This is a blog about the native conifers of the Pacific Northwest. It is a companion to the Northwest Conifers site. The blog will focus on timely and interesting details about our conifers, their connections to the rest of the environment, and our connection to them.

Wednesday, July 4, 2018

Focus on Lodgepole Pine

Lodgepole pine has adapted to several very different habitats in the Pacific Northwest. It grows along the Pacific Coast, where it is often called “shore pine.” But it also grows in the mountains, occasionally right up to the timber line. This split in its range may be explained by the fact that it does not compete well with most other conifers. So it is often limited to locations where other conifers cannot grow, in one case along the coast where the trees are buffeted by wind and salt spray, and in the other, sites with poor soils or frequent severe fires. The conditions where it grows also explain its different growth forms. Growing in dense stands subject to frequent fires, it grows straight and tall to a height of 160 feet (50 meters), in character with its “lodgepole” namesake. Along the coast and on windy mountain ridges, it is usually much shorter and rarely straight. It is short and bent, even shrub-like in form, in character with its scientific name, Pinus contorta.






Recognizing lodgepole pine

  • Needles: Lodgepole pine is easy to identify, because it is the only pine native to the Northwest with 2 needles per bundle.
  • Cones: The egg-shaped cones are 2 inches long and have sharp prickles on the scales.
  • Bark: The bark is dark gray and scaly with small furrows.

Fire

Lodgepole pine is often characterized as a fire-dependent species, because the mature cones remain closed until heated by a fire, a feature called serotiny. After a fire, the serotinous cones open and disperse their seeds, generating a new stand of pines. This is what happened in 1988 when spectacular fires burned large stands of lodgepole pine in Yellowstone National Park. In the years after the fires many of the burned areas were alive with new seedlings, the beginnings of a new lodgepole pine forest.


However, this feature of the cones is variable. It varies between the different varieties described below and varies as the tree ages with older trees producing more serotinous cones. It also varies based on the local fire history. Trees growing in areas where there are frequent fires are more likely to produce serotinous cones. This is no surprise. It’s just another example of the adaptability of lodgepole pine. Serotiny is even variable among the cones growing on one tree, enabling its offspring to adapt to changing conditions. Evolution rules! And lodgepole pine is perhaps its most ardent agent of change among the conifers.


Varieties

As lodgepole pine has adapted to different environments, many of its features have changed, especially the cones. Writers* generally identify three varieties:
  • Shore pine (var. contorta) grows all along the Coast from California to Southeast Alaska. The cones are curved, and they usually open and disperse their seeds when mature. The needles are shorter (less than 2 inches – 6 cm) and thinner than the other varieties (with needles up to 3 inches – 8 cm). After seed dispersal, the cones may remain on the tree for some time.
  • Sierra-Cascade lodgepole pine (var. murrayana) grows in the Cascades of Oregon. It also grows in the Sierra Mountains of California. Its cones are nearly symmetrical, and they nearly always open and disperse their seeds as soon as they mature, dropping the cones soon after.
  • Rocky Mountain lodgepole pine (var. latifolia) grows in the Cascades of Washington and the mountains in the northeast corners of Oregon and Washington. It also grows throughout much of the Rocky Mountains. The cones are curved and variably serotinous, often remaining closed until heated by a fire. The non-serotinous cones can remain on the tree for some time after dispersing its seeds.


Note that the borders between the varieties are not necessarily recognized by the trees. Try as we will to classify all of nature into tidy little boxes with clearly drawn lines, nature doesn’t usually color inside the lines. Lodgepole pines are no exception. They interbreed at the borders between the varieties and adapt to local conditions.  
Shore Pine at Oceanside, Oregon
Uses

Native Americans used this pine for teepee poles (lodge poles) wherever the trees were available in the western U.S. Some traveled great distances to find suitable poles in the mountains where they grew. Today lodgepole pine is used to make paper, paneling, plywood and fiberboard, and to build barns and other post-and-beam structures.


Chief Joseph pine in the Winter
Garden at Hoyt Arboretum
 
Chief Joseph Pine

The Chief Joseph pine is a dwarf variety of lodgepole pine that surprisingly turns golden-yellow in the winter. Doug Will of Sandy, Oregon discovered this amazing golden tree growing in the Wallowa Mountains and named it for the famous leader of the Nez Perce tribe. It looks like a normal lodgepole pine in spring and summer. But in late fall, the needles turn to a bright golden color. You might expect it to shed its needles like a larch, but they remain on the tree all winter and then turn green again in the spring. Its striking color and extraordinary growth habit have made it a popular item at nurseries across the country.

You can see a Chief Joseph pine in its winter color here.






_________________

*Chris Earle (www.conifers.org), Aljos Farjon, A Handbook of the World’s Conifers, James Eckenwalder, Conifers of the World, Zsolt Debreczy and Istvan Racz, Conifers Around the World. Common names from Eckenwalder and the USFS Silvics Manual 

Saturday, January 13, 2018

Focus on Subalpine Fir



As its name suggests, subalpine fir is a high elevation tree that often grows at the timberline. It may not be the tallest of the firs, but it is arguably the most stately. It is easily recognized by its slender, spire-shaped form, a clever adaptation to heavy snowfall. Longer branches would break under the weight of the snow. It is a picturesque accessory to the majestic alpine scenery, where you can see it framing your view of snow-capped mountains. Below the timberline, it can grow to over 150 feet (45 meters).


You can easily identify subalpine fir by the needles, which curve upward and have bands of white stomatal bloom on both sides, two on one side and one on the other. Pacific silver fir and noble fir also grow near the timberline, but Pacific silver fir has stomatal bands only on the lower side of the needles, and noble fir has straight needles with a sharp curve where they attach to the twig. At the timberline, subalpine fir hangs out with mountain hemlock, notable for its drooping top. You are also likely to see whitebark pine nearby, distinguished by its bundles of five needles.



The cones sit upright on branches near the treetop and fall apart at maturity, dispersing both seeds and scales, and leaving a cone core spike on the branch. The cones often ooze a white resin.

Subalpine fir grows in the Cascades, Olympics, and the mountains of northeast Oregon and Washington. It also grows throughout the Rocky Mountains and ranges from Arizona to Alaska. It grows from 4000 feet to the timberline in the Pacific Northwest, to 12,000 feet in Arizona, and down to sea level in Alaska. Although subalpine fir is moderately shade-tolerant, it does not compete well with other Northwest conifers when it is growing in the shade. You often see it in or around the edges of open meadows. 

The seedlings of subalpine fir grow slowly, often growing just an inch in a year. But these trees have a creative alternative way to reproduce at higher elevations. The lower branches of trees can be pressed to the ground by heavy snow and grow roots where they touch the ground. This process, called layering, creates mats of tree branches. Trees will also sprout and grow from these mats, producing islands of subalpine fir trees. 

As the climate warms, subalpine fir will be able to move to higher elevations, especially in wet areas. Warmer temperatures have already enabled the firs to invade some alpine meadows to the consternation of wildflower lovers. However, lower elevation trees may not be able to tolerate the warmer and drier conditions. This may seem like an even trade for the subalpine firs, but it is not. Due to the usually conical shape of Cascade Mountains, the higher elevation area is much less than the area at lower elevations.

While it has few commercial uses, subalpine fir is an important component of the subalpine forest community, providing habitat for animals and protecting watersheds that collect our drinking water. Although not readily available at local Christmas tree lots, it would make a shapely Christmas tree. It’s a long distance to go for a Christmas tree, but you can find subalpine fir in Norway, where it is becoming a popular “exotic” species for Christmas tree production. Locally, you can find cultivars of subalpine fir at nurseries, especially dwarf cultivars. 

The scientific name of subalpine fir is Abies lasiocarpa. The species name, lasiocarpa, means "hairy fruit," a reference to the fuzzy cones. Other common names: alpine fir, white fir, balsam fir, and Rocky Mountain fir. 

______________________

See also

The Gymnosperm Database
Wikipedia 
Christmas trees in Norway
Vegetative Reproduction by Layering
Climate change and subalpine fir:
    Growth response in the Olympic Mountains
    Subalpine fir in meadows
    Predicted range maps of subalpine fir 


Saturday, December 30, 2017

Pacific Silver Fir

Pacific silver fir at Hoyt Arboretum

Pacific silver fir is a high-elevation tree that can reach a height of 200 feet (60 meters). At the timberline where winters are cold and the snow is deep, silver fir grows closer to the ground where the snow can protect it from the wind and cold. If you venture there in the winter, you will notice that the dark green needles look nearly black in the winter whiteness.

Although it is generally easy to identify our native conifers, the firs can be tricky. However, Pacific silver fir isn’t closely related to other native firs and doesn’t hybridize with any of them. It is easy to distinguish this fir from other high-elevation firs by its needles and unique bark. 


Pacific silver fir has needles similar to grand fir, dark green on top with white lines underneath.  But the needles point forward and upward rather than lying flat like grand fir needles. However, both of these trees have a mischievous habit of impersonating the other. Grand fir needles growing in direct sunlight will often point upward. And silver fir needles growing in deep shade will often lie flat like grand fir needles. Look for branches growing in moderate shade to distinguish the species. It’s easy to distinguish Pacific silver fir from subalpine fir and noble fir. They both have white lines on both the upper and lower sides of the needles.




Young bark is gray and smooth with resin blisters. Older bark breaks into gray, scaly plates. These large irregular plates are unique to Pacific silver fir, distinguishing it from the furrowed bark on other native firs.


The cones sit upright on the branch and turn from green to purple. Like other firs, the cones fall apart at maturity, leaving a cone core spike on the branch. Pacific silver cones are much larger than grand fir or subalpine fir, but much smaller than noble fir. The immature pollen cones look like delicious tiny raspberries, but certainly are not edible. 





Pollen cones

Pacific silver fir grows at higher elevations in the Cascades, the Olympic Mountains, and a few locations in the Coast Range in Oregon and Washington. On the Olympic Peninsula and north to southeast Alaska, it grows down to sea level. It often grows in pure stands of large trees and sometimes near the timberline, mixed with subalpine fir and mountain hemlock.




Like grand fir, Pacific silver fir is more shade tolerant than our other native firs. You can find it growing in the understory in stands of towering mountain hemlock, for example, on the trail between Mount Hood Meadows and the Timberline Trail. Pure stands of Pacific silver fir grow in the Badger Creek Wilderness near Flag Point on the Tygh Creek Trail. 

Native people used the boughs for floor bedding, chewed the pitch as gum, and used the wood for firewood. Like hemlock and most other firs, the wood is not generally regarded as high quality. Construction lumber from these trees is sold as “hem-fir.” It’s not as strong as Douglas fir, but it has some honorable uses. Many moldings are made from these species. The wood is soft, doesn’t split when nailed, and stains nicely. More commonly these trees are made into plywood, perhaps an acceptable fate, or suffer the final indignity of being made into paper.

The common name reflects the color of the lower surface of the needles and the silvery bark. The scientific name is Abies amabilis. Scottish botanist David Douglas named it Picea amabilis when he found it growing near the Columbia River. It was later classified as Abies, but kept its species name, amabilis, which means "lovely." Other common names: White fir, red fir, lovely fir, amabilis fir, and Cascades fir.







Unless you like snowy winter sports, you won’t see any Pacific silver fir until next summer. But if you can’t wait, you can see some planted just west of the Visitor Center at Hoyt Arboretum in Portland.