PS 28-156 - Pedogenesis, permafrost, and C dynamics of alpine ecosystems in the Snowy Range Mountains, Wyoming

Tuesday, August 8, 2017
Exhibit Hall, Oregon Convention Center
Karen Vaughan, Zoe Ash-Kropf and Linda T.A. van Diepen, Ecosystem Science and Management, University of Wyoming, Laramie, WY
Background/Question/Methods

High alpine ecosystems provide a unique environment within which to examine complex biological, chemical, and physical processes on the fringe of extreme climatic conditions. These fragile environments exist in cold, harsh climates and in some cases, provide conditions for the formation and/or occurrence of permanently frozen ground, or permafrost. Permafrost is of particular importance because it is vulnerable to thaw under potential future warmer climate scenarios. The effect on alpine pedogenic process due to thawing permafrost is unknown. Permafrost soils contain large concentrations of organic carbon that upon oxidation and methane production could result in large amounts of greenhouse gasses (CO2 and CH4) being released into the atmosphere. Although not well documented, it is predicted that permafrost exists above 3,300 m in the Snowy Range Mountains of the Medicine Bow-Routt National Forest in Wyoming. A model of the spatial extent and vertical profile of permafrost has been developed using a combination of remote sensing and geophysical tools coupled with on the ground pedological and ecological techniques. The objective of the research is to examine the influence of climate on high alpine belowground ecosystems including pedological processes and C biogeochemistry related to permafrost.

Results/Conclusions

After the conclusion of a single field season, active permafrost has yet to be observed. Abundant evidence exists, including oriented rocks and patterned ground, that permafrost was at one time active in the region, however, current conditions appear to prove that permanently frozen ground is absent from the upper 2 m. Soil organic C content coupled with bulk density measurements of soil samples collected in alpine areas proves high potential for C sequestration in these ecosystems. Our results lead to conclusions that high concentrations of C is sequestered in alpine soils at a rate greater than would be expected had the ground not been permanently frozen for some time. Although preliminary, these results conclude that forces of cryoturbation, dust accumulation, and melanization of C in the soils drives ecosystem processes in belowground alpine environments of the Snowy Range Mountains.