HR: 08:45h
AN: NB41C-02    [Abstracts]
TI: Dissolved O₂, CO₂, CH₄, and N₂O as indicators of biogeochemical processes in headwater streams.
AU: * Beaulieu, J J
EM: jbeaulie@nd.edu
AF: Univ. of Notre Dame, Dept. of Biological Sciences, Notre Dame, IN 46628
AU: Hamilton, S K
AF: Michigan State Univ., Kellogg Biological Station, Hickory Corners, MI 49060
AU: Bohm, S
AF: Michigan State Univ., Kellogg Biological Station, Hickory Corners, MI 49060
AU: Tank, J L
AF: Univ. of Notre Dame, Dept. of Biological Sciences, Notre Dame, IN 46628
AU: Bernot, M J
AF: Univ. of Notre Dame, Dept. of Biological Sciences, Notre Dame, IN 46628
AU: Ashkenas, L R
AF: Oregon State Univ., Dept. of Fisheries and Wildlife, Corvallis, OR 97331
AU: Crenshaw, C L
AF: Univ. of New Mexico, Dept. of Biology, Albuquerque, NM
AU: Dahm, C
AF: Univ. of New Mexico, Dept. of Biology, Albuquerque, NM
AU: Dodds, W K
AF: Kansas State Univ., Div. of Biology, Manhattan, KS 66506
AU: Findlay, S E
AF: Institute of Ecosystem Studies, IES, Millbrook, NY 12545
AU: Gregory, S
AF: Oregon State Univ., Dept. of Fisheries and Wildlife, Corvallis, OR 97331
AU: Grimm, N
AF: Arizona State Univ., School of Life Sciences, Tempe, AZ 85287
AU: Hall, R O
AF: Univ. of Wyoming, Dept. of Zoology and Physiology, Laramie, WY 82071
AU: Johnson, S L
AF: Pacific Northwest Research Station, US Forest Service, Corvallis, OR 97331
AU: McDowell, W H
AF: Univ. of New Hampshire, Dept. of Natural Resources, Durham, NH 03824
AU: Merriam, J L
AF: Univ. of New Hampshire, Dept. of Natural Resources, Durham, NH 03824
AU: Mulholland, P J
AF: Oak Ridge National Laboratory, Environmental Sciences Division, Oak Ridge, TN 37831
AU: Peterson, B J
AF: Marine Biological Laboratory, Ecosystems Center, Woods Hole, MA 02543
AU: Sheibley, R W
AF: Arizona State Univ., School of Life Sciences, Tempe, AZ 85287
AU: Thomas, S
AF: Marine Biological Laboratory, Ecosystems Center, Woods Hole, MA 02543
AU: Valett, M H
AF: Dept. of Biology, Virginia Polytechnic Institute and State University, Blacksburg, VG 24061
AU: Webster, J R
AF: Dept. of Biology, Virginia Polytechnic Institute and State University, Blacksburg, VG 24061
AB: The concentrations of carbon dioxide (CO₂), oxygen (O₂), methane (CH₄), and nitrous oxide (N₂O) dissolved in streamwater are determined by both in-stream biogeochemical transformations and chemical properties of the gases. Dissolved gas concentrations deviating from those expected based solely on atmospheric equilibrium indicate the influence of biogeochemical activity. To assess patterns in dissolved gas concentrations we sampled 23 headwater streams varying in watershed land-use. These streams were distributed across 8 biomes in the U.S. CH₄ concentrations were variable ranging from below detection to >4000 times equilibrium concentrations (bd-10 μmol CH₄/L) and 87% of the streams were supersaturated, suggesting that methanogenesis is common in small streams. N₂O concentrations were less variable, ranging from 0.4 to 10 times equilibrium concentrations (3.2 -86 νmol N₂O/L), and 86% of the streams were supersaturated with N₂O, presumably due to denitrification and perhaps nitrification. Finally, all but two streams were supersaturated with CO₂ (10.3-1335 μmol CO₂/L), which is consistent with the ubiquitous nature of aerobic heterotrophic respiration. These data demonstrate that headwater streams are often supersaturated with trace gases, likely due to both in-stream biogeochemical processes and inputs of groundwater with high dissolved gas concentrations.
DE: 1806 Chemistry of fresh water
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly