October and November, the golden age of larch

By CHRIS PETERSON

Hungry Horse News

Late October and early November mark the golden age of Northwest Montana’s landscape, when the western and alpine larch turn yellow and drop their needles for the winter.

Larch live in the Northwest Pacific Maritime Forest, according to Stephen Arno, author of “Golden Trees of the Mountain West” which is a short, but definitive book on the western larch and its cousin, the alpine larch.

The Maritime Forest is a unique “peninsula” type forest that extends from the West Coast nearly to the Continental Divide. It is noted by its conifer forests as opposed to the broadleaf forests of the East.

The reason is the conifers are better adapted to the hot, dry summers as opposed to wet, humid summers in the east. Western larch are common in Washington,  parts of Idaho, Northwest Montana and British Columbia. They are far less common east of the divide,  though in the Bob Marshall Wilderness and Glacier National Park an observant hiker may run into an occasional tree.

Tamaracks are the western larch’s cousin, but they grow in the east and then stretch to the west but farther north. There’s about a 200-mile gap between the species in the West.

Western larch are also able to grow where other trees can’t, such as talus slopes where they find moisture far beneath the rocks.

While larch are shade intolerant, in opens spaces, such as a post-fire environment, they can outgrow other species and as mature trees, they’ll grow as tall as 160 to 200 feet. 

Mature trees have bark that is five to six inches thick, which offers protection from wildfire. In some post fire environments, mature larch are the only trees to survive.  In addition, their deciduous foliage grows back faster than evergreens, Arno notes.

The wood of the larch is one of the hardest of the softwoods and a larch log can weigh more than oak, because it’s full of water. The alpine larch grow at higher elevations in harsh conditions. Locally, they’re most common in the Whitefish range, making a living in the rocky soils above what would normally be treeline for other species.

Alpine larch are slow growers, Arno notes. It can take 25 to 30 years for a tree to grow a foot in some places, according to research done in Canada.

In addition to growing at higher elevations (although they are few and far between in Glacier National Park) alpine larch needles and branches are far more feathery than western larch.

The tree also isn’t as fire resistant as western larch.

Larch bear both male (pollen) and female (seed) bearing cones. The cones are fully mature by October. 

Larch can live hundreds of years. The largest known larch, nicknamed “Gus” is near Seeley Lake and is about 1,000 years old. It is 160 feet tall with another 10 feet of dead top.

Alpine larch have been known to live to be 800 years or more as well.

As for its wood, western larch is highly coveted. Its building strength is high and it’s very resistant to decay.  It’s sold as premium lumber and makes excellent flooring and window frames, Arno notes, as well as plywood and other wood products.

It’s also excellent firewood because it has high density and straight grain making it easier to split and it puts out a lot of heat when burned.

The gum from the larch, called arabinogalactan reportedly has medicinal qualities and has even been used to treat certain liver cancers, though it is not approved by the Food and Drug Administration.

Larch also have significant ecological qualities. Older trees are often “living snags” full of holes drilled by woodpeckers that, in turn, become homes for other songbirds and small mammals. Young trees are a favorite early spring food for bears that will strip off the outer bark to get at the cambium layer, which is high in nutrients.

Allen Chrisman, a North Forker who runs a tree farm, told Arno his solution was to simply plant more larch than the local bears would damage in a spring.