A south-facing bluff overlooking the Tanana looks like a bald patch of steppe in a land of trees and bogs. The Bonanza Bluff doesn’t quite belong.
This place is rest-stop for hunters and biologists alike. Gyrfalcons screech at one another as they soar into the clumps of white spruce surrounding the bluff. You get there by pulling off the Parks Highway and navigating the myriad of dirt roads that stitch together the Bonanza Creek Long Term Ecological Research Station.
Biologically, this place is also a refuge – you find species at steppes like this that don’t exist anywhere else in Alaska. The steppes provide speckles of arid communities in a watershed dominated by trees and sandbars. For example, of the 70 bryophytes (mosses, liverworts, hornworts) found on these steppes, 11 were new to Alaska, and three were new to North America, according to Francis Chapin III in his 2006 book, “Alaska’s Boreal Forest.” Many of these bryophytes thrived in dry places elsewhere.
The bluff is extremely steep, with little patches of forbs holding it in place. The sun hits it head-on, desiccating the soils. There’s not enough water for trees here – if the climate were to become drier, this sort of community might become more common, Chapin wrote.