Previous photo pair1976 - 2005: Toklat Basin Lowlands near Toklat Basin64/214Next photo pair
lake and stream photo pair
Photo Credits: Fred Dean (1976), Carl Roland (2005)
Ecoregion: Alaska Range Mountains
Change Type: Changing treelines
Changing treelinesAnnotation is available
This photo pair shows a view towards the north with Eight Mile Lake in the background (west of the town of Healy). This is an area dominated by low vegetation growing in permafrost soils, except in areas of the landscape more deeply thawed (i.e. areas near running water or increased solar energy like south-exposed slopes). The low-statured vegetation that shows-up with a reddish or a tan color in the 1975 photo (dominated by heath family plants, dwarf birch and cotton grass), is underlain by permafrost very near the surface. Soil conditions in these areas are characterized by very cold and wet conditions with low pH (i.e. very acidic) and low nutrient availability. Large-statured vegetation such as trees and tall shrubs is generally excluded from these areas due to harsh growing conditions. The vegetation in the less permafrost influenced areas in this photo pair (the polygons with green-colored taller shrubs and trees in 1975) has changed more rapidly over the period separating these two photos, with an increase in the stature of the vegetation and in the density of trees throughout much of the more deeply thawed terrain.