Decadal Landscape-Scale Land Cover Change Near Barrow, Alaska
Paula Crouse, Craig E. Tweedie, Robert D. Hollister, and Patrick WebberIntroduction & Relevance:
Fig. 1 - Air Photo - 1973
Fig. 2 - Air Photo - 2001 (Grid points indicated)
The capacity for plants to respond to environmental changes at this latitude is limited due to low temperatures, low annual levels of insolation for photosynthetic capture, and slow decomposition rates relative to lower latitudes.
Differences in Alaskan Arctic Slope land cover patterns due solely to climate change are difficult to separate from ongoing successional processes, the thaw-lake cycle, and disturbance from herbivores. In addition, local human disturbance can interfere. Tracks of off-road vehicles for example cause noticeable shifts in vegetation composition, hydrology, and active layer dynamics.
Magnitude of land cover change can be assessed by generating landscape scale vegetation maps and analyzing shifts in vegetation classes over time. Nearly thirty year old research sites evidence apparent changes in dominant vegetation types and their relative position in the topography of polygonized tundra.
The polygons, which are the result of seasonal freeze-thaw activities and associated underground ice wedges, create a diversified land surface composed of rims, troughs, low center, and high center ground.
Each characteristic position in the microtopography has closely associated vegetation types. The aim of this study is to observe and map land decadal cover change on a 4.29 hectare grid originally established in 1973 as a part of the International Biological Program (IBP).
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