Sunday, June 30, 2013
Western Red Cedar
Weather: Rain Friday sank down half an inch in the driest land; 14:34 hours of daylight today.
Smoke from the north (Colorado’s West Fork fires), smoke from the south (Silver fire), smoke from the east (Jaroso fire), smoke from the west (Thompson Ridge fire). Whenever the wind blows, the air gets worse. They gusted to 47 mph in Los Alamos yesterday.
What’s blooming in the area: Hybrid roses, daylilies, silver lace vine, bouncing Bess, purple salvia, blue flax, alfalfa, brome grass. Some grape vines finally putting out leaves.
Beyond the walls and fences: Trumpet creeper, tamarix, cholla cactus, scurf, scarlet and sweet peas, showy milkweed, buffalo gourd, purple mat flower, leather-leafed globe mallow, bindweed, greenleaf five-eyes, scarlet bee blossom, velvetweed, goat’s beard, Hopi tea, Tahoka daisy, strap-leaf and golden hairy asters, horsetail, rice grass; some catalpa leaves already whitening from dry soil.
In my yard, looking east: Baby’s breath, coral bells, pink evening primrose, winecup mallow.
Looking south: Rugosa, floribunda and miniature roses.
Looking west: Lilies, Johnson Blue geranium, catmints, sea lavender, ladybells, white mullein, white spurge, Shasta daisy peaked.
Looking north: Golden spur columbine, coral beardtongue, Hartweig primrose, butterfly weed, chocolate flowers, anthemis, yellow yarrow.
In the open, along the drive: Dutch clover, hollyhock, Shirley and California poppies, larkspur, white yarrow, blanket flower, coreopsis, yellow, red and mixed Mexican hats; buds on black-eyed Susans; pods forming on catalpa.
Bedding plants: Wax begonias, pansies, snapdragons, French marigolds, gazanias.
What’s blooming inside: Zonal geraniums, aptenia.
Animal sightings: Rabbit, hummingbird, goldfinches and other small brown birds, disoriented bumble bee, small bees, cricket, grasshoppers, harvester and smaller ants.
Weekly update: My wooden fence wouldn’t provide much protection against a wild fire. But, then, with the temperatures generated by forest fires, no fencing would: steel softens, mortar crumbles.
Western red cedar isn’t the worst choice. It’s flame spread index is 70. For most domestic woods used in construction, the score’s 90 to 160. The lower the better. Red cedar’s permitted for exit corridors.
Of course, fire resistence isn’t in its DNA. The cousin of the arborvitae grows in British Columbia and adjacent wet parts of the northwest where fires occur every 50 to 350 years.
Surface roots scorch, canopies vanish. Young trees often die. Surprisingly, older dead trees don’t decay. The bark persists for at least five years, protecting the interior. Some can still be used for lumber a hundred years later.
The reason you use red cedar, or any solid fencing material, is privacy. My neighbor installed the first part of my fence nearly 20 years ago, when he erected a metal building.
He’s from the north where cedar fences turn silvery gray. Ultraviolet light from the sun interacts with humidity in the air to alter the lignin in the wood, leaving the cellulose.
In New Mexico, we have stronger light, and very little humidity. His fence and my additions have not grayed. Instead, some boards are brown, some darker. Fungus of some kind is exploiting the surfaces.
Fungus shouldn’t be touching the boards. The reason you buy Thuja plicata, instead of pine, is the presence of anti-fungal chemicals that prevent decay. It not supposed to rot.
Thujaplicins are members of a chemical class with rings of seven carbon atoms. Tropolones were discovered in the 1940s by scientists doing research with penicillins. Last year, a team at the University of Bristol demonstrated the biochemical steps used by fungi to create one of them, stipitatic acid.
Earlier, Lehong Jin discovered one fungus, a Sporothrix, neutralizes the antibacterial chemical in red cedar. Later, another species, a Poriarivulosa, attacks. Many of the oldest specimens in old growth forests are hollow. One located near Quinault Lake in Washington is thought to be at least 2,000 years old.
Trees, as I learned, but didn’t comprehend as a child, are composed of a living exterior and an abandoned interior. The first is the sapwood where nutrients flow between the roots and leaves through the xylem and the phloem. These are created every year, resulting in tree rings.
The interior heartwood no longer has a biological function: it’s not even needed to support the leaves and branches. Yet, trees expend the energy every year to create it.
Dan Peng and Xiao-Quan Wang believe the Thuja genus evolved during or before the Paleocene. The era was warmer and wetter than ours. Following the extinction of the dinosaurs and other species, fungi flourished for a brief period, feasting on decaying plant matter. The first rain forests came later.
It may be, the chemical dynamics within red cedar wood were more important to species survival then than they are today.
Jason Ray Nault showed, in 1988, that thujaplicins aren’t equally distributed across the trunk. The amount increases from the center pith outward. However, the outmost edges have none. He suggested younger trees would be less resistant to decay than older ones.
Others since have found variations within trees on the coast and those growing inland. Applied botanists are hoping to select the best for propagating in plantations that might replace the natural forests where commercial red cedar is now harvested.
The variations are obvious in my fence. Lumbermen tell you the wood is straight grained, knot free, and doesn’t warp.
Mine has knots.
Some say that’s because not enough horizontal wood was used.
Others attribute it to differences in environments between where the wood was processed and where it’s used. Wood moved from one area to another always absorbs or releases water until it matches its new atmosphere.
I suspect mine warps where there are moisture differences between two parts of a board. The worst are the boards facing the western sun with Virginia creeper growing on the other side.
It’s nearly impossible to find someone to install a fence in this area. You can’t suggest how they do it. If they propose different sized boards and different fence posts you say, yes, of course, you’re right.
You certainly don’t suggest they use screws instead of nails, or request they use non-rusting materials. They always know more than the experts. Discoloration is supposed to be part of the aesthetic appeal.
Twenty years ago, my neighbor used ordinary nails. The iron interacted with the wood’s chemicals. Within a year, holes developed around them.
Spring winds push against them. Every year, some nails pull out and my neighbor replaces them with screws. The boards are usually those nearest the uprights where the differences in wind velocities are the greatest.
Last summer, my backhoe operator ran into it. The man he hired to fix it only replaced the boards that were completely gone. If there were broken, but still attached, he said they were good enough. This year, my neighbor replaced them.
He left me with the broken boards. They were too long for a trash bag.
If I had a wood stove, I could have burned them. They aren’t the best fire wood, but they work as kindling. A cord of dried wood produces 15.4 to 17.4 million BTUs of heat. Live oak can generate 36.6, black locust 31.4 million, and ash 26 million. Cottonwood is only marginally better at 16.8.
Even though the boards were old and dry, they wouldn’t break. I finally drove my car over them. The wood has good tensile strength. They bent. Its ability to withstand bending increases when it dries, as does its ability to compress.
It takes nearly 5,000 pounds to destroy a board by bending it. 4,900 to compress it. My car weighs about 2,500 pounds, and that’s distributed over four tires. The backhoe, of course, weighed considerably more.
You can burn it, bend it, but not break it. The sun can change its composition, but not destroy it. Fungus can colonize its surface, but not rot it. It can last for centuries hidden deep inside trees, after it’s technically dead. Western red cedar wood can even survive New Mexico handymen and Virginia creeper. Only a wild fire could decimate it.
California Energy Commission. Consumer Energy Center. Website on "Firewood" has information on BTUs of heat generated.
Davison, Jack, Ahmed al Fahad, Menghao Cai, Zhongshu Song, Samar Y. Yehia, Colin M. Lazarus, Andrew M. Bailey, Thomas J. Simpson, and Russell J. Cox. "Genetic, Molecular, and Biochemical Basis of Fungal Tropolone Biosynthesis," National Academy of Sciences Proceedings 109:7642-7647:2012.
Gonzalez, Josefina S. Growth, Properties and Uses of Western Red Cedar (Thuja plicata Donn ex D. Don.), 1997 edition; on mechanical properties.
Jin, Lehong, Bart J. Van Der Kamp, Jack Wilson, and Eric P. Swan. "Biodegradation of Thujaplicins in Living Western Red Cedar," Canadian Journal of Forest Research, 18:784-788:1988.
Nault, J. "Radial Distribution of Thujaplicins in Old Growth and Second Growth Western Red Cedar (Thuja Plicata Donn)," Wood Science and Technology 22:73-80:1988.
Peng, Dan and Xiao-Quan Wang. "Reticulate Evolution in Thuja Inferred from Multiple Gene Sequences: Implications for the Study of Biogeographical Disjunction Between Eastern Asia and North America," Molecular Phylogenetics and Evolution 47:1190-202:2008.
Taylor, Adam M., Barbara L. Gartner, and Jeffrey J. Morrell. "Western Redcedar Extractives: Is There a Role for the Silviculturist?" Forest Products Journal 56:58-63:2006.
Tesky, Julie L. "Thuja plicata," 1992, in United States Department of Agriculture, Forest Service, Fire Effects Information System, available on-line.
White, Robert H. and Mark A. Dietenberger. "Fire Safety of Wood Construction" in USDA, Forest Products Laboratory, Wood Handbook, 2010; the flame spread index.
1. Back fence, 28 June 2013. The beige line above the fence is the far arroyo. The dark band is the bad lands on the other side of the Río Grande. Behind them are the Jémez. The sky is a mix of smoke and rain. Rugosa roses and four-winged salt bushes in front.
2. Side fence, 28 June 2013, with sweet peas and Saint John’s wort.
3. Side fence, 5 February 2008.
4. Close up of side fence, 29 June 2013.
5. Back fence, 28 June 2013. Badlands to the south and smoke mixed with rain.
6. Knot in back fence, 26 June 2013.
7. Warping base of wide board in side fence, 28 June 2013.
8. Back side of side fence built by neighbor with Virginia creeper, 26 June 2013. He notched 4 x 4 treated wood posts to hold 3.5" dog-eared boards with nails.
9. Back side of drive fence built by a good fence builder, 26 June 2013. He used metal posts in concrete and clamps with 5.5" dog-eared boards with nails. He didn’t cap the posts. What possible harm can come of water accumulating in a hollow steel tube?
10. Discoloration from screw in back fence, 26 June 2013.
11. Deterioration and discoloration from nail in drive fence, 26 June 2013.
12. Repaired fence. The backhoe hit the most vulnerable place, the point where the construction methods changed. The differences in color in the new wood are because the ones on the left are 3.5" one from store, and the others 5.5" from another.
13. Broken board with gray surface in original side fence, 28 June 2013. Broken when my neighbor was removing the Virginia creeper. Not replaced; after all, dogs and rabbits won’t get in because it’s broken.
14. After I drove over the boards a few times, sections compressed. I was able to break them where they had bent.
15. Back side of back fence, 29 March 2013. This was built after some utility made a rough road near the property line that was being colonized by winterfat and Russian thistles. The journeyman fence builder was told to match the work of the good fence builder, only to use screws and not nails. I had to supply the post caps.