1. Assessing the Resilience and Vulnerability of Permafrost Landscapes to Environmental Change
Torre Jorgenson, Yuri Shur,
Mikhail Kanevskiy, Matt Dillon, and Eva Stephani

2. Approach to Assessing Permafrost Stability
Define permafrost in relation to climate and ecosystems
Determine ground ice characteristics in relationships to terrain units
Assess magnitude of positive and negative feedbacks related to vegetation and water
Compare permafrost stability in relation to terrain

3. Redefined Permafrost in Terms of Climate-Ecosystem Relationships
Shur, Y. L. and Jorgenson, M. T Patterns of permafrost formation and degradation in relation to climate and ecosystems. Permafrost and Periglacial Processes 18: 7-19.

4. Climate-driven, Ecosystem-modified Permafrost
Ecologically mediated ice aggradation increases vulnerability to degradation
Vegetation-soil processes in the thinning active layer allow accumulation of 2-3 m of excess ice during floodplain evolution. Buildup of excess ice in upper permafrost form conditions for development of thaw lakes, even under cold climates
Floodplain evolution
Thermokarst lake development at MAATs of -12 C

5. Ecosystem-Driven Permafrost
Ground ice aggradation in relation to Sphagnum growth
Soil drainage after permafrost degradation

6. Ecosystem-Protected Permafrost
Fish Creek
MAAT C
Naknek Lake
MAAT +1.5 C
Layered ice in epigenetic permafrost formed in “warm” climates
Ataxitic ice in syngenetic permafrost formed in cold climates

7. A New Permafrost Map for Alaska
Map based on terrain units and climate
From Jorgenson et al Permafrost Characteristics of Alaska. NICOP Proceedings

8. Relating Ground Ice to Terrain Units
Glaciomarine
Kanevskiy et al. submitted
Loess Kanevskiy et al. submitted
Colluvium
From Jorgenson et al Permafrost Characteristics of Alaska. NICOP Proceedings

9. Ice Volume in Relation to Terrain Units
Lacustrine Organic Silt
Eolian Sand

10. Buried Glacier Ice Barter Island
Abundant in Wisconsin and Little Ice Age Moraines
Toolik Lake, NE14
Basal Ice
Matanuska Glacier
Basal Ice
Barter Island
Kanevskiy, M., T. Jorgenson, Y. Shur, and M. Dillon (2008), Buried glacial basal ice along the Beaufort Sea Coast, Alaska, Eos Trans. 89, 53, C11D-0531.

11. Generalized ice profiles for common types of permafrost
Resilience and vulnerability of permafrost depends on type and amount of ground ice
Conceptual model by M. Kanevskiy
Jorgenson, M. T., Romanovsky, V., Harden, J., Shur, Y., O’Donnell, J., Schuur, E. A. G. and Kanevskiy, M Resilience and Vulnerability of Permafrost to Climate Change. Canadian J. Forest Research.

12. Feedbacks Strongly Affect Permafrost Stability
Permafrost can degrade at MAATs of -20 C due to surface water
Permafrost can persist at MAATs of +2 C due to protection by vegetation and organic soil
Jorgenson, M. T., Romanovsky, V., Harden, J., Shur, Y., O’Donnell, J., Schuur, E. A. G. and Kanevskiy, M Resilience and Vulnerability of Permafrost to Climate Change. Canadian J. Forest Research.

13. Effects of Vegetation-Soil and Water on Ground Temperatures
Positive Feedback from Water
Negative Feedback from Vegetation-Soils
Vegetation and soil reduce permafrost temperatures by 7 deg. C.
Water can raise ground temperatures by 12 deg. C.
Positive and negative feedback effects are larger than predicted climate warming
Thermal modeling by V. Romanovskiy in:
Jorgenson, M. T., Romanovsky, V., Harden, J., Shur, Y., O’Donnell, J., Schuur, E. A. G. and Kanevskiy, M Resilience and Vulnerability of Permafrost to Climate Change. Canadian J. Forest Research.

14. Landform–Soil–Vegetation-Permafrost Relationships
Gravel Riverbed
Upland Wet Needleleaf Forest
Alpine Rocky Dry Dwarf Scrub
Upland Moist Broadleaf Forest
Upland Moist Needleleaf Forest
Lowland Wet Forest
Lowland Wet Low Scrub
Upland Moist Tall Scrub
Loess
Permafrost
Thick Peat
Retransported Silt
Bedrock
Stratified Silt and Sand
Riverine Barrens
Lowland Bog Meadow
Lowland Fen Meadow
Lowland Tussock Bog PF
Lowland Broadleaf Forest
Lake

15. Upland Lowland
Loamy Rocky

16. Resilience of Silty Uplands
Slopes shed water, reduce positive feedback
High ice content and latent heat slow thawing
Vegetation recovery after fire, allow negative feedbacks to stabilize permafrost. Ice-poor silt freezes back.

17. High Vulnerability of Silty Lowlands
Innoko Flats
Flat terrain allows water to impound, creating positive feedback to ground temperatures

18. Gravelly Lowlands with Thaw Lake Sinks
Yukon Flats
Lake drainage after losing permafrost curtain?

19. CONCLUSIONS
Large climate gradient across Alaska creates range of permafrost temperatures and ground ice conditions
Ground ice develops in response to temperature, soil texture, and ecology
Permafrost can be highly resilient due to vegetation-soil development, yet highly vulnerable due to water
Permafrost degradation sensitive to many interacting factors but can be broadly grouped by topography and soils.