DSL2004006 ANDENCOV Jornada Basin LTER

NMSU, Wooton Hall, Room 200 2995 Knox Street, Room 200 Box 30003, MSC 3JER Las Cruces NM 88003

(505) 646-7918 (505) 646-5889 datamanager@jornada.nmsu.edu http://jornada-www.nmsu.edu ORG0000001 Rodolfo R Di Marco

unknown Responsible Investigator Rodolfo R Di Marco

unknown Researcher English Cover and density of winter annual plants on the perimeters of ant nests were compared with those of adjacent reference sites in three habitats at Jornada LTER, New Mexico, USA. There was a distinct floristic assemblage of winter annual plants on ant nest perimeter in comparison to reference sites. Descurainia pinnata, Lesquerella gordonii, Malacothrix fendleri and Eriogonum abertianum were strongly associated with ant nest perimeters and had higher cover on ant nest perimeters. The floristic assemblages and cover were least affected by presence of harvester ant nests in the grama grassland habitat and most affected in the basin slope mixed habitat. Soil chemical analyses did not show large generalized differences in nutrient contents. However, there were higher concentrations of NO3-N and inorganic P on ant nest perimeters and also, there were different ratios of resources (e.g., water and N and P availability) due to ant soil disturbance on ant nest perimeter. Floristic assemblage could be determined by a fortuitous juxtaposition of clumped seeds at beginning of winter, by intra and interspecific competition of winter annual during February and March, and mediated by ant clipping at the end of April and May. There were no significant differences in below ground biomass between ant nest perimeter and reference sites. This many be due to intense clipping of annual plants by ants on nest perimeters in April. Chihuahuan Desert Las Cruces NM Southwest USA Dona Ana County JRN Jornada Basin LTER LTER ants plant cover belowground biomass annual plants

This dataset is released to the public and may be used for academic, educational, or commercial purposes subject to the following:

The Jornada Basin LTER Information Management System provides protocol and services for data collection, verification, organization, archives, and distribution.

Data managers interact with researchers during the entire scientific process--from the initial planning of sampling designs and field data collection to archiving and distribution of long-term data. The goal of data management is to build and maintain an archive of Jornada Basin LTER data files that are fully documented, error free, and organized in useful ways. Our protocol for data collection and processing seeks maximum interaction between researchers and data management personnel to avoid confusion and potential loss of data or problems with integrity of data. The data manager helps researchers to construct data forms that allow convenient data entry and analysis. Data documentation forms are completed by principal investigators prior to data entry. Data are entered into computer data files by data entry personnel using programs that error- check and verify the data as it is entered. Computer files are subjected to further verification by graphing and/or error-checking programs, and/or examination by field investigators. Error-checked data files are stored with associated documentation files on floppy disks and on a hard-disk database. Back-up data files are maintained as "hard-copy," on multiple floppy disks, and on read/write 30- year magneto-optical disks. Various sets of these data are stored at different sites on the NMSU campus. The final responsibility for quality assurance (both in data and documentation content) rests with the principal investigator who submits the data for inclusion in the Jornada Basin LTER Information Management System. To facilitate quality assurance, the data management staff will provide copies of data and documentation submitted by a principal investigator to that investigator upon request.

All data collected during a calendar year should be submitted to the Jornada Basin LTER data manager prior to July first of the following year. Data must be submitted with standard Jornada Basin LTER forms (both Project Abstract and Data Set documentation) which include objectives of the study, methods, as well as format and content of the data.

Data will be made publicly available no later than 2 years after submission of the data unless an earlier date is specified by the principal investigator. In the event that an extension of the 2 year period is necessary, the principal investigator may petition the Jornada Basin LTER Executive Committee for a longer protected period.

Individuals and institutions utilizing data from the Jornada Basin LTER database are requested to place the following acknowledgment in any publication in which these data are mentioned: Data sets were provided by the Jornada Basin Long-Term Ecological Research (LTER) projects. Funding for these data was provided by the U.S. National Science Foundation (Grants DEB-92-40261 and DEB 94-11971). Please send 1 copy of any publication that cites Jornada Basin LTER data to: John P. Anderson Jornada Experimental Range P.O. Box 30003, MSC 3JER New Mexico State University Las Cruces, NM 88003-0003

http://jornada-www.nmsu.edu/datacat.htm Jornada Basin,Chihuahuan Desert, 17 miles NE of Las Cruces, NM, USA -107.002148 -106.502641 32.831393 32.428919 1188 2658 meter 1987-01-19 1987-06-19

4 times (January, February, March, mid-May)

Data set title - Density and cover of winter annual plantsData set file name - ANDENCOV.DSD----------------------------------------------------------------mm/dd/yyyy - Date of CommentInt - Initials of person making CommentJPA = John P. AndersonKR = Ken RamseyChanges/Updates - List any changes made to documentmm/dd/yyyy Int Changes/Updates---------- --- -----------------------------------------------02/04/1998 JPA Data set documentation completed.09/13/2004 KR Added Dataset ID and Project ID to top of form.Changed format for Attributes and AssociatedFiles section.Removed Missing/Questionable data section andincorporated into Attributes section.10/04/2004 KR Updated T variable description and noted incomments section.Updated Associated Files section.-------------------------------------------------------------------

Data Manager

NMSU, Wooton Hall, Room 200 2995 Knox Street, Room 200 Box 30003, MSC 3JER Las Cruces NM 88003

(505) 646-7918 (505) 646-5889 datamanager@jornada.nmsu.edu http://jornada-www.nmsu.edu Data Manager

NMSU, Wooton Hall, Room 200 2995 Knox Street, Room 200 Box 30003, MSC 3JER Las Cruces NM 88003

(505) 646-7918 (505) 646-5889 datamanager@jornada.nmsu.edu http://jornada-www.nmsu.edu Debra Peters

USDA-ARS Jornada Experimental Range P.O. Box 30003, MSC 3JER New Mexico State University Las Cruces NM 88003-0003

505 646 2777 505 646 5889 debpeter@nmsu.edu ORG0000001 ----------------------------------------------------------------During winter 1987, eight Pogonomyrmex rugosus nests at site1, five Pogonomyrmex rugosus nests at site 2 and sevenPogonomyrmex rugosus nests at site 3 were randomly selected andsystematically sampled. At each nest, a 0.16 square meterquadrat frame was randomly placed at the ant nest edge, a second0.16 square meter quadrat was also placed on the ant nest edgeopposite to the first quadrat. Two additional quadrat frameswere placed 5 meters distance from the two at the edge of the antnests. These quadrats represent the soil unmodified by theactivity of the ants and served as a reference.The density and the cover of all winter annual plants weremeasured at regular intervals (approximately 30 days). Densitywas expressed as the number of individuals of a species persquare meter. The cover of each species was calculated as thearea covered by a perpendicular (not vertical) projection of itsaerial parts onto the ground surface and expressed in coveredarea (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 requiredthree to four days to complete. Affinity for ant nest edge foreach species was calculated as mean cover of a species on theedge of an ant nest divided by the sum of mean cover of thatspecies n the edge of an ant nest and mean cover on the referencesites. This was expressed as percentage. Mean cover of allspecies was determined as an arithmetic mean throughout theexperiment.

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Rodolfo R Di Marco

Responsible Investigator Cover and density of winter annual plants on the perimeters of ant nests were compared with those of adjacent reference sites in three habitats at Jornada LTER, New Mexico, USA. There was a distinct floristic assemblage of winter annual plants on ant nest perimeter in comparison to reference sites. Descurainia pinnata, Lesquerella gordonii, Malacothrix fendleri and Eriogonum abertianum were strongly associated with ant nest perimeters and had higher cover on ant nest perimeters. The floristic assemblages and cover were least affected by presence of harvester ant nests in the grama grassland habitat and most affected in the basin slope mixed habitat. Soil chemical analyses did not show large generalized differences in nutrient contents. However, there were higher concentrations of NO3-N and inorganic P on ant nest perimeters and also, there were different ratios of resources (e.g., water and N and P availability) due to ant soil disturbance on ant nest perimeter. Floristic assemblage could be determined by a fortuitous juxtaposition of clumped seeds at beginning of winter, by intra and interspecific competition of winter annual during February and March, and mediated by ant clipping at the end of April and May. There were no significant differences in below ground biomass between ant nest perimeter and reference sites. This many be due to intense clipping of annual plants by ants on nest perimeters in April. Dr. Debra Peters

USDA-ARS Jornada Experimental Range P.O. Box 30003, MSC 3JER New Mexico State University Las Cruces NM 88003-0003

505 646 2777 PE00000002 Information Manager Historical Perspective: The Chihuahuan Desert , similar to many arid and semiarid ecosystems of the world, has experienced dramatic changes in vegetation structure and ecosystem processes over the past several centuries. The reasons for the expansion of woody plants and decrease in perennial grasses are numerous and controversial, including livestock grazing, drought, climate change, reduction in fire frequency, and change in small animal populations. The problem is further complicated by the existence of interactions among these factors that feature positive feedbacks and that create threshold behavior and nonlinearity in ecosystem responses. A general consensus does not exist regarding the key factors that control the desertification process or the conditions that explain varying patterns of shrub invasion or grass persistence under similar conditions. It is also unclear why many attempts to remediate shrublands back to grasslands have failed whereas some methods have worked well, but with long time lags. Site History: The Jornada Basin Long Term Ecological Research Program (JRN LTER), supported by major funding from the National Science Foundation, has been investigating desertification processes since 1982. We benefit from a legacy of long-term data available from 1912 onwards, thanks to collaboration with our research partner, the Jornada Experimental Range Agricultural Research Service (JER ARS). Significant progress has been made in understanding the causes and consequences of desertification, although important problems still remain. In particular, several key questions are unresolved, including (1) can we predict spatial and temporal variation in ecosystem properties related to desertification and grass recovery? (2) how do we integrate diverse observations about vegetation, climate, soils, hydrology, and animal populations to accomplish this prediction? This integration is the focus of current LTER studies. Research Topics: desertification; ecosystem indicators and vegetation dynamics; geomorphology and wind; ecohydrology; animal interactions; factors affecting primary production; animal-induced soil disturbances; direct and indirect consumer effects; vertebrate and invertebrate population dynamics; grazing effects on ecosystem structure and function; biodiversity and ecosystem. Jornada Basin Climate and Vegetation NSF Award DEB-0080412 description. uid=JRN,o=lter,dc=ecoinformatics,dc=org all public read ANDENCOV.DAT Data file ANDENCOV.DAT column 3 1 1 6 1 8 1 10 1 12 5 20 6 30 1 40 5 43 7 53 T T Sample time Integer PLACE PLACE Location Integer REP REP Replicate Integer TRT TRT Treatment Integer SIDE SIDE Sampling quadrat Integer NPT NPT total # of plants per m2 (#plants/m2) Float SFT SFT total plant cover (cm2/m2) Float SP SP plant species code Character SPN SPN # of specific species per m2 (#plants/m2) Float SPS SPS specific species plant cover Float ANDENCOV.DSD Data set documentation, File Format: ASCII, File Type: Text file ANDENCOV.DSD ASCII Text file Metadata file ANTNESTS.PRJ Project documentation, File Format: ASCII, File Type: Text file ANTNESTS.PRJ ASCII Text file Metadata file B1.SAS SAS analysis file including raw data set, File Format: ASCII, File Type: Text file B1.SAS ASCII Text file Data entry, verification, and analysis file B111.SAS SAS analysis file including raw data set, File Format: ASCII, File Type: Text file B111.SAS ASCII Text file Data entry, verification, and analysis file B12.SAS SAS analysis file including raw data set, File Format: ASCII, File Type: Text file B12.SAS ASCII Text file Data entry, verification, and analysis file B15.SAS SAS analysis file including raw data set, File Format: ASCII, File Type: Text file B15.SAS ASCII Text file Data entry, verification, and analysis file B19.SAS SAS analysis file including raw data set, File Format: ASCII, File Type: Text file B19.SAS ASCII Text file Data entry, verification, and analysis file PROG1.SAS SAS analysis file, File Format: ASCII, File Type: Text file PROG1.SAS ASCII Text file Data entry, verification, and analysis file PROG2.SAS SAS analysis file, File Format: ASCII, File Type: Text file PROG2.SAS ASCII Text file Data entry, verification, and analysis file PROG4.SAS SAS analysis file, File Format: ASCII, File Type: Text file PROG4.SAS ASCII Text file Data entry, verification, and analysis file Readme.txt General information file, File Format: ASCII, File Type: Text file Readme.txt ASCII Text file Other