+------------------------------------------------------------------+ | 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: --------------- Density and cover of winter annual plants 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): -------------------------------------------- January 1987 6) Date data collection terminated (mm/dd/yyyy or ONGOING): -------------------------------------------------------- June 1987 7) Expected duration of study: --------------------------- 6 months 8) Frequency of measurement: ------------------------- 4 times (January, February, March, mid-May) 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 sties 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 density and cover of all winter annual plants measured at regular intervals. Density is expressed as the number of individuals of a species per square meter. The cover of each species was calculated as the area covered by a perpendicular (not vertical) projection of its aerial parts onto the ground surface and expressed in covered area (cm squared) per square meter. 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 -------- ------ -------- -------- ------------------------- T I1 N/A 1,4,6,7 Sample time: January 1987 35,36,38, February 1987 40 February 1987 63,69,70, March 1987 73,74,78 March 1987 111,112, April 1987 113 April 1987 127 May 1987 T I1 N/A 7 Time 1=January 1987 38 Time 2=February 1987 78 3=March 1987 4=mid-May 1987 PLACE I1 N/A 1,2,3 1=burrograss-tobosa swale 2=playa fringe 3=upper basin slope 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 SIDE I1 N/A 1,2 Sampling quadrat NPT F5.2 #plants/m2 N/A # of plants per m2 (total plants) SFT F6.3 cm2/m2 N/A total plant cover SP C1 N/A A Eriogonum abertianum B Eriogonum rotundifolium C Xanthocephalum sphaerocephalum D Eriastrum diffusum E Machaeranthera gracilis F Cryptantha angustifolia G Cryptantha micrantha H Eschscholzia mexicana I Lesquerella gordonii J Descurainea pinnata K Lepidium lasiocarpum L Phacelia intermedia M Malacothrix fendleri N Oenothera primaveris O Erodium texanum P Astragulus tephodes Q Lupinus concinnus R Euphorbia species S Unknown plant species SPN F5.2 #plants/m2 N/A # of specific species per m2 SPS F6.3 cm2/m2 N/A specific species plant cover 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.) ---------------------------------------------------------------- During winter 1987, eight Pogonomyrmex rugosus nests at site 1, five Pogonomyrmex rugosus nests at site 2 and seven Pogonomyrmex rugosus nests at site 3 were randomly selected and systematically sampled. At each nest, a 0.16 square meter quadrat frame was randomly placed at the ant nest edge, a second 0.16 square meter quadrat was also placed on the ant nest edge opposite to the first quadrat. Two additional quadrat frames were placed 5 meters distance from the two at the edge of the ant nests. These quadrats represent the soil unmodified by the activity of the ants and served as a reference. The density and the cover of all winter annual plants were measured at regular intervals (approximately 30 days). Density was expressed as the number of individuals of a species per square meter. The cover of each species was calculated as the area covered by a perpendicular (not vertical) projection of its aerial parts onto the ground surface and expressed in covered area (cm2) per m2 and in percentage. Overlap was always counted, resulting in the potential for total cover to exceed 100%. Density and cover is measured four times, at the end of January, February and March and in mid-May. Each measurement required three to four days to complete. Affinity for ant nest edge for each species was calculated as mean cover of a species on the edge of an ant nest divided by the sum of mean cover of that species n the edge of an ant nest and mean cover on the reference sites. This was expressed as percentage. Mean cover of all species was determined as an arithmetic mean throughout the experiment. 16) Key literature (Citations that describe sampling procedures, [reference of a published paper, thesis, etc.]): ---------------------------------------------------------------- 17) Keywords (keywords that describe data set; maximum of 10): ---------------------------------------------------------------- ants, plant cover, belowground biomass, 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.] ---------------------------------------------------------------- 19) Associated computer accounts: ---------------------------------------------------------------- 20) Files associated with this data set: ---------------------------------------------------------------- A) Metadata files FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- ANTNESTS.PRJ Project documentation ANDENCOV.DSD Data set documentation ------------ ----------------------------------------------- B) Data files FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- ANDENCOV.DAT Data set file (ASCII) ------------ ----------------------------------------------- C) Data entry, verification, and analysis files FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- ------------ ----------------------------------------------- D) Other (Any other related files.) FILE NAME DESCRIPTION OF FILES ------------ ----------------------------------------------- ------------ ----------------------------------------------- 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 - Density and cover of winter annual plants Data set file name - ANDENCOV.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. ------------------------------------------------------------------- END OF DATA SET FILE -------------------------------------------------------------------