Pitchy Trees
Going far outside of New England, I stumbled on this interesting article:
At old ranches and on some remaining farms near the foothills, one can see old barbed-wire-fence “pitch posts.” These relics of a bygone era artistically reveal some Colorado history and provide an interesting forestry lesson.
Pitch posts were cut and split from the dense and heavy wood of live pitchy trees. Pitch is a resin found in evergreen trees and it forms when trees are injured. When the injury is caused by heat from ground-surface, low-intensity forest fires, and the fire has not killed the tree, more sap is made. This resin then concentrates in outer layers of sap-wood.
Long ago, forest fires were started from lightning and often times by indigenous people. Native Americans knew that a flush of new and tender vegetation that sprouts after fire meant well-nourished game and thus better hunting. With no human effort to suppress forest fires, they were frequent, and trees were often injured by fire.
In those conditions, a “relatively young,” 150-year-old tree may have received fire damage three, four, five or more times in its lifetime. A living tree exposed to that many fires accumulates high concentrations of pitch all the way from its heartwood center out to the bark.
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Back then, many forest fires persisted for months. These long-lasting fires took on a variety of day-to-day behavior, depending upon weather, terrain and fuel conditions in their path. Some fires smoldered underground for a long time as root fires, only to be rekindled with a strong, dry wind. Over centuries of time, subsequent fires affected miles and miles of forest, covering a wide range of aspects and elevations.
