OOS 72
Microbial Efficiency: Perspectives on the Fate of Metabolized Organic Carbon in a Changing World

Thursday, August 13, 2015: 1:30 PM-5:00 PM
315, Baltimore Convention Center
Organizer:
Kevin M. Geyer
Co-organizers:
Serita Frey and A. Stuart Grandy
Moderator:
Serita Frey
Defining and measuring microbial efficiency (i.e., ME - the proportion of carbon directed towards biosynthesis during microbial metabolism) is a difficult challenge faced by ecologists and ecological modelers alike. Our current understanding of this variable has developed from numerous valuable, yet unstandardized, approaches (e.g., physiological, ecological, mathematical). Because ME has the potential to tip the balance between ecosystem-level sequestration and net release of carbon, it is both timely and necessary that the ecological community develop an integrated understanding of this topic. For example, existing techniques for measuring ME (e.g., 13- or 14-C uptake, calorespirometry) are inherently limited by various methodological assumptions and recognizing these limitations will help to explain the range of ME estimates regularly published. The sensitivity of ME to environmental (e.g. temperature, carbon substrate diversity), physiological (e.g. growth rate), and community (e.g. r vs. K strategist) parameters is also of primary importance. The goal of this session is to review the current state of inquiry surrounding microbial efficiency from a variety of approaches in both soil and aquatic environments. We will cover 1) new and traditional methods for estimating ME and their inherent advantages/disadvantages for addressing specific questions, 2) existing terminology used in ME research and efforts towards a universal, integrated conceptual framework, 3) the response of ME to various stressors, 4) the sensitivity to ME of model projections for future scenarios of carbon cycling, and 5) future directions for examining ME that can provide direct and immediate insights towards mitigation of human-induced environmental change.
1:30 PM
Unifying concepts for communicating and interpreting measures of microbial efficiency
Kevin M. Geyer, University of New Hampshire; Emily Kyker-Snowman, University of New Hampshire; A. Stuart Grandy, University of New Hampshire; Serita Frey, University of New Hampshire
1:50 PM
Carbon and nitrogen use efficiency of heterotrophic microbial communities: Concepts and emerging techniques
Andreas Richter, University of Vienna; Lucia Fuchslueger, University of Vienna, Austria; Christina Kaiser, University of Vienna; Karoline Klaus, University of Vienna; Maria Mooshammer, University of Vienna, Austria; Joerg Schnecker, University of Vienna, Austria; Marie Spohn, University of Vienna, University of Bayreuth, Germany; Mounir Takriti, University of Vienna, Austria, Lancaster University, UK; Wolfgang Wanek, University of Vienna, Austria; Birgit Wild, University of Vienna, Austria, University of Gothenburg, Sweden
2:10 PM
Microbial life histories
Thomas Schmidt, University of Michigan; Benjamin Roller, University of Michigan
2:30 PM
Bacterial growth efficiency: Do consumer and resource diversity influence the fate of carbon in aquatic ecosystems?
Mario E. Muscarella, Indiana University; Jay T. Lennon, Indiana University
3:10 PM
3:20 PM
Biochemistry and ecology of carbon use efficiency in soil ecosystems
Paul Dijkstra, Northern Arizona University; Shannon Hagerty, Northern Arizona University, University of California, Santa Barbara; Kees-Jan van Groenigen, Northern Arizona University; Bruce A. Hungate, Northern Arizona University; Jane C. Marks, Northern Arizona University; George W. Koch, Northern Arizona University; Egbert Schwartz, Northern Arizona University
3:40 PM
Macroscale analysis of microbial community homeostasis
Robert Sinsabaugh, University of New Mexico; Daryl L. Moorhead, University of Toledo; Stuart E.G. Findlay, Cary Institute of Ecosystem Studies; Kevin A. Kuehn, University of Southern Mississippi; Jennifer Follstad Shah, University of Utah
4:00 PM
Modeling carbon use efficiency at multiple levels of system complexity
Emily Kyker-Snowman, University of New Hampshire; Kevin M. Geyer, University of New Hampshire; Will R. Wieder, National Center for Atmospheric Research; A. Stuart Grandy, University of New Hampshire; Serita Frey, University of New Hampshire
4:20 PM
Implications of representing microbial physiology in soil C projections across scales
Will R. Wieder, National Center for Atmospheric Research; A. Stuart Grandy, University of New Hampshire; Philip G. Taylor, University of Colorado; Cynthia Kallenbach, University of New Hampshire; Emily Kyker-Snowman, University of New Hampshire; Gordon Bonan, NCAR