Trees and Shrubs
Because the tundra floor is frozen year round, only the hardiest of trees can survive here. In Bering Land Bridge National Preserve, most of these happen to be willows or birch, which can thrive with a shallow root system, low-growing structure, and high tolerance to wind and cold temperatures. Although many of these may look the same at first glance, upon closer inspection they are in fact quite different, and well-adapted to their respective niches in the environment.
Arctic Willow (Salix arctica)
This small, shrubby willow is well adapted to the tundra environment, with its low-lying structure and shallow root system that allows it to thrive in nutrient-poor soils and rocky ground. The arctic willow even produces its own pesticide to keep insects away during its growing season. It is typically about 7 inches tall with 1 inch oval leaves covered in thick hairs.
NPS Photo - Andrea Wilingham
Alaska Willow (Salix alaxensis)
The Alaska Willow blooms late May through early June and is typically a tall (15-20 ft.) shrub with oval, pointed leaves densely covered with white hairs. Alaska willows are known to sometimes turn into "diamond willows," which develop when a fungus eats diamond-shaped patches into the trunk. This creates a highly prized wood for some woodworkers. In addition, the young buds and inner bark can be eaten raw for medicinal purposes as a painkiller.
NPS Photo - Andrea Willingham
Dwarf Birch (Betula nana)
With smaller and more rounded leaves than willows, the dwarf birch grows thick in densely vegetated areas of the Alaskan tundra. The twigs can be resinous and hairy, with thick, leathery leaves, and the seeds are distributed mainly by the wind.