Global warming is rapidly thawing permafrost along the Arctic Coastal Plain of northern Alaska, with a cascading effect that results in coastal subsidence, inundation by salt water, and subsequent changes to habitat distribution and quality. As part of the USGS Changing Arctic Ecosystem Initiative, scientists at the Alaska Science Center are using WorldView-2 and -3 satellite imagery to map changes taking place to goose “grazing lawn” (GL) habitat (http://pubs.usgs.gov/fs/2014/3088/). In the figure, the class “GL Transition” represents tundra recently dominated by freshwater graminoids that has subsided and is changing into habitat dominated by salt-tolerant species (GL Dense, Moderate, and Sparse). These new GL habitats are preferentially grazed by some avian herbivores and appear to benefit the energetic and reproductive success of several species of geese. Habitat maps are being created using all 8 WorldView spectral bands, plus two derived bands (Normalized Difference Vgetation Index(NDVI) and Red Edge NDVI) in proven classification algorithms. The USGS is establishing the location and areal extent of salt-tolerant graminoid habitats across the full extent of the Arctic Coastal Plain (Point Barrow east to Oliktok Point). These maps complement ongoing research to 1) estimate the biomass and nutrients available to waterfowl in salt-tolerant graminoid habitat, 2) plan for the location of coastal subsidence, inundation, and habitat change monitoring stations, and 3) retroactively analyze and forecast future coastal habitat change for Department of Interior management agencies and local governments and residents.
WorldView-2 map imagery showing the study site on the Arctic Coastal Plain of Alaska, and detailed perspectives of the study area. The class GL (grazing lawn) Transition in the middle left image represents tundra recently dominated by freshwater graminoids that has subsided and is changing into habitat dominated by salt-tolerant species (GL Dense, Moderate, and Sparse).