AVA-AK: Umiat (Churchill 1955)

Arctic Vegetation Archive - Alaska: Umiat.

Early vegetation sampling on Alaska’s North Slope was undertaken by Ethan D. Churchill while stationed at Umiat on the Colville River. Churchill’s field work, completed in July and August of 1951, endeavored to identify plant communities, determine their relationship to environmental conditions, and obtain data for aerial photographic interpretation. The work was supported in part by the U.S. Air Force and Navy and culminated in a dissertation (Churchill 1954) and an article in the journal Ecology (Churchill 1955).

In July and August of 1951, 51 stands (areas of unified vegetation) were subjectively located and sampled. Stands were determined by aerial photography and ground reconnaissance to ensure homogeneity. Ten, 1-square meter plots were systematically located as uniformly and widely as possible within homogeneous vegetation of the stand but restricted so that transitional areas into adjacent stands were avoided. Plant species cover was recorded using a modified Hult-Sernander scale where: + (trace), 1 (covers less than 1/6 of the area), 2 (covers 1/6 to 1/8), 3 (covers 1/8 to 1/4), 4 (covers 1/4 to 1/2), 5 (covers 1/2 to 3/4), 6 (covers 3/4 to 4/4). Plant communities occur in 6 broad habitat types including: 1) Willow shrub vegetation of riparian areas and warm habitats (south-facing slopes) (2 plots), 2) Moist to wet acidic tussock and nontussock (Eriophorum vaginatum-Carex bigelowii-Sphagnum-Hylocomium) tundra (40 plots), 3) Dry acidic prostrate-shrub heaths (Arctous alpina, Salix phlebophylla, Empetrum heaths) (2 plots), 4) Frost boil vegetation in nonacidic tundra (Juncus biglumis, Saxifraga oppositifolia) (2 plots), 5) Alder communities (2 plots), and 6) Sedge grass and dwarf shrub mire and fen vegetation (3 plots).

Stands were not permanently marked and very little plot specific environmental data were recorded. A floristic-characteristic-species combination for each stand was identified and a preliminary analysis of the data is presented. Plot data for plant species cover and environmental variables came from the publication (Churchill 1955), while photographs were obtained from the thesis (Churchill 1954).

The Umiat data is included in both a PhD thesis and publication.


Churchill, E.D. 1954. Phytosociological and environmental characteristics of some plant communities in the Umiat region of Alaska. PhD thesis, Catholic University of America, Washington, D.C.

Churchill, E. D. 1955. Phytosociological and environmental characteristics of some plant communities in the Umiat region of Alaska. Ecology. 36:606-627.

Data and Resources

Additional Info

Field Value
Data Curator None
Last Updated September 16, 2020, 14:53 (+0200)
Created September 16, 2020, 14:53 (+0200)
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harvest_url https://arcticatlas.geobotany.org/catalog/dataset/
Spatia {"type": "Point", "coordinates": [-152.1411, 69.366767]}