Proceedings - Teaching and Learning Centre - Simon Fraser ...

Fraser River Action Plan 3rd Research Workshop
Conclusions
To summarize, these results suggested that semi-forested conditions are conducive to maintaining ecosystem
balance. Although assemblage trends differed among taxa and were not always consistent across sites,
biodiversity for riparian and aquatic fauna should both be maintained under partially forested conditions. Such
conditions:
1. allow bank stabilization, contaminant filtering, shading, and detrital input that benefit aquatic
invertebrates and fishes; and,
2. maintain floral habitat diversity for riparian wildlife.
The trends for habitat and biological diversity may reflect the fact that semi-forested (cottonwood-pine) and
unforested (bunchgrass-sagebrush) conditions have historically characterized southern interior stream valleys,
such that native riparian and aquatic animals are adapted to partially wooded conditions.
Recommendations
Habitat and biological trends may not have been consistent across sites because of confounding factors such as
urbanization, mining, irrigation, pesticide and other human impacts, as well as differing compositions of
riparian-floral species and benthic sediments (not assessed here). Therefore, examination of several biological
parameters should provide a more robust assessment of human impacts. Ability to establish biological indicators
should be improved by increasing spatio-temporal replication (examining a greater number of sites and
comparing samples sollected among seasons) and by conducting manipulative experiments (where possible, such
as in northern B.C.). Such efforts will require interdisciplinary coordination. The information provided in the
present paper should benefit researchers and managers in the province, by providing solid databases and
standardized methodologies for human-impact assessment of inland watersheds. Local (SR-NR) citizens
developing biological monitoring programs should find the biological indicators developed here useful for
monitoring the success of their tree planting programs.
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