Wednesday, August 14, 2019: 8:00 AM-11:30 AM
M103, Kentucky International Convention Center
Organizer:
Eugenie Euskirchen
Co-organizer:
Jennifer M. Fraterrigo
Moderator:
Eugenie Euskirchen
The Arctic is warming more rapidly than other regions on the planet. This warming is shifting vegetation and changing plant productivity in the Arctic tundra while also causing thawing of carbon rich permafrost. Satellite imagery and repeat photography reveal a dramatic “greening” of vegetation apparent over the last several decades, including widespread increases in woody shrub growth, abundance, and cover. While pan-arctic model-based predictions suggest that generally at least half of all vegetated areas in the Arctic will shift to a different physiognomic class and woody cover will increase by as much as 52% by 2050, vegetation models applied to the Arctic have been confounded by a lack of parameterization data and a simplistic treatment of a highly heterogeneous region. For example, in the past, all arctic tundra vegetation types have often been treated simply as a C3 grass, and only recently, have permafrost processes been incorporated into arctic vegetation models. Furthermore, many of these models currently employ a limited set of parameterization data, with little understanding of how variations in these parameters may influence model outputs.
Although progress has been made in understanding changing tundra vegetation effects on aboveground physical processes and some work has been performed to represent them in arctic vegetation models, tundra vegetation effects on belowground processes remain poorly understood and underrepresented in current vegetation models for projecting future change. The over-simplification of belowground processes in models results in high uncertainty in estimates of C balance and changes in soil organic carbon, thus severely limiting capacity to quantify and predict carbon storage in these permafrost ecosystems.
The goal of this proposed session is to bring together experts in both arctic vegetation modeling and observationalists to discuss the most recent modeling approaches and how newly available arctic tundra field data, including field studies related to belowground processes, may best be incorporated into arctic vegetation models. In the proposed set of talks, we will ask speakers to provide information pertaining to the most important parameter uncertainties limiting model performance, identify species- and site-specific trait variations and belowground processes that confound current PFT-based models, and provide preliminary recommendations for alternative modeling approaches.
8:00 AM
Missing pieces to modeling the arctic-boreal puzzle
Joshua Fisher, California Institute of Technology;
Deborah Huntzinger, Northern Arizona University;
Daniel J. Hayes, University of Maine;
Christopher Schwalm, Northern Arizona University;
Kevin Schaefer, National Snow & Ice Data Center;
Eric Stofferahn, Conservation Science Partners
9:20 AM
Functional traits of absorptive roots in northern Alaska
Weile Chen, Zhejiang University;
Ken D. Tape, University of Alaska Fairbanks;
Eugenie Euskirchen, University of Alaska Fairbanks;
Shuang Liang, University of Illinois at Urbana-Champaign;
Jennifer M. Fraterrigo, University of Illinois at Urbana-Champaign
9:50 AM
Alder expansion and consequences for nitrogen availability on the Seward Peninsula
Verity G. Salmon, Oak Ridge National Laboratory;
Amy L. Breen, International Arctic Research Center, University of Alaska Fairbanks;
Jitendra Kumar, Oak Ridge National Laboratory;
Mark Lara, University of Illinois;
Peter E. Thornton, Oak Ridge National Laboratory;
Stan D. Wullschleger, Oak Ridge National Laboratory;
Colleen Iversen, Oak Ridge National Laboratory
10:10 AM
Cancelled
OOS 13-7