ORGANIC MATTER FLUXES IN A SMALL COASTAL PLAIN STREAM.

G.M. Ward and H. Jin. Aquatic Biology, University of Alabama, Tuscaloosa, AL 35487

Since 1996, measurements of organic matter fluxes have been conducted at Payne Creek, a small, sandy-bottom Coastal Plain stream. Community respiration, gross primary production, annual litterfall, benthic particulate organic matter (BOM) storage, and organic matter exports (CPOM, FPOM, and DOM) have been measured. Mean annual aerial litterfall contributed 678 g m^-2 of organic matter input, while the contribution by GPP was insignificant. Channel storage of CPOM (1.68 kg m^-2) and FPOM (1.77 kg m^-2) was unchanged over the annual cycle. Community respiration accounted for a loss of 388 g m^-2 of organic matter annually. Annual hydrologic export was dominated by FPOM (10,267 kg), followed by DOM (1,530 kg) and CPOM (23.3 kg). Hydrologic exports greatly exceeded aerial litterfall inputs, suggesting that more attention to lateral inputs of FPOM and DOM is deserved.