Mark (presentation) Permafrost zones uses Payways model with recent datapoints Continuous Discontinuous Sporatic Very few instances Temp regimes Gelic Prudhow Bay Pergelic – Atigun Pass Subgelic – Denali Subgelic – Fit within the temp regime requirements Gelic and Cryic Occur based on the surface cover, aspect Subgelic Static and dynamic properties determine whether Gelisols will be present Static site properties Slope/ Aspect Thermal properties Other site characteristics location to water bodies, etc – Dynamic properties main factor of permafrost or not – Loss of surface cover Soils that have been burned will thaw; they may refreeze but may not stay frozen through the summer Once the Organic mat gets enough it will stay frozen through the summer and permafrost will remain These would be Gelisols when they are frozen before burn, after burn Inceptisols/Entisols – Pergelic Temp Class Gelisols occur in all landscapes with some exceptions High conductivity materials common Surfaces with high flooding frequency Dynamic soil properties Fire Organic mat removed No thermal conductivity Permafrost moves much deeper in the profile Loation to a water body Slope/Aspect have very little influence
Mark (presentation) Permafrost zones uses Payways model with recent datapoints Continuous Discontinuous Sporatic Very few instances Temp regimes Gelic Prudhow Bay – Pergelic Atigun Pass – Subgelic Denali – Subgelic Fit within the temp regime requirements Gelic and Cryic Occur based on the surface cover, aspect Subgelic Static and dynamic properties determine whether Gelisols will be present Static site properties Slope/ Aspect Thermal properties Other site characteristics – location to water bodies, etc Dynamic properties – main factor of permafrost or not Loss of surface cover Soils that have been burned will thaw; they may refreeze but may not stay frozen through the summer Once the Organic mat gets enough it will stay frozen through the summer and permafrost will remain These would be Gelisols when they are frozen before burn, after burn – Inceptisols/Entisols Pergelic Temp Class Gelisols occur in all landscapes with some exceptions High conductivity materials common Surfaces with high flooding frequency Dynamic soil properties Fire Organic mat removed No thermal conductivity Permafrost moves much deeper in the profile Loation to a water body Slope/Aspect have very little influence
nrcs142p2_051208.docx