+------------------------------------------------------------------+ | JORNADA LTER | | New Mexico State University | | Data Set Documentation Form | +------------------------------------------------------------------+ All Jornada Desert Site NSF/LTER data sets must be documented on the following form. This applies to any data set intended for permanent archiving. All raw data sets collected under the auspices of the Jornada NSF/LTER Program will be described by the following standardized form. Information that is not available at this time, must be included when available. For these fields, enter . For fields that will not have information, enter . See data manager for any questions regarding this form. -------------------------------------------------------------------- 1) Data set access (RESTRICTED or UNRESTRICTED): --------------------------------------------- UNRESTRICTED 2) Data set title: --------------- Transect particle size analysis 3) Project title: -------------- Transect soil physics 4) Responsible investigator(s): ---------------------------- J. Wierenga 5) Date data collection commenced (mm/dd/yyyy): -------------------------------------------- Spring 1982 - Spring 1984; see comments 6) Date data collection terminated (mm/dd/yyyy or ONGOING): -------------------------------------------------------- Spring 1982 - Spring 1984; see comments 7) Expected duration of study: --------------------------- Three Years 8) Frequency of measurement: ------------------------- One time 9) Researchers: (Personnel who will be obtaining data and who would need to be contacted directly if there is a problem in the raw data): ---------------------------------------------------------------- Mohammed Nash 10) Methods of recording (field data sheets, instrumental, etc.): ---------------------------------------------------------------- Field data sheets 11) Site location (Describe in sufficient detail that the site can be relocated): ---------------------------------------------------------------- In the spring of 1982, as part of the establishment of the Jornada Long-Term Ecological Research site in southern New Mexico, a 135 ha portion of a 1500 ha, internally drained, watershed was exclosed from grazing by domestic livestock. Prior to exclosure the watershed, as well as the rest of the Jornada basin, had been moderately to heavily grazed for the past 100 years. Concurrent with grazing, the vegetation had undergone a dramatic change from desert grassland, with an almost continuous cover of C4 perennial grasses, to isolated patches of the original grassland in a mosaic with desert shrub dominated plant communities (Buffington and Herbel, 1965). The exclosure lies along a northeast facing piedmont slope at the base of a steep isolated mountain peak, and covers a variety of component landforms from the foot of the mountain to the basin floor. The northeast side of the exclosure is immediately upslope of the College Playa located near the NMSU College Ranch. Three parallel transects (2.7 km in length) run from the middle of the College Playa up into the foot of Mt. Summerford. The Control transect is to the west, the Treatment transect on the east side of the Control transect, and the Alternate Control to the east of the Treatment transect. Each transect is 30 meters wide with a 45 meter buffer zone between each transect. The Treatment transect was treated annually until 1987 with NHNO3 in a concentration equal to 10g N/m2. The station markers at 30 meter intervals along each transect. Only the control transect was used in this study. 12) Data set description (State the hypothesis and / or objectives which collection of data set addresses): ---------------------------------------------------------------- Variation in the soil from place to place is a fact of nature and is substantial. It is a major source of uncertainty in soil survey and causes many of the difficulties of applying mathematics to the study of soil. Soil variability within small areas can be studied by using a straight line (transect) laid over a tract of known distance and can be sampled and observed equidistantly. Line transects give an indication of both the local and the general variation. The technique, however, may depend strongly on direction of the transect. Soil along the LTER I Control transect was sampled at 30 meter intervals from station C01 through C89. Soil characteristics were measured at 4 depths (30, 60, 90, and 120 cm) for the percent composition of clay, silt, sand, very coarse sand, coarse sand, medium sand, fine sand, very fine sand, calcium carbonate, organic carbon and coarse fragments greater than 2mm. 13) Attributes measured: ------------------------------------------------------------------- Variable name: blank Number of columns between fields CCCCCCCC See attribute description Format: C = character (C3: Three characters [XXX]) I = integer (I2: Integer with two places [##]) F = floating point (F4.2: Total places with decimal point = 4, with 2 decimal places. [#.##]) Variable code: * See attribute description listing See external listing of variable codes N/A = Not applicable VARIABLE MEASURED VARIABLE NAME FORMAT UNITS CODE ATTRIBUTE DESCRIPTION -------- -------- -------- -------- ------------------------- SA I2 N/A 1-89 Sample Number D I1 cm 1 Depth = 30 2 = 60 3 = 90 4 = 120 CLAY F5.2 % N/A Clay SILT F5.2 % N/A Silt SAND F5.2 % N/A Sand VCSA F4.2 % N/A Very Coarse Sand CSAN F5.2 % N/A Coarse Sand MSAN F5.2 % N/A Medium Sand FSAN F5.2 % N/A Fine Sand VFSA F5.2 % N/A Very Fine Sand CACAR F5.2 % N/A Calcium carbonate ORGC F4.2 % N/A Organic carbon CFRAG F4.2 % N/A Coarse Fragments (>2mm) 14) Missing or questionable values (describe how these are represented in the data set): ---------------------------------------------------------------- 15) Methodology (Provide sufficient detail such that an unaware reader could repeat the described data collection procedures.) ---------------------------------------------------------------- *A transect of 2670 meters in length served as a reference in the study area. Soil texture was determined on soil samples taken at 30 meter intervals along the transect at 30, 60, 90, and 120 cm depth on a parallel transect 7 m to the northwest side of the main transect (LTER I Control transect). Particle size distribution was determined with the pipette method, and sand fractions were separated by sieving (Day 1965). Those samples were taken in layers rather than genetic horizon. Individual mixed bulk samples were taken of each depth. The number of samples were 356 (89 locations X 4 depths). These samples were taken by an auger of 7 cm diameter and stored in water resistant bags to preserve the samples. **Calcium carbonate. Carbonates were determined by a titrimetric procedure, using a 0.5 N HCl soil treatment with a 0.5 N NaOH back titration with a Fisher Titralizer II titration system. **Particle size analysis. The pipette method was used to determine the percent of sand, silt and clay after pretreatment to remove organic matter and carbonate. The sand fractions (USDA sizes) were determined by dry sieving. **Organic carbon. The percentage or organic carbon by weight was determined by reduction of potassium dichromate by organic matter (Peech, 1965). 16) Key literature (Citations that describe sampling procedures, [reference of a published paper, thesis, etc.]): ---------------------------------------------------------------- Day, P.R. 1965. Particle fractionation and particle-size analysis. In: Black, C.A. (ed.), Methods of Soil Analysis, Part 1. pp. 545-566. Madison, WI: American Society of Agronomy. Wierenga, P.J., J.M.H. Hendrickx, M.H. Nash, J. Ludwig, and L.A. Daugherty. 1987. Variation of soil and vegetation with distance along a transect in the Chihuahuan Desert. Journal of Arid Environments 13:53-63. 17) Keywords (keywords that describe data set; maximum of 10): ---------------------------------------------------------------- soil, sand, clay, silt, physical, calcium carbonate, organic carbon, particle size 18) Treatment of data: (List any programs used in analysis of the data): [Note: Programs should be appended and stored with this form.] ---------------------------------------------------------------- 19) Associated computer accounts: ---------------------------------------------------------------- 20) Files associated with this data set: ---------------------------------------------------------------- A) Metadata files FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- TRANPHYS.PRJ Project documentation SOIL_ANA.DSD Data set documentation ------------ ----------------------------------------------- B) Data files FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- SOIL_ANA.DAT Transect soil structure data (ASCII) ------------ ----------------------------------------------- C) Data entry, verification, and analysis files FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- ------------ ----------------------------------------------- D) Other (Any other related files.) FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- CATIONS5.DAT Transect cations data (ASCII) CATIONS5.DSD Transect cations documentation (ASCII) PHOSPHAT.DAT Transect phosphate data (ASCII) PHOSPHAT.DSD Transect phosphate documentation (ASCII) ------------ ----------------------------------------------- 21) Comments (Include any comments here that more fully describe this data set): ---------------------------------------------------------------- *Taken from original documentation and Wierenga et al. (1987); see key literature. **Taken from Nash, et al. This data set corresponds to Table A1 in Nash, Mohammad H., and LeRoy A. Daugherty. 1990. Soil-Landscape Relationships in Alluvium Sediments in Southern New Mexico, Bulletin 746. New Mexico Agricultural Experiment Station, Las Cruces, New Mexico. There is no documentation indicating exact timing of soil core sampling; Wierenga et al. (1987) states the work was done between Spring 1982 and Spring 1984. Because two stations (90 and 91) extended onto the base of the mountain and had extremely different species composition relative to the other transect stations, we elected to exclude them from our analyses. [Stations C90 and C91 on the Control transect are on undifferentiated rocklands with large boulders. Soil cores would not have been possible. J Anderson 1/21/03] 22) Data set documentation history log: ---------------------------------------------------------------- Data set title - Transect particle size analysis Data set file name - SOIL_ANA.DSD ---------------------------------------------------------------- mm/dd/yyyy - Date of Comment Int - Initials of person making Comment JPA = John P. Anderson JW = J. Wierenga SMG = Sophia M. Gehlhausen MAB = Michelle A. Buonopane Changes/Updates - List any changes made to document mm/dd/yyyy Int Changes/Updates ---------- --- ----------------------------------------------- 03/02/1984 JW Form completed by investigator 05/07/1997 SMG Form updated to current format 11/20/2002 MAB Completed and/or corrected fields. 01/21/2003 JPA Expanded Data Set Description to include variables measured. Added sections to Methodology. ------------------------------------------------------------------- END OF DATA SET FILE -------------------------------------------------------------------