PARENT SESSION
Poster Session # 4: Paleoecology.
Monday, August 4 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Ecology of testate amoebae in Rocky Mountain peatlands and their application to paleohydrological reconstruction.
Zygmunt, Jennifer*,1, Booth, Robert1, Jackson, Stephen 1, 1 Department of Botany, University of Wyoming, Laramie, WY, USA
ABSTRACT- Testate amoebae (Protozoa: Rhizopoda) are abundant and well-preserved in Sphagnum-dominated peatlands, where their distribution is primarily controlled by surface moisture. Recent work has demonstrated that testate amoebae are sensitive paleohydrological indicators, and quantitative paleoclimate reconstructions with multi-decadal to centennial-scale resolution have been obtained from North America in the western Great Lakes region. However, baseline data describing testate amoeba ecology are needed to support paleohydrological studies in other regions. We investigated the relationship between environmental conditions and testate amoebae in 139 samples collected from 15 Sphagnum-dominated peatlands of the central Rocky Mountain region. Our primary objectives were to: 1) identify environmental controls on testate amoeba distribution in the region, 2) develop transfer functions to infer environmental conditions from fossil testate amoeba assemblages, and 3) compare testate amoeba assemblages and species-environment relationships between the central Rocky Mountains and western Great Lakes regions to assess biogeographical patterns. Our results indicate that substrate moisture, measured as depth to the water table, is the dominant control on assemblage composition. Assuming good modern analogues, past changes in water-table depth can be reconstructed from fossil assemblages with a mean error of 7.0 cm. Over 50% of the taxa encountered in the western Great Lakes region are also found in Rocky Mountain peatlands, and moisture preferences of these taxa are similar in both regions. We use our calibration dataset to infer hydrological history of a Sphagnum-dominated peatland in Yellowstone National Park. Our preliminary results suggest testate amoebae have great potential for generating sensitive, high-resolution records of past moisture variability in the central Rocky Mountain region.
Key words: paleoclimate, climate variability, testate amoebae, Rocky Mountains