U.S. flag

An official website of the United States government

The Ag Data Commons is migrating

The Ag Data Commons is migrating to a new institutional portal on Figshare. The current system is available for search and download only. The new platform is open for submission with assistance from Ag Data Commons curators. Please contact NAL-ADC-Curator@usda.gov, if you need to publish or update your datasets.

Other Access

The information on this page (the dataset metadata) is also available in these formats:

JSON RDF

via the DKAN API

Data Extent

Walnut Gulch Experimental Watershed, Kendall (Carbon Dioxide and Water Flux)

Atmospheric carbon dioxide and moisture concentrations were measured with an infrared gas analyzer (IRGA) (LI-6262, LI-COR, Inc. Lincoln, Nebraska, USA). Measurements were made from 1997 through the present at the Kendall site. The meteorological data and Bowen ratio energy balance systems (BREB) (Model 023/CO2 Campbell Scientific Inc., Logan, Utah, USA) data are used to calculate carbon dioxide and evapotranspiration (ET) fluxes. The stored Bowen ration instrument data from the measurement site were transmitted by radio daily to our research station in Tombstone, AZ. From there, they were transferred through an Internet connection to Tucson, AZ. The data were then divided into 5-day increments and inserted into a Quattro1 Pro spreadsheet file which had all the formulations to calculate flux of soil heat, latent heat, sensible heat, evapotranspiration rates (ET), and CO2 rates on the 20-min time step of the data. All instrument and calculated data were graphed in the spreadsheet file and thoroughly reviewed for any instrument problems or data stream collection issues.

Carbon dioxide and water fluxes are important components of watershed function. In order to study carbon dioxide and water flux as they exist over the Walnut Gulch Experimental Watershed (WGEW), two sites were selected on the basis of their ecosystem composition, one site being dominated by shrubs and the other a grass dominated plant community. The grass site is identified as Kendall (109560800W, 314401000N; elevation; 1526 m). The soils at the Kendall site are a complex of Stronghold (coarse-loamy, mixed, thermic Ustollic Calciorthids), Elgin (fine, mixed, thermic, Ustollic Paleargids), and McAllister (fine-loamy, mixed, thermic, Ustollic Haplargids) soils, with Stronghold the dominant soil [NRCS Soil Survey, 2003]. Slopes range from 4 to 9%. The Stronghold surface A horizon (0-3 cm) contains 670 g kg1 sand, 160 g kg1 silt, and 170 g kg1 clay with 790 g kg1 coarse fragments >2 mm, 11 g kg1 organic carbon, and 7 g kg1 inorganic carbon. Vegetation is dominated by herbaceous plants, predominately black grama (Bouteloua eriopoda (Torr.) Torr.), sideoats grama (Bouteloua curtipendula (Michx.) Torr.), three-awn (Aristida sp.) and cane beardgrass (Bothriochloa barbinodis (Lag.) Herter). Vegetation canopy height at the grass site ranged from 0.4 to 0.7 m during the growing season.

FieldValue
Tags
Modified
2022-01-05
Release Date
2008-02-14
Identifier
WalnutKendall_jjm_2015-03-20_1241
Spatial / Geographical Coverage Area
POLYGON ((-110.2 31.773, -109.9 31.773, -109.9 31.662, -110.2 31.662))
Publisher
U.S. Department of Agriculture - Agricultural Research Service
Temporal Coverage
January 1, 1997
License
Contact Name
Armendariz, Gerardo
Contact Email
Public Access Level
Public
Program Code
005:040 - Department of Agriculture - National Research
Bureau Code
005:18 - Agricultural Research Service
Source ID
WalnutKendall_jjm_2015-03-20_1241
Harvested from Geodata Harvest
Harvest Source TitleGeodata Harvest
Harvest Source URIhttps://geodata.nal.usda.gov/geonetwork/srv/eng/csw
Last Harvest PerformedThu, 04/22/2021 - 01:01