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Communication at the NABS Annual meeting, Keystone, 2000
(308) CONTROLS ON STREAM METABOLISM DETERMINED BY AN INTERBIOME COMPARISON STUDY.
P.J. Mulholland1, C.S. Fellows2, J.L. Tank3, S.K. Hamilton4, E. Marti5, L.R. Ashkenas6, W.B. Bowden7, W.K. Dodds8, W.H. McDowell9, J.L. Meyer10, B.J. Peterson11, and J.R. Webster12. 1Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, 2Department of Biology, University of New Mexico, Albuquerque, NM, 87131, 3Department of Natural Resources and Environmental Sciences, University of Illinois, N-411 Turner Hall, Urbana, IL, 61801, 4Kellogg Biological Station, Michigan State University, 3700 E Gull Lake Dr, Hickory Corners, MI, 49060, 5Department of Zoology, Arizona State University, Tempe, AZ 85287, 6Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, 97331, 7Landcare Research, P.O. Box 69, Lincoln 8152, New Zealand, 8Division of Biology, Kansas State University, 232 Ackert Hall, Manhattan, KS, 66506, 9Department of Natural Resources, James Hall, University of New Hampshire, Durham, NH, 03824, 10Institute of Ecology, University of Georgia, Athens, GA, 30602, 11Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA, 02543, 12Department of Biology, Virginia Tech., Blacksburg, VA, 24061
Rates of stream metabolism were determined for 9 North American streams using the upstream-downstream diurnal oxygen change technique. This study was part of the Lotic Intersite Nitrogen Experiment (LINX), and included forested streams from the tropics (Puerto Rico) to the north temperate zone (New Hampshire, Oregon) and one grassland stream (Kansas). Measurements in each stream were made on one date under baseflow and clear to partly cloudy weather during one season, and related to various ecosystem characteristics. Gross primary production rates (GPP) ranged from 0.1 gO2 m-2d-1 in Quebrada Bisley, Puerto Rico and Upper Ball Creek, NC, in autumn to 15 gO2 m-2d-1 in Sycamore Creek, AZ, in spring. Light was the primary determinant of GPP (r2=0.64, P=0.018), and together light and streamwater phosphorus concentration explained 85% of the variance in GPP. Ecosystem respiration rates (R) ranged from 1.9 gO2 m-2d-1 in Walker Branch, TN, in spring to 9.6 gO2 m-2d-1 in Mack Creek, OR, in summer. Stream phosphorus concentration was the primary determinant of R (r2=0.62, P=0.021), although transient storage zone size was a marginally-significant predictor (r2=0.45, P=0.067). Based on these results, terrestrial biome and season appear to have a stronger effect on GPP than on R.
Presented at 2:15 PM on Thursday, June 1, 2000 in Nutrient Dynamics I
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