Populations

LTER Core Area: Populations

Dataset: 

Study number: 

262

Data set ID: 

210262001

Date range: 

2008-04-21 to 2014-10-30

Original investigator: 

Brandon Bestelmeyer

Data contact: 

Abstract: 

   Dataset consists of plant measurements used to calculate the annual aboveground net 
   primary production (ANPP) across 3 habitats grouped by plant form and total ANPP.  
   The habitats are grassland, mesquite shrubland, and the ecotone between the 2. The 
   plant forms are winter annual forb, annual forb, bi-annual forb, perennial forb, 

   Dataset consists of plant measurements used to calculate the annual aboveground net 
   primary production (ANPP) across 3 habitats grouped by plant form and total ANPP.  
   The habitats are grassland, mesquite shrubland, and the ecotone between the 2. The 
   plant forms are winter annual forb, annual forb, bi-annual forb, perennial forb, 
   annual grass, perennial grass, shrub, and sub-shrub.

   OBJECTIVE:  The purpose of the study is to investigate how pulses of precipitation
   translate into pulses of plant aboveground net primary productivity (NPP) and how the
   small mammal community responds to such changes also in relation to shrub gradient
   across the landscape.  Particularly we are interested in how the energy flows through
   the ecosystem in response to pulses of rain, how the small mammal community partition
   resources (in terms of C3 (forbs and shrubs) and C4 (grasses) plants) and how the
   genetic structure of some species (e.g., Dipodomys spp.) is affected by their
   population dynamics.

   HYPOTHESES:

   1) Small mammal abundance should respond positively to precipitation and NPP.

   2) On a temporal scale, the small mammal energy use should show parallel fluxes along
   the shrub gradient.

   3) The small mammal community should consume C3 and C4 plants according to their
   availability (or NPP).

   4) At low population density, dispersal should be limited and the genetic variance will
   be distributed among populations rather than within (i.e., Fst will trend towards
   higher values).  After pulses of rain and NPP, population densities will be greater,
   dispersal prevalent, and the genetic variance of populations will be distributed within
   populations (i.e., Fst will approach zero) as dispersal homogenizes populations.

   Total aboveground annual net primary productivty is calculated for winter annual forb,
   annual forb, bi-annual forb, perennial forb, annual grass, perennial grass, shrub,
   sub-shrub, and the total of these.
 

Data download: 

Description: 

Data file (CSV) for Jornada dataset: Ecotone Study: Quadrat Plant Measurement Data

Data file (CSV) for Jornada dataset: Ecotone Study: Quadrat Plant Measurement Data

Keywords: 

Dataset: 

Study number: 

461

Data set ID: 

210461001

Date range: 

1996-02-27 to 2009-10-27

Original investigator: 

Kris Havstad

Abstract: 

The goal of this sampling effort is to describe the vegetation response to treatments.  Data were collected following the line-point intercept method (Herrick et al.

2009).  Although the original LPI data set was in multivariate form with separate columns for canopy layers and soil surface, this data set has been transposed into vertical form, implementing a “layer” variable, so that all species and soil surface codes appear in one column.  Within each exclosure, 4837 points were sampled with the following exceptions:

year

exclosure

total_points_sampled

1996

5

4825

1996

7

4836

1996

9

4836

1996

10

4836

1997

1

4830

1997

2

4830

1997

3

4830

1997

4

4830

1997

5

4830

1997

6

4830

1997

7

4830

1997

8

4830

1997

9

4830

1997

10

4830

1997

11

4830

1997

12

4830

1997

13

4830

1997

14

4830

1997

15

4830

1997

16

4830

1997

17

4830

1997

18

4830

2002

12

4835

 

Data download: 

Description: 

Dataset: 

Study number: 

308

Data set ID: 

210308002

Date range: 

2008-06-10 to 2012-06-28

Original investigator: 

Debra Peters

Data contact: 

Abstract: 

    Line-Point Intercept data are collected annually for this project beginning in 2008. No data were
    collected in 2011. There are 4 pairs of plots consisting of control and treatment. Each plot is
    8x8 meters with an 8x8 meter buffer plot above and below it. Treatment plots have connectivity modules
    Line-Point Intercept data are collected annually for this project beginning in 2008. No data were
    collected in 2011. There are 4 pairs of plots consisting of control and treatment. Each plot is
    8x8 meters with an 8x8 meter buffer plot above and below it. Treatment plots have connectivity modules
    (conmods) installed to decrease gap size between perennials.  Buffer plots do not have conmods.
    Four 24-meter transects run through the plot and 2 buffer plots. These transects are spaced
    0.8, 2.8, 4.3, and 7.2 meters across the plots (denoted as 1, 3, 5, and 7 meters in the database),
    paralleling the long axis of the combined buffer plots and central plot.
         Aeolian site:         Control plots 2,4,5,8  Treatment plots 1,3,6,7
         Dona Ana site:        Control plots 2,4,5,7  Treatment plots 1,3,6,8
         Gravelly Ridges site: Control plots 1,3,5,7  Treatment plots 2,4,6,8
 

Data download: 

Description: 

Data file (CSV) for Jornada dataset: Conmod Pilot Study:  Annual vegetation transect Line Point Intercept measurements

Data file (CSV) for Jornada dataset: Conmod Pilot Study:  Annual vegetation transect Line Point Intercept measurements

Keywords: 

Dataset: 

Study number: 

308

Data set ID: 

210308001

Date range: 

2008-06-10 to 2012-06-28

Original investigator: 

Debra Peters

Data contact: 

Abstract: 

Canopy Gap and Basal Gap Intercept data are collected annually for this project beginning in 2008. No data were collected in 2011. There are 4 pairs of plots consisting of control and treatment. Each plot is 8x8 meters with an 8x8 meter buffer plot above and below it. Treatment plots have connectivity modules (conmods) installed to decrease gap size between perennials.
Buffer plots do not have conmods. Four 24-meter transects run through the plot and 2 buffer plots. These transects are spaced 0.8, 2.8, 4.3, and 7.2 meters across the plots (denoted as 1, 3, 5, and 7 meters in the database), paralleling the long axis of the combined buffer plots and central plot.
Aeolian site:                Control plots 2,4,5,8  Treatment plots 1,3,6,7
Dona Ana site:            Control plots 2,4,5,7  Treatment plots 1,3,6,8
Gravelly Ridges site:  Control plots 1,3,5,7  Treatment plots 2,4,6,8

Data download: 

Description: 

Data file (CSV) for the Jornada dataset: Conmod Pilot Study:  Annual plant canopy gap and basal gap intercept data

Data file (CSV) for the Jornada dataset: Conmod Pilot Study:  Annual plant canopy gap and basal gap intercept data

Keywords: 

Dataset: 

Study number: 

120

Data set ID: 

210120001

Date range: 

1986-09-24 to 2015-12-01

Original investigator: 

Walter G Whitford

Data contact: 

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 all perennial plant species from the plant line intercept measurements on either side of the LTER-I exclosure East and West boundary fence. Data is sorted by treatment (grazed, ungrazed), year, fence line, station, then species i.d. Along the East Boundary fence line, the east side is ungrazed (control) and the west side is grazed (treatment). Along the West Boundary fence line, 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 for each species along a 30-meter line oriented perpendicular to the fence. Summary data presented in this data set is the average percent cover for the outer-most 2 5-meter segments for the respective treatment (grazed or ungrazed). The term outer-most is relative to the fence. The 5-meter segment on either side of the fence is not included in the cover estimates due to fence line effect disturbances; e.g., cattle trails, tumbleweeds trapped along fence, etc. This summary data does not include the first year of measurement in 1982 because of numerous problems with species codes used that could not resolved.

Data download: 

Description: 

Data file information for the following Jornada data set: East and west boundary fence plant line intercepts - percent cover for all species beginning 1986

Data file information for the following Jornada data set: East and west boundary fence plant line intercepts - percent cover for all species beginning 1986

Dataset: 

Study number: 

120

Data set ID: 

210120002

Date range: 

1982-10-01 to 1992-09-11

Original investigator: 

Walter G Whitford

Data contact: 

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 download: 

Description: 

Data file information for the following Jornada data set: East and west boundary fence plant line intercepts - percent cover for 9 species 1982-1992

Data file information for the following Jornada data set: East and west boundary fence plant line intercepts - percent cover for 9 species 1982-1992

Dataset: 

Study number: 

351

Data set ID: 

210351001

Date range: 

1915-06-01 to 2001-12-31

Original investigator: 

William Ridgely Chapline

Data contact: 

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.
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 download: 

Description: 

Data file information for the following Jornada data set: Jornada Experimental Range Permanent Quadrat Chart data beginning 1915 - plant cover

Data file information for the following Jornada data set: Jornada Experimental Range Permanent Quadrat Chart data beginning 1915 - plant cover

Keywords: 

Dataset: 

Study number: 

8

Data set ID: 

210008001

Date range: 

1996-02-16 to 2001-08-17

Original investigator: 

David Lightfoot

Data contact: 

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 will be collected for the duration of the LTER program in order to provide data to test these hypotheses. Data for arthropods captured in pitfall traps on LTER III consumer plots at 2 month intervals. Data includes order, family, genus, species, and number.

Description: 

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

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: 

We use vegetation cover as a proxy for plant biomass to avoid confounding spatial and temporal variability or confounding the impact of harvesting. The rate of biomass change is Aboveground net primary production, a key variable that will respond to our PPT and nutrient manipulations.

Measured variables: individual cover of plant species measured as cm of green biomass that intercepts a 250cm long line, then averaged for 3 lines/plot.

Data download: 

Description: 

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

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)

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