LTER Core Areas
Atmospheric deposition as found in dryfall (dust) and wetfall precipitation has been collected and analyzed since 1983 using an Aerochem Metrics wetfall/dryfall collector located at the Jornada LTER weather station north of Las Cruces, NM, USA. Wetfall occurring as precipitation is collected after each event with a sample size large enough to analyze. Each sample is analyzed for Br, Ca, Cl, F, HPO4, K, Mg, Na, NH4, NO3/NO2, SO4, Total N, and Total P. Analysis of Sr and Dissolved Organic Nitrogen was discontinued in 2003. Dryfall data are available as a separate data package.
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