Soil

Soil dataset or project

Dataset: 

Study number: 

228

Data set ID: 

210228001

Date range: 

2008-03-24 to 2013-05-23

Original investigator: 

Dale A Gillette

Data contact: 

Abstract: 

Dataset consists of horizontal dust flux at multiple heights from BSNE dust collectors located in treatment plots (different percent vegetation removed) and adjacent downwind effect plots. Year 2008 was an annual collection. Collection in subsequent years occurred before and after the wind season. The experiment was designed to test the effects of increasing wind erosion on soil and vegetation properties at the Jornada.  In order to increase wind erosion rates, vegetation was removed to increase bare surface area and stimulate erosion (the less vegetation present the greater the wind erosion).  The basic experimental design includes three treatment blocks.  Each block has four treatment plots with different level of vegetation removed (25-100%) and a control treatment.  Treatment plots are 25x50m with 25m buffers between.  The vegetation removal includes grasses and small shrubs (like XASA and ZIGR), but not mesquite or yucca or any of the larger shrubs).  Also, adjacent downwind plots are included in the design.  These plots are strictly for monitoring of soil and vegetation properties, so no maintenance is required on these areas.

Project: 

Study Number: 301

Project ID: 

210301000

Original Investigator: 

Greg Okin

Abstract: 

In a large-scale grass removal experiment (NEAT), we identified several important thresholds that impact the conversion of grasslands to shrublands.

Between 75%-100% grass loss, aeolian transport increases dramatically, but carbon and nitrogen in windborne sediment display another threshold between 50%-75% grass loss (Li et al. 2007). With lower grass cover, nutrient additions to the soil are overwhelmed by aeolian emissions, resulting in a net loss of soil nutrients (Li et al. 2008). The sediment that is deposited downwind of the vegetation is both coarser (Li et al. 2009b) and lower in nitrogen (Li et al. 2009a) than the source sediment. Increased aeolian sediment flux downwind decreases grass cover and increases shrub cover (Alvarez et al. 2011). Wet years increased competition among grasses and decreased competition between grasses and shrubs (Alvarez et al. 2012). These data were used to develop and validate a model of aeolian sediment flux (Okin et al. 2006, Okin 2008).

     Hypothesis: As bare gap sizes increase, a connectivity threshold level is reached that sets the stage for nonlinear increases in the spatial extent of shrub dominance owing to negative effects on grass persistence [1(a)] and positive feedbacks to shrub establishment and growth. This hypothesis will be tested on plots established in 2004 in the NEAT where 0, 50, 75, or 100% of original herbaceous cover was removed (and maintained thereafter) from 25 x 50 m plots in each of three blocks (Li et al. 2007). These removals generated varying levels of grass fragmentation with consequent effects on shrub expansion and grass loss in contiguous downwind plots that have been qualitatively observed (Alvarez et al. 2012). We propose to quantify (a) downwind effects at different fetch lengths, (b) vegetation feedbacks on gap size and aeolian transport, and (c) effects of interactions between climate and dust flux on plant mortality through time. We will continue to monitor aeolian sediment flux, vegetation composition (line-point intercept and gap-size distribution; Herrick et al. 2005), individual plants (sensu Alvarez et al. 2011), and soil C and N (sensu Li et al. 2008) and will relate dynamics in these variables to precipitation. Results will be analyzed by ANCOVA with flux, bare gap size, or herbaceous cover as continuous variables. We will also use the wind and vegetation dynamics components of our ENSEMBLE model to identify threshold effects of grass cover on connectivity by wind for different amounts of precipitation, and to determine feedbacks to shrub establishment and growth via changes in the deposition or erosion of soil and nutrients.

Funding Source: 

NSF

Research Area: 

Data Category: 

Dataset: 

Study number: 

338

Data set ID: 

210338004

Date range: 

2010-06-06 to 2011-09-30

Original investigator: 

Ryan Templeton

Dataset: 

Study number: 

122

Data set ID: 

210122001

Date range: 

1995-09-01 to 2011-12-31

Original investigator: 

Dale A Gillette

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.

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 download: 

Dataset: 

Study number: 

27

Data set ID: 

2100278001

Date range: 

2007-07-24 to 2009-08-10

Original investigator: 

Lara G Reichmann

Data contact: 

Abstract: 

Volumetric soil water is used to measure the effectiveness of the water manipulation treatments. Soil water content is monitored at 2 depths (5-10, 30-50 cm) using ECH2OTM moisture probes connected to an ECH2O check handheld.

Volumetric soil water is used to measure the effectiveness of the water manipulation treatments. Soil water content is monitored at 2 depths (5-10, 30-50 cm) using ECH2OTM moisture probes connected to an ECH2O check handheld.

Data download: 

Dataset: 

Study number: 

36

Data set ID: 

2100365001

Date range: 

1933-01-01 to 2011-12-31

Original investigator: 

Robert S Campbell

Abstract: 

In 1933 and 1935, two transects were established in the Natural Revegetation Exclosure and Pasture 8b, respectively, to measure long-term soil movement in areas undergoing mesquite invasion.

These two transects, established in a Prosopis-Bouteloua ecotone, were to: "measure any future changes in the extent or succession of three contiguous zones of vegetation, Bouteloua eriopoda, Gutierrezia, and Prosopis glandulosa dunes. Thus, future chartings of this transect should show whether, under the range management practiced, the succession is progressing toward the black grama climax or whether it is retrogressing toward mesquite sandhills." (E.L. Little, 1935, unpublished report) Soil movement at these transects was measured by the distance between the soil surface and a notch in 50 cm t-posts located every 15.2 m (50 ft). The 1731-m Natural Revegetation Exclosure tranect runs north-south through the center of the exclosure and extends 61 m (200ft) beyond the boundary fence on either end. It is located in primarily deep, loamy sand soils. The 457-m Pasture 8b transect is oriented WSW-ENE, and is located in shallower soils. These transects were measured in 1950 (8b only), 1955 (8b only), every five years from 1980-2000, and most recently in 2011. Most steel posts were remeasured at these intervals, but some were lost due to excavation or burial. These were for the most part replaced, with a new baseline notch height initiated on the posts. Data fields correspond to each year of collection, as well as measures of soil deposition or deflation during the intervals. Spatial data include post locations and identifiers.

Project: 

Study Number: 365

Project ID: 

210365000

Original Investigator: 

Robert Gibbens

Abstract: 

In 1933 and 1935, two transects were established in the Natural Revegetation Exclosure and Pasture 8b, respectively, to measure long-term soil movement in areas undergoing mesquite invasion.

These two transects, established in a Prosopis-Bouteloua ecotone, were to: "measure any future changes in the extent or succession of three contiguous zones of vegetation, Bouteloua eriopoda, Gutierrezia, and Prosopis glandulosa dunes. Thus, future chartings of this transect should show whether, under the range management practiced, the succession is progressing toward the black grama climax or whether it is retrogressing toward mesquite sandhills." (E.L. Little, 1935, unpublished report) Soil movement at these transects was measured by the distance between the soil surface and a notch in 50 cm t-posts located every 15.2 m (50 ft). The 1731-m Natural Revegetation Exclosure tranect runs north-south through the center of the exclosure and extends 61 m (200ft) beyond the boundary fence on either end. It is located in primarily deep, loamy sand soils. The 457-m Pasture 8b transect is oriented ESE-WNW, and is located in shallower soils. These transects were measured in 1950 (8b only), 1955 (8b only), every five years from 1980-2000, and most recently in 2011.

Funding Source: 

N/A

Research Area: 

Data Category: 

Dataset: 

Study number: 

28

Data set ID: 

2100288001

Date range: 

1998-03-14 to 2015-05-28

Original investigator: 

Dale A Gillette

Data contact: 

Abstract: 

Collections of airborne sand are obtained at the 15 NPP sites and the Geomet site. The collections are taken using BSNE collectors. The collectors are turned into the wind with wind vanes. The amount of material collected corresponds to the horizontal flux at the height of the collector and the opening area of the collector and the duration of the sampling time.

The five heights of the BSNE collectors above the soil surface are 5, 10, 20, 50, and 100 centimeters for every location where samples are taken. The hypothesis of the experiment is that the vertical flux of the particles smaller than 10 micrometers is a constant ratio of the horizontal sand flux. The objectives of the experiment are to find patterns of sand flux rates as affected by soil and vegetation.

Data download: 

Project: 

Study Number: 288

Project ID: 

210288000

Original Investigator: 

Dale A Gillette

Abstract: 

Collections of airborne sand are obtained at 16 locations at the Jornada LTER area, the 15 NPP sites and the Geomet site. The collections are taken using BSNE collectors.

The collectors are turned into the wind with wind vanes. The amount of material collected corresponds to the horizontalflux at the height of the collector and the opening area of the collector and the duration of the sampling time. The five heights of the BSNE collectors are 5, 10, 20, 50, and 100 centimeters for every location where samples are taken. The collected amounts are fitted to a function m(z) = a exp(bz +czz) where m(z) is the mass of sand collected, z is height above ground, and a, b, and c are constants. The hypothesis of the experiment is that the vertical flux of the particles smaller than 10 micrometers is a constant ratio of the horizontal sand flux. The objectives of the experiment are to find patterns of sand flux rates as affected by soil and vegetation.

Funding Source: 

LTER III, IV, V

Research Area: 

Data Category: 

Project: 

Study Number: 122

Project ID: 

210122000

Original Investigator: 

Dale A Gillette

Abstract: 

The project was designed to test the hypothesis that the abrasion of a surface crust is proportional to the vertical flux of kinetic energy delivered by saltating sand grains.

This flux energy is related to the mass flux of saltating grains. The site was selected since it had a flat crust that was not greatly effected by atmospheric precipitation or freeze/ thaw and moistening/drying cycles. The objective of the project was to measure the kinetic energy flux during saltation, the mass flux of saltation particles and to relate those fluxes to the abrasion of the crust. Abrasion of the crust is measured monthly, sand mass flux samples are collected approximately every two weeks, and sand motion and wind speeds at four heights are measured every 20 minutes during wind erosion episodes at three towers placed parallel to the prevailing direction of wind erosion.

Funding Source: 

Jornada LTER III

Research Area: 

Data Category: 

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