HR: 10:30h
AN: NB42A-01 [Abstracts]
TI: Plant genes link forests and streams
AU: * LeRoy, C J
EM: CJL2@dana.ucc.nau.edu
AF: Northern Arizona University
Department of Biological Sciences, PO Box 5640, Flagstaff, AZ 86011 United States
AU: * LeRoy, C J
EM: CJL2@dana.ucc.nau.edu
AF: Merriam Powell Center for Environmental Research, 207 Hanley Hall, Flagstaff, AZ 86011 United States
AU: Whitham, T G
EM: Thomas.Whitham@nau.edu
AF: Northern Arizona University
Department of Biological Sciences, PO Box 5640, Flagstaff, AZ 86011 United States
AU: Whitham, T G
EM: Thomas.Whitham@nau.edu
AF: Merriam Powell Center for Environmental Research, 207 Hanley Hall, Flagstaff, AZ 86011 United States
AU: Keim, P
EM: Paul.Keim@nau.edu
AF: Northern Arizona University
Department of Biological Sciences, PO Box 5640, Flagstaff, AZ 86011 United States
AU: Marks, J C
EM: Jane.Marks@nau.edu
AF: Northern Arizona University
Department of Biological Sciences, PO Box 5640, Flagstaff, AZ 86011 United States
AB:
Recent terrestrial research demonstrates the importance of genetic variation within tree species such as oaks, aspen and
cottonwoods in affecting the function of forest ecosystems. We show similarly that genetic variation within cottonwoods can
affect stream ecosystem function through litterfall. The genetic makeup of cottonwood leaf litter directly affects in-stream
leaf decomposition rates, aquatic fungal accumulation and macroinvertebrate assemblages. This genetic variation is especially important in the western United States because cottonwoods are a dominant riparian tree and are currently in dramatic
decline. In western rivers, cottonwood genetic diversity may be elevated due to naturally-occurring hybridization zones. We
collected litter from five genotypes of each of four cottonwood cross types from common garden trees and measured
decomposition rates using litterbag techniques in the Weber River (UT). Among the cottonwood genotypes decomposition rates
ranged on average from 0.0077 ± 0.0003 day-1 for backcross to P. angustifolia hybrids to 0.0105 ± 0.0003
day-1 for P. fremontii. Similar and substantial differences among F1 and backcross hybrids provide evidence
for genetic control over in-stream decomposition rates. Prior studies have shown that species diversity influences litter
quality and stream function. This study extends this by linking genetic diversity to stream ecosystem function.
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly