Jornada Data

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Responsible investigator: John Anderson
Date range: 1988 - 1988
Abstract: Ammonia volatilization was measured at three sites in the Chihuahuan Desert of southern New Mexico, U.S.A. In dry soils, ammonia volatilization ranged from 9 to 11 micrograms of nitrogen per square meter per day, but rates increased to 95 micrograms of nitrogen per square meter per day in a shrubland site after an experimental addition of water. Ammonia volatilization also increased with experimental additions of NH4Cl and decreased with additions of sucrose. Competition by nitrifiers for available NH4+ had little effect on NH3 volatilization: N-Serve, added to inhibit nitrification, decreased NH3 volatilization in a grassland site and had little effect at other sites. We suggest that NH3 volatilization is controlled by the rate of mineralization of NH4+ from soil organic... more

Dataset ID: DSL2002031

Responsible investigator: John Anderson
Date range: 1989 - 1994
Abstract: Data for rabbits, birds, and lizards recorded from the LTER II animal transects. Data consists of species names, numbers of individuals, and distances observed from transects. Data is collected from each transect once every two weeks. See history file for exceptions.

Dataset ID: 110009001

Responsible investigator: John Anderson
Date range: 1987 - 1987
Abstract: 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+,... more

Dataset ID: DSL2004007

Responsible investigator: John Anderson
Date range: 1987 - 1987
Abstract: 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 % organic matter of soils sampled in January 1987 from ant nests and adjacent reference sites.

Dataset ID: DSL2004008

Responsible investigator: John Anderson
Date range: 1987 - 1987
Abstract: 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 soil water content data measured gravimetrically at monthly intervals from January to May. Soil samples were taken from ant nest edge and from adjacent reference sites (5 m apart).

Dataset ID: DSL2004009

Responsible investigator: John Anderson
Date range: 2000 - 2000
Abstract: LTER-I Transect plant line intercept data. This data set is as transcribed (UNSORTED) from cassette tape with one intercept observation per record. Data consist of week number, transect, station, segment number, plant species, and length of species intercepted by line stretched between 2 rebar the length of the 30 meter plant line intercept transect. Measurements are made on 30-meter line intercept transects located perpendicular to each of 91 stations on each of the 2.7 km long Control, Treatment, and Alternate Control Transects established at the beginning of LTER-I. Each plant line transect is divided into 6 5-meter segments. Annuals are measured only in the first meter of segments 1, 2, and 3 and in the last meter of segments 4, 5, and 6. Perennials are measured for the... more

Dataset ID: DSL2002054

Responsible investigator: John Anderson
Date range: 2000 - 2000
Abstract: On March 19, 2000, an arson burn occurred of 2.5 acres of the upper grassland area on the Summerford bajada just below the powerline road. The area affected included portions of the LTER-I Transect Plant Line Intercept study that was begun in 1982. To evaluate the impact of the burn on those lines, the line intercepts were read for the upper grassland area extending from immediately above the creosotebush fringe to the base of Summerford Mountain. The stations measured were C73-C89, T75-T90, and X76-X91 (Control, Treatment, and Alternate Control, respectively). Measurements were made immediately after the burn, after the spring growing season, and after the fall growing season in 2000 only. In the initial sampling period, the burn area intercepted by the line was noted in the... more

Dataset ID: DSL2002053

Responsible investigator: John Anderson
Date range: 1988 - 1994
Abstract: Data for arthropods captured in pitfall traps on LTER II consumer plots. Data includes order, family, genus, species, and number.

Dataset ID: 110008002

Responsible investigator: John Anderson
Date range: 1995 - 2000
Abstract: Objectives. Desertification is hypothesized to have altered the spatial and temporal availability of resources required by the biota. Results of desertification on the Jornada include changes to shrub dominated communities and major soil changes. We hypothesize that these shifts in vegetation have changed resources temporally for many of the consumers. If grassland systems respond to rainfall without significant lags, but shrub systems do not, then consumer species should reflect these differences. In addition, shifts from grassland to shrubland results in greater structural heterogeneity of the habitats. We have hypothesized that consumer populations, diversity, and densities of some consumers will be higher in grasslands than in shrublands. Diversity and/or densities are... more

Dataset ID: 110008001

Responsible investigator: John Anderson
Date range: 1985 - 1986
Abstract: *We conducted a field study to test the hypothesis that creosotebush (Larrea tridentata) shrubs growing in naturally nutrient-rich sites had better quality foliage and supported greater populations of foliage arthropods than shrubs growing in nutrient-poor sites. This is data for foliage arthropods sampled from LVAR creosotebush shrubs. Sampling was done in April of 1985 and 1986. Shrubs were sampled from 5 separate sites designated A-E. 10 shrubs of 3 different types, R=random, H=high quality, L=low quality were sampled at each site. Total numbers of taxa and individuals of each major trophic group, herbivores, predators, omnivores, from each of the 30 shrubs/site are listed.

Dataset ID: DSL2005016

Responsible investigator: John Anderson
Date range: 1999 - 1999
Abstract: Pilot study to examine feasibility of measuring individual species response to competing vegetation removal

Dataset ID: DSL2002057

Responsible investigator: John Anderson
Date range: 1997 - 2004
Abstract: Design and hypotheses. The treatments are designed to distinguish the effects of plant biomass per se from those of plant functional groups and plant species richness within functional groups. We recorded the mass of plants removed from the plots when the treatments were imposed in 1995; the total biomass removed from a plot is an index of the disturbance associated with the start of the experiment. One hypothesis is that plant biomass, rather than the species or functional group composition of the plants, is the critical regulator of ecosystem function. If so, most response variables would be highly correlated with initial biomass removed in the early seasons of the experiment. If remaining species increase in biomass over time, to the point where all treatments support... more

Dataset ID: DSL2011005

Responsible investigator: John Anderson
Date range: 1996 - ongoing
Abstract: These data are collected to provide a measurement of rainfall at the Biodiversity site. They are detailed records providing a time stamp of month/day/year hour:minute:second for each tip of the tipping bucket rain gauge (equal to 0.1 mm of precipitation).

Dataset ID: DSL2002002

Responsible investigator: John Anderson
Date range: 1996 - ongoing
Abstract: These data are collected to provide a measurement of rainfall at the Biodiversity site. They are Daily Summary data providing daily totals for those dates that precipitation occurred. Values are in millimeters (mm).

Dataset ID: DSL2002003

Responsible investigator: John Anderson
Date range: 1995 - 1995
Abstract: Sum of dry mass removed for each plant growth form from each plot of biodiversity experiment. Amount of plant material removed in initial establishment of plant diversity treatments was recorded for later use as covariate or measure of disturbance. Material was weighed in the field by species, and species-level data are available from Huenneke; however, this file summarizes plant material removed (dry mass) by growth form (shrub, subshrub, perennial grass, succulent) and by total live dry mass. Also provided are mass of dead material collected from plots (same species as live material removed for each treatment) and total dry mass, live plus dead.

Dataset ID: DSL2002058

Date range: 1986 - 1986
Abstract: *We have hypothesized that large rhizobial population densities can occur at considerable depths in woody legume systems where deep moisture also occurs. However, associated with deep soil environments are low concentrations of soil nutrients that might affect nodulation and also limit survival of free-living rhizobia. The objectives of this study were to (1) determine if results from a previous study of a mesquite woodland utilizing groundwater in the Californian Sonoran desert were generizable to mesquite systems in other deserts where root depth varied with ecosystem type and (2) examine possible relationships of soil properties and host-plant phenology to rhizobial concentrations. Data set contains analyses for SO4, sodium, calcium, manganese, sodium-absorption-ration,... more

Dataset ID: DSL2005050

Responsible investigator: John Anderson
Date range: 1986 - 1986
Abstract: Soil cores were collected under mesquite (Prosopis glandulosa) trees at playa, wash, sand dune, and grassland sites on the Jornada LTER site to depths of 15, 9, 7, and 4 m. Soil cores (to 4 m) were also taken under creosote bush (Larrea tridentata) near the wash site. Soils were extracted and analyzed for micronutrients, Zn, Cu, Fe, and Mn.

Dataset ID: DSL2005047

Responsible investigator: John Anderson
Date range: 1986 - 1986
Abstract: *We have hypothesized that large rhizobial population densities can occur at considerable depths in woody legume systems where deep moisture also occurs. However, associated with deep soil environments are low concentrations of soil nutrients that might affect nodulation and also limit survival of free-living rhizobia. The objectives of this study were to (1) determine if results from a previous study of a mesquite woodland utilizing groundwater in the Californian Sonoran desert were generizable to mesquite systems in other deserts where root depth varied with ecosystem type and (2) examine possible relationships of soil properties and host-plant phenology to rhizobial concentrations. Data set contains total nitrogen, total phosphorous,NH4-N, NO3-N, PO4-P, percent moisture,... more

Dataset ID: DSL2005049

Responsible investigator: John Anderson
Date range: 1986 - 1986
Abstract: Soil cores collected under mesquite (Prosopis glandulosa) trees at several sites and under Larrea at one site at the Jornada LTER were incubated to determine the N-mineralization potential.

Dataset ID: DSL2005048

Responsible investigator: John Anderson
Date range: 1986 - 1986
Abstract: **We addressed the question, are microarthropod assemblages present in soils throughout the rhizosphere of a deep-rooted desert plant? If microarthropods are present, what is the taxonomic and functional structure of that assemblage? The presence of a generalist microarthropod assemblage would suggest functional relationships among deep soil biota similar to the relationships documented in shallow soils. Data set consists of microarthropods and microarthropod numbers found at different soil depths associated with four mesquite ecosystems (playa, coppice dune, arroyo, and grassland).

Dataset ID: DSL2005046

Responsible investigator: John Anderson
Date range: 1987 - 1987
Abstract: 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... more

Dataset ID: DSL2004006

Responsible investigator: John Anderson
Date range: 1992 - ongoing
Abstract: This primary purpose of this data set is to validate the LTER Weather Station tipping bucket rain gauge data. The dipstick rain gauge (DSRG) data is measured at least weekly during scheduled maintenance trips to the LTER Weather Station to maintain the evaporation pan water levels. During the summer months this may be twice a week. Additionally, DSRG data is collected after any rain event that requires the collection of the Wetfall/Dryfall precipitation buckets which are located about 10 meters from the DSRG. This is usually any amount greater than 0.02". DSRG data is also collected after very small events when personnel are in the vicinity.

Dataset ID: DSL2002017

Responsible investigator: John Anderson
Date range: 1996 - 2000
Abstract: Principal questions include: How fast do key physiological functions (CO2 assimilation, stomatal conductance, leaf water status, leaf area , PS II function) recover upon soil rewetting after drought, and in what order? Details include: Does stomatal conductance follow the Ball-Berry model, gs = m A hs/Cs + b, with A = CO2 assimilation rate, hs, Cs = relative humidity and CO2 mixing ratio at the leaf surface, and m, b= empirical constants (but almost universally near 10 and 0 for well- watered plants of diverse species and biomes) Do the stomatal parameters vary systematically with leaf and soil water status? Does recovery depend systematically upon neighbor biomass, net soil water input per area (dependent upon topography of water distribution), and plant size? Conversely... more

Dataset ID: DSL2008001

Responsible investigator: John Anderson
Date range: 1983 - ongoing
Abstract: Dry atmospheric fallout (dryfall) is collected monthly using an Aerochem Metrics wetfall/dryfall collector located at the LTER weather station. Each sample is analyzed for NO3, NH4, Cl, SO4, Ca, Mg, Na, K, Total N, & Total P.

Dataset ID: DSL2002019

Responsible investigator: John Anderson
Date range: 1982 - 1992
Abstract: BACKGROUND. 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... more

Dataset ID: DSL2005021

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