HR: 11:00h
AN: NB32B-03    [Abstracts]
TI: Stream insect distributional patterns and metapopulation models: effects of spatial scale and sampling intensities
AU: * Heatherly II, T
EM: heatherly75@yahoo.com
AF: Southern Illinois University, Department of Zoology Mailcode 6501 Southern Illinois University Carbondale, Carbondale, IL 62901 United States
AU: Whiles, M R
EM: mwhiles@zoology.siu.edu
AF: Southern Illinois University, Department of Zoology Mailcode 6501 Southern Illinois University Carbondale, Carbondale, IL 62901 United States
AU: Gibson, D J
EM: dgibson@plant.siu.edu
AF: Southern Illinois University, Department of Plant Biology Mailcode 6509 Southern Illinois University Carbondale, Carbondale, IL 62901 United States
AU: Collins, S L
EM: scollins@sevilleta.unm.edu
AF: University of New Mexico, Department of Biology University of New Mexico , Albuquerque, NM 87131 United States
AU: Huryn, A D
EM: huryn(at)bama.ua.edu
AF: University of Alabama, A230 Bevill Building Box 870206 , Tuscaloosa, AL 35487 United States
AU: Jackson, J K
EM: jkjackson@stroudcenter.org
AF: Stroud Water Research Center, 970 Spencer Road , Avondale, PA 19311 United States
AU: Palmer, M
EM: mpalmer@umd.edu
AF: University of maryland, Plant Sciences BLDG 4112, College Park, MD 20742 United States
AB: Understanding patterns of distribution of organisms and factors underlying them is a fundamental goal of ecology. We used stream insect datasets from Alabama, Alaska, Maine, Maryland, New York, and the northwest Pacific Coast to examine occupancy-frequency patterns and to assess the effects of changing spatial scales and sampling intensities (number of sites) on these patterns. Differences in proportions of satellite taxa (those occurring in <10% of sites) and core taxa (occurring in >90% of sites) contributed to differences in modality in occupancy-frequency patterns. Core taxa were usually widespread and speciose genera. Cases where satellite taxa dominated community structure, which was often, tended to show unimodal occupancy-frequency patterns. Cases where core taxa contributed substantially to richness tended to show bimodal patterns. Proportions of core taxa decreased with increasing spatial scales and sampling intensities. Proportions of satellite taxa increased with spatial scale, and showed positive log relationships with sampling intensity (r² = 0.74 - 0.96). There was also a pattern of increasing proportions of core taxa with decreasing latitude (r² = 0.92, P = 0.01). Results indicate that spatial scale and sampling intensity influence occupancy-frequency patterns of stream insects and may thus influence interpretation of metapopulation models when applied to these systems.
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly