GIS-based drainage types of Alaska. Light colors are excessively well drained, dark colors are very poorly drained. Clicking on the photo will bring up an enlarged image. Click here for a paper on soil drainage and carbon in Alaska. |
|
Our primary modeling objective is to establish a strategy for the regionalization of field measurements in order to
- maximize the utility of and insights gained from our field data
- strengthen existing carbon models by introducing a process-level understanding of carbon exchange.
Previous work has demonstrated the importance of including soil drainage and fire disturbance as key parameters in defining the fate of carbon due to their effect on fire severity, decomposition, and vegetation structure/function. Our modeling efforts include:
- The Terrestrial Ecosystem Model (TEM). Work by the group of David McGuire
(USGS/Univ. of Alaska) has expanded TEM to include important environmental factors such as moss and snow thermal conductivity and thickness (all of which impact soil temperatures in organic soil layers),
soil factors such as soil carbon lability and carbon-nitrogen interactions, and disturbances such as fire.
- A site-specific process model aimed at determining the key soil mechanisms that must be represented when scaling from the site to the regional level.
This model is being developed by Jason Neff.
- GIS-based modeling of soil drainage and fire history combined with long-term carbon mass balance.
Modeling efforts are breaking new ground by dealing with both soil drainage (from a spatial perspective) and fire (from both a spatial and temporal perspective). Process-based models will help test the sensitivity of carbon to factors such as fire combustion, plant structure,
permafrost, and mineral/organic complexation. Spatially explicit process-based models are being used to produce carbon exchange estimates that, in addition to soil drainage and fire occurrence, will incorporate spatial and temporal variation in climate and atmospheric CO2.
Future modeling collaborations will be within the scope of the new permafrost research with both Vladimir Romanovsky at the University of Alaska, Fairbanks and Qianlai Zhuang at Purdue University.
|
U.S. Department of the Interior |
U.S. Geological Survey