HR: 1330h
AN: NB33M-08    [Abstracts]
TI: National Clusters of Lotic Macroinvertebrate Assemblages in the United States and Their Relationship to Existing Spatial Classification Schemes
AU: * Sifneos, J C
EM: sifneos@science.oregonstate.edu
AF: Dept. of Geosciences, Oregon State University, Wilkinson Hall, Corvallis, OR 97331 United States
AU: Herlihy, A T
EM: alan.herlihy@oregonstate.edu
AF: Dept. of Fisheries & Wildlife, Oregon State University, Nash 104, Corvallis, OR 97331 United States
AU: Gerth, W J
EM: gerthw@onid.orst.edu
AF: Dept. of Fisheries & Wildlife, Oregon State University, Nash 104, Corvallis, OR 97331 United States
AU: Hughes, R M
EM: hughes.bob@epa.gov
AF: Dept. of Fisheries & Wildlife, Oregon State University, Nash 104, Corvallis, OR 97331 United States
AB: Conducting biological assessments at a national scale requires a classification scheme to report results, define reference conditions, and interpret data. Analyzing stream biological assemblage data across the conterminous 48 United States is difficult due to the lack of synoptic assemblage data. In the last 10 years, however, the number and scope of bioassessments has increased dramatically. We compiled a national-scale database of lotic macroinvertebrate assemblages containing 4,950 sample sites from available national and state agency data. Cluster analysis (Bray-Curtis distance) and indicator species analysis were used to cluster the data, identify clusters, and describe them. We developed national clusters of macroinvertebrate assemblage groups that were well-described by indicator species and predicted using both discriminant function analysis and classification tree analysis. We also examined the relationship of existing spatial classification schemes to assemblage similarity. Existing schemes did not capture the majority of the within-group similarity expressed in biologically derived clusters. Schemes based on ecoregion, physiography, hydrologic units, and geopolitical boundaries had very similar mean within-group assemblage similarities.
DE: 0400 Biogeosciences
DE: 1845 Limnology
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly