HR: 1330h
AN: NB33B-11    [Abstracts]
TI: Spatial And Temporal Periphyton Distributions And Ecological Indices In An Anthropogenic-Influenced Montane-Desert Great Basin Stream
AU: Fritsen, C H
EM: chris.fritsen@dri.edu
AF: Desert Research Institute, 2215 Raggion Parkway, Reno, NV 89512-1095
AB: The Lower Truckee River (LTR), Nevada, USA has multiple anthropogenic influences along its' gradient, including a water treatment facility, irrigation diversions, channelization, and urbanization of the watershed. The seasonal dynamics of periphyton biomass and community composition was documented in the LTR in 2000-2002, and showed biomass maxima (>150ug/cm²) in the winter (stalked diatoms) and early spring (filamentous green). Siltation tolerant genera, Eutraphentic genera, Genera Diversity, and Chlorophyll a standing stocks varied substantially along the LTR. These community characteristics were used to derive a equally weighted and normalized index. Evaluation of the index has identified a prevalent upstream to downstream decrease in scores, from 0.83 to 0.53 downstream, and potential in-stream reference conditions. This work not only provides a means to document the temporal-spatial biomass and assemblage composition for a high order montane to desert stream, it offers a preliminary periphyton based index that aids in the ecological assessment of the Great Basin region.
DE: 9810 New fields (not classifiable under other headings)
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly