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|                             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
<NOT AVAILABLE>.  For fields that will not have information, enter
<NONE>. See data manager for any questions regarding this form.
--------------------------------------------------------------------

 1) Data set access (RESTRICTED or UNRESTRICTED):
    ---------------------------------------------
    UNRESTRICTED

 2) Data set title:
    ---------------
    Ant nest soil nutrients

 3) Project title:
    --------------
    Effects of harvester ant nests on soil properties and vegetation

 4) Responsible investigator(s):
    ----------------------------
    Rodolfo R. Di Marco

 5) Date data collection commenced (mm/dd/yyyy):
    --------------------------------------------
    24 June 1987

 6) Date data collection terminated (mm/dd/yyyy or ONGOING):
    --------------------------------------------------------
    24 June 1987

 7) Expected duration of study:
    ---------------------------
    one day

 8) Frequency of measurement:
    -------------------------
    once

 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):
    ----------------------------------------------------------------
    Rodolfo R. Di Marco

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):
    ----------------------------------------------------------------
    This study was conducted at three sites on the Jornada LTER
    during winter-spring 1987.  A burrograss-tobosa swale grassland
    was site 1, an area dominated by the perennial grasses
    Scleropogon brevifolia (burrograss) and Hilaria mutica (tobosa).
    This area is located 3,000 ft. (1,000 m) SE of the playa bottom
    or playa basin (College Playa) and subject to rare sheet
    flooding.  A playa fringe (College Playa) was site 2, an area
    characterized by scattered Prosopis glandulosa (mesquite) mixed
    with Yucca elata and Larrea tridentata (creosotebush).  The upper
    basin slope was site 3, an area characterized by a fairly uniform
    cover of Xanthocephalum sarothrae (snakeweed) and a high
    diversity of annual forbs and grasses.  The soil series described
    on the watershed by Wierenga et al. (1987) from site 1 to site 3
    are Dalby (Typic Torrerts, fine), Headquarter (Ustollic
    Haplargid, fine loamy), Bucklebar (Typic Haplargid, fine-loamy),
    and Dona Ana (Typic Haplargid, coarse-loamy), respectively.

12) Data set description (State the hypothesis and / or objectives
                         which collection of data set addresses):
    ----------------------------------------------------------------
    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 chemical analyses for soil samples collected
    from five ant nests for each of the three sites for total
    nitrogen, (ammonium, nitrate), inorganic phosphorus,
    and exchangeable cations (K+, Na+, Ca2+ and Mg2+). Also included
    is belowground biomass from five ant nests for each of the three
    sites.

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
    --------  ------  --------   --------  -------------------------
    SAMPLE    I1      N/A        1,2       Replicate sample analysis
    PLACE     I1      N/A        1,2,3     1=burrograss-tobosa swale
                                           2=playa fringe
                                           3=upper basin slope mixed grasses
    REP       I1      N/A        1-8       When PLACE=1
                                 1-5       When PLACE=2
                                 1-7       When PLACE=3
    TRT       I1      N/A        1         Ant nest perimeter
                                 2         Reference site
    NA        F4.2    meq/100g   N/A       Na+
    K         F4.2    meq/100g   N/A       K+
    CA        F5.2    meq/100g   N/A       Ca2+
    MG        F4.2    meq/100g   N/A       Mg2+
    NO3       F5.2    mg/kg soil N/A       NO3-N
    NH4       F4.2    mg/kg soil N/A       NH4-N
    P         F5.2               N/A       Phosphorus
    PP        F5.3    mg/kg soil N/A       PO4-P
    TN        I4      mg/kg soil N/A       Total nitrogen
    BIO       F5.3    g/1000cm3  N/A       below ground biomass

14) Missing or questionable values (describe how these are
    represented in the data set):
    ----------------------------------------------------------------
    <NONE>

15) Methodology (Provide sufficient detail such that an unaware
                reader could repeat the described data collection
                procedures.)
    ----------------------------------------------------------------
       On 24 June 1987, soil samples were collected from five ant
    nests for each of the three sites for nalysis of total nitrogen,
    (ammonium, nitrite, nitrate), inorganic phosphorus, and
    exchangeable cations (K+, Na+, Ca2+ and Mg2+).  The two quadrats
    of the ant nest edges were randomly sampled once with a 400-cm3
    core (20 cm depth) and the soil samples were mixed together.  The
    same procedures were used for the two quadrats of adjacent
    reference sites.
       All chemical analyses were determined on the < 2-mm soil
    fraction.  Total nitrogen was measured by microKjeldahl digestion
    (Bremmer & Mulvaney, 1982) and analyzed twice.  Ammonium (NH4-N),
    nitrite (NO3-N), and nitrate (NO3-N) were extracted with 100 ml of
    2 N KCl on 10-g soil samples and were measured as described by
    Keeney and Nelson (1982).  Inorganic phosphorus (P) was extracted
    with 100 ml of 0.5 M NaHCO3 on approximately 10-g soil samples and
    was measured on an autoanalyzer.  Exchangeable cations (K+, Na+,
    Ca2+ and Mg2+) were extracted with 1 N ammonium acetate (pH 7.0)
    and were analyzed with an atomic absorption spectrophotometer.
       On 24 June 1987, below ground biomass was measured at only
    five ant nests from each of the three sites.  A 400 cm3 soil core
    sample was taken from each quadrat (edges and reference).  Roots
    were cleaned with a 2-mm sieve, oven-dried for 72 hours at 60 C
    and carefully weighed.

16) Key literature (Citations that describe sampling procedures,
                    [reference of a published paper, thesis, etc.]):
    ----------------------------------------------------------------
    Bremmer, J.M. and C.S. Mulvaney. 1982. Total nitrogen. In: A.L.
    Page, R.H. Miller, and D.R. Keeney, editors. Methods of soil
    analysis. Part 2. Chemical and microbiological properties. Second
    edition. American Society of Agronomy. Soil Science Society of
    America, Madison, Wisconsin.

    Keeney, D.R. and D.W. Nelson. 1982. Nitrogen-inorganic forms.
    Pages 643-698. In: A.L. Page, R.H. Miller, and D.R. Keeney,
    editors. Methods of soil analysis. Part 2. Chemical and
    microbiological properties. Second edition. American Society of
    Agronomy. Soil Science Society of America, Madison, Wisconsin.

17) Keywords (keywords that describe data set; maximum of 10):
    ----------------------------------------------------------------
    ants, soil nutrients, annual plants

18) Treatment of data: (List any programs used in analysis of the data):
    [Note: Programs should be appended and stored with this form.]
    ----------------------------------------------------------------
    <NONE>

19) Associated computer accounts:
    ----------------------------------------------------------------
    <NONE>

20) Files associated with this data set:
    ----------------------------------------------------------------
    A) Metadata files

         FILE NAME   DESCRIPTION OF FILES
       ------------  -----------------------------------------------
       ANTNESTS.PRJ  Project documentation
        ANSNUTR.DSD  Data set documentation
       ------------  -----------------------------------------------

    B) Data files

         FILE NAME   DESCRIPTION OF FILES
       ------------  -----------------------------------------------
        ANSNUTR.DAT  Data set file
       ------------  -----------------------------------------------

    C) Data entry, verification, and analysis files

         FILE NAME   DESCRIPTION OF FILES
       ------------  -----------------------------------------------
       <NONE>
       ------------  -----------------------------------------------

    D) Other (Any other related files.)

         FILE NAME   DESCRIPTION OF FILES
       ------------  -----------------------------------------------
       <NONE>
       ------------  -----------------------------------------------

21) Comments (Include any comments here that more fully describe
               this data set):
    ----------------------------------------------------------------
    No documentation was completed by the investigator.  Project and
    data set documentation was completed by the LTER Data Manager
    with information obtained from Di Marco (1987) and header infor-
    mation from SAS files which also contained the data.  The raw
    data which composes this data set was extracted from provided SAS
    files prior to analyses.

22) Data set documentation history log:
    ----------------------------------------------------------------
    Data set title     - Ant nest soil nutrients
    Data set file name - ANSNUTR.DSD
    ----------------------------------------------------------------
         mm/dd/yyyy         - Date of Comment
         Int                - Initials of person making Comment
                              JPA  =  John P. Anderson
         Changes/Updates    - List any changes made to document

    mm/dd/yyyy  Int  Changes/Updates
    ----------  ---  -----------------------------------------------
    02/04/1998  JPA  Data set documentation completed.

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                         END OF DATA SET FILE
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