Chemistry of stream water from the Luquillo Mountains

Stream water is collected weekly at the Luquillo Mountain sites listed below. These data sets begin as early as 1983; LTER sampling began in 1988. Stream water samples are grab samples taken from the water/air interface at stream channel center on the sampling day (usually Tuesdays). A continuous record of stream stage (height) is recorded by a datalogger at all ongoing stream sampling sites. Average daily streamflows are available from the USGS and at other locations (Hydrology and Meteorology) on this site. All samples are measured for pH and conductivity, and then filtered (pre-combusted Whatman GF/F glass fiber filter) prior to further analysis. From 1983-1994 samples were cooled and returned to the San Juan chemistry laboratory for analysis. During those years, samples for NH4 and NO3 analyses were refrigerated continuously until analysis. Subsamples for NH4 analysis were also preserved with 1 molar H2SO4. From 1994 on, samples for NH4 and NO3were frozen until analysis, were not acidified, and all analyses were conducted at the University of New Hampshire. Stream water Sampling SitesDescriptions of LTER LUQ stream water weekly sample chemistry data from 1988 onwards. Chemical concentrations are recorded as mg/L or mg/L as appropriate. Values below detection limits are recorded as 1/2 the detection limit.  Site Abbreviation Description Comments Quebrada Sonadora QS El Verde stream.   Quebrada Toronja QT = QT1 El Verde stream.   Rio Espiritu Santo RES4 LEF North Stream LEF= Luquillo Experimental Forest Quebrada Prieta A QPA El Verde stream   Quebrada Prieta B QPB El Verde stream   Quebrada Prieta QP El Verde stream   Puente Roto Mameyes MPR Bisley stream Previously "PRM" Quebrada uno-Bisley Q1 . Bisley stream   Quebrada dos-Bisley Q2  Bisley stream   Quebrada tres-Bisley Q3 . Bisley stream   Rio Mameyes Gage  MG Bisley stream   Rio Icacos RI LEF South stream   Rio Sabana RS LEF West stream   Quebrada Guaba QG Icacois stream Â