Long-Term Hydrological Reconstruction From a Beaver Meadow Using Testate Amoebae
Abstract
Beaver ponds contribute up to 0.8 Tg/yr of atmospheric methane (CH4) globally (Whitfield et al., 2014) and were found to be the largest CH4 emitters among all the wetland types in boreal environments (Roulet et al., 1992). However, the sources and underlying mechanisms of carbon emission and sequestration in beaver ponds requires further elucidation. Here we present the historical development of a beaver meadow located in the Sibbald Research Wetland in the Rocky Mountains of Kananaskis Provincial Park, Alberta, Canada. We use a combination of testate amoebae, plant macrofossils, and other geochemical proxies to provide high-resolution reconstructions along three peat cores extracted in hydrologically distinct portions of the meadow. To our knowledge, this is the first attempt at reconstructing long-term hydrological conditions in these systems. Testate amoebae (Protozoa: Rhizopoda) are single-celled organisms that inhabit moist substrates and produce a decay-resistant test. As each taxon generally occupies a discrete ecological niche related to soil moisture and pH, testate amoebae are good indicators of past and ongoing hydrological change. Preliminary analysis of testate amoebae assemblages downcore suggests that this proxy is suitable to reconstruct hydrological changes in meadows, with wetter and drier communities being in good agreement with wetter and drier plant macrofossil assemblages. The nitrogen isotopic signature of peat samples (ongoing) will be used as a proxy for changes in nutrient input; it could become a proxy for past beaver activity.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.B23B0585V
- Keywords:
-
- 0315 Biosphere/atmosphere interactions;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 1615 Biogeochemical cycles;
- processes;
- and modeling;
- GLOBAL CHANGEDE: 1890 Wetlands;
- HYDROLOGY