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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Land/Water Interfaces
CARBON AND NITROGEN DISTRIBUTION ALONG HYDROLOGIC-REDOX POTENTIAL GRADIENTS IN TWO RIPARIAN MEADOWS, NORTHEAST OREGON.
K.A. Dwire1, E.J. Brookshire2, and J.B. Kauffman3. 1USDA Forest Service, Rocky Mountain Research Station, Laramie, Wyoming 82070, 2Department of Biology, Virginia Polytechnic and State University, Blacksburg, VA 24061, 3Department of Fisheries and Wildlife, Oregon State University, Corvallis OR 97333
As low gradient depositional floodplains, montane meadows may serve as important sinks for organic matter. To increase understanding of organic matter dynamics between riparian meadows and streams, we quantified carbon (C) and nitrogen (N) pools in plant biomass and soil along hydrologic-redox potential gradients that extended from streamside wet meadow communities to dry meadow communities, located on floodplain terraces. Plant biomass carbon (0.40 to 2.01 kg m-2) and nitrogen (0.01 to 0.04 kg m-2) pools were dominated by belowground components, and differed among communities (wet > moist > dry meadow). In contrast, soil pools were highest in dry meadows and similar in wet and moist meadows. 'Biomass + soil' C pools were composed of 2 to 4% aboveground biomass, 2 to 23% belowground biomass, and 81 to 95% mineral soil; N pools were composed of 0.07 to 1.6% aboveground biomass, 1.5 to 6% belowground biomass, and 94-98% mineral soil. Total biomass C and N pools, soil N pools, and soil C:N were strongly correlated to median water table elevation and redox potential, suggesting that hydroperiod is a dominant control over accumulation and storage of C and N in these riparian meadows.
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