mountains Meadow
Site Location: Magdelena Mountains, west of Socorro
Site Coordinates: 33.99204766, -107.17438462, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 3033.6 m
Site Geology:
Site Soil:
Site Vegetation: High elevation forest-meadow
Site History:
:
:
Site Name:: Location 10, Rio Salado
Site Location: Rio Salado
Site Coordinates: 34.29572804, -106.92662418, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1509.54 m
Site Geology:
Site Soil: sandy soil
Site Vegetation: Chihuahua desert with creosote dominant
Site History:
:
:
Site Name:: Location 11, Red Tank
Site Location: Red Tank, in foothills of ladrone Peak
Site Coordinates: 34.39791210, -107.03647141, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1767.12 m
Site Geology:
Site Soil:
Site Vegetation: Great Basin grass-shrub
Site History:
:
:
Site Name:: Location 12, Blue Springs
Site Location: Blue Springs, (lower goat draw), northeast corner of SNWR
Site Coordinates:
Site Size: 5 x 5 m
Site Landform:
Site Elevation:
Site Geology:
Site Soil:
Site Vegetation: grass-juniper savannah
Site History:
:
:
Site Name:: Location 13, 5 points
Site Location: east of actual road junction near site of grassland-creosote webs
Site Coordinates: 34.33272200, -106.73100528, NAD83
Site Size: 5 x 5 m
Site Landform:
Site Elevation: 1613.89 m
Site Geology:
Site Soil:
Site Vegetation: creosote
Site History:
-107.089501
-106.513623
34.422253
34.185570
1428
1790
meter
1990
1999
\log
7/18/2003 - File created by Kristin Vanderbilt
\doc
Sevilleta LTER Information Manager
Department of Biology
167 Castetter Hall
1 University of New Mexico
Albuquerque
New Mexico
87131-0001
USA
505-277-5355
data-use@sevilleta.unm.edu
Sevilleta Long Term Ecological Research
Department of Biology
167 Castetter Hall
1 University of New Mexico
Albuquerque
New Mexico
87131-0001
USA
505-277-5355
Sample Collection Methods
For each individual location collection, three replicate bags
are placed in zip-lock bags and are identified by species,
field location, collector initials, and date of collection. A
general maintenance survey of each location is done at this
time by the collector(s). At the time of placement, three bags
of each species were collected and placed into a gallon-sized
zip-loc bag for transport to the lab. This method insured that
each replicate was handled the same way with bouncing during
transport and sample handling consistent for all samples. These
three samples taken at the time of placement determine the
starting (incubation in the field time 0) replicate
litters. For each collection date, 28 gallon-size zip-lock bags
were be needed.
Sample Analysis Methods
Overview: Handling of the field samples involves three phases:
(1) initial cleaning and oven-dry weight; (2) grinding and ash
correction; and (3) chemical analyses. Once in the laboratory,
field samples will come in with 3 replications/plant type in a
bag labelled with the site, plant material, and collection
date. In Phase 1, the samples are cleaned, oven dried at 60° C
for a minimum of 24 hours, and oven-dry weight recorded. The
samples are then transferred to coin envelopes, ground on the
Tecator grinder, and stored back in the coin envelope. In Phase
2, ground plant material is then used for ash-free weight
determinations. In Phase 3, the remaining ground plant litter
is used for chemical analyses.
Phase 1. WEIGHING
Overview
Specifics
The following equipment is needed for weighing out the samples:
Balance
Large and small weigh boats
Oven: 60° C
Cafeteria tray
Permanent marker
Staple remover
Scissors
Decomp Record Book
Desiccators
Make sure to reserve all equipment as needed ahead of time.
1. Select a zip-loc bag with field samples to begin weighing
out. Select one mesh bag, you have now arbitrarily assigned this
sample a replicate number and Sample ID number.
Label a weigh boat (large for the grasses and cottonwood, small for
salt bush, creosote, pinyon, yucca, and juniper) with the site
number, plant type and Sample ID number. Tare the balance and weigh
the empty weigh boat, recording the weight in the record book.
Carefully remove any foreign material from the outside of the bag,
such as: differen plant material, mud, ROCKS, etc, making sure to
lift up the side folds to release any trapped rocks. MAKE SURE YOU
REMOVE ALL ROCKS, OR ELSE YOU MAY DESTROY THE GRINDER ROTOR LATER
ON (not to mention throwing off the weight).
Carefully remove the staples from the top fold ONLY. MAKE SURE that
should any staples break you retrieve ALL parts of it, so that your
weight is accurate, and so that you don't attempt to grind it later
on (ouch!).
Place the weighed and labelled weigh boat on a sheet of paper in
front of you, and empty the contents of the bag into the weigh
boat.
NOTE: for cottonwoods and the grasses, first reach the scissors
into the mesh bag and cut up the material into SMALL pieces,
keeping in mind that the smaller they are now, the easier it will
be to stuff into the coin envelopes and the faster it will be to
grind.
For yucca, remove the numbered tag, and record that number in the
record book to the left of the replication number, and cut it up
into small pieces.
Repeat this for all samples, weighing out a mix of big and small
weigh boats (they fit better in the oven that way), and place in
the oven. BE CAREFUL not to weigh out more samples than you have
oven space! Make several trips to the oven instead of one big load
to gauge oven capacity.
2. Dry for a minimum of 24 hours at 60° C, although longer times will
not hurt the sample, it has not been found to be beneficial.
Remove the weigh boats filled with dried samples, and place in a desiccator to cool for about 20 minutes.
Reweigh the filled weigh boat, record the weight in the record book.
Working over a piece of paper, stuff the plant material into a
coin envelope labelled with the collection date, site number,
plant type, and Sample ID number.
GRINDING
NOTE: MAKE SURE YOU READ THE FULL SET OF INSTRUCTIONS FOUND IN THE DRAWER UNDER THE Tecator GRINDER.
Overview
Plant material is ground in order to perform ash-free weight
corrections and chemical analyses. The only plant material needed to
be ground using liquid N are: pinyon, juniper and creosote. All others
are ground warm.
SUGGESTED ITEMS USEFUL FOR GRINDING
Mortar & pestle
Small kimwipes
Flat-edged spatula
Paint brush
Q-tips
Ethanol
Toothbrush
Small beaker (Et2OH)
Liquid N
Brown gloves
Plastic beaker on a string for liquid N
EVERY DAY BEFORE GRINDING
Before grinding, take apart the machine to make sure it is clean:
1.Remove the rotor, using the wrench and the L shaped piece of
metal. Scrape out any residue on the underside of the rotor and
clean it with an ethanol-soaked Q-tip.
2.Clean the flat piece under the rotor (with concentric circles) with
a wet Q-tip. Lift out this piece and make sure any dust is cleaned
out of the area.
3.Replace the rotor, finger tightening the nut. Then only SLIGHTLY
tighten it back with the wrench. IF you don't tighten it with the
wrench, the grinder will make an awful noise when you turn it on.
4.Reassemble the grinder, inspecting the rotor blades, sample pan,
screen (arrow up), lid and funnel for residue. Clean as
necessary. Replace the black screw knobs and you're ready to go.
TURNING ON THE GRINDER SO AS NOT TO BLOW A FUSE
ALWAYS start the machine in this order:
1.Plug into the wall circuit
2.Have the speed button on I (15000 rpm)
3.Turn on the ON switch.
4.Turn on the timer to 5 or so.
5.Wait for the orange light to come on before adding the sample.
6.Add the sample SLOWLY or you will overload the motor and blow a fuse.
Phase 2. ASH-FREE WEIGHT CORRECTION METHOD
Methods 1989 through 1991:
1. ASH THE EMPTY CRUCIBLES.
Line up a sufficient quantity (about 40) of the tall, narrow, numbered
porcelain crucibles. Wipe them out with a Kimwipe. Load them into the
muffle furnace making sure not to touch the oven sides or each
other. Use the shelf to fit them all in.
Close the muffle furnace. Turn on the exhaust fan. Turn the controller
to 5.0, and turn the timer to 2 hours. After about 1.5 - 1.75 hours,
check to verify that the temperature has or will reached 500 °C. If
it hasn't, add additional time to the controller. When it does hit 500
°C, it is hot enough and ready to shut off. Let cool, closed,
overnight. The next day the crucibles can be removed, USING TONGS (DO
NOT TOUCH WITH YOUR HANDS) and stored in a desiccator.
2. DRY THE GROUND MATERIAL.
The ground material in their envelopes should be placed in the 60 °C
oven for 24 hours prior to weighing out for ashing. When the crucibles
are thoroughly cooled, weigh the empty crucible and then place out
approximately 1 gram using the analytical balance (BE SURE TO MIX THE
SAMPLE WELL BECAUSE PARTICLES TEND TO SEPARATE DURING STORAGE AND
HANDLING) of ground material into the crucible, and then record the
filled crucible weight on the data charts in the front of this
book. Remember to weigh and include a blank (empty) crucible with each
run.
4. ASH THE WEIGHED SAMPLE.
Using tongs, load the crucibles into the muffle furnace, making sure
not to touch the oven sides or each other. Use the shelf to fit them
all in. Close the muffle furnace. Turn on the exhaust fan. Turn the
controller to 5.0, and turn the timer to 2 hours. After about 1.5 -
1.75 hours, check to verify that the temperature has reached 500
°C. If it hasn't, add an extra 15 minutes to the timing. When it does
hit 500°C, and the timer has turned off the furnace, turn the
controller to 2.0, and the timer to 2 hours. Let cool, closed,
overnight.
5. WEIGH THE ASHED SAMPLES.
Using tongs, remove the crucibles to a desiccator. When they are
thoroughly cooled, use the same analytical balance and record the
filled crucible weight on the data charts in the front of this
book. Remember to weigh and include the blank (empty) crucible from
each run. Dump out the ashed sample into the garbage, wiping the
crucible with a Kimwipe if necessary. The crucibles are now ready to
be filled again and fired. No need to ash the empty crucibles between
runs AS LONG AS YOU KEEP THEM CLEAN!
Methods after 1991:
Ashing methods were changed in 1991 when the use of porcelain
crucibles was replaced by use of disposable aluminum boats. All
methods stayed the same EXCEPT: The disposable aluminum boats did not
need to be 'tared' or fired before use. The clean boats were taken
directly from the package and placed into use. To identify the boat,
the SAMPLE ID # was 'written' (etched indented with a pencil-pen) on
the bottom of the boat. The boat weight was recorded and the sample
(WITH MIXING!) was added (about 1 gram). The rest of the procedures
remained the same. If the muffle furnace was allowed to exceed 550 °C,
the aluminum boats would melt and significant changes in their weight
could occur. Blank boats are run with each operation to insure no
significant loss-gain during firing.
Analytical Methods Used:
Kjeldahl Nitrogen and Phosphorus by Technicon Industrial Method
No. 369-75A (Revised 8/21/75) Digestion and sample preparation for the
analysis of total kjeldahl nitrogen and/or phosphorus in food and
agricultural products using the technicon BD-20 Block digestor. and
Technicon Industrial Method 334-74A (revised 8/21/75)
Individual/simultaneous determination on nitrogen and phosphorus in BD
acid digests
Percent Nitrogen and Percent Carbon were determined by High
Temperature combustion, the resulting gases were eluted on a gas
chromatography column and detected by thermal conductivity and
integrated to yield carbon and nitrogen content. Analyses were
performed on a ThermoQuest CE Instruments NC2100 Elemental Analyzer,
ThermoQuest Italia S.p.A., Rodano, Italy. Study
Instrumentation:ThermoQuest CE Instruments, NC2100, Elemental Analyzer
(Nitrogen and Carbon)
CHAIN OF CUSTODY
1. Field personnel.
The number of personnel involved in the field collection of Sevilleta
LTER Decomposition study samples is usually limited to 1 or 2
individuals. The collection procedure is relative simple and is
dominated by time taken driving from location to location. It is
important that the field personnel responsible for sample collections
be familiar with the collection protocol, sample identifications,and
location locations. It is the responsibility of the field personnel to
deliver the samples to the laboratory personnel, as quickly and
carefully as possible.
2. Laboratory personnel.
Once delivered by the field personnel, the inventory, storage and
management of the samples becomes the responsibility of the laboratory
personnel. The laboratory personnel are responsible for conducting all
analytical laboratory procedures, in addition to attaining, entering,
verifying and archiving any relevant data. These tasks usually were
performed by student technicians, but the samples are the direct
responsibility of the staffed Sevilleta LTER laboratory technician,
under supervision of the Laboratory Director.
Sample Collection Methods
For each individual location collection, three replicate bags
are placed in zip-lock bags and are identified by species,
field location, collector initials, and date of collection. A
general maintenance survey of each location is done at this
time by the collector(s). At the time of placement, three bags
of each species were collected and placed into a gallon-sized
zip-loc bag for transport to the lab. This method insured that
each replicate was handled the same way with bouncing during
transport and sample handling consistent for all samples. These
three samples taken at the time of placement determine the
starting (incubation in the field time 0) replicate
litters. For each collection date, 28 gallon-size zip-lock bags
were be needed.
Sample Analysis Methods
Overview: Handling of the field samples involves three phases:
(1) initial cleaning and oven-dry weight; (2) grinding and ash
correction; and (3) chemical analyses. Once in the laboratory,
field samples will come in with 3 replications/plant type in a
bag labelled with the site, plant material, and collection
date. In Phase 1, the samples are cleaned, oven dried at 60° C
for a minimum of 24 hours, and oven-dry weight recorded. The
samples are then transferred to coin envelopes, ground on the
Tecator grinder, and stored back in the coin envelope. In Phase
2, ground plant material is then used for ash-free weight
determinations. In Phase 3, the remaining ground plant litter
is used for chemical analyses.
Phase 1. WEIGHING
Overview
Specifics
The following equipment is needed for weighing out the samples:
Balance
Large and small weigh boats
Oven: 60° C
Cafeteria tray
Permanent marker
Staple remover
Scissors
Decomp Record Book
Desiccators
Make sure to reserve all equipment as needed ahead of time.
1. Select a zip-loc bag with field samples to begin weighing
out. Select one mesh bag, you have now arbitrarily assigned this
sample a replicate number and Sample ID number.
Label a weigh boat (large for the grasses and cottonwood, small for
salt bush, creosote, pinyon, yucca, and juniper) with the site
number, plant type and Sample ID number. Tare the balance and weigh
the empty weigh boat, recording the weight in the record book.
Carefully remove any foreign material from the outside of the bag,
such as: differen plant material, mud, ROCKS, etc, making sure to
lift up the side folds to release any trapped rocks. MAKE SURE YOU
REMOVE ALL ROCKS, OR ELSE YOU MAY DESTROY THE GRINDER ROTOR LATER
ON (not to mention throwing off the weight).
Carefully remove the staples from the top fold ONLY. MAKE SURE that
should any staples break you retrieve ALL parts of it, so that your
weight is accurate, and so that you don't attempt to grind it later
on (ouch!).
Place the weighed and labelled weigh boat on a sheet of paper in
front of you, and empty the contents of the bag into the weigh
boat.
NOTE: for cottonwoods and the grasses, first reach the scissors
into the mesh bag and cut up the material into SMALL pieces,
keeping in mind that the smaller they are now, the easier it will
be to stuff into the coin envelopes and the faster it will be to
grind.
For yucca, remove the numbered tag, and record that number in the
record book to the left of the replication number, and cut it up
into small pieces.
Repeat this for all samples, weighing out a mix of big and small
weigh boats (they fit better in the oven that way), and place in
the oven. BE CAREFUL not to weigh out more samples than you have
oven space! Make several trips to the oven instead of one big load
to gauge oven capacity.
2. Dry for a minimum of 24 hours at 60° C, although longer times will
not hurt the sample, it has not been found to be beneficial.
Remove the weigh boats filled with dried samples, and place in a desiccator to cool for about 20 minutes.
Reweigh the filled weigh boat, record the weight in the record book.
Working over a piece of paper, stuff the plant material into a
coin envelope labelled with the collection date, site number,
plant type, and Sample ID number.
GRINDING
NOTE: MAKE SURE YOU READ THE FULL SET OF INSTRUCTIONS FOUND IN THE DRAWER UNDER THE Tecator GRINDER.
Overview
Plant material is ground in order to perform ash-free weight
corrections and chemical analyses. The only plant material needed to
be ground using liquid N are: pinyon, juniper and creosote. All others
are ground warm.
SUGGESTED ITEMS USEFUL FOR GRINDING
Mortar & pestle
Small kimwipes
Flat-edged spatula
Paint brush
Q-tips
Ethanol
Toothbrush
Small beaker (Et2OH)
Liquid N
Brown gloves
Plastic beaker on a string for liquid N
EVERY DAY BEFORE GRINDING
Before grinding, take apart the machine to make sure it is clean:
1.Remove the rotor, using the wrench and the L shaped piece of
metal. Scrape out any residue on the underside of the rotor and
clean it with an ethanol-soaked Q-tip.
2.Clean the flat piece under the rotor (with concentric circles) with
a wet Q-tip. Lift out this piece and make sure any dust is cleaned
out of the area.
3.Replace the rotor, finger tightening the nut. Then only SLIGHTLY
tighten it back with the wrench. IF you don't tighten it with the
wrench, the grinder will make an awful noise when you turn it on.
4.Reassemble the grinder, inspecting the rotor blades, sample pan,
screen (arrow up), lid and funnel for residue. Clean as
necessary. Replace the black screw knobs and you're ready to go.
TURNING ON THE GRINDER SO AS NOT TO BLOW A FUSE
ALWAYS start the machine in this order:
1.Plug into the wall circuit
2.Have the speed button on I (15000 rpm)
3.Turn on the ON switch.
4.Turn on the timer to 5 or so.
5.Wait for the orange light to come on before adding the sample.
6.Add the sample SLOWLY or you will overload the motor and blow a fuse.
Phase 2. ASH-FREE WEIGHT CORRECTION METHOD
Methods 1989 through 1991:
1. ASH THE EMPTY CRUCIBLES.
Line up a sufficient quantity (about 40) of the tall, narrow, numbered
porcelain crucibles. Wipe them out with a Kimwipe. Load them into the
muffle furnace making sure not to touch the oven sides or each
other. Use the shelf to fit them all in.
Close the muffle furnace. Turn on the exhaust fan. Turn the controller
to 5.0, and turn the timer to 2 hours. After about 1.5 - 1.75 hours,
check to verify that the temperature has or will reached 500 °C. If
it hasn't, add additional time to the controller. When it does hit 500
°C, it is hot enough and ready to shut off. Let cool, closed,
overnight. The next day the crucibles can be removed, USING TONGS (DO
NOT TOUCH WITH YOUR HANDS) and stored in a desiccator.
2. DRY THE GROUND MATERIAL.
The ground material in their envelopes should be placed in the 60 °C
oven for 24 hours prior to weighing out for ashing. When the crucibles
are thoroughly cooled, weigh the empty crucible and then place out
approximately 1 gram using the analytical balance (BE SURE TO MIX THE
SAMPLE WELL BECAUSE PARTICLES TEND TO SEPARATE DURING STORAGE AND
HANDLING) of ground material into the crucible, and then record the
filled crucible weight on the data charts in the front of this
book. Remember to weigh and include a blank (empty) crucible with each
run.
4. ASH THE WEIGHED SAMPLE.
Using tongs, load the crucibles into the muffle furnace, making sure
not to touch the oven sides or each other. Use the shelf to fit them
all in. Close the muffle furnace. Turn on the exhaust fan. Turn the
controller to 5.0, and turn the timer to 2 hours. After about 1.5 -
1.75 hours, check to verify that the temperature has reached 500
°C. If it hasn't, add an extra 15 minutes to the timing. When it does
hit 500°C, and the timer has turned off the furnace, turn the
controller to 2.0, and the timer to 2 hours. Let cool, closed,
overnight.
5. WEIGH THE ASHED SAMPLES.
Using tongs, remove the crucibles to a desiccator. When they are
thoroughly cooled, use the same analytical balance and record the
filled crucible weight on the data charts in the front of this
book. Remember to weigh and include the blank (empty) crucible from
each run. Dump out the ashed sample into the garbage, wiping the
crucible with a Kimwipe if necessary. The crucibles are now ready to
be filled again and fired. No need to ash the empty crucibles between
runs AS LONG AS YOU KEEP THEM CLEAN!
Methods after 1991:
Ashing methods were changed in 1991 when the use of porcelain
crucibles was replaced by use of disposable aluminum boats. All
methods stayed the same EXCEPT: The disposable aluminum boats did not
need to be 'tared' or fired before use. The clean boats were taken
directly from the package and placed into use. To identify the boat,
the SAMPLE ID # was 'written' (etched indented with a pencil-pen) on
the bottom of the boat. The boat weight was recorded and the sample
(WITH MIXING!) was added (about 1 gram). The rest of the procedures
remained the same. If the muffle furnace was allowed to exceed 550 °C,
the aluminum boats would melt and significant changes in their weight
could occur. Blank boats are run with each operation to insure no
significant loss-gain during firing.
Analytical Methods Used:
Kjeldahl Nitrogen and Phosphorus by Technicon Industrial Method
No. 369-75A (Revised 8/21/75) Digestion and sample preparation for the
analysis of total kjeldahl nitrogen and/or phosphorus in food and
agricultural products using the technicon BD-20 Block digestor. and
Technicon Industrial Method 334-74A (revised 8/21/75)
Individual/simultaneous determination on nitrogen and phosphorus in BD
acid digests
Percent Nitrogen and Percent Carbon were determined by High
Temperature combustion, the resulting gases were eluted on a gas
chromatography column and detected by thermal conductivity and
integrated to yield carbon and nitrogen content. Analyses were
performed on a ThermoQuest CE Instruments NC2100 Elemental Analyzer,
ThermoQuest Italia S.p.A., Rodano, Italy. Study
Instrumentation:ThermoQuest CE Instruments, NC2100, Elemental Analyzer
(Nitrogen and Carbon)
CHAIN OF CUSTODY
1. Field personnel.
The number of personnel involved in the field collection of Sevilleta
LTER Decomposition study samples is usually limited to 1 or 2
individuals. The collection procedure is relative simple and is
dominated by time taken driving from location to location. It is
important that the field personnel responsible for sample collections
be familiar with the collection protocol, sample identifications,and
location locations. It is the responsibility of the field personnel to
deliver the samples to the laboratory personnel, as quickly and
carefully as possible.
2. Laboratory personnel.
Once delivered by the field personnel, the inventory, storage and
management of the samples becomes the responsibility of the laboratory
personnel. The laboratory personnel are responsible for conducting all
analytical laboratory procedures, in addition to attaining, entering,
verifying and archiving any relevant data. These tasks usually were
performed by student technicians, but the samples are the direct
responsibility of the staffed Sevilleta LTER laboratory technician,
under supervision of the Laboratory Director.
Description of Initial Study:
The decomposition study began with litter grown during 1989,
which was harvested in the fall of1989, prepared during the
winter and placed in the field the following spring. The initial
study was designed by Dr. J. Gosz and Dr. R. Parmenter with
C.S. White the project manager. The basic design included
placement of three (3) primary litter-types (black grama
(Bouteloua gracilis), juniper (Juniperus monosperma), and Indian
rice grass (Oryzopsis hymenoides)) at seven (7) locations. The
seven locations included: along an approximate north-south
transect from grass habitat to creosote habitat, Location 1 =
Black Butte; Location 2 = Deep Well; Location 3 = 1 mi. east of
5 points (central point along the transect representing a
grass-juniper-creosote junction); Location 4 = between Location
3 and south boundary within a creosote stand (Larea); and
Location 5 = south boundary at a stand of Ocotillo (Ocotillo);
and along an approximate east transect from location 3; Location
6 = Sepultura Canyon; and Location 7 = Cerro Montoso (increasing
favorable juniper habitat and into pinyon). There were two other
locations off the Sevilleta NWR in the first year: Location 8 at
the Bosque del Apache (which later was lost during a fire at
that location); Location 9 in the Magdelena Mountains west of
Socorro.
At all locations (except Bosque del Apache), litter of the three
common species were included. Litter of different species were
placed at locations where that litter may be dominant. The other
litter types included: creosote (locations 2 and 4), blue grama
(location 2), 4-wing saltbush (location 2), yucca (location 2),
pinyon (location 7), cottonwood (location 8); and Arizona fescue,
Douglas fir, Ponderosa pine, and aspen (location 9).
At each location and for each species, the experimental design
included placement of enough bags for three replicate bags per
collection date; one collection at the time of placement and
eight additional collections over a two year period, and 7
additional bags to allow for some mortality of bags (34 bags
total). Each bag initially contained 5.00 g +/- 0.05 g (4.95-5.05
g) air-dried material. Bags were placed at each location in late
February, 1990. Collections are projected to be made in: (1), May
1990 (2), July 1990 (3), Sept. 1990 (4), January 1991 (5,
one-year), May 1991 (6), Sept 1991 (7), and January 1992 (8,
two-year).
Changes in 1990:
In 1990, litter was only placed at the Deep Well location (#2)
and only litters of black grama, juniper, rice grass, creosote,
blue grama and saltbush were used. It was decided that all the
sites were not worth continuing because there were no other data
associated with the site that could be used to explain why
decomposition may or may not vary at that site versus and other
site. Thus, the location with the most complete meteorological
data was maintained (Deep Well, location 2).
Changes 1991 through 1998:
Starting with litter collected in the fall of 1991 and continuing
through litter collected in 1997, litter bags were placed at four
(4) locations that represented the range of climates present on
the Sevilleta and that were all near meteorological
stations. Deep Well (location 2) and Cerro Montoso (location 7)
were retained from the previous work because they were near
meteorological stations. Cerro Montoso (location 7) represented a
pinyon-juniper forest, upper elevation climate (wettest of all
locations), Deep Well (location 2) represented a short-grass
prairie climate, a location near the Rio Salado (new, location
10) represented a Chihuahuan desert climate (driest of all
locations), and Red Tank (new, location 11) represented a Great
Basin grass-shrub climate. Deep Well and Cerro Montoso (location
1 and 7, respectively) are on the east side of the Sevilleta
while Rio Salado and Red Tank (locations 10 and 11, respectively)
are on the west.
At these four locations, black grama, creosote, Indian rice
grass, and juniper litter were placed every spring. Blue grama
litter also was placed at Deep Well to maintain a long-term blue
and black grama comparison.
Changes in 1998:
Beginning with placement of litter collected in the fall of 1998,
efforts to conserve resources and to address changes across
vegetation transition zones lead to addition of 2 new locations:
Blue Springs (location 12), a juniper-short grass prairie
mixture; and 5 points (location 13), a creosote area near the
Deep Well short grass-desert grass area. No new litter was placed
at Rio Salado and Red Tank (locations 10 and 11), but remaining
litter were collected for the 1 year decomposition measurement in
Feb. of 1999 and will be collected again in Feb. of 2000 for the
two year decomposition measurement. The four common litter types
were placed at Cerro Montoso, Blue Springs, Deep Well, and 5
points (locations 7, 12, 2, and 13, respectively) with blue grama
also at Deep Well.
Study Methods:Experimental Design:
Setting up each location: 1989 through 1991:
The design of this decomposition study includes placement of three (3)
primary litter-types (black grama, juniper, and indian rice grass) at
seven (7) locations. Litter of each species was collected after
senescence in the fall. The grasses were clipped from standing plants
before the litter was on the ground. All material that was not
produced during the previous growing season was discarded. All
reproductive parts were discarded. If there was any doubt about
whether or not the material was produced that growing season, it was
discarded. Juniper was collected from trees with senescent material or
that had recently died and were still on the branch. Juniper litter
consisted of only that material that still had bracts (woody stems
without bracts were discarded). Pinyon was collected from trees that
still retained senescent needles by shaking and capturing on a cloth
or plastic sheet. Branches of 4-wing saltbush were trimmed from
bushes in October when material looked senescent and leaves were
picked from the branches and air-dried. Creosote leaves were attempted
to be collected by spreading sheets on the ground; however, litterfall
is very episodic and not enough material could be collected. Thus,
creosote was collected by cutting live plants and drying in a
forced-air oven at 60 °C; then the freshly dried leaves were removed
from the branch and any reproductive parts (seeds) were
discarded. Yucca was collected by cutting leaves from a recently dead
yucca plant. Cottonwood leaves were collected in plastic trays as they
fell and before the fresh litter was rained on. Arizona fescue,
douglas fir, ponderosa pine and aspen were collected by others and we
do not know what methods were used. All litters were sorted and
damaged material or reproductive parts were discarded. Unless
previously dried, litter was air-dried in the laboratory. Litter bags
consisted of coated fiberglass window screen material cut into 12 by
7.5 sheets, which were folded in half and two of the edges folded over
and stapled. Litter was inserted through the unstapled edge, which
then was folded over and stapled. Each bag initially contained 5.00 g
(4.95-5.05 g) of air-dried material. For each litter type, a total of
34 bags were prepared for placement at each location. All the litter
bags of one species for an individual location were placed in a
separate bag and the bag was sealed for transport the field.
At each location and for each species, the experimental design
included placement of enough litter bags for three replicate bags
per collection date; one collection at the time of placement,
eight collections over a two year period, and 7 additional bags to
allow for some mortality of bags (34 bags total per location).
When the litter bags were placed at each location, the location
was marked with fence posts as a warning. Each location was
identified by a color-coded marker. The color-coded markers for
each location are as follows: location (1)=plain, (2)=tan,
(3)=green, (4)=orange, (5)=orange/green, (6)=tan/green,
(7)=green/tan, (8)=green/orange, and (9)=tan/orange.
Litter bags were placed on bare soil between plants at all
times. Each litter bag was anchored by inserting a 16 penny nail
through diagonal corners of the bag and into the
ground. Decomposition bags with creosote, blue grama, yucca
(tethered, not bagged), and four-wing saltbush all were placed at
the deep well location (location 2); and cottonwood at the Bosque
del Apache (location 8).
In the fall of 1990, only 5 litter types (black grama, blue
grama, juniper, creosote, and Indian ricegrass) were collected
for placement in Feb. of 1991. Blue grama litter was only placed
at Deep Well, while the four other litter types were place at 4
locations (#2, 7, 10, 11). Litter was collected as described in
the previous year and bags were placed on bare soil at each
location.
In February of 1999, the Rio Salado and Red Tank sites did not
get new litter bag placements; instead the new locations at Blue
Springs and 5 points were established and the 4 common litter
types were placed at these locations along with Deep Well and
Cerro Montoso.
Sevilleta LTER
Dr.
Scott
Collins
Department of Biology, MSC03 2020
University of New Mexico
Albuquerque
NM
87131
scollins@sevilleta.junm.edu
Principal Investigator
The overarching goal of the Sevilleta LTER is to understand how abiotic pulses and constraints affect dynamics and stability in an arid landscape. Key landscape components of the Sevilleta LTER include desert grassland and shrubland, piñon-juniper woodlands and the Middle Rio Grande riparian corridor.
NSF grants BSR 88-11906, DEB 9411976,DEB 0080529 and DEB 0217774
uid=SEV,o=lter,dc=ecoinformatics,dc=org
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decomp.txt
ID
Sample Number
natural
numbers
NA
none given
START
Date of initial placement of sample in field
mm/dd/yy
.
none given
DUR
Duration of sample
natural
days
1
natural
.
none given
SITE
Location of data collection
natural
1=Black Butte,2=Deep Well,3=Old Five Points,4=Old
Larrea,5=Ocotillo,6=Sepultura Canyon,7=Cerro Montosa,8=Bosque del Apache, 9=Magdelena,10=Rio Salado,11=Red Tank,12=Blue Springs,13=New Five Points
.
none given
SPPN
Species name
na
species codes
.
none given
REP
Replicate sample number
natural
NA
0
natural
.
none given
DWT
Dry weight of sample
grams
0.01
real
.
none given
ASHC
Ash correction factor
real
grams
0.01
real
.
none given
AFWT
Ash free dry weight
real
grams
0.01
real
.
none given
PC
percent carbon
percent
0.01
real
.
none given
PN
Percent Nitrogen
percent
0.01
real
.
none given
TKN
Total Kjeldahl Nitrogen
natural
ug/g
1
natural
.
none given
.
none given
TKP
Total Kjeldahl phosphorus
ug/g
1
real
.
none given