HR: 10:45h
AN: NB52E-02    [Abstracts]
TI: Predicting Changes in Geomorphology, Biodiversity, and Ecosystem Processes Following a Dam Removal
AU: * Marks, J C
EM: Jane.marks@nau.edu
AF: Department of Biology, Northern Arizona University, Flagstaff, AZ 86011 United States
AU: Carter, C
AF: Department of Biology, Northern Arizona University, Flagstaff, AZ 86011 United States
AU: Gibson, C
AF: Department of Biology, Northern Arizona University, Flagstaff, AZ 86011 United States
AU: Haden, A
AF: Department of Biology, Northern Arizona University, Flagstaff, AZ 86011 United States
AU: Dinger, E
AF: Department of Biology, Northern Arizona University, Flagstaff, AZ 86011 United States
AB: A large hydropower dam will be decommissioned in Fossil Creek, Arizona in 2005. Water has been diverted from the stream for over a century. A unique attribute of Fossil Creek is the high levels of calcium carbonate which historically formed large travertine dams. Travertine dams are only formed in a 1 km reach but historical records suggest that most of the river had travertine dams prior to the water diversion. Restoration of flow should increase travertine dam formation changing the geomorphology of the stream creating steep waterfalls and deep pools. We compared decomposition, nitrogen uptake length, productivity, and fish and macroinvertebrate diversity in an area of the stream with remnant travertine dams with an area with a traditional riffle/pool structure. Primary and secondary productivity, insect diversity and native fish diversity were all higher in the travertine reach. Geomorphologists expect a ten fold increase in travertine deposition following return of full flows. Dam decommissionings provide powerful experimental designs for testing how changing flow regimes affect geomorphology, biodiversity, and ecosystem processes.
DE: 1824 Geomorphology (1625)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly