One in fifteen trees in #Colorado forests are dead

From The Fort Collins Coloradoan (Jacy Marmaduke):

The influence of the lingering dead — the product of decades of misguided forest management — trickles down to nearly every Colorado resident. It puts the state in the crosshairs of devastating wildfire and compromises the delicate relationship between forests and the people who rely on them for clean and plentiful water.

The forests that coat Colorado’s western terrain tell a story of loss, both past and future: the High Park Fire and beetle kills, smoky skies and barren branches. But as the dead fall and the young grow stronger, these forests tell a story of hope, too.

You need only look a little closer.

But West doesn’t blame beetles alone for the state of Colorado’s forests. The roots of today’s problems trace back to the early 1900s, when the commercial timber industry was booming and forest fires were blackening millions of acres across the West.

A newborn federal agency called the U.S. Forest Service started funneling resources into fighting those fires.

In 1935, the forest service’s “10 a.m. rule” mandated that all fires be suppressed by 10 a.m. the day after the initial report. In 1944, the forest service introduced Smokey the Bear as the huggable face of fire prevention.

Those well-intended efforts would eventually set up Colorado for huge wildfires like the High Park Fire, which burned more than 87,000 acres and 259 homes west of Fort Collins in 2012.

Forests need fire. The flames thin out overgrown stands, making room for younger trees to grow and regenerate forests.

Removing wildfire from the equation left Colorado forests with a monoculture: Thick, overgrown stands of trees that are the same species, size and age. Some low-elevation ponderosa pine forests have 100 trees per acre where there should be 40, forcing the trees to compete with their neighbors for resources.

Enter bark beetles, which West calls “the sanitizers of the forest.” The bugs are a sort of Lysol spray that scrub away the weak, the diseased and the lightning-damaged. Add a dash of bark beetles to overpopulated forests, though, and you end up with an all-you-can-eat beetle buffet.

“You throw on top of that a drought, and it allows these bark beetle populations to build up to the point where the trees are basically defenseless,” West said.

Trees protect themselves with resin, a natural armor. Some tree resins wage chemical warfare on insects, while others trap and smother the attackers.

But trees stressed by drought or facing a swelling army of insects can’t hold out forever. Eventually their defenses fail.

When that happens, bark beetles gnaw a hole in the tree’s inner tissues and have celebratory sex right in the entryway. With plenty of grub and faltering tree defenses, beetles breed en masse and work their way through every large tree in the area before moving on. They leave the small trees behind for the grandkids.

This happened with the mountain pine beetle, which swept across about 3.4 million acres of Colorado forests — 14 percent — between 1996 and 2016. Now it’s happening with the spruce beetle, which infested 1.7 million acres in the same period and has been Colorado’s most-harmful tree pest for five straight years.

West doubts the spruce beetle will ease up anytime soon as Colorado forests continue to face overcrowding and the effects of climate change.

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