Vegetation Environmental

This type was defined at the alliance hierarchical level?the next coarser scale above plant association?because the sampled plots could not be reliably defined into separate plant associations. Alnus sinuata dominates (20% to 85% cover) the tall shrub layer of the alliance and the understory species composition is highly variable between sites. Other overstory shrubs include Vaccinium uliginosum, Salix alaxensis and Salix lanata. Alnus sinuata averages 1.8 meters in height. A variety of herbaceous species occur including Calamagrostis canadensis, Equisetum pratense and Sanguisorba stipulata. Moss cover varies from 1 to 60%.

This alliance is uncommon but widespread throughout the subalpine region of the park. Elevations range from 777 to 1,085 meters. It occurs on floodplains and mountain sideslopes (ranging from 5% to 22%), and the hydrologic regime ranges from moist to wet with limited standing water.