Data Set

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Dataset: 

Study number: 

40

Data set ID: 

210409002

Date range: 

2007-07-25 to 2008-09-20

Original investigator: 

Heather Throop

Abstract: 

Increases in woody vegetation and declines in grasses in arid and semi-arid ecosystems have occurred globally since the 1800s, but the mechanisms driving this major land-cover change remain uncertain and controversial.

Working in a shrub-encroached grassland in the northern Chihuahuan Desert where grasses and shrubs typically differ in leaf-level nitrogen allocation, photosynthetic pathway, and root distribution, we asked if differences in leaf level ecophysiology could help explain shrub proliferation. We predicted that the relative performance of grasses and shrubs would vary with soil moisture due to the different morphological and physiological characteristics of the two life-forms. In a 2-year experiment with ambient, reduced,and enhanced precipitation during the monsoon season, respectively, the encroaching C3 shrub (honey mesquite Prosopis glandulosa) consistently and substantially outperformed the historically dominant C4 grass (black grama Bouteloua eriopoda) in terms of photosynthetic rates while also maintaining a more favorable leaf water status. This data set includes leaf water potential for each leaf measured while data on photosynthetic rates can be found in package 210409001. This study is complete. Please refer to: Throop, H., Archer, S. R. , and L. G. Reichmann. 2011. Response of dominant grass and shrub species to water manipulation: an ecophysiological basis for shrub invasion in a Chihuahuan Desert Grassland. Oecologia 169: 373-383.

Data download: 

Description: 

Data file information for the following Jornada data set: Pre-dawn water potential for leaves from 5 precipitation treatments

LTER Core Area(s): 

Dataset: 

Study number: 

40

Data set ID: 

210409001

Date range: 

2007-07-25 to 2008-09-20

Original investigator: 

Heather Throop

Abstract: 

 

Increases in woody vegetation and declines in grasses in arid and semi-arid ecosystems have occurred globally since the 1800s, but the mechanisms driving this major land-cover change remain uncertain and controversial. Working in a shrub-encroached grassland in the northern Chihuahuan Desert where grasses and shrubs typically differ in leaf-level nitrogen allocation, photosynthetic pathway, and root distribution, we asked if differences in leaf level ecophysiology could help explain shrub proliferation. We predicted that the relative performance of grasses and shrubs would vary with soil moisture due to the different morphological and physiological characteristics of the two life-forms. In a 2-year experiment with ambient, reduced,and enhanced precipitation during the monsoon season, respectively, the encroaching C3 shrub (honey mesquite Prosopis glandulosa) consistently and substantially outperformed the historically dominant C4 grass (black grama Bouteloua eriopoda) in terms of photosynthetic rates while also maintaining a more favorable leaf water status. This study is complete.

Please refer to:

Throop, H., Archer, S. R. , and L. G. Reichmann. 2011. Response of dominant grass and shrub species to water manipulation: an ecophysiological basis for shrub invasion in a Chihuahuan Desert Grassland. Oecologia 169: 373-383.

Data download: 

Description: 

Data file information for the following Jornada data set: Photosynthetic rates for leaves from 5 precipitation treatments

LTER Core Area(s): 

Dataset: 

Study number: 

384

Data set ID: 

210384001

Date range: 

2000-03-24 to 2000-08-29

Original investigator: 

Debra Peters

Data contact: 

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 full length of all segments. 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 data set using a "species" code of BURN. 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.

Description: 

Data file information for the following Jornada data set: Arson burn on LTER-I Transect plant line intercepts - field data (tape format)

LTER Core Area(s): 

Dataset: 

Study number: 

384

Data set ID: 

210384002

Date range: 

2000-02-27 to 2000-05-26

Original investigator: 

Debra Peters

Data contact: 

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 data set using a "species" code of BURN. Average percent coverage of each plant species per 5-meter segment along a 30-meter line intercept perpendicular to each of 91 stations on each of the three LTER-I permanent transects. Data consists of week number, transect, station number, species, carbon reduction pathway, habit, form, and average percent cover. It is sorted by transect, station number, then plant species. 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. Following January 1, 1987, spring line- intercepts will only record cover of annual species. All perennial cover data will be limited to fall samples. Both annuals and perennials are measured during the fall. Measurements were made biannually from 1982 - 1988. After this they are measured every 5 years. Annuals are measured through 1998; however, after this only perennials are measured and only in the fall. 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 full length of all segments. 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.

Data download: 

Description: 

Data file information for the following Jornada data set: Arson burn on LTER-I transect plant line intercepts - LT series (percent cover)

LTER Core Area(s): 

Dataset: 

Study number: 

381

Data set ID: 

210381004

Date range: 

1995-06-01 to 1996-07-31

Original investigator: 

William H Schlesinger

Data contact: 

Abstract: 

This data set was collected to provide data for comparison of the losses of dissolved nitrogen and phosphorus in the runoff from grass- and shrub- dominated plots in the Jornada Basin of southern New Mexico. This summary dataset contains the following columns for the shrub plots: Plot: the identification number for the 6 grassland plots.

Q: the mean rate of discharge during the entire experiment, obtained by dividing the total runoff by l800 sec. The units are cubic centimeters per second. Total N yield: the total yield of dissolved nitrogen discharged from the plot during the duration of the experiment. The units are grams per square meter per l800 sec. This yield has been adjusted, by subtracting the content of total dissolved N applied in the simulated rainfall. Organic N yield: the yield of dissolved organic N, as above. Inorganic N yield: the yield of NH4-N plus NO3-N discharged from the plot during the duration of the experiment, as above. Total P yield: the yield of total dissolved P discharged from the plot during the duration of the experiment. The units are grams per square meter, per l800 sec. Organic P yield: the yield of dissolved organic P, as above. Inorganic P yield: the yield of PO4-P discharged from the plot during the duration of the experiment. Fines: the percent of the plot surface covered by materials < 2.0 mm diameter Gravel: the percent of the plot surface covered by materials > 2.0 mm diameter Vegetation: the percent of the plot surface covered by vegetation. Litter: the percent of the plot surface covered by plant litter. Slope: it was not possible to measure slope in plots with a shrub in them, since the mound dominated the slope in the plot.

Description: 

Data file information for the following Jornada data set: Nutrient losses in runoff from grassland and shrubland habitats in southern New Mexico: I.

Rainfall simulation experiments --SUMMARY of SHRUB nitrogen and phosphorus chemistry

LTER Core Area(s): 

Dataset: 

Study number: 

381

Data set ID: 

210381003

Date range: 

1995-06-01 to 1996-07-31

Original investigator: 

William H Schlesinger

Data contact: 

Abstract: 

This data set was collected to provide data for comparison of the losses of dissolved nitrogen and phosphorus in the runoff from grass- and shrub- dominated plots in the Jornada Basin of southern New Mexico. This summary dataset contains the following columns for the intershrub plots: Plot: the identification number for the 6 grassland plots.

Q: the mean rate of discharge during the entire experiment, obtained by dividing the total runoff by l800 sec. The units are cubic centimeters per second. Total N yield: the total yield of dissolved nitrogen discharged from the plot during the duration of the experiment. The units are grams per square meter per l800 sec. This yield has been adjusted, by subtracting the content of total dissolved N applied in the simulated rainfall. Organic N yield: the yield of dissolved organic N, as above. Inorganic N yield: the yield of NH4-N plus NO3-N discharged from the plot during the duration of the experiment, as above. Total P yield: the yield of total dissolved P discharged from the plot during the duration of the experiment. The units are grams per square meter, per l800 sec. Organic P yield: the yield of dissolved organic P, as above. Inorganic P yield: the yield of PO4-P discharged from the plot during the duration of the experiment. Fines: the percent of the plot surface covered by materials < 2.0 mm diameter Gravel: the percent of the plot surface covered by materials > 2.0 mm diameter Vegetation: the percent of the plot surface covered by vegetation. Litter: the percent of the plot surface covered by plant litter. Slope: the plot in degrees

Description: 

Data file information for the following Jornada data set: Nutrient losses in runoff from grassland and shrubland habitats in southern New Mexico: I.

Rainfall simulation experiments --SUMMARY of INTERSHRUB nitrogen and phosphorus chemistry

LTER Core Area(s): 

Dataset: 

Study number: 

381

Data set ID: 

210381002

Date range: 

1995-06-01 to 1996-07-31

Original investigator: 

William H Schlesinger

Data contact: 

Abstract: 

This data set was collected to provide data for comparison of the losses of dissolved nitrogen and phosphorus in the runoff from grass- and shrub- dominated plots in the Jornada Basin of southern New Mexico. This summary dataset contains the following columns for the grassland plots: Plot: the identification number for the 6 grassland plots.

Q: the mean rate of discharge during the entire experiment, obtained by dividing the total runoff by l800 sec. The units are cubic centimeters per second. Total N yield: the total yield of dissolved nitrogen discharged from the plot during the duration of the experiment. The units are grams per square meter per l800 sec. This yield has been adjusted, by subtracting the content of total dissolved N applied in the simulated rainfall. Organic N yield: the yield of dissolved organic N, as above. Inorganic N yield: the yield of NH4-N plus NO3-N discharged from the plot during the duration of the experiment, as above. Total P yield: the yield of total dissolved P discharged from the plot during the duration of the experiment. The units are grams per square meter, per l800 sec. Organic P yield: the yield of dissolved organic P, as above. Inorganic P yield: the yield of PO4-P discharged from the plot during the duration of the experiment. Fines: the percent of the plot surface covered by materials < 2.0 mm diameter Gravel: the percent of the plot surface covered by materials > 2.0 mm diameter Vegetation: the percent of the plot surface covered by vegetation. Litter: the percent of the plot surface covered by plant litter. Slope: the plot in degrees

Description: 

Data file information for the following Jornada data set: Nutrient losses in runoff from grassland and shrubland habitats in southern New Mexico: I.

Rainfall simulation experiments --SUMMARY of GRASSLAND nitrogen and phosphorus chemistry

LTER Core Area(s): 

Dataset: 

Study number: 

381

Data set ID: 

210381001

Date range: 

1995-06-01 to 1996-07-31

Original investigator: 

William H Schlesinger

Data contact: 

Abstract: 

This data set was collected to provide data for comparison of the losses of dissolved nitrogen and phosphorus in the runoff from grass- and shrub- dominated plots in the Jornada Basin of southern New Mexico. This dataset contains the following columns: Plot: the identification number for the plots, which are grouped for grass, shrub or intershrub areas.

Fill Time: the time in seconds used to collect an individual sample of discharge from the plot. Time: the time in minutes (from the beginning of the rainfall simulation) at which each individual collection of discharge began. In each case, the first time listed is the time at which discharge was first observed. Time b/w samples: the time in seconds between the beginning the collection of a given sample of discharge and the beginning of the next collection. Q: the rate of discharge during each collection, in cubic centimeters per second. AveQ/time: the total discharge during an interval in cubic centimeters. For example, the discharge between 16 and 20 minutes is calculated as the mean of the discharge at l6 and 20 minutes multiplied by 4 minutes. InorgN-rain (adjusted inorganic N): the concentration of NH4-N + NO3-N in the discharge sample collected, corrected for the sum of the concentration of these ions in the simulated rainfall applied. Concentration is given in milligrams per liter for N contained in the sum of these forms. Analysis for NH4-N and NO3-N was performed using the Bran-Luebbe Traacs 800 Autoanalyzer, as detailed in Schlesinger et al. (l999). Total N-rain (adjusted total N): the concentration of total dissolved N in the discharge sample collected, corrected for the concentration of total dissolved N in the simulated rainfall applied. Concentration is given in milligrams per liter of total dissolved N in the sample. The concentration of total dissolved N was performed using the Traacs 800 Autoanalyzer, following a persulfate digestion of the sample, as detailed in Schlesinger et al. (l999). OrgN-rain (adjusted organic N): the concentration of N contained in dissolved organic forms, corrected for the concentration of dissolved organic N in the simulated rainfall applied. Dissolved organic N is calculated as the difference, in any sample, between the total dissolved N and the sum of NH4-N and NO3-N. Values are in milligrams per liter. Total P-rain (adjusted total P): the concentration of total dissolved phosphorus, corrected for the concentration of total dissolved phosphorus in the simulated rainfall applied, both in milligrams per liter. Org-P-rain (adjusted org P): the concentration of dissolved organic phosphorus, corrected for the concentration of dissolved organic phosphorus in the simulated rainfall applied, both in milligrams per liter. Inorg-N-rain (adjusted inorganic N), the yield in grams of NH4-N plus NO3-N in the discharge collected. TotalN-rain (adjusted total N), the yield in grams of total dissolved N in the discharge collected. OrgN-rain (adjusted organic N), the yield in grams of forms of dissolved organic N in the discharge collected. Total P-rain (adjusted total P), the yield in grams of total dissolved phosphorus in the discharge collected. OrgP-rain (adjusted organic P), the yield in grams of forms of dissolved organic phosphorus in the discharge collected. InorgN-rain (adjusted inorganic N) load, is the rate of loss, in grams per second, of the sum of NH4-N plus NO3-N during the period of the sample collection. Total N-rain (adjusted total N) load, is the rate of loss, in grams per second, of total dissolved N during the period of the sample collection. OrgN-rain (adjusted organic N) load, is the rate of loss, in grams per second, of dissolved organic N during the period of the sample collection. Total P-rain (adjusted total P) load, is the rate of loss, in grams per second, of total dissolved P during the period of the sample collection. Org-P-rain (adjusted organic P) load, is the rate of loss, in grams per second, of dissolved organic P during the period of the sample collection.

Data download: 

Description: 

Data file information for the following Jornada data set: Nutrient losses in runoff from grassland and shrubland habitats in southern New Mexico: I.

Rainfall simulation experiments --Nitrogen and phosphorus chemistry

LTER Core Area(s): 

Dataset: 

Study number: 

39

Data set ID: 

210392001

Date range: 

1939-01-01 to 2001-12-31

Original investigator: 

Ken A Valentine

Abstract: 

The purpose of this study is to quantify vegetation dynamics in response to lagomorph and shrub exclusion. Data consist of vertical line intercept measures of the perennial grasses, suffretescents and shrubs. Sixteen plots at each of 3 sites (Gravelly Ridges, Dona Ana exclosure, and Parker Tank) were established in 1938-39 by Ken Valentine.

Plots were 21.3 x 21.3 m in 4 rows of 4 plots with a 7.6 m buffer zone. All plots were sampled before treatments. Plots were divided into east and west halves and 14 randomly located 10.65 m transects were located in each half plot. Vegetation (black grama, dropseeds, bush muhly, fluff grass, other grasses, creosotebush, honey mesquite, tarbush, mariola, and other shrubs) was measured using vertical line point intercepts. Plots have been re-read in 1947, 1956, 1960, 1967, 1989, 1995, and 2001 for Gravelly Ridges and 1939, 1947, 1960, 1967, and 2001 for Dona Ana and Parker Tank using the same methods. Treatments were applied factorially yielding a control plot, single factor plots, and plots with varying degrees of combinations of factors. The factors were lagomorph exclusion (using wire fencing), shrub removal (hand grubbing at the ground surface), furrowing (shallow, hand raked furrows to trap surface water), and seeding (broadcast applications of seeds of native perennials). Seeding and furrowing treatments were only applied in 1939. Lagomorph exclusion has persisted since establishment, and shrub removal treatments have been reapplied immediately following all years of vegetation sampling. This study is complete.

For more information, refer to:

Havstad, K.M., R.P. Gibbens, C.A. Knorr, and L.W. Murray. 1999. Long-term influences of shrub removal and lagomorph exclusion on Chihuhuan Desert vegetation dynamics. Journal of Arid Environments 42: 155-166.

 

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Description: 

<p>Data file information for the following Jornada data set: Line intercept data of long-term vegetation responses to shrub removal and lagomorph exclusion in a creosotebush community</p&g

t;

LTER Core Area(s): 

Dataset: 

Study number: 

28

Data set ID: 

210288001

Date range: 

1998-03-14 to 2015-11-25

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.

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Description: 

LTER Core Area(s): 

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