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park road photo pair
Photo Credits: Fred Dean (1976), Carl Roland (2005)
Ecoregion: Alaska Range Mountains
Change Type: Changing shrublines
Changing shrublinesAnimation is available
This is an aerial view looking west out the Denali park Road in the section between the Eielson Bluffs and Wonder Lake. This subalpine area is dotted with lakes and ponds with low shrub birch-ericaceous tundra on permafrost, with patches of alders (Alnus viridis) in riparian areas and steep slopes (which show up as dark green patches in these images). This pair of photos shows an increase in the density and extent of the alder thickets in this region. This increase in alders may reflect thawing permafrost, changes in drainage patterns, or the influence of tall shrubs on local environments that facilitates additional expansion of shrub vegetation due to trapping snow and reducing the effects of winter winds. Can you pick out the places where alder has increased in the past three decades?