If a tree falls in the forest…it will be overtaken by spruce beetles
Two weeks ago Gunnison County officials and the Gunnison and Uncompahgre National Forests enacted Stage I fire restrictions, prohibiting smoking outside of enclosed areas, campfires except in designated permanent fire pits or fire grates, and fireworks of all kinds. This is the second summer in a row that restrictions have been placed before the Fourth of July, and the question now becomes, Is this a harbinger of things to come?
The warning
If the wind is blowing just right, if the sky stays clear in the afternoon rather than filling with rain and towering thunderheads, if the jet stream cooperates, then it’s possible to smell it. To see its haze—yellow and dirty like a city’s smog gone AWOL. Smoke in the valley.
On June 5, lightning strikes sparked fires in southern Colorado in the rugged areas of San Juan and Rio Grande national forests. The flames traveled quickly through swaths of drought-compromised underbrush and beetle-killed trees, forcing home evacuations and road closures.
Now, a month later, the fire continues to rage, having burned more than 96,742 acres.
At just 4 percent containment, officials have said there is no telling when it will be put out. At the rate it’s going, the West Fork Complex fire may simply continue to burn, sending acrid plumes of smoke north toward Crested Butte, where unwary Buttians sit in ignorance of the danger waiting on their own doorstep.
Colorado is no stranger to wildfire. Last year alone, more than one million acres of public and private land went up in flames. The cost to fight these fires was upward of several billion dollars, while the cost to the environment and local populations was immeasurable. However, not one of the major 2012 wildfires occurred in Gunnison County. In fact, it has been decades since Gunnison County saw a large-scale wildfire.
That exemption, said Colorado state forester Sam Pankratz, is contributing to a building complacency for people living in the county.
“The conditions we have in Gunnison County and around Crested Butte are approaching those that led to the West Fork Complex fire,” said Pankratz. “Drought conditions, dead trees, insect problems, poor access to forested areas where home sites are located—to some degree it’s only luck that we have not yet seen a devastating wildfire in the area.”
What Pankratz is saying in so many words is that the West Fork Complex is a warning.
Drought in our forests
Surrounding the Upper Gunnison Valley is a mixed forest of evergreen and deciduous trees. At the lower elevations and along the valley floor, aspen trees cover the landscape. Moving upslope, the vegetation turns to firs and spruce, with the occasional lodgepole pine.
At first glance the trees, which range in color from acid green to olive, look healthy. But look deeper. See the red tinge that seems to dust the trees growing on Whetstone, Red Lady, Axtel. While it’s not a sickness, that color could be a subtle warning that things aren’t quite right.
In some years conifers will produce an increased number of pollen cones, to the point that the entire tree will take on a red or yellowish tint, said Pankratz. This seems to be the case this year, and it could be due to an increased level of stress on the evergreen trees.
“Stress in the forest can take on a variety of forms,” said Pankratz. “Water—too much, or too little—insects, competition, fire, changing climate. Here, what we’re likely seeing is a drought-stressed ecosystem. Despite the decent snow year last year, our region is in a decades-long drought, and its impact can be seen in a variety of ways throughout the forested landscape. Once the trees are weakened by drought, they become much more susceptible to other forms of disease and fire.”
According to the National Drought Mitigation Center, the majority of southwestern Colorado is currently in some level of drought, with conditions expected to worsen as summer progresses.
“Many people don’t realize that drought is cumulative,” said Pankratz. “We may have glimpses of hope, but one decent snow-year does not make up for 10-plus years of poor snow, and the result is an incredibly dry and disease-prone forest.”
Here come the bugs
As of last year the spruce beetle, a quarter-inch long, dark-brown bug that looks like a cross between a tiny hornless rhinoceros and a naked mole rat, became the most dangerous insect threat to the state’s forestlands. It’s an insect capable of causing significant mortality in high-elevation forests, particularly those with large populations of Engelmann spruce, like the forests around Crested Butte.
According to the 2012 Report on the Health of Colorado’s Forests, last year the state mapped 311,000 acres of tree mortality attributable to spruce beetle. That’s compared to 262,000 acres in 2011, 208,000 acres in 2010, 114,000 acres in 2009 and 64,000 acres in 2008.
“Spruce beetle is the sleeping giant in terms of impact to forest health,” said Pankratz. “We don’t see it on the Front Range so it hasn’t made huge headlines, yet. But it’s a primary reason behind the severity of the West Fork Complex, and it’s moving this way at a rapid pace. We have many of the same conditions they have, and we’re primed for an infestation to move into the area.”
While the well-known mountain pine beetle kills its host in a year, leaving behind only standing dead trees with bright red needles to mark its passing, the spruce beetle is much more subtle. Female beetles bore through the bark of trees and deposit their eggs in clumps called egg galleries, which can vary in size from a few inches to more than a foot long. When the larvae emerge from these galleries they rapidly begin to feed on the phloem (the innermost bark of the tree). Once the phloem is sufficiently damaged the tree will die. It’s a two-year process, and unless it’s being looked for, one that’s easy to miss.
“A dead spruce doesn’t garner a ton of attention,” said Pankratz. “The needles turn yellow then grey, so even a small clump of trees may not stick out on the landscape. That doesn’t mean it shouldn’t act as a large red flag that requires active management in the form of promoting overall forest health.”
A manufactured ecosystem
High up in the Trappers Crossing subdivision just outside of the town of Crested Butte, million-dollar homes sit perched upon rock outcroppings and hidden behind thick stands of spruce and fir. The presence of these houses amid an otherwise forested landscape exemplifies many of the challenges of modern forest management.
“Before we moved into and across the landscape, away from centralized towns and cities, wildfires were allowed to burn,” said Pankratz. “They are a natural part, and process, of a healthy ecosystem and served to thin the forest, reduce insect populations and fuel sources and foster more diversity within the forest. By fighting all fires, we’ve created a very unnatural ecosystem that requires human intervention to maintain health.”
Intervention at Trappers, which is considered an area of extreme danger should fire occur, in large part due to the single roadway, has come in the form of a multi-year project to thin trees along the one roadway in and out of the development. By conducting mechanical thinning, Pankratz hopes to increase the safety of area residents should a fire occur by creating a defensible route through which people could exit and fire personnel could access the fire, and thereby decrease the likelihood of a catastrophic fire in general.
“By removing the ladder fuels, small trees and shrubs that help a fire move from the ground to the canopy, we create a better opportunity to control a fire should it occur,” he said. “Before treatment you’re seeing incredibly dense stands of trees filled with dead branches that reach all the way to the ground. It’s a recipe for canopy fire, and that’s how homes are lost.”
Thinning projects also help promote species diversity within the forest, leading to better overall health.
“Without intervention, the forest begins to look like a monoculture. If it weren’t trees it could be a cornfield,” said Pankratz. “And within that homogeneity there is huge potential for disease, which then leads to increased fire danger.”
Pankratz works directly with property owners in Trappers to develop management plans for their land. He said in general residents have been excited to work with him, despite the necessity of cutting a few trees.
“We’ve gone into this project knowing we’re altering an existing ecosystem and that takes time,” said Pankratz. “You don’t want to just jump into something that has the potential to last for hundreds of years, but at the same time forest management is not just about managing for the current day, or the current season. I think we have to look at what we want this valley to look like in 400 years.
“When you choose to live in one of these areas, you need to accept the responsibility associated with that choice,” said Pankratz. “We’re here to help you protect yourself and your property, but it is also your job to manage for fuel reduction and defensible space.”