disturbance

Disturbances often shape ecosystems by periodically reorganizing or destroying them, allowing for significant changes in plant and animal populations and communities.

Soil Long Term Manipulation Experiment

Abstract: 

A long-term soil manipulation experiment has been conducted as part of the McMurdo Dry Valleys Long Term Ecological Research (LTER) project. The response of soil organisms (nematodes, rotifers and tardigrades) to the treatments is monitored by sampling soil on an annual basis.

Core Areas: 

Data set ID: 

4001

Additional Project roles: 

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Short name: 

LTM

Methods: 

The experimental design is a randomized block, with 8 replicates per treatment. Within each block are 8 plots measuring approximately 1m x 1m, with a central circular area of 85 cm diameter (approx 0.57 m2) used for treatments and sampling. The treatments are as follows:

(C) control plots (no manipulations)
(T) enhanced soil temperature using ITEX conical open-top chambers made of solar fiberglass
(W) Nanopure water added to field capacity to 10 cm depth (5.6 L/plot) once per season
(TW) temperature enhancement and water addition
(WS) sucrose added in solution (15.82 g sucrose in 5.6 L water per plot) once per season
(WM) mannitol added in solution (17.01 g mannitol in 5.6 L water per plot) once per season
(TWS) temperature enhancement plus sucrose addition
(TWM) temperature enhancement plus mannitol addition.

 

Soil samples were taken for organism enumeration and moisture content analysis as follows: Sampling bags were prepared with one sterile 'Whirlpak' bag and clean plastic scoop per sample. Samples were taken from within the 85 cm diameter circular area of each plot. The location of the sampling was recorded each year so that areas were not re-sampled. Using the plastic scoop, soil was collected to 10 cm depth. Very large rocks (>20 mm diameter) were excluded from the sample. The soil was shoveled into the 'Whirlpak' bag until three quarters full (about 1.5 kg soil). The soil was mixed well in the bag, then the bag was closed tightly, expelling as much air as possible. The so il samples were stored in a cooler for transportation. On return to the laboratory (within 8 hours of sampling), the soils were stored at +5°C until further processing.

In the laboratory, soil samples were handled in a laminar flow hood to prevent contamination. The Whirlpak bags of soil were mixed thoroughly prior to opening. Approximately 200 cm3 of soil was placed in a pre-weighed 800 mL plastic beaker. Rocks greater than 3-4 mm in diameter were removed from the sample. A sub-sample of approximately 50g was removed and placed in a pre-weighed aluminum dish, and weighed on a balance accurate to 0.01g. This sample was dried at 105C for 24 hours. The sample was removed, placed in desiccator to cool down, and re-weighed. These data were used to calculate water content of the soil and to express data as numbers of soil organisms per unit dry weight of soil.

The remaining soil in the plastic beaker was weighed. Cold tap water was added up to 650 mL. The soil suspension was stirred carefully (star stir or figure of 8) for 30 seconds, using a spatula. Immediately the liquid was poured in to wet screens - a stack of 40 mesh on top of a 400 mesh. The screens were rinsed gently with ice cold tap water (from a wash bottle) through the top of the stack, keeping the screens at an angle as the water filtered through. The water was kept on ice at all times. The top screen was removed, and the lower screen rinsed top down, never directly on top of the soil, but at the top of the screen and from behind. The water was allowed to cascade down and carry the particles into the bottom wedge of the angled screen. The side of the screen was tapped gently to filter all the water through. The suspension was rinsed from the front and the back, keeping the screen at an angle and not allowing the water to overflow the edge of the screen. The soil particles were back washed into a 50 mL plastic centrifuge tube, tipping the screen into the funnel above the tube and rinsing the funnel gently. The suspension was centrifuged for five minutes at 1744 RPM. The liquid was decanted, leaving a few mL on top of the soil particles. The tube was filled with sucrose solution (454g sucrose per liter of tap water, kept refrigerated) up to 45 mL. This was stirred gently with a spatula until the pellet was broken up and suspended. The suspension was centrifuged for one minute at 1744 RPM, decanted into a wet 500 mesh screen, rinsed well with ice cold tap water and back washed into a centrifuge tube. Samples were refrigerated at 5C until counted.

Samples were washed in to a counting dish and examined under a microscope at x10 or x20 magnification. Rotifers and tardigrades were identified and counted. Nematodes were identified to species and sex, and counted. Total numbers in each sample were recorded on data sheets. All species of nematode, and all rotifers and tardigrades found in the sample were recorded. Data were entered in to Excel files, printed, and checked for errors.

For measurements of pH, 40 of DI water was added to 20 g of soil in a clean, DI- rinsed glass beaker (coarse fragments >2 mm were removed). The samples were stirred until thoroughly mixed (about 5-10 sec). After sitting to equilibrate for 10 minutes the samples were stirred again and a reading was taken with a Beckman 0265 pH meter. For measurements of electrical conductivity, an additional 60 ml of DI water was then added (totaling 100 ml water). The samples were stirred until thoroughly mixed (about 5-10 sec). After sitting to equilibrate for 10 minutes the samples were stirred again and a reading was taken with a YSI 30 conductivity meter. Extraction of chlorophyll from the soil. All procedures were carried out in the dark or very low irradiance to avoid degradation of the chlorophyll. The soil samples were mixed thoroughly in the vials, and a sample of approximately 5 g was weighed out in to a 50 mL plastic centrifuge tube with a screw-top cap. 10 mL of a 50:50 DMSO/90% acetone solution was added to each sample and they were mixed thoroughly on a bench-top Vortex mixer for about 5 seconds. The vials were placed in a -4°C constant temperature room, in the dark, and left for 12-18 hours. Determination of chlorophyll a concentration - This was determined fluorometrically using a Turner model 111 fluorometer. A calibration using a known concentration of chlorophyll was carried out prior to sample analysis. The machine was blanked using a 50:50 DMSO/90% acetone solution. Each vial was mixed thoroughly, then centrifuged for 5 minutes at about 1800 RPM. A sample of approximately 4mL of the DMSO/acetone solution was taken from the top of the sample with a pipette, being careful not to get any soil particles in the solution. The sample was placed in a cuvette, in to the fluorometer and the fluorescence was recorded. This was done fairly quickly in order to prevent light from breaking down the chlorophyll. This measurement is called Fo, the initial fluorescence. After taking this reading, 0.1 mL of 1N HCl was added directly to the cuvette and the cuvette was gently agitated. After 20 s, the fluorescence was re-measured. (During this step, the acid converts the chlorophyll to phaeophytin by releasing a magnesium ion in an acidic environment). This measurement is called Fa, the fluorescence after acidification. The solution was discarded in to a waste container, and the cuvette rinsed 3 times with DMSO/90% acetone solution before proceeding with the next sample.

Season Notes on Sampling and Maintenance

1993/1994

Comments. These samples were taken on 28 December 1993 from the LTM experiment at the South side of Lake Hoare. The only organisms found in these samples, were nematodes (Scottnema, Eudorylaimus, unknown) and eggs. [E Pella Brinkman, 8 April 1997]. A copy of this file (without the 'log' sheet) was sent to the MCM LTER data manager in Boulder on 20 August 1997. The file name was changed to a DOS 8+3 format: 9312ltwo.xls. [Andy Parsons 20 August 1997].

File log. The initial iteration of this file was created by Ed Kuhn on 31 March, 1997. The original data were in the Excel file LTM.worms.Dec93.raw. This file was reformatted to a common format on 31 March 1997 by Ed Kuhn. Number of organisms per kg dry soil was calculated. Nematodes in the "other" column were included in the "total Scott" and "total nemas" calculations. The new file was named LTM.worms.Dec93.calc. [Ed Kuhn 31 March,1997]. The file log was incorporated into this Excel file and the "comments" text box was added on 8 April 1997 by Pella Brinkman. [E Pella Brinkman, 8 April 1997]. Several changes were incorporated by Dan Bumbarger on 1-August 1997. These changes were:

1. Addition of a 'Date Sampled' column 
2. The format of the 'Date Counted' column was changed so that the year was apparent.
3. The first 'Soil wt.' label was changed to 'fresh weight of soil used for extraction (g)'.
4. The labels 'L' and 'D' were replaced with 'live' and 'dead'.
5. The label 'juvs' was replaced with 'juveniles'.
6. The label 'Scott' was replaced with 'Scottnema' and italicised.
7. The label 'nema' was replaced with 'nematodes'.
8. The label '(# in extraction)' was added to the column headings for the counts of organisms in the sample.
9. The subtitle 'unclassified nematodes', which implies nematodes which could not be sexed or placed in an age class, were added under the other group heading.
10. An additional label 'Other organisms (# in extraction)' was added above the columns with counts for non-nematode organisms and unclassified nematodes.
11. The label 'trdgrds' was changed to 'tardigrades'.
12. New labels were added for the columns used to determine the water content of the soil. Both columns were headed with 'Soil sample used to determine water content', the first column was changed to 'Fresh weight of soil (g)' and the second was re-labelled 'Dry weight of soil (g)'. [Dan Bumbarger 1 August 1997]. Columns concerning eggs were moved to the end of the file, and columns were added to make the file conform to a common format. [Dan Bumbarger, 23 Feb 98] 

1994/1995

Comments. These samples were taken on 17-18 November 1994 at the LTM experiment at Lake Hoare. Scottnema and Eudorylaimus were found at the site. [Drew W Hall, 9 April 1997]. A copy of this file (without the 'log' sheet) was sent to the MCM LTER data manager in Boulder on 20 August 1997. The file name was changed to a DOS 8+3 format: 9411ltwo.xls. [Andy Parsons 20 August 1997].

File log.

The initial iteration of this log was created on 9 April by Drew Hall. The original data was in the Excel file LTM.worms.Nov94.raw. The file was checked against the hard-copy forms by Ed Kuhn on 28 February 1997. The file was reformatted to a common format. Number of organisms per kg dry soil was calculated on 18 March 1997 by Ed Kuhn. The new file was named LTM.worms.Nov94.calc. The file log and the "comments" text box were added to this Excel file on 9 April 1997 by Drew Hall. [Drew W Hall, 9 April 1997]. Latest editing by Ed Kuhn on 17 April 1997 (reworded text in comments). [Ed A Kuhn, 17 April 1997]. Several changes were incorporated by Dan Bumbarger on 28 July 1997. These changes were:

1. Addition of a 'Date Sampled' column
2. The format of the 'Date Counted' column was changed so that the year was apparent, and the column was moved so that it was after 'Date sampled'
3. The first 'Soil wt.' label was changed to 'fresh weight of soil used for extraction (g)'.
4. The labels 'L' and 'D' were replaced with 'live' and 'dead'.
5. The label 'juvs' was replaced with 'juveniles'.
6. The label 'Scott' was replaced with 'Scottnema' and italicised.
7. The label 'nema' was replaced with 'nematodes'.
8. The label '(# in extraction)' was added to the column headings for the counts of organisms in the sample.
9. An additional label 'Other organisms (# in extraction)' was added above the columns with counts for non-nematode organisms.
10. the label 'trdgrds' was changed to 'tardigrades'.
11. New labels were added for the columns used to determine the water content of the soil. Both columns were headed with 'Soil sample used to determine water content', the first column was changed to 'Fresh weight of soil (g)' and the second was re-labelled 'Dry weight of soil (g)'. [Andy Parsons 24 July 1997]. Columns were added to make the file conform to a common format. [Dan Bumbarger, 3 March 98]

Numbers per kg dry soil changed by M L Haddix using formula 1000*(#individuals/(extraction mass*(mass of dry soil/mass of soil used for moisture calc))) 7/22/13 Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13

File was abbreviated for website only counts in #/kg dry soil was left along with log, 7/22/13 MLHaddix

SOIL_WATER_CONTENT The gravimetric soil water content calculated as the g of water divided by the g of oven dry soil % g/g
SML Scottnema Male Live #/kg dry soil
SMD Scottnema Male Dead #/kg dry soil
SFL Scottnema Female Live #/kg dry soil
SFD Scottnema Female Dead #/kg dry soil
SJL Scottnema Juvenile Live #/kg dry soil
SJD Scottnema Juvenile Dead #/kg dry soil
SA Scottnema Adult #/kg dry soil
SJ Scottnema Juvenile #/kg dry soil
STL Scottnema Total Live #/kg dry soil
STD Scottnema Total Dead #/kg dry soil
STLD Scottnema Total Live Dead #/kg dry soil
EML Eudorylaimus Male Live #/kg dry soil
EMD Eudorylaimus Male Dead #/kg dry soil
EFL Eudorylaimus Female Live #/kg dry soil
EFD Eudorylaimus Female Dead #/kg dry soil
EJL Eudorylaimus Juvenile Live #/kg dry soil
EJD Eudorylaimus Juvenile Dead #/kg dry soil
EA Eudorylaimus Adult #/kg dry soil
EJ Eudorylaimus Juvenile #/kg dry soil
ETL Eudorylaimus Total Live #/kg dry soil
ETD Eudorylaimus Total Dead #/kg dry soil
ETLD Eudorylaimus Total Live Dead #/kg dry soil
PFL Plectus Female Live #/kg dry soil
PFD Plectus Female Dead #/kg dry soil
PJL Plectus Juvenile Live #/kg dry soil
PJD Plectus Juvenile Dead #/kg dry soil
PA Plectus Adult #/kg dry soil
PJ Plectus Juvenile #/kg dry soil
PTL Plectus Total Live #/kg dry soil
PTD Plectus Total Dead #/kg dry soil
PTLD Plectus Total Live Dead #/kg dry soil Comments.

These samples were taken on 7 January 1995 at the LTM experiment at Lake Hoare. Scottnema and Eudorylaimus were found at the site. [Drew W Hall, 9 April 1997]. A copy of this file (without the 'log' sheet) was sent to the MCM LTER data manager in Boulder on 20 August 1997. The file name was changed to a DOS 8+3 format: 9501ltwo.xls. [Andy Parsons 20 August 1997].

File log. The initial iteration of this log was created on 9 April 1997 by Drew Hall. The original data was in the Excel file LTM.worms.Jan95.raw. The file was checked against the hard-copy forms by Ed Kuhn on 5 March 1997. The file was reformatted to a common format. Number of organisms per kg dry soil was calculated on 18 March 1997 by Ed Kuhn. The new file was named LTM.worms.Jan95.calc. The file log and the "comments" text box were added to this Excel file on 9 April 1997 by Drew Hall. [Drew W Hall, 9 April 1997]. Latest editing by Ed Kuhn on 17 April 1997 (added/reworded text in comments and file log boxes). [Ed Kuhn 17 April 1997]. Several changes were incorporated by Dan Bumbarger on 28 July 1997. These changes were:
1. Addition of a 'Date Sampled' column
2. The format of the 'Date Counted' column was changed so that the year was apparent.
3. The first 'Soil wt.' label was changed to 'fresh weight of soil used for extraction (g)'.
4. The labels 'L' and 'D' were replaced with 'live' and 'dead'.
5. The label 'juvs' was replaced with 'juveniles'.
6. The label 'Scott' was replaced with 'Scottnema' and italicised.
7. The label 'nema' was replaced with 'nematodes'.
8. The label '(# in extraction)' was added to the column headings for the counts of organisms in the sample.
9. An additional label 'Other organisms (# in extraction)' was added above the columns with counts for non-nematode organisms.
10. the label 'trdgrds' was changed to 'tardigrades'.
11. New labels were added for the columns used to determine the water content of the soil. Both columns were headed with 'Soil sample used to determine water content', the first column was changed to 'Fresh weight of soil (g)' and the second was re-labelled 'Dry weight of soil (g)'.
12 .Added the date sampled, 07-Jan- 95, to this data sheet. [Dan Bumbarger 28 July 1997]. Columns were added to make the file confrom to a new common format. [Dan Bumbarger, 3 March 98] Numbers per kg dry soil changed by M L Haddix using formula 1000*(#individuals/(extraction mass*(mass of dry soil/mass of soil used for moisture calc))) 7/22/13

Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13

File was abbreviated for website only counts in #/kg dry soil was left along with log, 7/22/13 MLHaddix

1995/1996

Comments: Sampled 13 Dec 1995 at the LTM site, south side of Lake Hoare. Organisms found; Scottnema, Eudorylaimus. Samples 3WS=20% Scott. w/eggs; 6T=25%;6W=12.5%;7WM=12%;8TWM=35.5%;8TWS=37.5%;8W=33.3%;8WM15.6% [Ed Kuhn, 28 Apr 1997]. A copy of this file (without the 'log' sheet) was sent to the MCM LTER data manager in Boulder on 20 August 1997. The file name was changed to a DOS 8+3 format: 9512ltwo.xls. [Andy Parsons 20 August 1997].

File log: This log and comment box was created on 28 Apr 1997 by Ed Kuhn. The original data is in the excel file--LTM.worms.Dec95.raw. This file was checked against raw hard-copy sheets by Ed Kuhn and Pella Brinkman on 26 Feb 1997. Numbers of Nematodes/kg dry soil calculated on 17 Feb 1997 , converted to a common format on 7 Apr 1997 by Ed Kuhn. New file--LTM.worms.Dec95.calc. [Ed A Kuhn 7 April 1997]. Several changes were incorporated by Dan Bumbarger on 30 July 1997. These changes were:

1. Addition of a 'Date Sampled' column
2. The format of the 'Date Counted' column was changed so that the year was apparent.
3. The first 'Soil wt.' label was changed to 'fresh weight of soil used for extraction (g)'.
4. The labels 'L' and 'D' were replaced with 'live' and 'dead'.
5. The label 'juvs' was replaced with 'juveniles'.
6. The label 'Scott' was replaced with 'Scottnema' and italicised.
7. The label 'nema' was replaced with 'nematodes'.
8. The label '(# in extraction)' was added to the column headings for the counts of organisms in the sample.
9. An additional label 'Other organisms (# in extraction)' was added above the columns with counts for non-nematode organisms and unclassified nematodes.
10. the label 'trdgrds' was changed to 'tardigrades'.
11. New labels were added for the columns used to determine the water content of the soil. Both columns were headed with 'Soil sample used to determine water content', the first column was changed to 'Fresh weight of soil (g)' and the second was re-labelled 'Dry weight of soil (g)'. [Dan Bumbarger 30 July 1997]. The columns for Plectus were removed by Andy Parsons on 20 August 1997. No Plectus have ever been found at this site, and no other LTM files have columns for this genus. [Andy Parsons, 20 August 1997]. Columns were added to make the file conform to a common format. [Dan Bumbarger, 4 March 98] This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix) Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13 File was abbreviated for website only counts in #/kg dry soil was left along with log, 7/22/13 MLHaddix

1996/1997

Comments: Sampled on 17 Dec 1996 at the LTM site on the south side of Lake Hoare. Organisms found--Scottnema, Eudorylaimus.. Counted by Laura Powers on 19-24 Dec 1996. [Ed Kuhn,12 June1997]. A copy of this file (without the 'log' sheet) was sent to the MCM LTER data manager in Boulder on 20 August 1997. The file name was changed to a DOS 8+3 format: 9612ltwo.xls. [Andy Parsons 20 August 1997].

File log. This log and comment box was created on 12 June 1997 by Ed Kuhn. The original data is in the excel file--LTM.worms.Dec96.raw. This file was checked against the hard-copy sheets by Ed Kuhn and Brian Nicole George on 29 Jan 1997. This file was converted to a common format on 1 Apr 1997 and numbers/kg dry soil calculated on 2O Feb 1997 by Pella Brinkman. New file name--LTM.worms.Dec96.calc. [Ed Kuhn, 12 June 1997] Several changes were incorporated by Dan Bumbarger on 30 July 1997. These changes were:
1. Addition of a 'Date Sampled' column
2. The format of the 'Date Counted' column was changed so that the year was apparent.
3. The first 'Soil wt.' label was changed to 'fresh weight of soil used for extraction (g)'.
4. The labels 'L' and 'D' were replaced with 'live' and 'dead'.
5. The label 'juvs' was replaced with 'juveniles'.
6. The label 'Scott' was replaced with 'Scottnema' and italicised.
7. The label 'nema' was replaced with 'nematodes'.
8. The label '(# in extraction)' was added to the column headings for the counts of organisms in the sample.
9. An additional label 'Other organisms (# in extraction)' was added above the columns with counts for non-nematode organisms and unclassified nematodes.
10. the label 'trdgrds' was changed to 'tardigrades'.
11. New labels were added for the columns used to determine the water content of the soil. Both columns were headed with 'Soil sample used to determine water content', the first column was changed to 'Fresh weight of soil (g)' and the second was re-labelled 'Dry weight of soil (g)'. [Dan Bumbarger 30 July 1997].
This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix)
Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13
File was abbreviated for website only counts in #/kg dry soil was left along with log, 7/22/13 MLHaddix

1997/1998

Comments: Sampled on 7 Jan 98 from the LTM Plots on the South Side of Lake Hoare by Diana Harrison Wall, Ross Virginia, Amy Treonis, Dan Bumbarger, Andy Parsons and Melody Brown Burkins. GPS coordinates are available in the 1997/1998 GPS coordinate file. In the field, Block 7 samples were put in Block 8 bags and vice versa. This was corrected on return to the lab and all the labels changed on the bags of soil and vials with soil for chlorophyll. Samples were processed on 8 Jan 1997 by Dan Bumbarger, Amy Treonis and Diana Harrison Wall. [Andy Parsons 9 Jan 1998]

-The LTM plots were sampled this year at the 7-9 o'clock position, with 12:00 being the top of the plot facing Lake Hoare. [Amy Treonis 12 Jan 1997]
- LTM 5T was sampled along a rock in the plot because it was in the way at the 7-9 o'clock position. [Amy Treonis 12 Jan 1997]
- Sample 2WM had one ciliate [Andy Parsons 16 Jan 98]

File log: This file was created on 9 Jan 1998 by Andy Parsons. Data were entered by Andy Parsons and proofed by Andy Parsons and Dan Bumbarger on 16 January 1998. [Andy Parsons 16 Jan 98]. This file was converted from a raw file to a calc file on April 3, 1998 by Dan Bumbarger. [Dan Bumbarger, 3 April 98]

This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix) Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13

File was abbreviated for website only counts in #/kg dry soil was left along with log, 8/05/13 MLHaddix

2001/2002

Comments: Sampled on 28 Dec 01 from the LTM Plots on the South Side of Lake Hoare by Diana Harrison Wall and Dorota Porazinska. GPS coordinates are available in the 1997/1998 GPS coordinate file. Helo pad coordinates 77 38 049S, 162 52 826E. Samples were processed on 29 Dec 01 by Dorota Porazinska, Nicole DeCrappeo and Steve Blecker. Plots were maintained (water, sugar and mannitol treatements added to appropriate plots, chambers re-positioned and bungees tightened when necessary) immediately after sampling by Steve Blecker, Nicole DeCrappeo, Diana H Wall, and Dorota Porazinska. Samples were taken at one o'clock (facing the lake). One chamber was missing (5T) and was replaced with one of the spares that are kept adjacent to the experiment. 5TWS, the harness was off the chamber, but was still in place. Plot 2W got half mannitol and half water. Chambers were not replaced. Samples were counted between 1-3 Jan 02 by Nicole DeCrappeo. 5WS was spilled, it ws subsequently re-extraced 3 Jan 02. [Steve Blecker 2 Jan 02]

File log: This file was created on 2 Jan 2002 by Steve Blecker. Data entered by Jeb Barrett on 020108. Data proofed by Andy Parsons and Dorota Porazinska on 8th Jan 2002. [Andy Parsons 8 Jan 2002]

This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix)

Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13

File was abbreviated for website only counts in #/kg dry soil was left along with log, 8/05/13 MLHaddix

2004/2005

Comments: Soil data was entered, and log was created, on 13 Jan 2005 by Holley Zadeh

File log: These data are for soils collected by Holley Zadeh and Diana Wall from the Lake Hoare LTM plots on 11 Jan 05. Emma Broos kept sample kits organized and cross-checked sampling locations with the map in the field book for every sample taken. Soil samples were taken at 7 o'clock as we faced the lake (North). One exception is that 3W was taken at 3 o'clock instead. Another thing to note is that plot 8TW (temp chamber) contained an amount of sediment that was deeper than the scoop that was used for sampling, so the sample is primarily sediment. Samples were extracted at the Crary lab on 11 & 12 Jan 2005 as follows:

*Holley Zadeh weighed soil under the laminar flow hood and recorded weights
*Diana Wall sieved soil at the sink
*Byron Adams spun samples in the centrifuge
*John Chaston and Emma Broos counted specimens at the microscope.

They were counted on the 12th and 13th of January 2005. Specimens were preserved on 14 Jan 05 by Holley Zadeh, Claire Ojima, & John Chaston. Just less than half of sample 5W was lost to spillage. This sample will not be re-run, as per OK by Diana Wall. 

Jeb Barrett calculated # of organisms per kg, sorted, calculated means and graphed preliminary data on Jan. 26. 

This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix)
Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/06/13
Related Files: LH_LTM_soil.xls; DNAExtr0405.xls
File was abbreviated for website only counts in #/kg dry soil was left along with log, 8/05/13 MLHaddix 

SOIL_WATER_CONTENT The gravimetric soil water content calculated as the g of water divided by the g of oven dry soil % g/g

2006/2007

This log was created by Dorota Porazinska on Jan 20 2007.

Soil samples were collected by Diana Wall, Byron Adams and Dorota Porazinska on 18 Jan 07. Treatments had not been applied for several years, therefore, this sampling was to assess recovery from treatment effects. Samples were extracted using sugar floatation method. Breana Simmons weighed the soil, Dorota Porazinska seived and Ed Ayres centrifuged.

Worms were extracted 19 Jan 2007, Dorota Porazinska and Diana Wall counted the worms on 19-20 Jan, Breana Simmons preserved them on 23 Jan 2007. The was entered by Ed Ayres on 21 Jan 2007. It was then proofed by Dorota Porazinska on 26 Jan 2007

Note on sheet: "4C and 3TWM were combined in the same tube due to Diana's late night operator error after counting them."

This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix) Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/24/13

Related files: LTM_soil.xls, LTM_soil_labels.xls, Algae._soil.xls, Algae_worms.xls

2008/2009

LOG: This file created on 12/28/08 by Karen Seaver.

COMMENTS: The Long term monitoring plot Experiment was sampled Nick "no dice" Demetras, Byron "bad apple" Adams, Tracy "Toad Stool" Smith, Diana "Divine Whine" Wall and Karen "Kaledi Scope" Seaver on December 22, 2008. There was no snow on plots. See related spread sheet for information on sampling for the Algal Amendment Long term plots.Chambers were placed on each plot and soil samples taken from near the center when there were no rocks. There was no sediment on the surface of the soils. Surface soil was sampled for soil algae; soil collected as usual.

Nematodes were counted by by Karen Seaver, Diana Wall, Byron Adams, Uffe Nielsen, Tracy Smith, and Nick Demetras on 12/23-26/08.

Data entered by Karen Seaver on 12/28/08.

Data checked by Zarvox and Karen Seaver on 12/28/08. This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix)

Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/24/13 RELATED FILES: LTM_LabelsDec08.xls LTM_soilsDec08.xls LTM_ET_COCDec08.xls Dryvalleydisturbance_08_09.xls (In Reports Folder)

GPS coordinates File was abbreviated for website only counts in #/kg dry soil was left along with log, 9/24/13 MLHaddix

SOIL_WATER_CONTENT The gravimetric soil water content calculated as the g of water divided by the g of oven dry soil % g/g

2011/2012

LOG: This file created on 1/13/12 by Zachary Sylvain. Data entered by Jeremy Whiting. Data checked by Jeremy Whiting. Calculations by Zachary Sylvain using the formula: (# individuals / dry soil) * 1000 This file was updated and corrected by MLVandegehochte, 4/02/13 (MLHaddix) Soil Moisture calculated as the (g of water/ g dry soil) *100 by M L Haddix 9/24/13

File was abbreviated for website only counts in #/kg dry soil was left along with log, 9/23/13 MLHaddix

SOIL_WATER_CONTENT The gravimetric soil water content calculated as the g of water divided by the g of oven dry soil % g/g

Data sources: 

SOILS_LTM

Maintenance: 

Metadata ported to DEIMS by Inigo San Gil, in 2015
 
This file contains archived data pulled from nemadisk and off of the field season directories by Jeb Barrett. 
 
The data page contains the raw data for nematode abundance in # of animals per kg oven dry weight equivalent. 

Additional information: 

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