Learn More
Current velocity significantly affected the biomass and shoot density of aquatic macrophytes in two slow-flowing rivers in western Canada. Studies of aquatic macrophyte communities at three sites on the Bow River, Alberta, Canada, between 1982 and 1985 showed that biomass decreased with increasing current velocity within the weed bed over the range 0.01-1(More)
Solar ultraviolet radiation (UVR) can reduce the photosynthesis and growth of benthic diatom communities in shallow freshwater. Nevertheless, greater amounts of algae accumulate in UVR-exposed habitats than in UVR-protected environments. Near-ultraviolet (UVA wavelengths of 320 to 400 nanometers) and mid-ultraviolet (UVB, wavelengths of 280 to 320(More)
Laboratory experiments were performed to identify the mechanisms by which three mayfly grazers, Baetis tricaudatus, Ephemerella aurivilli and Paraleptophlebia heteronea deplete algae from substrates. Field observations indicated these mayflies foraged predominantly (>70% of all individuals) within small (1–2 cm diameter), low biomass areas where algal(More)
The value of distinguishing native from nonnative invasive species has recently been questioned. However, this dichotomy is important for understanding whether a species' successful dominance is caused by introductions, changing environmental conditions that facilitate an existing population, or both processes. We highlight the importance of knowing the(More)
  • 1