On 7 August 1997, we collected 5.2-cm diameter soil cores (up to 30 cm depth depending on depth of thaw) from six randomly selected locations (between tussocks) at each site. The cores were separated into organic and mineral horizons, all live plant material and coarse roots were removed, and each horizon from each core was homogenized separately. Dried and ground soils (using a coffee grinder) for each horizon and from each of the six locations at each site were analyzed for exchangeable base cations (Ca, Mg, K, Na) using ammonium acetate extraction followed by ICP (Thomas 1982). Soils within horizons and sites were bulked for analyses of cation exchange capacity and percent base saturation, determined by the sum of base cations extracted with ammonium acetate followed by ICP and exchangeable acidity extracted by barium chloride (Thomas 1982; Soil Conservation Service 1992). Analyses were done at the University of Minnesota's Research Analytical Laboratory..

Calculations: Kcmol (Kppm x 100)/(39.1 x 1000)
Cacmol (Cappm x 100 x 2)/(40.1 x 1000)
Mgcmol (Mgppm x 100 x 2)/(24.3 x 1000)
Nacmol (Nappm x 100)/(22.9 x 1000)

Reference Citations: Hobbie, SE and L Gough. In press. Foliar and soil nutrients in tundra on glacial landscapes of contrasting ages in northern Alaska. Oecologia