Michael D. McArthur

MMStreamB.Sc. Hons. Ecology & Evolution. UWO (1997), M.Sc., Department of Forest Sciences, UBC (1999).

Email: mmcarthu@home.com

Project: Microbial utilization of dissolved organic matter (DOM) leached from riparian tree species of different seral stages

The goal of this study is to examine the heterotrophic bacterial use of various DOM sources. Specifically, the experiment set out to measure the differential transfer of organic matter from various riparian vegetation types to the biomass of benthic bacteria in streams. By measuring the incorporation of [3H]leucine, an amino acid known to be a requirement of bacterial protein, by bacteria this study aims to provide estimates of the relative quality of various DOM types based on the bacterial biomass they support. To better understand why we may observe differences in bacterial growth, several chemical parameters were compared amongst the DOM types tested here. Leachates dervived from the litterfall of riparian tree species of different seral stages was chosen as the DOM source because their inputs to the stream vary spatially, temporally and with land use related changes to forests. Also, the leaching of litterfall has been shown to be an important component of daily DOM exports from small forested streams.


Glass beads as used for instream incubation of bacteria