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Vegetation cover from line intercept transects in lagomorph exclosure and shrub removal plots at the Jornada Experimental Range, southern New Mexico, USA, 1938-2001
,This package contains data from a study to quantify vegetation dynamics in response to lagomorph and shrub exclusion on the Jornada Experimental Range from 1938-2001. 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. Plots were 21.3 x 21.3 m with a 7.6 m buffer zone between each. Plots were divided into east and west halves and 14 randomly located 10.65 m transects were located in each half plot. Vegetation was measured using vertical line intercepts in 1938, 1947, 1956, 1960, 1967, 1989, 1995, and 2001 for the Gravelly Ridges site, and in 1938/9, 1947, 1960, 1967, and 2001 for the Parker Tank and Dona Ana sites. The treatments include 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. The dataset contains information on the site, year of data collection, plot number, line number, vegetation, and number of vegetation present on each line. 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 Chihuahuan Desert vegetation dynamics. Journal of Arid Environments 42: 155-166. https://doi.org/10.1006/jare.1999.0516,,
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Annual measurements of vegetation cover on line-point intercept transects from the three Conmod Pilot study locations at Jornada Basin LTER, 2008-2016
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,This data package contains annual measurements of vegetation cover, species, and height from transects at the Connectivity Modifier (Conmod) Pilot study on the Jornada Experimental Range from 2008-2016. There were 3 sites for this study: Gravelly Ridges, Aeolian, and Dona Ana. Within each site, there were 8 study plots, 4 of which were treatment plots where connectivity modules (conmods) were installed to decrease gap sizes between perennial vegetation. The plots were 8 x 8 meters and had an 8 x 8 meter buffer zone on both sides of the plot (upwind and downwind). Beginning in 2008, vegetation cover by species, and vegetation heights were collected annually in all plots using the line-point intercept method. These data were collected in 2008-2010, 2012 and 2016. At each plot, four parallel 24-meter transects crossing the upwind buffer, the plot, and the downwind buffer were measured. These parallel transects were spaced at 0.8, 2.8, 4.3, and 7.2 meter intervals across the plot and buffer areas. Vegetation cover and height were read at points arranged at 25 centimeter increments along each transect. This study is complete (finished in 2016) and was the pilot study to the newer Cross Scale Interactions Study.,,
Annual measurements of vegetation canopy and basal gap intercepts from the three Conmod Pilot study locations at Jornada Basin LTER, 2008-2016
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,This data package contains annual measurements of vegetation canopy and basal gap sizes from transects at the Connectivity Modifier (Conmod) Pilot study on the Jornada Experimental Range from 2008-2016. There were 3 sites for this study: Gravelly Ridges, Aeolian, and Dona Ana. Within each site, there were 8 study plots, 4 of which were treatment plots where connectivity modules (conmods) were installed to decrease gap sizes between perennial vegetation. The plots were 8 x 8 meters and had an 8 x 8 meter buffer zone on both sides of the plot (upwind and downwind). Beginning in 2008, vegetation canopy and basal gap sizes were collected annually in all plots using the gap intercept method. These data were collected in 2008-2010, 2012 and 2016. At each plot, four parallel 24-meter transects crossing the upwind buffer, the plot, and the downwind buffer were measured. These parallel transects were spaced at 0.8, 2.8, 4.3, and 7.2 meter intervals across the plot and buffer areas. This study is complete (finished in 2016) and was the pilot study to the newer Cross Scale Interactions Study.,,
Quadrat-based monitoring of desert grassland vegetation at the Jornada Experimental Range, New Mexico, 1915-2016
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The data set covers a 101-year period (1915-2016) of quadrat-based plant sampling at the Jornada Experimental Range in southern New Mexico. At each sampling event, a pantograph was used to record the location and perimeter of living plants within permanent quadrats. Basal area was recorded for perennial grass species, canopy cover area was recorded for shrub species, and all other perennial species were recorded as point data. The data set includes 122 1m by 1m permanent quadrats, although not all quadrats were sampled in each year of the study and there is a gap in monitoring from 1980-1995. These data provide a unique opportunity to investigate changes in the plant community over 100 years of variation in precipitation and other environmental conditions. We provide the following data and data formats: (1) the digitized maps in shapefile format; (2) data table containing coordinates (x,y) of perennial species within quadrats, including cover area for grasses and shrubs; (3) data table of counts of annual plant individuals per quadrat; (4) species list indicating growth form and habit of recorded species; (5) table of dates when each quadrat was sampled; (6) table of the pasture each quadrat was located within (note that pasture boundaries have changed over time). Additional data to help characterize plant-scale factors related to vegetation dynamics at the quadrat locations are: (7) data table of depth to caliche layer; (8) data table of soil particle size analysis and sand fractionation; and (9) data table of local and patch topography. This data package was created to support a specific data paper. Data are also available in data packages knb-lter-jrn.210351001, knb-lter-jrn.210351002, and knb-lter-jrn.210351003. Pantograph sampling is currently conducted at 5 year intervals by USDA-ARS staff, and new data will be added to those data packages periodically.
SGS-LTER Bouteloua gracilis Removal Experiment Vegetation Density Data on the Central Plains Experimental Range, Nunn, Colorado, USA 1997-2008
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,This data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Digital Collections of Colorado (http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection. Six sites approximately 6 km apart were selected at the Central Plains Experimental Range in 1997. Within each site, there was a pair of adjacent ungrazed and moderately summer grazed (40-60% removal of annual aboveground production by cattle) locations. Grazed locations had been grazed from 1939 to present and ungrazed locations had been protected from 1991 to present by the establishment of exclosures. Within grazed and ungrazed locations, all tillers and root crowns of B. gracilis were removed from two treatment plots (3 m x 3 m) with all other vegetation undisturbed. Two control plots were established adjacent to the treatment plots. Plant density was measured annually by species in a fixed 1m x 1m quadrat in the center of treatment and control plots. For clonal species, an individual plant was defined as a group of tillers connected by a crown Coffin & Lauenroth 1988, Fair et al. 1999). Seedlings were counted as separate individuals. In the same quadrat, basal cover by species, bare soil, and litter were estimated annually using a point frame. A total of 40 points were read from four locations halfway between the center point and corners of the 1m x 1m quadrat. Density was measured from 1998 to 2005 and cover from 1997 to 2006. All measurements were taken in late June/early July.,,