HR: 14:45h
AN: NB13A-06    [Abstracts]
TI: Macroinvertebrate assemblages and secondary production in three wood-poor, second-growth, headwater streams in the Upper Peninsula of Michigan.
AU: * Entrekin, S A
EM: sentreki@nd.edu
AF: University of Notre Dame, Department of Biological Sciences, Notre Dame, IN 46556 United States
AU: Rosi-Marshall, E J
EM: erosi@luc.edu
AF: Loyola University Chicago, Departments of Biology and Natural Sciences, Chicago, IL 60626 United States
AU: Tank, J L
EM: tank@nd.edu
AF: University of Notre Dame, Department of Biological Sciences, Notre Dame, IN 46556 United States
AU: Lamberti, G A
EM: lamberti.1@nd.edu
AF: University of Notre Dame, Department of Biological Sciences, Notre Dame, IN 46556 United States
AB: Benthic organic matter (BOM) is retained by in-stream wood in forested streams and is often the primary food resource for aquatic macroinvertebrates. We sampled BOM and macroinvertebrates in three, forested headwater streams within the same watershed and predicted that BOM standing stocks would be high and, therefore, macroinvertebrate functional feeding groups would be dominated by shredders and gatherers. However, all streams had low annual average standing stocks of BOM (75 to 166 gAFDM m^-2), and low shredder biomass (<5% of total) and gatherer biomass (<10%). Shane and Walton Creek macroinvertebrate biomass was dominated by predators (48% of total), scrapers (20%), and filterers (13%). Macroinvertebrate abundance peaked in June-July and again in November, while biomass peaked in November. In contrast, State Creek was dominated by scrapers (51%) and predators (33%), and abundance and biomass peaked in March and May, respectively. State Creek had the highest annual mean abundance (1198 individuals m^-2), biomass (427 mgDM m^-2), and secondary production (1000 mgDM m^-2 yr^-1). Macroinvertebrates in State Creek likely relied on algae and bryophytes for food and habitat. We conclude that macroinvertebrate communities in these streams are limited by BOM that was not retained in-stream because of reduced wood inputs from past logging.
DE: 1845 Limnology
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly