Random Forest

A forest of straight trees in the afternoon sun
“Random Forest”, 16in x 12in, acrylic on canvas

There is a time, once a year, when we should avoid the forest. This was that time, and we were caught off guard.

About mid-summer a peculiar brand of bureaucrat invades the woods to conduct the yearly tree survey — gathering data, interrogating trees, and annoying the denizens with long questionnaires. I thought they had done it last week and you thought it would be next week, so we were okay either way, but we were both wrong.

“What’s that man doing there?” you asked, as we walked along a favorite path.

“Talking to that oak, it looks like.” He wore a checked tweed jacket with matching vest and brown corduroy pants — suitable for the English countryside in 1890 perhaps, but not the usual outfit for a casual hiker in these parts. “Oh, no. He’s got a clipboard or something. I think he’s one of those surveyors.”

“They’re not supposed to be here yet. Can we get past him?”

He was standing next to the path and we didn’t feel like turning back, so we forged ahead, hoping he’d still be engaged with his current victim, a gnarled red oak who must have been two hundred years old.

“I bet he’ll be busy for a while,” I said. “Some of those old-timers just won’t shut up when you ask their opinion.”

No such luck. As we were about to pass, the surveyor finished up with “Thank you for your time,” and turned our way.

He had a contraption on his head that let him switch between a variety of eye pieces — thick spectacles for examining bark, binoculars for looking into the higher branches, and normal glasses for reading his electronic notepad, which I had earlier mistaken for a clipboard.

When he saw us approach, he stepped into the path and went into his routine, not seeming to notice we didn’t belong to the plant kingdom. He hadn’t adjusted his lens gadget properly, so we probably looked like any other woody perennial with a single trunk and lateral offshoots.

“Good day. I’m from the Arbor Polling Service and we’re conducting our annual survey of trees. May I ask you a few brief questions? Good,” he said, without waiting for a reply. “Species type?”

I thought of the old personality question: If you were a tree, what kind of tree would you be? We couldn’t decide, so you just said, “Pine.” A safe answer, if a bit generic, though maple would have sufficed.

“Mm-hmm,” he said, tapping on his screen. “How many branches?”

“Branches?” I wasn’t sure how to handle that one.

“Limbs. Growths. Boughs,” he patiently explained, squinting at me.

“Four?” you said with a shrug.

He gave you a sharp look. “Had an accident, or did you lose them from disease?”

Four was too few, so I calculated fingers and toes and told him, “Twenty.”

“No, forty, all together,” you said, including us both.

“Ah.” He tapped that in, satisfied. “How many rings?” 

Neither of us were wearing any, but that’s not what he was after. He just wanted our ages. “Well, in dog years… no, wait.” Wrong conversion factor. “In tree years, um…” Is that a thing? 

“About three decades,” you said. “I mean, thirty rings.” That was close, if you averaged our two ages.

“Any saplings?”

We’d never really discussed having children, though we’ve planted plenty of trees together — two weeks one summer crawling up and down desolate slopes inch by inch on our hands and knees with a group of conservationists. Hot sun, pesky insects, aching backs. Good times.

“No offspring,” you answered. 

“Squirrels,” I explained. “Those darned critters eat all the seeds. Or nuts. And don’t get me started on the deer. We once had a tender young seedling, newly sprouted, bright green and cute as can be. But this hungry six-point buck came along and just munched the poor little— Oh, it’s too horrible to recount.” I teared up, almost believing my tale. You glared at me.

“I see. Legal resident of the forest?”

“Just visiting,” you said quickly, before I could invent another story.

“Hmm. Are you now, or have you ever been, a member of an aspen grove?”

Never!” I answered that one. “We don’t associate with communes.” Technically, clonal colonies, but it amounts to the same thing — all those trees sharing a single root system. As bad as inbreeding with cousins. And look at what that did to the Hapsburgs.

He finished with the demographic info, then tapped his pad to bring up a new page and gave us a friendly look.

“Now, what is your opinion of the use of mulch in society today?”

I tackled that one. “Mulch is, and always will be, the bedrock of our communities.” He frowned at my metaphor, but I stood by my statement.

“Do you support any bird’s nests or avian families?”

“No,” you said, “but we give to the Audubon Society.” That part was true.

“If you could change just one thing about the forest, what would it be?”

“Fewer trees,” I said, “maybe none. It’s just too hard to see the forest because of all the trees in the way. Something should be done about it.”

He hesitated before entering the response, as if deciding how to word it. He finally started tapping something in, but I could see you were getting impatient. We needed to continue our hike if we wanted to be home by supper.

You tugged on my arm and we began walking off, but the surveyor followed us with brisk, efficient steps. “Just a few questions about soil health… and grooming habits… and your exercise routine…”

He wasn’t about to leave us alone, which is why we wanted to avoid him in the first place. But there’s one sure way to handle this type — turn the tables.

“Let me ask you a question,” I said, wheeling around to face him. “What kind of statistical model do you use to analyze the data?”

“Model? I don’t—”

“And how do you calculate your confidence intervals? Or guarantee you have enough of a representative sample to draw the correct inferences about the target population?”

“Well, uh…”

You joined in and hit him with: “This survey obviously suffers from selection bias by including an over representation of trees residing near the path. How do you rationalize that?”

“But… but…”

“You need better random sampling,” I suggested, “though that would entail a lot more walking.” I poked him in the chest. “Why are you ignoring the opinions of those ridgeline trees? You’re marginalizing them.”

He was backing up now, but we pressed on.

“Which machine learning algorithms do you apply?”

“If a tree falls in the forest, how many are left?”

“Are you now, or have you ever been, a member of the Logger’s Union?”

“Who are you really working for?”

He looked uneasily at the remaining questions on his notepad, glanced up at us, and turned on his heels. He was far along the path before we could say another word.

“I think it was the tweed jacket,” you said. “Just not the right look for these woods.”

That bothered me too. We discussed proper forest attire as we headed down the homeward trail in the lengthening shadows of afternoon.