Larch light up area forests in curious yellow

Although they hid among the green firs and pines all summer, yellowing needles are helping larch trees stand out in the crowd during autumn.

Larch will soon be catching the eyes of hikers, hunters and anyone else who heads into the mountains in October. We don’t think about them so much when they stand naked during winter, or when they sprout their feathery fleece of green in the spring.

But autumn arouses the question again as it has for centuries:

Why do these otherwise respectable conifers turn color and drop needles as though they were leaves?

Even scientists have yet to come up with an answer as clear as an autumn morning.

Larch, known poetically by Algonquian “tamarack” and scientifically by Latin “larix,” is a tree praised by both poets and foresters the world over.

Ten larch species grow in the northern hemisphere, three in the United States and two – alpine and Western – in the Inland Northwest.

Alpine larches grow on high ridges and are often aging and crooked, resembling old trolls with outreaching arms. The gnarled tree has little practical value, other than providing handy branches for hoisting campers’ food beyond reach of grizzly bears.

Western larch, however, grows tall and straight and is prized by the timber industry. Because of their handsomeness, larch logs are peeled for the outside layer of plywood sheets.

The toughest, heaviest 2-by-4 in the frame of your house probably is a Western larch.

Woodcutters know that a dead larch splits easily and burns like coal. Grouse hunters have seen larch needles shower the path of a missed shot. Backpackers brush off the yellow “rain” that mixes in the fleece of a sweater on a windy autumn day.

I walked out of the Purcell Mountains of British Columbia after sundown recently, gaining an extra 15 minutes of safe-hiking visibility from the glow of larch needles littering the trail.

Chilean poet Pablo Neruda used larch as a metaphor for his lover’s softness. Oregon poet George Vern made the tree a symbol for the strength of his love.

Larch species can grow in swampy bottoms as well as on rocky ridges. They can thrive in old burns, where the history of a mountain comes alive in the young trees under towering silver-weathered snags.

Bull elk rub antlers on larch saplings. Woodpeckers bore in the decay of larch geriatrics.

Peter the Great imported larch to Russia to grow masts for warships.

But for all the scholars know about larch, it remains uncertain why the tree’s needles turn from green to yellow and sprinkle to the ground each autumn.

The trait probably helps larch withstand cold and more efficiently use nutrients drawn from the soil, they say.

On the other hand, maybe they do it just to be pretty.