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Wednesday, May 28, 2008 - 11:45 AM
417
A quick and cheap (and hopefully not too nasty) method for periphyton dry mass and chlorophyll using a hand-held fluorometer, with a case study of periphyton distribution at different scales along an altitudinal gradient
Timothy P. Moulton1, Marcelo L. Souza1, Felipe A. M. Krsulovic1, Rodrigo V. Koblitz1, Ernesto F. Brito1, and Taldi L. Walter2. (1) Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rusa São Francisco Xavier 524, Maracanã, Rio de Janeiro, 20550-013, Brazil, (2) Alaska Outreach Coordinator, Audubon Society, 1150 Connecticut Avenue, NW #600, Washington, DC 20036
Periphyton is routinely quantified as its dry mass and chlorophyll. This is usually done by filtering samples onto glass-fiber filters and weighing (in the case of dry mass) and extracting pigments (in the case of chlorophyll). The procedure consumes a moderate amount of time, effort and costs for materials. We developed a method which estimates the dry mass and chlorophyll of a sample of periphyton at the time of sampling, using a hand-held fluorometer (Aquafluor 8000, Turner Designs) to measure the turbidity and fluorescence of the sample. We calibrated the measurements and assessed their precision using standard methods. The method is cheap (essentially not consuming materials), rapid and reasonably precise.
Often it is strategic to obtain precision by taking more samples rather than by spending time and effort on more precise measurements of fewer samples. As well, spatial scales are important for understanding processes and for sampling efficiently. We apply our cheap and rapid method to a question for which we need many samples – the distribution of periphyton at different scales along an altitudinal gradient. Periphyton is distributed unevenly and we sought to quantify the variability at the scales of individual boulders, boulders within sites and inclination of sampled surface.
Often it is strategic to obtain precision by taking more samples rather than by spending time and effort on more precise measurements of fewer samples. As well, spatial scales are important for understanding processes and for sampling efficiently. We apply our cheap and rapid method to a question for which we need many samples – the distribution of periphyton at different scales along an altitudinal gradient. Periphyton is distributed unevenly and we sought to quantify the variability at the scales of individual boulders, boulders within sites and inclination of sampled surface.
Web Page: fluorometry, methodology, spatial distribution
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)
See more of Contributed Sessions
See more of The Nabs 56th Annual Meeting (25-28 May, 2008)