A fir wave is a set of alternating bands of fir

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s in sequential stages of development, observed in

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s on exposed

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually highe ...

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.

Formation

Fir waves form by the

ecological Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

process of wave-regeneration. When a tree falls, a gap in the canopy is formed. This exposes trees at the leeward edge of the gap to greater wind. These trees are thus more likely to die from damage and desiccation than

windward Windward () and leeward () are terms used to describe the direction of the wind. Windward is ''upwind'' from the point of reference, i.e. towards the direction from which the wind is coming; leeward is ''downwind'' from the point of reference ...

trees. These leeward trees eventually die, gradually expanding the gap downwind. At the same time, young trees start to grow in the wind shadow in the windward portion of the gap, protected from the high winds by the surviving trees. The combination of dying trees at the leeward edge and regenerating trees at the windward edge results in the propagation of the fir waves in the direction of the predominant prevailing wind. The period of the waves is variable, typically about 60 years in

Balsam Fir ''Abies balsamea'' or balsam fir is a North American fir, native to most of eastern and central Canada (Newfoundland west to central Alberta) and the northeastern United States (Minnesota east to Maine, and south in the Appalachian Mountains to ...

(''Abies balsamea''). One can view these from the Appalachian Trail as it ascends the Hunt Spur of

Mount Katahdin Mount Katahdin ( ) is the highest mountain in the U.S. state of Maine at . Named Katahdin, which means "Great Mountain", by the Penobscot Native Americans, it is within Northeast Piscataquis, Piscataquis County, and is the centerpiece of Bax ...

Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and ...

. "Looking out to the Owl" and "The Brothers" are extensive areas of this phenomenon.

References and further reading

Wave-Regeneration in High Elevation Subalpine Fir Forests
from Forest and Landscape Ecology course material at Michigan Tech.

ecological research by J. Silvertown and M. Dodd.{{dead link, date=May 2012

from ''Teaching Issues and Experiments in Ecology''. *Sprugel, D. G. 1976. Dynamic structure of wave-regenerated Abies balsamea forests in the north-eastern United States. Journal of Ecology 64: 889-911. *Shibuya, M., Hagai, N., Sasaji, T., Kikuchi, S., Haruki, M., Noda, M., Takahashi, K., and Matsuda, K. 2004. Stand and self-thinning dynamics in natural Abies stands in northern Hokkaido, Japan. Ecological Research 19:301
''Article abstract''
Forest ecology Montane ecology

Formation

See also

References and further reading