Dietary influences on production, stoichiometry and decomposition of particulate wastes from shredders. (21st November 2014)

• Record Type: Journal Article
• Authors: Halvorson, Halvor M.; Fuller, Chris; Entrekin, Sally A.; Evans‐White, Michelle A.
• Is Part Of: Freshwater biology. Volume 60:Number 3(2015:Mar.)
• Page Start: 466
• Page End: 478
• Publication Date: 2014-11-21
• Subjects: Freshwater biology -- Periodicals; Biologie d'eau douce -- Périodiques; 577.605
• DOI: 10.1111/fwb.12462
• Languages: English
• ISSNs: 0046-5070

Abstract

<abstract abstract-type="main" id="fwb12462-abs-0001"> <title>Summary</title> <p> <list id="fwb12462-list-0001" list-type="order"> <list-item> <p>Aquatic shredders produce large quantities of fine particulate organic matter (FPOM) as fragments and egesta, but the significance of shredder FPOM as a pathway of consumer‐mediated nutrient transformation remains understudied.</p> </list-item> <list-item> <p>We fed the stream shredders <italic>Pycnopsyche lepida</italic>, <italic> Lepidostoma</italic> sp. and <italic>Tipula abdominalis</italic> oak or maple litter conditioned under contrasting phosphorus concentrations to produce gradients in dietary carbon:phosphorus (C:P) and carbon:nitrogen (C:N) content (range = 850–4480 and 30–49 by moles, respectively). We measured total production and stoichiometry of FPOM to estimate particulate N and P release rates, compared resultant rates to those of P excretion and measured microbial decomposition of FPOM.</p> </list-item> <list-item> <p>FPOM production was lowest for <italic>Lepidostoma</italic> and higher for <italic>Tipula</italic> and <italic>Pycnopsyche</italic>; FPOM production by <italic>Tipula</italic> increased on higher‐nutrient diets. The C:P, C:N and N:P of FPOM from <italic>Pycnopsyche</italic> and <italic>Tipula</italic> often diverged from diet stoichiometry depending on litter type, and rates of particulate N and P release by shredders were greater with increasing nutrient content of the diet.</p> </list-item> <list-item> <p>Shredders fed high‐nutrient diets produced FPOM with greater microbial decomposition rates, although these trends differed between litter types.</p> </list-item> <list-item> <p>Bottom‐up changes in litter type and nutrient content may modify production, stoichiometry and decomposition of FPOM from shredders, and shredder‐mediated nutrient transformations may differ across shredder species.</p> </list-item> </list> </p> </abstract>