Succession on River Alluvium in Northern Alaska

Abstract

During the summer of 1953, a study was made of the vegetation adjacent to several of the major rivers on the Arctic Slope of Alaska. Much of the descriptive work and all of the quantitative sampling included here were carried out along the Colville River near Umiat, Alaska (N 690 22', W 1520 08'; elevation approximately 350 feet). These data were supplemented through observations by the second author at several other poin-ts on the Arctic Slope. This portion of Alaska, except possibly under the deeper lakes, is underlain by continuous permafrost. The vegetation of the region, except on and immediately adjacent to the river floodplains, is composed of one or more, usually several, of the various tundra plant communities (Spetzman 1951, Cantlon & Bormann 1953, Churchill 1955, Bliss 1956). On the floodplains and lower terraces, plant communities occur in which the plants are both of a lower life-form and of a somewhat higher life-form than the adjoining tundra communities. These are, respectively, the open, perennial-herb pioneer community and the tall (up to 20 feet), fairly dense, feltleaf willow (Salix alaxensis2) communities. Both are of successional status and as the direct influence of the river becomes less through meander migration, they give way by stages to one of the several tundra types that are not dependent upon the river influence. The object of the present study is to describe in a preliminary way the zonation and apparent successional relationships of the vegetation along rivers in the area.