CS34 River Dynamics
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
ChengX, Stroud Water Research Center, Avondale, USA, xcheng@stroudcenter.org
Kaplan , L, A, Stroud Water Research Center, Avondale, USA, lakaplan@stroudcenter.org
Battin, T, J, Institute of Ecology and Conservation Biology, University of Vienna, Vienna, Austria, tomba@pflaphy.pph.univie.ac.at
 
APPLICATION OF AN IMPROVED HPLC/PAD METHOD TO FOLLOW THE DYNAMICS OF CARBOHYDRATES IN A PIEDMONT STREAM
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We improved the method for analysis of dissolved carbohydrates and used it to follow the daily, diel, and storm dynamics of carbohydrates in a piedmont stream. Over 16 consecutive days of baseflow discharge, concentrations of dissolved free monosaccharides (DFMS) varied 52% and dissolved total saccharides (DTS) 47%. Diel concentration variations were greater for both DFMS (278%) and DTS (58%), exhibited an increase during daylight, and decline at night. DTS dynamics correlated with temperature (r2=0.59) and were characterized by a decrease in the ratios deoxysugars:glucose, deoxysugars:pentoses and hexoses/pentoses. These characteristics suggest a dominant role for periphyton excretion. A spring storm with a 9-fold increase in discharge to 810 l/s compared to baseflow discharge of 89 l/s increased fluxes of DFMS and DTS 70-fold. The flux of DFMS increased from 0.12 to 8.76 mg C/sec and DTS from 4.5 mg C/sec to and 324.4 mg C/sec. The storm did not alter the ratio of DTS:DFMS concentrations (37) or the yields of these carbohydrate fractions (DFMS 0.11; DTS 4), but delivered high concentrations of bioavailable DOM to the stream ecosystem.