Effects of fine wood addition on invertebrate drift in boreal forest streams
(English)Manuscript (preprint) (Other academic)
Fine woody debris (FWD) is a key habitat component for stream-living organisms, but there have been few tests of its importance for macroinvertebrate drift in boreal forest streams. We experimentally investigated the effect of FWD addition on the drift fauna at seven sites in four boreal forest streams, from early June to mid-August 2011. This was done by anchoring bundles of FWD at each site and measuring drift upstream (within site control) and downstream of each bundle. We hypothesized that addition of FWD would increase drift density and biomass of stream invertebrates as well as drift taxon richness. Variation between sites was high, with site-specific minimum values of drift biomass of 0.2 - 4.1 mg wet mass/100 m3 and maximum values of 3.9 - 41.7 mg/100 m3. Despite this variation, there was a significant increase in total aquatic drift density and biomass 8 to 10 weeks after wood addition. Aquatic taxon richness in the drift also increased significantly after FWD addition. This study shows for the first time that FWD can increase drifting invertebrate density, biomass and taxon diversity in small boreal forest streams.
fine wood, fine woody debris, stream, invertebrates, aquatic larvae
Research subject Biology
IdentifiersURN: urn:nbn:se:kau:diva-31670OAI: oai:DiVA.org:kau-31670DiVA: diva2:703933