The vegetation associated with cryoturbated frost-heave features on the North Slope, Alaska was described by Kade et al. (2005) as part of the "Biocomplexity associated with biogeochemical cycles in arctic frost-boil ecosystems" project (National Science Foundation grant OPP-0120736) from 2002 to 2006. The study sites spanned a latitudinal gradient from the Arctic Ocean (bioclimate subzone C) and Coastal Plain (bioclimate subzone D) to the Arctic Foothills (bioclimate subzone E), Alaska.
Seven study sites were established along a N-S-transect, with a total of 117 relevé plots on frost-heave features and surrounding stable tundra. Nine community types were identified in three bioclimate subzones: dry nonacidic nonsorted circles (10 plots), dry nonacidic dwarf-shrub tundra (5 plots) and coastal nonacidic willow-sedge tundra (5 plots) in bioclimate subzone C; moist nonacidic nonsorted circles (42 plots), moist nonacidic dwarf shrub-sedge tundra (20 plots) and wet nonacidic sedge tundra (5 plots) in bioclimate subzone D; and moist acidic lichen- and dwarf shrub-rich nonsorted circles and earth hummocks (15 plots), moist acidic tussock tundra (10 plots) and wet acidic nonsorted circles (5 plots) in bioclimate subzone E.
The study plots were chosen subjectively in areas of homogeneous, representative vegetation, permanently marked and geo-referenced. For each plant community, the minimum sampling area was determined. At each study plot, site variables were recorded and a soil sample of the upper 10 cm of the mineral horizon was collected. The raw environmental data were published in a data report (Barreda et al. 2006). The vegetation data were analyzed using the Braun-Blanquet approach, and the plant community types, including three new associations, were published in Kade et al. (2005). Subsets of the vegetation and environmental data were used in several subsequent publications (Kade et al. 2006, Kade and Walker 2008, Raynolds et al. 2008, Walker et al. 2008, Walker et al. 2011, Walker et al. 2012).
Barreda, J. E., Knudson, J. A., Walker, D. A., Raynolds, M. K., Kade, A. N., and Munger, C. A. 2006. Biocomplexity of patterned ground, Dalton Highway, 2001-2005. Data Report, Alaska Geobotany Center, University of Alaska Fairbanks. 252 pp.
Kade, A., Walker, D. A., and Raynolds, M. K. 2005. Plant communities and soils in cryoturbated tundra along a bioclimate gradient in the Low Arctic, Alaska. Phytocoenologia 35:761-820.
Kade, A., Romanovsky, V. E., and Walker, D. A. 2006. The N-factor of nonsorted circles along a climate gradient in Arctic Alaska. Permafrost and Periglacial Processes 17:279-289.
Kade, A., and Walker, D. A. 2008. Experimental alteration of vegetation on nonsorted circles: effects on cryogenic activity and implications for climate change in the Arctic. Arctic, Antarctic, and Alpine Research 40:96-103.
Raynolds, M. K., Walker, D. A., Munger, C. A., Vonlanthen, C. M., and Kade, A. N. 2008. A map analysis of patterned-ground along a North American Arctic Transect. Journal of Geophysical Research - Biogeosciences 113:G03S03.
Walker, D. A., Epstein, H. E., Romanovsky, V. E., Ping, C. L., Michaelson, G. J., Daanen, R. P., Shur, Y., Peterson, R. A., Krantz, W. B., Raynolds, M. K., Gould, W. A., Gonzalez, G., Nicolsky, D. J., Vonlanthen, C. M., Kade, A. N., Kuss, P., Kelley, A. M., Munger, C. A., Tarnocai, C. T., Matveyeva, N. V., and Daniëls, F. J. A. 2008. Arctic patterned-ground ecosystems: A synthesis of field studies and models along a North American Arctic Transect. Journal of Geophysical Research – Biogeosciences 113:G03S01.
Walker, D. A., Kuss, H. P., Epstein, H. E., Kade, A. N., Vonlanthen, C., Raynolds, M. K., and Daniëls, F. J. A. 2011. Vegetation of zonal patterned-ground ecosystems along the North American Arctic Transect. Applied Vegetation Science 14:440-463.
Walker, D. A., H. E. Epstein, M. K. Raynolds, P. Kuss, M. A. Kopecky, G. V. Frost, F. J. A. Daniels, M. O. Leibman, N. G. Moskalenko, G. V. Matyshak, K. O. VV, A. V. Khomutov, B. C. Forbes, U. S. Bhatt, A. N. Kade, C. M. Vonlanthen, and L. Tichý. 2012. Environment, vegetation and greenness (NDVI) along the North America and Eurasia Arctic transects. Environmental Research Letters 7:015504.