One effect of pine beetles: Massive forest fires, like the one we experienced the summer of 2012. That isn’t a cloud behind the trees—it’s smoke. Just after I snapped this picture, we evacuated for weeks while the fire raged.
The death toll starts to become visible in late winter, up here in the Rockies.
No, not snowbound neighbors. At least, not the human kind.
These neighbors are trees. Lodgepole and ponderosa pines, which make up most of the forest that runs pretty much unbroken from our little home all the way to Rocky Mountain National Park.
Normally, these pines would be dark green in February. But some aren’t the usual rich deep green. They’re a paler shade, a subtle difference that not many people notice.
But that off-color now says “death” to me, and I start mourning the loss of those trees as soon as we spot the signature hue. By April, those winter-pale trees will be rusty brown, a sign of death that no one overlooks.
Mountain pine beetles (Dendroctonus ponderosae), tiny guys about the size of fruit flies, are the cause. They’re killing the western forests so fast that whole mountainsides are brown throughout the Rockies.
By the time husband Matt and I notice the slight difference in color on a tree, it’s too late.
Not that we can do anything, anyhow. The plague has to run its course, and there’s simply no way to protect our trees or halt its progress.
Mountain pine beetles are natives, and they’re a natural part of forest life. They kill off sick trees, diseased trees, trees stressed by fire or drought or old age.
They’re also cyclical, building in numbers until it’s not only the puny, sickly trees that they kill, but the healthy ones as well.
As soon as the weather warms up—usually in June or July, but it’s been April the past few years—the new adult beetles go airborne, leaving their larval homes under the bark and swarming in search of mates.
Then they lay eggs, and the cycle continues, until the beetles start to run out of food… because all of the trees are dead.
They’re fascinating critters, despite the damage they cause. Their tiny bodies harbor the spores of a fungus that works with them to kill trees, infiltrating the wood as the larvae chew, and leaving it stained a lovely blue.
The signature blue streaks in beetle-kill lumber are a side effect of pine beetles, which spread the staining fungi as they tunnel through trees. The wood makes for beautiful furniture and countertops, like this one at our friends George and Mugg’s home. George made it himself from a beetle-killed tree he cut down on their place.
Summer is the eating season, and boy, do they ever eat! The itty-bitty larvae tunnel through the living sapwood right under the bark, eagerly feasting—but also cutting off the supply of water and nutrients from the roots as surely as a girdling strand of embedded fence wire, but a lot faster.
No worries, though, because, come metamorphosis, they’ll just emerge and fly off to find a new victim.
I’ve gotten used to seeing the other sure sign of death-to-come. The poor pines try their darndest to expel the invaders, oozing frothy sap into their tunnels as profusely as they can.
The sap studs the trunks like hundreds of pieces of brown popcorn, graphic evidence of how many beetles are at their nefarious work.
Beetle-killed trees are prone to toppling, so we target them first for firewood. In just three years, the hillside above our home has changed from a forest to a meadow, and plants are changing, too. Those that thrived in shade quickly are replaced by species that can take the sun.
Instead of seeing little gentians (yes, that’s the common name for Gentiana amarella), harebells (Campanula rotundifolia), and blue columbines (our glorious Aquilegia caerulea), we now see tall blue penstemons (Penstemon strictus), gaillardia, fringed sagebrush (Artemisia frigida), and Indian paintbrush, to name a few, where the trees used to be.
Harebells (Campanula rotundifolia) like some shade, not full sun. As trees disappear because of the beetle infestation, the harebells are being replaced by gaillardia and other sun-loving plants.
Another sign of the transition of the forest arrived in force last spring. Pine sawyer beetles.
These aren’t tiny guys. They’re huge. (I keep saying I want to have one for a pet.) And they have a propensity for flying into any large object outside—especially people. I’m guessing their vision is poor, and they’re mistaking us for trees.
Pine sawyers don’t damage living trees. Their larvae eat dead wood.
And we’ve got a lot of dead wood.
Pine sawyers are such big, goofy, bumbling things, I want to keep one for a pet. They move in to lay their eggs on dead trees after tiny pine beetles do the dirty deed of killing the tree.
We also have way more woodpeckers than we used to have.
Pine beetle larvae are just as minuscule as their parents, but woodpeckers gladly ferret them out, because there’re so many of them.
Pine sawyer larvae are giant-sized, and an even better prize for woodpeckers. Just one 2-inch white grub can keep a whole yammering family satisfied. For ten minutes, anyhow, until the other parent comes back to the nest with a full beak.
In years past, downy and hairy woodpeckers (our main species of hammerheads) lived far apart up here on the mountain. They needed big territories to supply the growing family, and we felt lucky to be hosting one pair near the house.
Last year, hairies drilled nest holes within shouting distance of each other all over the woods. Plenty of food = smaller territory.
A natural control of pine beetles in normal times, hairy woodpeckers can’t multiply fast enough to be much help. Though they try.
Sometimes, I’m not real fond of the way nature works. Although I’ve become hardened by the death of so many trees, I still mourn particular favorites when I notice they’re under attack. Oh no, that one with the curvy trunk…. Oh no, that one right by my garden… Oh no, not that one growing right in the rock! It just seems so unfair, since living conditions aren’t exactly easy street to start with up here.
But I feel like a pioneer, too, in these changing times, and that’s fun. What will this spring bring?
It’s been a hard, cold winter, and I have my fingers crossed—everybody says that cold winters kill pine beetles.
And even though we haven’t had the extended extreme cold that experts say is needed (thank you, climate change), I have my fingers crossed.
I’d much rather see more pine sawyers, more woodpeckers, and maybe even a resident Lewis’s woodpecker, like the one who stopped by briefly last fall for the first time, than see trees marked for doom.
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