Purdue Climate Change Research Center

Impact of Permafrost Degradation on Carbon and Water in Boreal Ecosystems

Funded by the National Science Foundation

This large-scale field and modeling study seeks to

  1. Assess interactive effects of climate change and fire on permafrost stability
  2. Quantify how the varying modes of permafrost degradation initiate various thaw regimes on the landscape by affecting the microtopography, drainage, and soil thermal regimes of boreal systems
  3. Determine how various thaw regimes such as drained or ponded systems affect carbon loss or accumulation in biomass and soils, and
  4. Characterize the export of dissolved organic carbon from watersheds in an effort to fingerprint the various thaw regimes induced by permafrost degradation.

Two field campaigns in years 2007 and 2008 have been completed at five study sites, with a third field season planned for summer, 2009. Temperature, moisture, and water table data will be collected to parameterize the physical conditions of each thaw regime and the team will test model results based on water melt chemistry and trace gas fluxes.

The process-based modeling system has been further developed to couple hydrology and heat conduction dynamics in soils and permafrost. The revised model has been applied to the Alaskan boreal forest and tundra ecosystems to examine changes in soil thermal and hydrological regimes and their impacts on plant phenology (Tang and Zhuang, 2009, in review, Journal of Climatic Change). The modeling system has explicitly considered the feedbacks between soil moisture and water table depth, and soil temperature profile and active layer depth, and PCCRC graduate student fellow Jinyun Tang served as lead author on the paper.

Investigator(s)

  • Qianlai Zhuang, EAS and Agronomy
  • J. Harden, USGS Menlo Park
  • R. Striegl, USGS Denver
  • Y. Shur, University Alaska, Fairbanks
  • D. Jorgenson, Alaska Ecological Survey

Contact Information

Purdue University
PCCRC
203 S. Martin Jischke Drive
MANN 105
West Lafayette, IN 47907