HR: 11:45h
AN: NB32B-06    [Abstracts]
TI: Persistence of Macroinvertebrate Communities in Reference Streams of Denali National Park, Alaska.
AU: * Milner, A
EM: a.m.milner@bham.ac.uk
AF: School of Geography, Earth and Environmental Sciences, University of Birmingham Edgbaston, Birmingham, B15 2TT United Kingdom
AU: * Milner, A
EM: a.m.milner@bham.ac.uk
AF: Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 United States
AU: Conn, S C
EM: saxconn1@bham.ac.uk
AF: Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 United States
AU: Ray, J M
EM: jdmray@hotmail.com
AF: School of Geography, Earth and Environmental Sciences, University of Birmingham Edgbaston, Birmingham, B15 2TT United Kingdom
AB: Macroinvertebrates were collected from riffles in six reference streams in Denali National Park and Preserve, Alaska every year from 1994 to 2001. Two of the streams were also sampled in 2002. The most persistent taxon was Baetis, but its abundance varied markedly from year to year, ranging from < 50 m-2 to nearly 2000 m-2. Rank abundance of the 10 most abundant members of the macroinvertebrate community (including and excluding Chironomidae) showed significant concordance over time using Kendall's W. Using Jaccard's Coefficient of Similarity, assemblage persistence was found to be highest in streams with greater channel stability and lower flow variability. Spearman's coefficients of rank abundance between years were significantly lower when snowfall was high, indicating the potential effects of spring runoff on persistence. Due to the marked variation in abundance and lack of persistence of individual taxa, a number of biotic ratio metrics (e.g. EPT/Total individuals, % Chironomidae), varied almost across their entire range in these unimpaired streams, making these metrics inappropriate for biomonitoring at higher latitudes. The lack of persistence of individual taxa may also have implications for biomonitoring using predictive models.e to the marked variation in abundance and lack of persistence of individual taxa, a number of biotic ratio metrics (e.g. EPT/Total individuals, % Chironomidae), varied almost across their entire range in these unimpaired streams, making these metrics inappropriate for biomonitoring at higher latitudes. The lack of persistence of individual taxa may also have implications for biomonitoring using predictive models.
DE: 1860 Runoff and streamflow
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly