USDA-ARS Long-Term Agroecosystem Research Network (https://www.tucson.ars.ag.gov/ltar)
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.
This ongoing data set contains percent canopy cover estimates of perennial plant species from transects that cross a grazed/ungrazed boundary fenceline of a single exclosure on the New Mexico State University Chihuahuan Desert Rangeland Research Center in Dona Ana County, New Mexico, USA. 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 canopy 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. Sampling occurs approximately every five years; it was last conducted in November 2015 and will take place again in 2020.
Boxplots at canopy cover by form: https://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/files/data/Canopy_cover_boxplots_1.jpg
Location on EDI: https://portal.edirepository.org/nis/metadataviewer?packageid=knb-lter-jrn.210120001
This ongoing dataset contains annual aboveground net primary productivity (ANPP) data from a study at the Jornada Experimental Range (JER) in southern New Mexico. The study was designed to assess the effect of interannual variability in precipitation on average aboveground net primary productivity (ANPP) in Chihuahuan Desert grasslands. The study began in 2009, has five precipitation treatments (see Methods) and contains 50 plots (10 per treatment). This data package contains 6-year (2009 to 2014) means of ANPP per plot. Annual and more recent data are available and will be released pending an upcoming publication.
Figure of 6-year ANPP by plant functional group: https://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/files/data/ANPP_figure.jpg
Location of dataset on EDI: https://portal.edirepository.org/nis/metadataviewer?packageid=knb-lter-jrn.210328001.1
t: The goal of this Master’s thesis project, which was carried out in July and August of 2016, was to assess the effect of inferred grazing intensity on 1) vegetation cover type and 2) soil organic carbon (SOC) at the Jornada Experimental Range in southern New Mexico. A sampling transect was established at each of 3 long term cattle water sources (85-106 years old), beginning 5m from the water source and continuing 1500m outward. Soil bulk density, soil organic carbon, soil organic nitrogen, and dominant plant cover type (shrub, grass, and bare soil) were sampled at 20 locations on each transect. Two hypotheses evaluated in this study are: 1) higher grazing pressure near the water source will lead to reduced vegetation cover and C inputs into the soil, leading to higher SOC stocks in soil with far proximity to the water source; and 2) Grazing very close to the water source will exert high disturbance and deposit SOC via defecation, leading to higher SOC stocks in soil with close proximity to the water source.
A figure of the data in this package: https://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/files/data/Cattle_soil_carbon_figure.jpg
Location on EDI: https://portal.edirepository.org/nis/metadataviewer?packageid=knb-lter-jrn.210472001.1
This completed dataset contains soil moisture data from a study at the Jornada Experimental Range (JER) in southern New Mexico. The study was designed to assess the effect of interannual variability in precipitation on average aboveground net primary productivity (ANPP) in Chihuahuan Desert grasslands. The study began in 2009 and has five precipitation treatments (see Methods). While the study began in 2009, contains 50 plots (10 per treatment) and is ongoing, these data were only collected from July 2011 to December 2013 in a subset of 20 plots (4 per treatment). This dataset is intended to provide information about the amount of water in the top 30 cm of soil as well as verify that experimental precipitation manipulations are effective. Figure of soil moisture by precipitation treatment: https://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/files/data/soil_moisture_figure.jpg Metadata and data on EDI: https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-jrn&identifier=210328003
This completed dataset, collected in 2001, contains soil particle size analysis (PSA) and sand fractionation data from soil cores collected at 116 quadrat locations that are part of the Jornada Experimental Range's long-term Permanent Quadrats study. The goal of this effort was to help characterize plant-scale factors related to vegetation dynamics observed in the Permanent Quadrats. At each quadrat location, 4 cores were collected at 2 depths (0-5cm and 5-20cm) and assessed for percent sand, silt and clay. The sand fraction, if large enough, was then separated into 5 sand size classes (53-106 micrometers, 106-250 micrometers, 250-500 micrometers, 500-1000 micrometers, 1000-2000 micrometers) to measure the percent fraction of each.
Composition of Sand Fraction at 116 Permanent Quadrats: https://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/files/data/Quadrats_Sand_Fractionation_0.jpg
Soil Particle Size Analysis at 116 Permanent Quadrats: https://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/files/data/Quadrats_PSA_0.jpg
Dataset consists of 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
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
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.
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.
Repeat digital groundbased photos are taken once to twice a year to document plant litter and
soil deposition or removal by wind and water transport on ten microplots located on each of the
8 plots at each of the Aeolian, Dona Ana, and Gravelly Ridges sites. Five photos are taken of
each microplot: One overhead (from directly over the microplot) and 4 lateral views at ground
level of the microplot from each cardinal direction.
Digital filenames are fully descriptive of the site, plot, microplot, photo view, and date taken.
Photo filename structure:
Where 1 = site: A=Aeolian: D=Dona Ana; G=Gravelly Ridges
2 = plot (1-8)
3 = microplot (1-10)
4= photo view (O=overview; E=looking east; N=looking north; S=looking south; W=looking west
5-6-7 = year month day of photo
8 = original image number assigned by camera
There are 3 sites for this study: Gravelly Ridges, Aeolian, and Dona Ana. Within each site,
there are 8 plots. The plots are 8x8 meters and have an 8x8 buffer zone on both sides of the
plot (up and down). There are four BSNE stands for each plot, 2 in each of the 2 buffer zones
(8 collectors per plot). Each stand contains 2 BSNE collectors with the collection opening at
10cm and 30cm height and an opening of 2 cm wide and 5 cm height. These BSNE collectors are in
a fixed position pointing into the direction of the prevailing wind, which corresponds to the
plot alignment. The collectors in the upwind buffer are facing away from the plot and the
collectors in the downwind buffer are facing into the plot. The idea is the upwind BSNEs
measure the amount of dust entering the plot, and the downwind BSNEs measure the amount of dust
moving off the plot. This provides a measure of the effectiveness of the plot obstructions to
wind blown dust. It is important the BSNEs are fixed in an orientation that points across the
full length of the plot.