Ponderosa pine near Sisters, Oregon |
When I
picture a ponderosa pine, it is growing in central Oregon
near Bend , or at
the east end of the Columbia Gorge near The
Dalles . I remember these stately trees fondly,
especially their distinctive, brightly colored bark. I missed seeing them after
moving to the Portland area from The Dalles . However, it
was a surprise to me to learn recently that ponderosa pine is also native to Oregon ’s Willamette
Valley . The ponderosas of
the Willamette Valley
are adapted to the wet conditions found west of the Cascade
Mountains . Even more surprising, these natives are better adapted
to wet areas than the Douglas firs that grow
in the valley. I remember that we had two large ponderosas growing next to a
creek on the farm where I grew up northwest of Eugene . Although I didn’t know a ponderosa
from a pond-lily at the time, I remember the distinctive look of these trees.
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Willamette Valley ponderosa at Tualatin Hills Nature Park |
The ponderosa pines that grow west of the Cascades and on
the west slopes of the Sierras in California
have been classified as a separate subspecies, sometimes called “Pacific
ponderosa pine” (scientific name: Pinus
ponderosa subspecies benthamiana).
Those that have adapted to the wet conditions of the Willamette
Valley are often called “Willamette Valley ponderosa pine.” Studies of ancient pollen show that these pines have been present in the Willamette Valley
for over 7,000 years.
Before European settlement in the 1850’s, ponderosas grew in
scattered locations in wet, boggy areas along with ash, and on hillsides with
white oak or Douglas fir. Like the ponderosas east of the Cascade Mountains, the
Willamette Valley natives depend on frequent fires
to eliminate competing conifers. These naturally occurring fires would burn up
the grasses, shrubs and other competing conifers like Douglas fir and grand
fir. But the thick bark on the ponderosas enabled them to survive these fires.
The earliest inhabitants of the Willamette
Valley understood this
and used it to their advantage, setting fires to clear brush and other
conifers. This maintained open ponderosa woodlands good for hunting. The
European settlement of the Willamette
Valley changed all that. These
newcomers cut down the trees for lumber and other uses, turning the woodlands
in the valley into farmland. It wasn’t long before there were few ponderosas
growing in the Willamette
Valley .
Willamette Valley pines at the Oregon Garden |
Pine-Oak woods at the Oregon Garden |
Ponderosa pines generally have long needles that grow in
bundles of three. You can identify the Willamette Valley
variety by the length of the needles. If they are 10 to 12 inches long, the
tree is likely native to the Willamette
Valley . The ponderosas
growing east of the Cascades have needles that are no longer than about 10
inches. However, the key to finding some of the Willamette Valley
ponderosas is just knowing where they are growing.
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Willamette Valley ponderosa bark |
The best location I’ve found for mature
Ponderosa at Hagg Lake |
On a recent hike at Henry Hagg Lake south of Forest Grove, I was
surprised to see a few ponderosas growing along the trail. Keep your eyes open
when you are hiking on local trails in the Willamette Valley .
You may see a Willamette
Valley ponderosa pine. If
the bark doesn’t have the bright colors of the ponderosas east of the Cascades,
be patient. This only appears on very old trees. Enjoy these stately trees as
they grow older. You may see the brightly colored bark in about 75 years.
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