Depth-Resolved Physicochemical Characteristics of Active Layer and Permafrost Soils in an Arctic Polygonal Tundra Region

Permafrost physicochemical property trends and variabilities.

The Science

Next-Generation Ecosystem Experiments (NGEE)–Arctic scientists from Oak Ridge National Laboratory (ORNL) explore the trends and variabilities of the permafrost physicochemical properties.

The Impact

These results are critical for identifying approaches to upscale point-based measurements and for improving model parameterization to predict permafrost carbon behavior and feedback under future climate.

Summary

NGEE-Arctic scientists from ORNL observed (1) consistent relationships between soil property and depth and between major parameters; (2) large contrasts of key soil parameters between active layer and permafrost, indicative of potentially different response of the permafrost carbon to warming when compared to the active layer; and (3) a correlation between soil hydraulic conductivity and topographic features that impacts soil hydrologic processes. This analysis suggests that the permafrost has a marine-derived chemical signature that differs from the active layer and shapes the physicochemical fingerprints of the different geomorphic features. Specifically, they revealed the unique signatures of the high-center polygons, indicative of possible microbial activity at depth (>1 m). Their study suggested consistent key soil parameter–depth correlations while demonstrating complex lateral and vertical variabilities.

Principal Investigator

Stan Wullschleger
Oak Ridge National Laboratory
wullschlegsd@ornl.gov

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

The Next-Generation Ecosystem Experiments (NGEE)–Arctic project is supported by the Office of Biological and Environmental Research, within the U.S. Department of Energy (DOE) Office of Science. This NGEE-Arctic research is supported through contract number DE-AC0205CH11231 to Lawrence Berkeley National Laboratory.

Related Links

References

Wu, Y., C. Ulrich, T. Kneafsey, and R. Lopez. "Depth-resolved physicochemical characteristics of active layer and permafrost soils in an Arctic polygonal tundra region". Journal of Geophysical Research: Biogeosciences 123 (4), 1366–1386  (2018). http://dx.doi.org/10.1002/2018JG004413.