LTAR

USDA-ARS Long-Term Agroecosystem Research Network (https://www.tucson.ars.ag.gov/ltar)

Dataset: 

Study number: 

338

Data set ID: 

210338004

Data sources: 

data_Jornada_338004_tromble_weir_soil_moisture

LTER Core Area(s): 

Dataset: 

Study number: 

338

Data set ID: 

210338002

Abstract: 

Precipitation at 1 minute intervals for rain gauges 2-5 with R1 excluded due to periods of interruption.  Spatially averaged rainfall over the watershed is calculated in this dataset based on relative coverage of each rain gauge determined from a Theissen polygon map.

Data sources: 

data_Jornada_338002_tromble_weir_precipitation

LTER Core Area(s): 

Keywords: 

Dataset: 

Study number: 

338

Data set ID: 

210338001

Abstract: 

This files presents all of the flux data post-EdiRe processing at 30 minute resolution.  Included in this file is: Ux = Mean wind speed in the x-direction, Uy = mean wind speed in the y-direction, Uz = mean wind speed in the z-direction, Co2 = CO2 atmospheric concentrations, H2O = Water atmospheric concentrations, Press = barometric pressure, Air Temp = atmospheric temperature, wind speed = mean wind speed towards 216 degrees from north, H Flux = sensible heat flux, LE Flux = latent heat flux, C Flux = carbon flux.

Data sources: 

data_Jornada_338001_tromble_weir_flux

LTER Core Area(s): 

Dataset: 

Study number: 

122

Data set ID: 

210122001

Abstract: 

Distance of crust surface to a crossbar set into the soil. Three "torvane" measurements that measure the torque needed to break the crust is also recorded. These measurements are made monthly near each of three monitoring towers (East, Middle, West) on the Scrape Site.

Data sources: 

data_Jornada_122001_crust_evolution_scrape_site_abrasion

LTER Core Area(s): 

Dataset: 

Study number: 

27

Data set ID: 

210278001

Abstract: 

A 2-year experiment with ambient, reduced, and enhanced precipitation was designed to compare the performance of the  encroaching C3 shrub (honey mesquite Prosopis glandulosa) to the dominant C4 grass (black grama Bouteloua eriopoda) in terms of photosynthetic rates and leaf water status. Precipitation manipulations dramatically enhanced natural variability and generated a range of rainfall scenarios that could have only been studied only after a multi-decade effort using natural conditions. Responses were highly asymmetric, with precipitation (PPT) additions generally influencing volumetric water content (vwc) to a greater extent than PPT reductions. Desert soils are usually close to their minimum water content  and thus when soils were dry, the effects of reducing PPT were relatively minor compared to the effects of adding PPT. Volumetric soil water content was, on average, lower and more variable at the shallower (0–5 cm) depth (mean 9.3 ± 0.14%; range 5.7–14.3%) than at the deeper (30–50 cm) depth (mean 14.4 ± 0.12%; range 10.8–18.1%. This study is complete. For further information and results, see:

Throop, H., L. G. Reichmann, Os. Sala, and S. Archer. 2012.  Response of dominant grass and shrub species to water manipulation: an ecophysical basis for shrub invasion in a Chihuahuan desert grassland. Oecologia 169: 373-383.

 

 

 

Data sources: 

JornadaStudy_278_changes_in_npp_water_availability_soil_water_content_data

LTER Core Area(s): 

Dataset: 

Study number: 

120

Data set ID: 

210120002

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 of component landforms from the foot of the mountain to the basin floor. This provided the opportunity to investigate the response of vegetation with respect to landscape characteristics as well as release from grazing. This summary data set consists of percent cover of 9 species from the plant line intercept measurements on either side of the LTER-I exclosure East and West boundary fence. Data is sorted by station, species i.d., then line segment. Along the East Boundary fence, the east side is ungrazed (control) and the west side is grazed (treatment). Along the West Boundary fence, the east side is grazed and the west side is ungrazed. Each plant line transect is divided into 6 5-meter segments. All perennials were measured at about 5 year intervals as the length of intercept along a 30-meter line perpendicular to the fence. Summary data includes only four of the 6 5-meter intervals due to disturbance along fenceline. Data from the 5-meter segment on either side of the fence was not included in summarizing the data. Summary data includes only 9 of the perennial species.

Data sources: 

data_JRN_120002_fence_plant_line_intercept_percent_cover_1982_92

LTER Core Area(s): 

Dataset: 

Study number: 

351

Data set ID: 

210351002

Abstract: 

The data set, along with other long-term data collected at multiple spatial scales, is being used to identify the landscape, climatic, and anthropogenic factors that influence grass abundance, growth, and persistence. Variable measured is plant density by species.

Data sources: 

JornadaStudy_351_permanent_chart_quadrat_perennial_forb_density_data

LTER Core Area(s): 

Dataset: 

Study number: 

351

Data set ID: 

210351001

Abstract: 

The data set, along with other long-term data collected at multiple spatial scales, is being used to identify the landscape, climatic, and anthropogenic factors that influence grass abundance, growth, and persistence. Variables measured are basal area of grasses, canopy area of shrubs, and perimeters of both.

Data sources: 

JornadaStudy_351_permanent_chart_quadrat_perennial_forb_density_data

LTER Core Area(s): 

Keywords: 

Dataset: 

Study number: 

16

Data set ID: 

210169002

Abstract: 

Wet atmospheric fallout (wetfall occurring as precipitation) 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.

Data sources: 

data_JornadaStudy_169_npp_atmospheric_deposition_adc_dust_collector_wetfall

LTER Core Area(s): 

Dataset: 

Study number: 

425

Data set ID: 

210425001

Abstract: 

Estimated daily precipitation is calculated for each of 15 aboveground net primary productivity (ANPP) sites located in the 5 dominant vegetation zones on the Jornada Basin. The 15 sites were formally established in 1989 as LTER Study 268, but these rainfall estimates begin in 1980 using the closest rain gauge that provides a minimum resolution of daily precipitation data. The Methodology section describes this in detail. The rain gauges are detailed inthe file raingauge_picks.csv.

Data sources: 

Jornada_425001_npp_estimated_precipitation_data

LTER Core Area(s): 

Keywords: 

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