soil water content

Dataset: 

Study number: 

27

Data set ID: 

2100278001

Date range: 

2007-07-24 to 2009-08-10

Original investigator: 

Lara G Reichmann

Data contact: 

Abstract: 

Volumetric soil water is used to measure the effectiveness of the water manipulation treatments. Soil water content is monitored at 2 depths (5-10, 30-50 cm) using ECH2OTM moisture probes connected to an ECH2O check handheld.

Volumetric soil water is used to measure the effectiveness of the water manipulation treatments. Soil water content is monitored at 2 depths (5-10, 30-50 cm) using ECH2OTM moisture probes connected to an ECH2O check handheld.

Data download: 

Dataset: 

Study number: 

12

Data set ID: 

210012002

Date range: 

1982-04-30 to 2011-06-28

Original investigator: 

Peter Wierenga

Data contact: 

Abstract: 

Soil water content measurements (cm3 H2O / cm3 soil) at 5 depths at each of 89 (2" O.D. diameter) aluminum access tubes on the Control transect and at every 5th station on the nitrogen fertilized Treatment transect using a neutron probe (Campbell Model 503DR Hydroprobe). Access tubes are installed such that there are 6 inches of tube aboveground. Stations are 30 meters apart.

Measurements are taken at 30cm, 60cm, 90cm, 110cm, and 130cm. Neutron probe readings taken in 6 lysimeters along transects are also included. 5 standard readings are taken at beginning and end of each transect, and after every 20 stations. Measurements taken at 2 week intervals from April 1982 to 1987, monthly since.

Dataset: 

Study number: 

12

Data set ID: 

210012001

Original investigator: 

Peter Wierenga

Data contact: 

Abstract: 

Soil water content measurements in the form of raw count readings are made at 5 depths at each of 89 (2" O.D. diameter) aluminum access tubes on the Control transect and at every 5th station on the nitrogen fertilized Treatment transect using a neutron probe (Campbell Model 503DR Hydroprobe). Access tubes are installed such that there are 6 inches of tube aboveground.

Stations are 30 meters apart. Measurements are taken at 30cm, 60cm, 90cm, 110cm, and 130cm. Neutron probe readings taken in 6 lysimeters along transects are also included. 5 standard readings are taken at beginning and end of each transect, and after every 20 stations. Measurements taken at 2 week intervals from April 1982 to 1987, monthly since.

Dataset: 

Study number: 

13

Data set ID: 

210013001

Date range: 

1989-07-05 to 2009-12-04

Original investigator: 

Ross Virginia

Data contact: 

Abstract: 

Once a month soil water content measurements are made at 10 depths (where possible) at each of 10 access tubes at each of the 15 LTER-II sites using a neutron probe (Campbell Model 503DR Hydroprobe).

Measurements are taken at 30cm, 60cm, 90cm, 120cm, 150cm, 180cm, 210cm, 240cm, 270cm, and 300cm when possible or to the greatest depth it was possible to install the access tubing before hitting impenetrable caliche. If fewer depths were measured, the missing depths have a zero in the raw data set of count values. These are changed to \\".\\" in converted water content data set. Calculated water content values equal to less than zero are changed to zero in converted water content data set. Converted water content values are a volume/volume relationship and represent cm3 water/cm3 soil. The hydroprobe currently used is Hydroprobe Model CPN503DR (Campbell Pacific Nuclear, Pacheco, CA) with data logger. This probe has a 50mCi241 Am-Be source and a 3He detector. Neutrons encountering hydrogen become thermalized. The detector totals the returning thermalized neutrons over a 16 second sample time which is the raw count value displayed. The raw count value is then substituted into the proper regression equation for cm3 of water per cm3 of soil. Data from neutron probe data logger is dumped to disk. Raw count data is then converted to water content. Two files per month are saved: raw count data (mmddyy-2.RAW; ex. 121189-2.RAW where -2 indicates LTER-II NPP site neutron probe readings) and calculated/sorted soil water content data appended to data file containing that year's data (NPPSWCyy.DAT; example NPPSWC89.DAT contains NPP soil water content data for 1989). See PROBE.HIS file for probe history and regressions used for different data periods when different probes were used.

Dataset: 

Study number: 

13

Data set ID: 

210013002

Date range: 

1989-07-05 to 2011-07-01

Original investigator: 

Ross Virginia

Data contact: 

Abstract: 

Once a month soil water content measurements are made at 10 depths (where possible) at each of 10 access tubes at each of the 15 LTER-II sites using a neutron probe (Campbell Model 503DR Hydroprobe).

Measurements are taken at 30cm, 60cm, 90cm, 120cm, 150cm, 180cm, 210cm, 240cm, 270cm, and 300cm when possible or to the greatest depth it was possible to install the access tubing before hitting impenetrable caliche. If fewer depths were measured, the missing depths have a zero in the raw data set of count values. These are changed to "." in converted water content data set. Calculated water content values equal to less than zero are changed to zero in converted water content data set. Converted water content values are a volume/volume relationship and represent cm3 water/cm3 soil. Data from neutron probe data logger is dumped to disk. Raw count data is then converted to water content using a Fortran program called WC2.FOR (water content for LTER-II). Water content data is then sorted by i.d. number using a LOTUS 123 macro found in WC2_SORT.WQ1 which creates final version of water content data set for the month in a separate file. Two files per month are saved: raw count data (mmddyy-2.RAW; ex. 121189-2.RAW where -2 indicates LTER-II NPP site neutron probe readings) and calculated/ sorted soil water content data appended to data file containing that year's data (NPPSWCyy.DAT; example NPPSWC89.DAT contains NPP soil water content data for 1989). Regression equation was derived by Mahlia Nash, and after datalogger upgrade was added to hydroprobe, by David Hudson, both working for Dr. Peter Wierenga (as of 1994 at university at Tucson (Hudson's phone # is 602-621-3236). See PROBE.HIS file for probe history and regressions used for different data periods when different probes were used. The hydroprobe used whenever possible is Hydroprobe Model CPN503DR (Campbell Pacific Nuclear, Pacheco, CA) with data logger. This probe has a 50mCi241 Am-Be source and a hydrogen detector. Neutrons encountering hydrogen become thermalized. The detector totals returning thermalized neutrons over a 16 second sample time which is the raw count value displayed. The raw count value is then substituted into the proper regression equation for cm3 of water per cm3 of soil.

Dataset: 

Study number: 

368

Data set ID: 

210368004

Date range: 

1987-01-01 to 1987-05-31

Original investigator: 

Rodolfo R Di Marco

Data contact: 

Abstract: 

The purpose of this investigation was to answer three general questions: 1. How does the modification of soil properties and the ratios of resources (e.g., water-N) by ants alter species assemblages of winter annual plants at the edge of the ant nests? 2.

How does the "spring cleaning", clipping, predation or herbivory by ants affect success of the winter annual plants at the edge of ant nests? 3. Are there significant differences in the floristic assemblage and belowground standing crop (root biomass) between the edge of ant nest and the surrounding unaffected soils? Data set contains soil water content data measured gravimetrically at monthly intervals from January to May. Soil samples were taken from ant nest edge and from adjacent reference sites (5 m apart).

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