OOS 29 - Linking Terrestrial Nitrogen Fixation, Element Cycling, and Biodiversity in a Changing World

Wednesday, August 9, 2017: 1:30 PM-5:00 PM
Portland Blrm 257, Oregon Convention Center
Duncan N. L. Menge, Columbia University
Efrat Sheffer, Hebrew University of Jerusalem; and Benton N. Taylor, Columbia University
Duncan N. L. Menge, Columbia University
Nitrogen fixation is the primary natural source of new nitrogen in ecosystems. This new nitrogen can fuel productivity and sustain carbon storage, but it can also cause nitrogen saturation, potentially exacerbating environmental issues such as eutrophication and greenhouse warming. How the diverse groups of plants and bacteria involved in nitrogen fixation respond to environmental change, then, has major implications for biodiversity and ecosystem functioning. Indeed, recent modeling efforts indicate that the dynamics of nitrogen fixation are integral to forecasting global carbon dynamics, suggesting that a better understanding of nitrogen fixation will greatly improve our predictions of global climate change. In addition to driving environmental issues, nitrogen fixation also responds to anthropogenic environmental changes, creating feedback loops. Recent work has made great inroads into resolving some of the key questions concerning terrestrial nitrogen fixation. Much of this recent work has focused on four topics: the roles of (1) biodiversity and traits that are evolutionarily linked to nitrogen fixation; of (2) elements such as carbon, nitrogen, phosphorus, and molybdenum; of (3) global environmental change; and of (4) the dynamics of the symbiotic interaction between nitrogen-fixing bacteria and their plant hosts. This session brings together some of the leaders of these recent efforts, with expertise ranging from ecosystem science to physiology to the evolutionary dynamics of symbioses, and across a range of ecosystem types. This wide range of perspectives on nitrogen fixation showcases the broad spectrum of research focused on linking the nitrogen inputs from fixation to the biodiversity and ecosystem functioning that both respond to and help determine future global environmental change.
1:50 PM
 Does a transition in nitrogen fixation strategy explain the latitudinal distribution of nitrogen-fixing trees?
Amelia A. Wolf, Columbia University; Duncan N. L. Menge, Columbia University; Jennifer L. Funk, Chapman University; Steven Perakis, US Geological Survey
2:10 PM
 Community dynamics at centimeter scales: Nitrogen fixation controls in dryland biological soil crusts
Sasha C. Reed, U.S. Geological Survey; Jayne Belnap, U.S. Geological Survey; Nichole N. Barger, University of Colorado Boulder; Stacy Schwabedissen, Idaho State University; Kathleen A. Lohse, Idaho State University
2:30 PM
 Woody legumes reveal links among biogeochemical cycles
Mark A. Adams, University of Sydney; Tarryn L. Turnbull, University of Sydney
3:10 PM
3:20 PM
 Longleaf pine savannas house diverse niches of nitrogen fixation
Julie Tierney, University of Georgia; Nina Wurzburger, University of Georgia
3:40 PM
 Time-lags in the regulation of symbiotic nitrogen fixation measured in real time
Thomas A. Bytnerowicz, Columbia University; Kevin L. Griffin, Columbia University; Duncan N. L. Menge, Columbia University
4:00 PM
 Effects of the legume-rhizobia mutualism on biodiversity-ecosystem function relationships
Kimberly J La Pierre, Smithsonian Environmental Research Center; Ellen Simms, University of California Berkeley
4:20 PM
 The spiny broom chronicle: N2-fixation strategies of perennial legumes in dry Mediterranean ecosystems
Guy Dovrat, The Hebrew University of Jerusalem; Efrat Sheffer, The Hebrew University of Jerusalem
4:40 PM
 Phylogenetic controls on symbiotic nitrogen fixation during secondary succession in the Atlantic Forest of Bahia, Brazil
Joy Winbourne, Brown University; Daniel Piotto, Universidade Federal do Sul da Bahia; W. John Kress, Smithsonian Institution; Stephen Porder, Brown University