Fir Wave

The bands of dead trees on the small mountain (Middle Cannonball) between Kinsman and Cannon are fir waves, migrating bands of dead balsam fir, with the dead zone propagating uphill (downwind). The taller trees (which shelter younger trees) are killed by wind and rime, then replace by new trees of uniform age. The dead zone advances at a rate of 3 to 10 feet per year, yielding trees that increase in age linearly with distance from the dead zone. Successive wave crests are separated by about 200 feet, on average, with the cycle repeating every 60 to 70 years. This phenomenon is seen only in the eastern US and Japan.