Fir wave

A fir wave is a set of alternating bands of fir trees in sequential stages of development, observed in forests on exposed mountain slopes in several areas, including northeastern North America and Japan.

Fir waves develop by wave-regeneration following wind disturbance, and is one of various types of patterned vegetation.

These leeward trees eventually die, gradually expanding the gap downwind.

The period of the waves is variable, typically about 60 years in balsam fir (Abies balsamea).

One can view these from the Appalachian Trail as it ascends the Hunt Spur of Mount Katahdin in Maine.

Winter view from Mt Garfield of fir waves on North Twin Mountain , White Mountains , New Hampshire