Vegetation Dynamics

vegetation dynamics

Conmod Pilot Study: Annual vegetation transect Line Point Intercept measurements

Study number: 

308

Data set ID: 

210308002

Date range: 

2008-06-10 to 2009-07-27

Original investigator: 

Debra Peters

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: 

Conmod Pilot Study: Annual plant canopy gap and basal gap intercept data

Study number: 

308

Data set ID: 

210308001

Date range: 

2006-06-10 to 2009-07-11

Original investigator: 

Debra Peters

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

Project ID: 

210308000

Original Investigator: 

Debra Peters

Abstract: 

This study is designed to generate predictions about the density, spatial arrangement and cover of obstructions to wind and water necessary to promote grass recovery in
shrub-dominated plant communities in the northern Chihuahuan Desert.  Specifically, we would like to "(a) to understand the density of vegetation regrowth in intershrub areas(such as we have seen as a result oi last summer) necessary for it to become self-sustaining and engender grass recovery in shrub-dominated plant communities and b) the extent to which we might trigger such regrowth through the use of artificial barriers to resource and propagule movement".  The objectives are to determine extent to which physical obstructions capture soil and litter (plant scale), and the extent to which they modify resource and propagule movement at the patch scale.  We will also document changes in plant cover at both plant and patch scales.

Funding Source: 

NSF

Research Area: 

Data Category: 

Soil water content in precipitation and nitrogen treatment plots at 2 depth profiles

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: 

East and west boundary fence plant line intercepts - percent cover for all species beginning 1986

Study number: 

120

Data set ID: 

210120001

Date range: 

1986-09-24 to 2005-10-29

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: 

East and west boundary fence plant line intercepts - percent cover for 9 species, Jornada Basin, 1982 to 1992

Study number: 

120

Data set ID: 

210120002

Date range: 

1982-10-08 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: 

Jornada Experimental Range permanent quadrat chart data beginning 1915 - plant density

Study number: 

351

Data set ID: 

210351002

Date range: 

1915-06-01 to 2001-12-31

Original investigator: 

William Ridgely Chapline

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.
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 download: 

Jornada Experimental Range Permanent Quadrat Chart data beginning 1915 - plant cover

Study number: 

351

Data set ID: 

2100351001

Date range: 

1915-06-01 to 2001-12-31

Original investigator: 

William Ridgely Chapline

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: 

Project ID: 

210351000

Abstract: 

Permanent quadrats record vegetation changes since 1915 in a range of vegetation and soil texture types.
More than 100 1 x 1 m**2 quadrats were set up between 1915 and 1932 to study the response of major forage species to cattle grazing and precipitation. A pantograph was used to chart the following variables:
  1. basal area of perennial grasses,
  2. locations of annual grasses, forbs, and shrubs, and sometimes
  3. canopy cover of major shrubs.
Almost all quadrats were charted annually until 1947, and a portion of the quadrats were charted annually between 1947 and 1979. One hundred and six quadrats were relocated and charted in 1995 and again in 2001. In 2006, 16 more quadrats were relocated. A total of 122 quadrats were sampled in 2006 and 2011/2012. Currently 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.

Funding Source: 

USDA

Research Area: 

Data Category: 

Plant cover in precipitation and nitrogen treatment plots (by species)

Study number: 

27

Data set ID: 

2100278002

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: 

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