Water Stewardship Information Sources

Citation Negishi, J.N. and J.S. Richardson. (2003). Responses of organic matter and macroinvertebrates to placements of boulder clusters in a small stream of southwestern British Columbia, Canada.Canadian Journal of Fisheries and Aquatic Sciences 60: 247-258.
Organization UBC
URL http://citeseerx.ist.psu.edu/viewdoc/download?doi=
Abstract/Description or Keywords Diversity and productivity of stream food webs are related to habitat heterogeneity and efficiency of energy
retention. We tested the hypothesis that experimental boulder placements in a second-order stream would increase
diversity and abundance of macroinvertebrates by restoring detrital retention and habitat heterogeneity. Two relatively
natural, upstream, reference reaches and a downstream treatment reach with a relatively straight channel and less
woody debris were studied for 3 months before and 1.2 years after the placement of six boulder clusters in the
treatment reach. Mean velocity and its coefficient of variation increased in the treatment reach (140 and 115%, respectively),
whereas the reference reaches remained relatively unchanged after the placements. Enhanced particulate organic
matter storage (550%) was accompanied by increased total macroinvertebrate abundance (280%) in the treatment reach,
converging with those of the reference reaches almost 1 year after the treatment. Detritivorous taxa numerically dominated
the macroinvertebrate community, the total densities of which were best predicted by the fine fraction of organic
matter biomass at microhabitat scale. However, the effect of boulder clusters on taxonomic richness was negligible. Our
findings suggest that boulder clusters can be used at least as a short-term means to restore macroinvertebrate
productivity in detritus-based stream systems.
Information Type article
Regional Watershed Lower Fraser
Sub-watershed if known
Aquifer #
Project status complete
Contact Name John Richardson
Contact Email [email protected]