Soil carbon residence time in the Arctic – model response to key environmental drivers

Deborah Nicole Huntzinger, Northern Arizona University, deborah.huntzinger@nau.edu (Presenter)
Joshua B. Fisher, NASA JPL, jbfisher@jpl.nasa.gov
Christopher R Schwalm, Woods Hole Research Center, schwalm.christopher@gmail.com
Daniel Hayes, University of Maine, daniel.j.hayes@maine.edu
Eric Stofferahn, Jet Propulsion Laboratory / Caltech, ericstofferahn@gmail.com
Wouter Hantson, University of Maine, wouter.hantson@maine.edu
Kevin M Schaefer, National Snow and Ice Data Center, kevin.schaefer@nsidc.org
Anna M Michalak, Carnegie Institution Of Washington, michalak@stanford.edu
Yuanyuan Fang, Carnegie Institution for Science, yyfang@carnegiescience.edu
Yaxing Wei, Oak Ridge National Laboratory, weiy@ornl.gov

Carbon residence time is one of the most important factors controlling carbon cycling in ecosystems. Residence time depends on carbon allocation and conversion among various carbon pools and the rate of organic matter decomposition; all of which rely on environmental conditions, primarily temperature and soil moisture. As a result, residence time is an emergent property of models and a strong determinant of terrestrial carbon storage capacity. However, residence time is poorly constrained in process-based models due, in part, to the lack of data with which to benchmark global-scale models in order to guide model improvements and, ultimately, reduce uncertainty in model projections. Here we focus on improving the understanding of the drivers to observed and simulated carbon residence time in the Arctic-Boreal region (ABR). Carbon-cycling in the ABR represents one of the largest sources of uncertainty in historical and future projections of land-atmosphere carbon dynamics. This uncertainty is depicted in the large spread of terrestrial biospheric model (TBM) estimates of carbon flux and ecosystem carbon pool size in this region. Recent efforts, such as the Arctic-Boreal Vulnerability Experiment (ABoVE), have increased the availability of spatially explicit in-situ and remotely sensed carbon and ecosystem focused data products in the ABR. Together with simulations from Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), we use these observations to evaluate the ability of models to capture soil carbon stocks and changes in the ABR. Specifically, we compare simulated versus observed soil carbon residence times in order to evaluate the functional response and sensitivity of modeled soil carbon stocks to changes in key environmental drivers. Understanding how simulated carbon residence time compares with observations and what drives these differences is critical for improving projections of changing carbon dynamics in the ABR and globally.

Associated Project(s): 

• Fisher-01

Poster Location ID: 40

Session Assigned: Modeling