Ice pruning is the natural process of selective vegetative pruning

Pruning

Pruning is a horticultural practice involving the selective removal of parts of a plant, such as branches, buds, or roots. Reasons to prune plants include deadwood removal, shaping , improving or maintaining health, reducing risk from falling branches, preparing nursery specimens for...

 on the windward side of a plant, executed by the impact of ice and snow particles driven by wind. The process is sometimes termed snow pruning. The time scale required for this phenomenon is typically over a multi-year growth period; moreover, a requirement to achieve the characteristic asymmetry is that prevailing winds during snow season has a decided bias in the wind rose

Wind rose

A wind rose is a graphic tool used by meteorologists to give a succinct view of how wind speed and direction are typically distributed at a particular location. Historically, wind roses were predecessors of the compass rose , as there was no differentiation between a cardinal direction and the wind...

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Examples

Ice pruning is often seen in far northern latitudes, such as locations above 50 degrees northern latitude. In parts of northern Canada, Black Spruce

Black Spruce

Picea mariana is a species of spruce native to northern North America, from Newfoundland west to Alaska, and south to northern New York, Minnesota and central British Columbia...

dominant forests demonstrate some individual trees that are distinctively ice pruned.