Recent Sphagnum peatland expansion on the North Slope of Alaska

Link To Share This Poster: https://cdmcd.co/ybPXML

Alexis Renee Stansfield, Earth & Environmental Sciences, Lehigh University, Bethlehem, PA, Robert K. Booth, Earth and Environmental Science, Lehigh University, Bethlehem, PA, Julie Loisel, Texas A&M and Ava Scally, Lehigh University

Background/Question/Methods
As the climate has warmed over the past several decades, high-latitude regions have warmed more than the rest of the world. The ecological effects of this arctic amplification have the potential to lead to strong climate feedbacks, particularly given the abundance of carbon-rich ecosystems in these regions. Recent observations on the North Slope of Alaska have revealed patches of Sphagnum peat within the more widespread matrix of sedge-dominated tundra communities. These “peat-patches” may represent incipient peatlands, potentially forming in response to the hydrological and climatic changes of the region over the last several decades or century. In this study, we used radiometric dating, plant macrofossils, and testate amoebae from a network of sediment cores collected from peat patches on the North Slope. We use these data to assess the timing of Sphagnum-peatland formation and characterize the hydrological conditions associated with peat-patch establishment.

Results/Conclusions
Results from seven sediment cores suggest that Sphagnum has been present on the North Slope for at least the last couple centuries. However, our analyses indicate that most peat patches likely formed in the last 30-40 years. Results of testate amoeba analysis indicate that the establishment of Sphagnum peat patches was associated with wetter and more stable surface-moisture conditions, and a shift toward domination of communities by Archerella flavum, a mixotrophic species that lives within the water film of wet, Sphagnum moss. Future work will focus on better constraining the timing of Sphagnum expansion across the North Slope from our network of cores, as well as quantifying changes in hydrology and carbon accumulation that resulted from Sphagnum peat-patch expansion.