Data set ID:
The data consists of chemical analyses of dissolved ions in samples of surface runoff from natural rainfall events collected from experimental hydrology plots in creosotebush scrub and grass- land
areas of the New Mexico State University Ranch and USDA Jornada Experimental Range. Chemical analyses are for F, Cl, NO3, SO4 by ion chromatography, NH4 by autoanalyzer, Ca, Mg, Na, K by atomic absorption spectrophotometry, and total N and P by auto- analyzer.
lab data sheets
Runoff plots of 2X2 m dimension were established in each of the four areas. Each plot consists of a metal frame that bounds the three upslope sides and excludes overland flow from entering the plots. The lower slope consists of a trough, which collects the runoff generated locally on the plot. The runoff is shunted into a large collecting carboy. After each rainfall, a sample of the supernate solution is taken from the carboy, preserved with phenylmercuric acetate (PMA) and shipped to Duke University for analysis. The volume of the remaining runoff solution is measured and the mass of sediment and suspended solids is estimated and recorded in other data sets (Bolton and Ward). At Duke University each sample is filtered through a 0.45 millipore filter and analyzed for F, Cl, NO3, SO4 by ion chromatography, NH4 by auto- analyzer, Ca, Mg, Na, K by atomic absorption spectrophotometry, and total N and P by autoanalyzer following persulvated digestion (D'Elia et al. 1977), Limnology and Oceanography 22:760-764. Beginning in 1990, samples were centrifuged at New Mexico State University before shipment to Duke.
Creosotebush zone plots (C) in Caliche area (CALI) about 40 meters upslope from C-CALI NPP site, and in area of termite studies (TERM) located about 300 meters west of Upper Trailer. Grassland (G) plots at Mt. Summerford (SUMM) upslope of powerline, and about 50 meters east of LTER-I Alternate Control Transect, and about 30 meters west of the southwest corner of the IBP exclosure on the USDA Jornada Experimental Range.
every runoff event