B31D-0595
Towards a better understanding of the sensitivity of permafrost and soil carbon to climate and disturbance-induced change in Alaska
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Neal J. Pastick1, Torre Jorgenson2, Bruce K Wylie3, Burke J Minsley4, Dana Nossov Brown5, Helene Genet6, Kristofer D Johnson7, Anthony David McGuire8, Andy Kass4 and Joseph F Knight9, (1)Stinger Ghaffarian Technologies Sioux Falls, Sioux Falls, SD, United States, (2)Alaska Ecoscience, Fairbanks, AK, United States, (3)USGS Earth Resources Observation and Science Center, Sioux Falls, SD, United States, (4)USGS, Denver, CO, United States, (5)University of Alaska Fairbanks, Fairbanks, AK, United States, (6)Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States, (7)U.S. Forest Service, Newtown Square, PA, United States, (8)U.S. Geological Survey, University of Alaska Fairbanks, Fairbanks, AK, United States, (9)University of Minnesota, Department of Forest Resources, St. Paul, MN, United States
Abstract:
Recent increases in air temperature and disturbance activity have led to amplified rates of permafrost degradation and carbon remobilization across portions of Alaska. Further warming, coupled with increases in disturbance frequency and severity (i.e. wildfire, thermokarst), may exacerbate permafrost thaw and disappearance, which would have a profound effect on high-latitude ecological and socio-economic systems. Here we present research aimed at characterizing the sensitivity of different permafrost landscapes to climate and disturbance-induced change through a compilation of in-situ observations, remote sensing and geophysical data, time series analyses, and spatio-temporal modeling. Our data-driven approach allowed for the development of a quantitative assessment of permafrost’s potential response to climate change. This analysis also identified indicators of permafrost’s susceptibility to disturbances in Alaska. Initial results suggest that further climate-induced permafrost degradation is most likely to occur in regions characterized by discontinuous permafrost and transition zones between tundra, boreal, and temperate forest ecosystems. Permafrost-affected soils, underlying upland ecosystems, are typically more prone to climate and fire-induced change than lowland ecosystems with relatively thicker organic soil layers. However, field and geophysical data indicate that carbon rich silty lowlands are also prone to deep permafrost thaw (> 5 m) following severe disturbance. Because a substantial amount of frozen soil carbon will become susceptible to decomposition upon permafrost thaw, we combined recently developed permafrost carbon maps and future projections of permafrost distribution to highlight areas that may become potential emission hotspots under warmer temperatures. Despite advances in understanding of the drivers of ecological change, more work is needed to integrate studies that link observations of permafrost dynamics to factors that drive those dynamics.
