PARENT SESSION
Poster Session 19: Biodiversity
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Hydrological/Biogeochemical Controls Over Microbial Diversity Across Varying Spatial Scales In Antarctic Hyporheic Zones.
Bobb, Michael*,1, Zeglin, Lydia1, Gooseff, Michael2, Barrett, John3, Dahm, Cliff1, Takacs-Vesbach, Cristina1, 1 University of New Mexico, Albuquerque, NM, United States2 Colorado School of Mines, Golden, CO, United States3 Dartmouth University, Hanover, NH, United States
ABSTRACT- Aquatic-terrestrial transition zones have been identified as biogeochemical hot-spots because of the importance of these margins in facilitating hydrologic and biogeochemical exchanges between terrestrial and aquatic ecosystems. In the McMurdo Dry Valleys, Antarctica, this is even more evident due to the paucity of water in this polar desert. The scale of investigation can affect the microbial diversity observed over such gradients. We used denaturing gradient gel electrophoresis (DGGE) to assess microbial diversity in replicate samples representing spatial scales ranging from millimeters to meters. Representative samples were cloned and sequenced to identify the microbial communities detected at differing scales and position within the ecosystem. Preliminary data indicate that different communities may be detected depending on the sample size chosen. We present a statistical framework by which we identified the appropriate sampling scheme to use during our next field season. The data is correlated to biogeochemical and physical parameters that control the spatial distribution of microbial communities. Our results are discussed with respect to the importance of spatial heterogeneity in determining sample size and frequency when characterizing overall microbial diversity within the aquatic-terrestrial interface of this ecosystem.
Key words: biodiversity, hyporheic zone