Cesium-137 Concentrations in Alaskan Arctic Tundra Vegetation, 1967

Samples of arctic tundra vegetation were collected in 1967 near Anaktuvuk Pass, Alaska, for cesium-137 analysis. Ten-gram dry weight samples were counted over a 10.2-cm diameter NaI (Tl) crystal. Results are expressed in picocuries (Ci × 10-12) of137Cs per gram, per 930 cm2(1 sq ft) of area, and 930 cm2of foliage cover. One-way analysis of variance on the count date for all samples indicated differences to be highly significant. Shrubby deciduous species had the lowest136Cs concentration, followed by moist heath plants, species with large amounts of carry-over, and finally dry lichen-heath mats and dry foliose lichens from areas of maximum seasonal exposure to fallout. Lichens of ridges provide winter feed for caribou and resultant high137Cs concentrations in flesh of animals killed during the spring migration.