Louis Calder CenterâBiological Field Station and Department of Biological Sciences, Fordham University, Armonk, NY, U.S.A. SUMMARY. 1. The biochemical ...
Freshwater Biology (2013) 58, 1447–1457
doi:10.1111/fwb.12142
Elevated light and nutrients alter the nutritional quality of stream periphyton MATTHEW J. CASHMAN, JOHN D. WEHR AND KAM TRUHN Louis Calder Center—Biological Field Station and Department of Biological Sciences, Fordham University, Armonk, NY, U.S.A
SUMMARY 1. The biochemical composition of primary food resources may affect secondary production, growth, reproduction and other physiological responses in consumers and may be an important driver of food-web dynamics. Changes in land use, riparian clearing and non-point nutrient inputs to streams have the potential to alter the biochemical composition of periphyton, and characterising this relationship may be critical to understand the processes by which environmental change can affect food webs and ecosystem function. 2. We conducted a manipulative, in situ experiment to examine the effect of light and nutrient availability on stream periphyton biomass, nutrient content, stoichiometry and fatty acid composition. Greater light increased periphyton biomass [chl-a, ash-free dry mass (AFDM)], periphyton carbon concentrations and monounsaturated fatty acids (MUFAs), but decreased saturated fatty acids (SAFAs). Greater light availability also increased levels of
