LTER

U.S. Long-Term Ecological Research Network (https://www.lternet.edu)

Dataset: 

Study number: 

8

Data set ID: 

210008001

Date range: 

1996-02-16 to 2001-08-17

Original investigator: 

David Lightfoot

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 hypothesized to be related to the NPP of the sites.  Data for arthropods captured in pitfall traps on LTER III consumer plots at 2 month intervals. Data includes order, family, genus, species, and number. This data collection has been completed.

Data download: 

Description: 

Data file information for the following Jornada data set: Arthropod Pitfall Traps-III in 5x1 grid at LTER II NPP sites

LTER Core Area(s): 

Dataset: 

Study number: 

27

Data set ID: 

210278002

Date range: 

2006-10-01 to 2008-09-30

Original investigator: 

Lara G Reichmann

Data contact: 

Abstract: 

A 2-year experiment with ambient, reduced, and enhanced precipitation as well as nitrogen additions 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.
A 2-year experiment with ambient, reduced, and enhanced precipitation as well as nitrogen additions 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.We use vegetation cover as a proxy for plant biomass to avoid confounding spatial and temporal variability or confounding the impact of harvesting.  Individual cover of plant species was measured  using three parallel transects per plot. This study is complete.

Data download: 

Description: 

Data file information for the following Jornada data set: Plant cover in precipitation and nitrogen treatment plots (by species)

LTER Core Area(s): 

Dataset: 

Study number: 

412

Data set ID: 

210412001

Date range: 

1916-01-01 to 2001-12-31

Original investigator: 

Kris Havstad

Abstract: 

Stocking rates for cattle, horses, and sheep are provided for the Jornada Experimental Range beginning in 1916. Goats were few and are included as part of the sheep category and not differentiated.

Stocking rates for cattle, horses, and sheep are provided for the Jornada Experimental Range beginning in 1916. Goats were few and are included as part of the sheep category and not differentiated.

Description: 

Data file information for the following Jornada data set: Jornada Experimental Range stocking rates for cattle, horses, and sheep beginning 1916

LTER Core Area(s): 

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): 

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