Beware the “Danger Tree”

An excerpt from the new book Fuzz: When Nature Breaks the Law

By Mary Roach

September 19, 2021

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Photo by Matauw/iStock

Excerpted from Fuzz: When Nature Breaks the Law by Mary Roach. Copyright (c) 2021 by Mary Roach. Used with permission of the publisher, W. W. Norton & Company, Inc. All rights reserved.

What a Douglas fir does, it does very slowly, and that includes dying. Possibly the least attractive feature of a nine-​hundred-​year life span is the century or two spent dying. Decomposition drags on for another hundred years or so. A tree is the rare organism to which the comparative deader is often and accurately applied. A recently dead, or “dead hard,” conifer progresses to “dead spongy,” then “dead soft,” limbs and top rotting and dropping off, until the last piece of standing trunk topples and the tree enters the final classification, “dead fallen.” At some point in its protracted twilight, a tree that stands near a road or path or building may earn a new classification: “danger tree.” Because if it falls, anyone it lands on will spend a very, very short time dying.

The victims of arboreal manslaughter may be, unlike the perpetrators, quite young. The Australian Journal of Outdoor Education published a summary of cases, since 1960, of children (and in two instances, their teachers) killed by falling branches or trees during school camping trips: six killed sleeping in their tents, one while swimming near a eucalyptus grove, and another six killed while hiking, including two teenagers crushed when the top of a mountain ash tree broke off and rolled down a hill onto the trail.

Wind is a common accomplice. The journal Natural Hazards reports that in the United States, between 1995 and 2007, trees toppled by strong winds caused the deaths of nearly four hundred people. My husband, Ed, and I were twenty feet away from a similar fate, awakened early one windy morning by the crack of a large branch breaking off an oak and landing near our tent.

Some trees kill in the normal course of life. The Coulter pine drops a cone as heavy as a bowling ball. According to “the largest review of coconut-​palm related injuries,” sixteen Solomon Islanders were struck by falling coconuts between 1994 and 1999. Balinese newspapers have three times in recent years reported on cases of bodies found beneath durian trees. The fruit of the durian tree makes an excellent murder weapon: big, heavy, and covered in hard spikes. The “suspect,” being a tree, cannot hide the weapon; a bloodied fruit lay beside one victim’s head. It is difficult for authorities to generate caution or concern. Confronted with the sign “Dropping Pine Cones, Proceed at Your Own Risk,” most will proceed.

The term “danger tree” is itself somewhat hilarious. It’s like “danger mitten.” The staff of Vancouver Island’s MacMillian Provincial Park, home to a stand of “legacy” conifers, find no humor here. Because the most geriatric trees are also the tallest and most majestic. They are the trees people pay money to hike and drive amid and the ones the public very badly doesn’t want cut down. This creates a conundrum and, very occasionally, a tragedy.

In 2003, an Alberta couple were passing through MacMillan’s Cathedral Grove, a stand of massive, centuries-​old conifers, when a fierce snowstorm hit. They pulled off the roadway to wait it out. One of the ancient firs, overburdened by snow and weakened from rot, fell onto their car and killed them.

“Some trees kill in the normal course of life. The Coulter pine drops a cone as heavy as a bowling ball. According to ‘the largest review of coconut-palm related injuries,’ sixteen Solomon Islanders were struck by falling coconuts between 1994 and 1999.”

Since then, MacMillan has maintained a relationship with a certified danger-​tree assessor. Twice a year and after any big storm, ongoing for fifteen years, Dean McGeough roams the woods looking for signs of dangerous decrepitude. Today is one of the semiannual inspections. Over the course of the day, Dean will flag trees he deems in need of mitigation: a limb lopped, or a top, or something more drastic. This is the part where, statistically, most of the manslaughter goes down. By a large margin, the people whom trees kill most often are the people bringing them—​or pieces of them—​down. An on-​the-​job fatality for a faller, as chainsaw wielders are known in these parts, is sixty-​five times more likely than it is for workers in general. These are men with compression bandages stuffed in their pockets the way my grandmother had Kleenex. Men whose fabric of choice is cotton-​Kevlar. Though it isn’t usually the blade that kills. It’s the tree. Sometimes it’s the one they’re cutting, but more often it’s a bystander. The tree may bend the branch of a neighbor as it falls, causing it to slingshot back at deathly speed. Pieces of other trees lodged in the branches—​a “swinging snag” or an “insecure hang-​up”—​may pull free and come down on the faller.

British Columbia has an active Forest Safety Council, and two members are here today. The title given on their business cards is Falling Safety Advisor. Earlier today I met a Falling Supervisor. The word falling has lost its slapstick for people in the logging industry. Someone will mention a guy from a long-​ago job, and someone else will go, “Is he still falling?”

The most dangerous trees to fall are (duh) danger trees. A healthy tree with sound wood can be made to fall in any direction. Like this: Rather than cutting straight through the trunk, the faller stops partway and goes around to the opposite side and makes a sloping undercut. Now when he goes to finish the cut, the trunk will tilt down onto the slope made by the undercut and fall in that direction. A rotting tree is hard to control in this manner, its fall impossible to predict with certainty. If a conifer is rotting from the top down, the softened portion may break off as the tree starts to lean and come down on the faller. Or the whole rotted trunk may “telescope”—​collapse straight down into itself. Or a rotted portion of trunk may suddenly crumble and change the direction of the fall. Think of those osteoporotic olds whose bone has grown so porous that one day a hip gives way when they shift their weight. (All these “overmature” trees may explain why the lumber company that once owned the grove donated it to the province in the first place: lotta punky lumber.)

Ideally, no one should be anywhere near a danger tree when the wood comes down. That is why very tall, very old, very dangerous trees are not cut down but, rather, blown up. Explosives aren’t exactly crib toys, but they can be detonated from a safe distance. So regardless of what comes down and from what direction, no faller will be felled.

After Dean finishes his inspections, expert faller blaster Dave “Dazy” Weymer will start work. (The nickname dates to his twenties and has to do with weed, not flowers.) Dazy has been blasting trees for thirty-​five of his sixty-​eight years. Both his father and his grandfather were loggers. He grew up in logging camps. He was, he says, “a bit doomed to be a logger.” I first saw Dazy in a YouTube montage, a sort of highlight reel of explosions and screaming chainsaws against a booming soundtrack of insistent strings and kettle drums. You need ear protection just to watch his videos.

*

The forest floor in Cathedral Grove is hardly like a floor. It’s an obstacle course of decomposing branches and logs, their surfaces and outlines obscured by a damp, spongy pelt of mosses and ferns. It is difficult to predict when your foot will connect and what will happen when it does. It may come to rest on a log or it may push straight through what appears to be a log but is in fact crumbling, log-​shaped mush. You will stumble and fall, but you won’t be hurt, just moist. Moist fallen.

While Dean makes his rounds, he and Dazy bring me up to speed on basic tree anatomy. The tree, I am learning, is not entirely unlike the human. The older, harder wood that runs through the tree’s core serves as the skeleton that supports it. Surrounding this spine of “heartwood” is the “sapwood,” the flesh through which courses, slowly, so slowly as to possibly demand a different verb, the blood of the tree—​the sap. 

Bark is of course the tree’s skin. It protects the flesh, and it is—​again, like our skin—​both an entry point for infection and a part of the immune system. Conifer bark secretes resin (a.k.a. pitch), a thick, sticky goo that seals wounds, traps bark beetles, kills pathogens. Also like us: A tree’s crown thins as it ages, and the point at which its circumference is greatest is called the butt. And there my trees-​as-​people comparison sputters out.

“There’s one I blasted.” Dazy has a deep voice that projects well when he needs it to, which he often does because he’s holding a conversation across a grove of trees or over the sound of an idling chainsaw. He’s pointing to a Douglas fir. These trees stand out from the others here by their bark—​thick, with deep vertical rifts.

From ten feet away, looking straight at it, the blasted fir looks no different from the live intact legacy trees all around it. Only the top third is gone, and to see the top third of this formerly 180-​foot tall tree, you would need to crane your neck all the way back. Removing just the upper third makes the tree lighter and more stable—​less dangerous—​and at the same time preserves the grove’s medieval Sherwood Forest vibe, what the tourism professionals call “visitor attractiveness.” At eye level, the living, the dead, and the blasted look the same: enormous mossy tree trunks. As Dazy says, “You wouldn’t know it wasn’t just another pretty tree.”

Elderly trees perform their own, more subtle version of what Dazy does. It’s called retrenchment. The tree’s trunk circumference and roots continue to grow, but it stops getting taller and the limbs of the crown die back and drop off. This makes it less top-​heavy. More importantly, there is less “sail,” meaning fewer surfaces for the wind to catch and less blowing about of the crown and risk of what forestry people call “windthrow”—​a tree uprooted and blown over by powerful gusts.

“Here is another reason not to cut a danger tree down to a stump. Dying and decomposing trees, far more so than young living trees, provide real estate for wildlife. … For this reason, a ‘danger tree’ is often classed as a ‘wildlife tree,’ too.”

I lean way back to try to see Dazy’s handiwork on the fir. This causes me to lose my footing and topple backward off a log. Falling Author. Dazy extends a hand. It is noticeably unlined for his age, probably because when he’s outdoors he’s usually wearing gloves. If other fallers read this, he will no doubt get grief about his lovely hands, but I believe a man named Dazy will handle it.

Here is another reason not to cut a danger tree down to a stump. Dying and decomposing trees, far more so than young living trees, provide real estate for wildlife. Rot-​hollowed trunks become dens for bears. Dead tree branches are hunting perches for raptors. Soft, rotting sapwood is easily excavated by woodpeckers and other cavity nesters. For this reason, a “danger tree” is often classed as a “wildlife tree,” too. Blasting off the upper third of the tree facilitates the process. It speeds the decay of the remaining trunk by letting rainwater seep into its interior via the jagged, open terminus—​the point where the blast took place. Dazy holds back a branch for me. “Biologists love blasted tops,” he says as I step through the opening. Provided, that is, that the work is not done during anyone’s nesting season.

Dean has marked a large Douglas fir for action. He breaks off a leathery-​looking disk, one of a half dozen protruding from the bark. “This is a conk,” he says, handing it to me, smiling vaguely. Dean has a kind of ongoing low-​grade smile, though never really seems pleased. A conk is the tip of the iceberg, rot-​wise. The symptoms of fungal infestations are often hidden until the disease is well-​entrenched. By the time conks show up on the outside of a tree, the inside is far rotten.

Still, there’s no real rush to take action. This tree has had conks the entire fifteen years Dean has been monitoring it. The bark comes off easily in vertical chunks, like wax drippings off the side of a candle. Dean breaks off a piece of bark and crumbles it between his fingers. Insects take advantage of the punkiness to work their way in and lay eggs. Contributing to yet more punkiness. “See this white powder?” Dean says. “This is frass.” Frass is insect excreta, and my favorite new word of the day. It replaces kerf, which refers to the width of the space left by a saw-​blade cut and is a useful word for Scrabble.

Dean walks out to the tree’s drip line, the outermost reach of the branches overhead. This typically indicates the end point, underground, of a tree’s roots. He shows me where the root mass is starting to lift on one side, because the tree is leaning. Danger tree! Dean adds it to the work list for tomorrow.

Lately, the trees of Cathedral Grove are succumbing to a root rot called Armillaria that spreads underground, an infected tree passing the fungus to its neighbors where the roots touch. Cedars prevail. They have chemicals that resist many of the fungal rotters (thus the wood’s popularity for roofing shingles and outdoor furniture). The current situation in the grove is ideal for cedars. They need a fair amount of light, so as their less rot-​resistant neighbors perish and fall, the cedars benefit from the newly admitted sun. It’s all cyclical, Dean is saying. At some point drought will take the cedars, and another species will thrive where they’ve perished.

Dean does a lot of tapping and sounding to gauge the extent of a tree’s inner rot. He’s been dropping Latin names faster than I can misspell them. Dazy keeps it simple: heart rot, butt rot, root rot. Dean and Dazy used to teach a falling safety class together. Dazy would talk about technique, and Dean covered regulatory matters. Dazy would throw some fucks into his first lecture to put the students at ease. Dean is not a cusser. His gear is immaculate, and he fills out paperwork promptly and legibly. He is exactly who you want keeping records on dozens of two-​ton trees that might topple over onto people.

As different as these two men are, they are similar in the degree to which they don’t fit my lumberjack stereotype. A few minutes ago, the group was comparing notes on their diets. Dean has two friends who each lost forty pounds on the keto diet, eating bacon “like it’s going out of style.”

“Man, I could do that,” a falling safety advisor said dreamily.

Dazy volunteered that he is doing high-​fat/low-​carb, for his heart, but remains wary of bacon. “I try to sorta dwell on avocados. And fish.”

“Fish,” Dean agreed. “There you go.”

Dean has tagged six trees for blasting tomorrow morning. We set a time to meet back here and call it a day. No one goes for beers. Carbs and all that.

*

The explosives are stored in an unmarked silver shed in the woods, five miles up a dirt logging road. Shed is the wrong word. Technically, an explosives storage structure is a “magazine.”[*] This one has walls six inches thick and filled with gravel, so yahoos and hunters with poor aim can’t shoot through them and blow the surrounding forest to mulch.

It’s 5:00 A.M. The sky is still black, the Milky Way at maximum milk. A half dozen men from a road crew mill around in the headlights of trucks, carrying bags of Austin Powder Company explosives. I watch Dazy load five “sticks” of Red-​D into the bed of his truck. It comes in plastic tubes and looks more like cookie dough than dynamite. Like many products in Canada, Austin’s are bilingually labeled. “Explosifs, Explosives”—​a rare instance where the French is briefer. At a supermarket in town, I saw a bag of “nourriture pour oiseaux sauvages.” Birdseed. Dazy wires a Day-​Glo sign to the cab of his truck: transporting dangerous goods. Now if we’re in a fiery crash on the way to the grove, the emergency responders will know to keep their distance. When we arrive, a morning meeting is convening around the hood of someone’s truck. Dean is here, and the falling safety advisors, and some men to cut up, or “buck,” downed treetops. Because the trees are near the highway, coners and flaggers are also here, to halt and direct lanes of traffic.

Dazy steps into his climbing harness and gets ready to ascend the first tree, a fir. He buckles climbing spurs onto his lower legs. By kicking the spurs into the sides of the tree—​left, right, left—​he ascends the trunk. Holding his upper body is a flip line looped around the trunk and into his harness. After every few kick-​steps, he uses the flip line to pull his body in close to the trunk, then flips the now slack line a foot or so higher. And repeat, all the way up to the height at which he’ll bore the hole for the explosive. Dazy has no fear of heights and has never fallen. “That seems to me a once-​in-​a-​lifetime sorta maneuver,” he said, when I’d asked.

It’s cold and drizzling and barely light out. A safety advisor lends me a work coat. Wood chips in the pockets. I can hear the flaggers’ chitchat over Dean’s radio handset. They’re at either end of the work zone, alternately stopping and waving on single lanes of traffic. “Hey,” one radios to the other. “Here comes yer girlfriend.”

Dazy lets down a rope, and the falling safety advisor ties the chainsaw to it. “There’s probably a special knot, but we’re not going to use it.”

The chainsaw ascends and Dazy unties it and then lets us know the rope is coming back down. Sawdust and noise begin spewing from his perch. When the hole is bored, the chainsaw Rapunzels down, and a backpack with the explosives goes up.

“I’m the guest detonator. I get to stomp the ‘thumper.’ This sets off a chain of minute explosions that travel, in an instant, along the shock tube fuse. Now comes the boom, followed by two sharp cracks as the tree’s top crashes through branches of an adjacent tree, then the thunderous whump as it hits the ground.”

Fifteen minutes later, Dazy’s work is done. He climbs back down, trailing fuse. Dean spools it out to the detonation site, three hundred feet distant. We all follow. The flaggers radio that traffic is stopped in both directions, and Dean blows the air horn, twelve blasts. I’m the guest detonator. I get to stomp the “thumper.” This sets off a chain of minute explosions that travel, in an instant, along the shock tube fuse. Now comes the boom, followed by two sharp cracks as the tree’s top crashes through branches of an adjacent tree, then the thunderous whump as it hits the ground and a coda of exuberant whooping from everyone except Dean. If a tree falls in the forest and no one is there to hear it, that’s a shame.

Dazy leads us back to the blast site. The accomplishments of “fragmentation and heave” lie all around us. A team of buckers slice the fallen top. The remaining tree, from our viewpoint down here among the mosses and ferns, looks just the same. Though of course it is different. It’s safer.

The safety advisor is still grinning. I am, too. I’m not sure why big (controlled) explosions cause humans such glee. We seem to be drawn to extremes: huge, tall, loud. It’s the pull of awe. It’s one reason we care about whales and not sprat[†], why people hug trees and step on clover.

No surprise, then, that Dazy’s work in this grove has from time to time drawn complaint. He once tried to talk to a protester, to explain that these trees were dying, and that they’d be coming down soon(ish) anyway. To which the protester replied, “We think the trees know when it’s their time to fall down.” Of course, it is not knowledge that prompts a tree’s fall, but some fatal brew of wind and gravity and damage and rot.

I can’t judge. We all have emotional connections to certain branches of the tree of life, and for some that branch is trees. We are irrational in our species-​specific devotions. I know a man who won’t eat octopus because of its intelligence. Yet he eats pork and buys glue traps for rats, though rats and pigs are highly intelligent, likely more intelligent—​I’m guessing, for I have not seen the SAT scores—​than octopuses. Why, for that matter, is intelligence the scale by which we decide whom to spare? Or size? Have the simple and the small less right to live?

Trees, the elders in particular, seem to evoke an urge to protect and defend. Perhaps that’s because the trees can’t do it themselves—​or not in ways easily evident. A tree can’t run away or fight back against anything larger than a beetle. Trees are vulnerable, peaceable, innocent. Plants in general have that vibe. Don’t be fooled.



[*] You can learn all about these structures on www​.explosivestoragemagazine​.com, which I at first took to be an online periodical about explosives storage. But it’s just a redundancy. The industry does have its own periodicals, however. For instance, the Journal of Explosive Engineers, which I would subscribe to for the title alone.

 

[†] The Abrau sprat is among 455 critically endangered fish, none of which are featured in conservation fundraising campaigns. Who will save the eightgill hagfish? Who cares about the razorback sucker and the delta smelt?