What does the bark beetle epidemic bode for elk country? by Christine Paige
66 • BUGLE • MAY/JUN 2014
SEAN CRANE / INSET: JAMES WOODCOCK /GAZETTE STAFF
onna McDonald and her family have been hunting elk and ranching cattle for three generations in southwestern Montana. She and her husband Jake run Upper Canyon Outfitters from the family’s homestead ranch tucked into a tight canyon where the Greenhorn, Gravelly and Snowcrest ranges merge to squeeze the Ruby River. During elk season, the McDonalds lead their clients up into these mountains in search of the trophy bulls that lurk among the lodgepoles, whitebark pines and high parks. Their business revolves around the seasons, and over the years Donna and her family have witnessed a lot of changes. “Back when I was in my 20s, we were excited to see one elk. Then we saw the population boom, and right now it’s in a bit of a decline. The weather seemed colder then. The snow seemed deeper and cars wouldn’t start, but maybe that’s just because I was young. In my mind it seems to be easier winters now.” Recently Donna and her family have also witnessed a far more obvious change: the green mountainsides they grew with up have turned red, then gray. Like many parts of the West, mountain pine beetles have swept through this area, devastating mature lodgepole and whitebark pine stands with astonishing speed. “You worry about the cover for wildlife, and about fire,” Donna says, adding that it has made hunting all the more challenging. “The ground is crunchy with dead pine needles, and the dead and falling trees make it hard to get around. I always have a saw in my saddle now. Day to day, you never know how it will be. We’re continually clearing trails of deadfall.” That experience is echoed by her father Bill Tate. “Now every time we get a big wind, the trees are falling down everywhere,” says Tate. “It’s very hard to maneuver— but it’s probably not impairing the elk as much as it is us people.” From an elk’s perspective, Donna sees one positive. “If we get more daylight and sunshine and more grass, that might be wonderful in some areas.” But the dying trees are not a welcome change for a business that attracts guests in part by the grandeur of the scenery. “It’s a concern to people when they come out here and see the brown, dead trees—it’s heart-wrenching. It’s not what any of us want to see, but we don’t get to choose what is happening.” Like a silent insect tsunami, bark beetles have swept through lodgepole pine forests from British Columbia to New Mexico, ravaged spruce forests from Alaska to the Rockies,
pounded pinyons and ponderosas in the Southwest, and attacked whitebark, limber and bristlecone pines in the alpine. In just about every landscape where you find elk in the West, beetles have left oceans of dead and dying trees in their wake. If you’re an elk hunter, chances are good you’ve noticed. In fact your favorite hunting spots may seem like skeletons of the conifer temples you fell in love with when you first started roaming them. Since 2000, bark beetles have invaded more than 46 million acres of conifer forests across the western United States. In Canada, beetles have impacted nearly 45 million acres in British Columbia alone. This rapid and radical transformation—one that will alter habitats and hydrology for many decades to come—may challenge our very conception of what these landscapes should look like, and perhaps more importantly, how elk use them. “The current
the head of a match and weighing about as much as a grain of rice, can topple a century-old tree weighing more than 30 tons. And they are doing it on an unprecedented scale. Bark beetles have gone from being mild nuisances to ravaging hordes. “I like to call insects nature’s first responders,” Six says. “But not in the sense that beetles are EMTs rushing in to save trees.” Finely attuned to environmental change, bark beetles respond rapidly both to warming temperatures and to stress in their host trees. “Then they blow up. This isn’t determined by forest structure, but by temperature—temperature and drought. Those two things are the trigger, and then those trees that are the right species and the right size are attacked.” When beetles bore in, healthy trees ooze pitch— toxic resins—that entombs beetle attackers. Stressed outbreak is their trees are unable to summon these defenses, and beetles can different,” Six observes. Native Insects on a Tear quickly overwhelm a mature Bark beetles have been tree. Typically, outbreaks subside “It is more than 10 times around in North America for once cooler, wetter conditions at least the past 12,000 years. return, or when beetles run out of larger on a continental Most bark beetle species target susceptible hosts. dying, dead and decaying trees, Since the early 1980s, western scale than what we’ve helping to speed the process of North America has experienced a decomposition and serving a steady trend of warmer average seen before.” valuable role in nutrient cycling. temperatures and severe droughts. “Bark beetles are present in low numbers most In fact the decade from 2000 to 2010 was the warmest of the time,” explains Diana Six, professor of forest on record according to the National Oceanic and entomology and pathology at the University of Atmospheric Administration, with 2005 tying 2010 Montana, where she studies the beetles, their close as the warmest years since NOAA began keeping relationships with the fungi they carry with them, records in 1880. For western forests, the drought and interactions with their tree hosts. Under typical of 2002 in particular inflicted an unprecedented conditions, particularly in forests with a mix of tree level of stress on forests. That was compounded species, ages and soils, these tiny, clumsy fliers poke by a string of mild winters without the severe cold along, infecting a few trees here and there across spells that typically keep beetle populations in check the landscape. by killing overwintering larvae. As a result, beetle A handful of bark beetle species, though, attack numbers exploded. live trees weakened by drought, stress and disease. Mountain pine beetles have been the They also tend to focus on mature trees that provide most aggressive and widespread of all the bark an ample inner bark layer for feeding. Researchers beetle species. know from historical records, tree-ring analyses and “Once mountain pine beetles get going, they lake sediment cores that beetle infestations are nothing keep going,” explains Barbara Bentz, U.S. Forest new—outbreaks occur every few decades. Historically, Service research entomologist with the Rocky beetles have overtaken anywhere from 10 acres to Mountain Research Station. Massive hatches can tens of thousands of acres. As natural as wildfire, bark overwhelm even young and healthy trees, and the beetles have long been an important driver of forest hungry mob may jump to less favored tree species change and renewal, opening the canopy, returning as needed. Spruce beetles, pinyon ips and other nutrients to the soil and stimulating regrowth. bark beetle species have also been on the rise in Yet what we’re seeing now is far from ordinary. many regions. A recent bark beetle symposium concluded that “The current outbreak is different,” Six observes. the current situation differs from historical outbreaks “It is more than 10 times larger on a continental scale in intensity, magnitude and “synchronicity”— beetle than what we’ve seen before. And the beetles have outbreaks across many forest types by many different moved up in elevation and several hundred kilometers bark beetle species happening all at once. Steve north into areas that were once too cold and harsh.” Running, an avid elk hunter who serves as professor A swarm of beetles, each beetle fitting easily on 68 • BUGLE • MAY/JUN 2014
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of forestry at the University of Montana and won the Nobel Peace Prize in 2007 for his work with the Intergovernmental Panel on Climate Change, simply calls it “the biggest forest epidemic on earth.” Although warming temperatures and drought are the triggers for beetle outbreak, the age and condition of forest stands have set the table for a beetle bonanza. Both aggressive fire suppression and timber harvest practices in the 20th century, well-intentioned as they were, altered forests across the West. Vast stands of even-aged trees now stand crammed together, fighting for scarce water and nutrients that have only grown scarcer in recent decades. In many lodgepole forests, fire now blackens only one percent of the acreage that annually burned a century ago. This has created huge swaths of elk country where 70 percent of these pines are more than 80 years old—triple what is normal, and ideal conditions for mountain pine beetles to mass attack.
A STICKY SITUATION: Pitch is a tree’s main defense against boring beetles, but record heat and drought have left many stands too parched to produce. Infested trees look like swiss cheese, their bark shotgunned with pitch tubes from trying to battle the invaders. Mild winters and long summers have allowed the bugs to breed multiple times per season, spawning swarms that overrun even healthy trees and alter forests on a scale never previously recorded.
Bark beetles include some 7,500 species of Scolytid beetles worldwide—tiny bullet-shaped borers that spend 98 percent of their lives tunneling through the dark interior of their host trees. For only a couple of weeks each summer, they emerge as adults and fly to find new host trees. Temperature drives everything. In the relatively cold environments typical of elk country across much of the Rockies, the mountain pine beetle needs two years to complete its life cycle from larvae to adult. The larvae overwinter in the host trees, metabolizing glycerol that acts as antifreeze. But they’re vulnerable to below-zero cold snaps in fall before larvae produce glycerol, and again in spring when they’re molting into their pupal stage. Mid-winter deep freezes can also kill off large numbers of beetle larvae, but only if temperatures drop to 30 degrees below zero Fahrenheit for at least several days in a row. Crank up the thermometer just a little, though, and beetles gain a big advantage: a small bump greatly accelerates their development and reproduction. Given slightly warmer temperatures, mountain pine beetles can produce a generation within a single season. Warm late autumns, early springs, and winters without deep cold all boost larvae survival rates. Suddenly the forest is awash in bark beetles looking for new trees to host their next generation.
A Little Warmer, A Lot Faster
Changing Landscapes: A Boost for Aspen and Other Species?
Falling Trees With millions of acres of beetle-killed timber on the landscape, hunters may find roads and trails blocked by deadfall. In the backcountry, don’t expect your routes to be cleared for you. Whether you’re on foot, horseback, ATV or in your truck, you’ll want to pack along a good saw and be ready for some slow going. When clearing trails of deadfall, try to use gravity to your advantage: cut through downed logs on the uphill side so they can be rolled away more easily once you make your slice, and cut from an angle that won’t pinch your sawblade. It’s also worth considering where to pitch your tent or park your rig. The first thing to do is to look around for dead and weak trees that could topple if the wind kicks up. If there are so many that it’s impossible to plant yourself at a safe distance from all of them, consider the prevailing wind direction. If it’s somewhat predictable, place your camp upwind from those trees that look most likely to crash down in a gust. But keep in mind that snags can come crashing down even on a calm day. Though it may sound obvious, if at all possible, avoid stands of dead timber if there is any likelihood of a windstorm. Although a tree falling is a hazard nearly anywhere, a forest of dead standing snags toppling over can be deadly. Hunters will find they need to be extra vigilant both in choosing safe campsites and while traveling through the woods. “I worry about my clients’ safety,” says Donna McDonald of Upper Canyon Outfitters, “and I hope we’re never in it in a big wind.”
In the first four years after a beetle attack, conifers fade from green to red to gray, their needles drying and then dropping, leaving snags standing bare. Eventually, those snags begin to topple. What follows an attack depends on what tree species live there, the average age of those trees, how dry the site is, the soils, water table, wildfire and innumerable other factors thrown into the mix. The crystal ball is pretty fuzzy, but researchers are scrambling to look into the future. Like wildfire, beetle outbreaks can hit the “reset” button on forests, leaving a patchwork of stands of different species, ages and densities. This could, in turn, boost wildlife as well as forage diversity as sunlight floods the ground and the soil warms, spurring grasses, shrubs and new tree seedlings to grow. Even in areas with heavy beetle attacks, not every tree perishes. Released from competition with their cohorts, the survivors can grow with new vigor, as can the tree species the beetles ignore. With lodgepole being the beetle’s food of choice, subalpine fir and Engelmann spruce may increase. When fire sweeps through, those lodgepole cones that depend on the heat of fire to release their seeds will produce a new generation. Over the past century, aspen have declined by 50 percent or more across much of the West as extended drought and lack of wildfire allowed conifers to encroach. In regions where aspen mix with lodgepoles or other conifers susceptible to mountain pine beetles, beetle-kill may help “release” aspen stands as they send up new shoots in the sunshine. If wildfire sweeps through, aspen readily re-sprout new suckers from their extensive interconnected root system, renewing and reinvigorating the stand, provided there is sufficient moisture. “What you get back really depends on the bio-physical setting,” says Barry Bollenbacher, regional silviculturist for the Forest Service’s Northern Region. “You reduce canopy density by 80 percent, and aspen will be released; grass, forbs and shrubs will be more prolific; and you may end up with much more diversity. Fire will affect the regeneration of trees, but it depends on how much fire we have. We had a lack of diversity from fire suppression, and I hope fire will reintroduce more diversity to these landscapes.” It’s natural to look out on mountain flanks covered in red and dying conifers or a sea of snags and imagine a primed tinderbox. Firefighters and fire ecologists are learning, however, that beetle-kill may not lead to extreme fire risk. Immediately after a beetle attack, there is a short period, one to four years, when there is indeed
that depend on tree canopies or mature forests, such as warblers, kinglets, crossbills, boreal owls and goshawks, may have a tougher go of it. On the other hand, a shift of tree species, remaining “legacy trees” unharmed by beetles, or a patchwork of stand types and ages, may produce more diversity and provide habitat for a much wider array of critters than found in endless forests of mature lodgepole. What about elk? They could hit the jackpot as the sunlit soil beneath dead pine stands rebounds in rich undergrowth. Wapiti tend to thrive in young forests stuffed with grasses, shrubs and aspen. An
a greater risk of crown fire. When a tree’s needles are still green but fading or once it has died and turned red, the drying needles are more flammable. After the needles fall, however, there are no fine fuels to carry crown fire, and an expanse of standing bare snags can actually become something of a fire break. Later, these snags litter the ground. Some may quickly rot while others stay dry. Either way they are tough to ignite—just as you could not light your campfire with a match set to a large log or damp tinder. But if that heavy mass of fuels does ignite, it becomes extremely tough to control. Ultimately, however, it is
DOES RED HAVE A SILVER LINING? People cringe at the sight of beetle-killed forests, but to elk it may look delicious. Without the umbrella of a tree canopy, sunlight and precipitation spill freely to the forest floor, which could spur a bonanza of grass, forbs, shrubs and elk.
fire weather—hot, dry and windy—that drives fire behavior, intensity and severity, whether a forest is green, red or gray.
Wildlife Boon or Bust?
“What are the realistic effects of beetle-kill on wildlife?” asks Eric Tomasik, Forest Service Northern Region wildlife program lead. “How much of this is just another disturbance? It’s only the current scale that’s unnatural. We know there will be wildlife winners and losers.” As the vegetation changes with time and succession, so too will the array of wildlife any particular site can support. Woodpeckers find a bonanza not only in the beetles but also the other wood-boring insects that colonize the beetle-killed trees for several years. Cavity nesters such as chickadees, owls and mountain bluebirds find an abundance of homes in dead snags. Other species
extensive tangle of dead and down trees could also provide more security from two-legged and some four-legged hunters. Colorado has witnessed a massive mountain pine beetle epidemic, affecting upwards of 3.3 million acres. Chad Bishop, assistant director for wildlife and natural resources for Colorado Parks and Wildlife, says the abundance of beetle-kill will likely invigorate the understory of aging forests across the higher mountains, which have been somewhat unproductive for elk in recent decades. Instead, elk will find a carpet of shrubs, grasses and forbs, and the security of boundless tangles of blowdowns. “We think this is going to add productivity in the central mountains, east of the Divide and in southwestern Colorado as well,” Bishop says. “But we know it will also impact access for sportsmen.” The division has worked hard in recent years to trim Colorado’s bumper elk herds. “We were well over population objectives five to six years ago, but we’re MAY/JUN 2014 • BUGLE • 71
Decoding the Medicine Bow
In southern Wyoming’s Sierra Madre Range, biologists are tapping hunters to help gauge the impacts of the beetle kill. Mountains here are dominated by lodgepole pines and dappled with high meadows and pockets of aspen, their flanks cloaked in serviceberry, mountain mahogany and chokecherry. The range straddles the Continental Divide, and 8,000 to 10,000 elk summer here, migrating down onto sagebrush lowlands as winter sets in. This herd draws more hunters than any other in Wyoming, and in 2012 produced the highest harvest in the state. Over the past eight years, mountain pine beetles
down to objective now through high cow harvests and late seasons. Beetle-kill could be a concern for a couple of herds—it could add challenge and impact our ability to manage in some areas. But we use many tools and have shown a good ability to bring populations to objective. Overall, the beetle-kill could provide greater productivity and hunter opportunity.” Prescribed burns in beetle-kill zones may be key to maximizing forage for elk and other wildlife, says biologist Larry Irwin. An expert in wildlife and forestry, Irwin spent eight years as a researcher and professor at the University of Wyoming before becoming wildlife program manager and principal
FIRING UP ASPEN: The threat of wildfire spikes immediately after a beetle-kill, but as needles drop, so does the risk. Aspens that have for decades faded away due to crowding by conifers and lack of fire may suddenly see a green light in this equation, which could in turn be a boon to elk herds.
scientist for the National Council for Air and Stream Improvement, where he’s conducted research for the past 27 years. He now sits on RMEF’s board of directors. Living in Montana’s Bitterroot Valley, he’s a passionate elk hunter, and says he spends much of that time chasing elk in burned areas where herds tend to be drawn by lush forage. “If beetles open up the stands enough, you will get some understory response, but it may not be enough to really attract the elk, especially in lodgepole pine stands” Irwin says. “But do some underburning and you’re likely to really have something, particularly in moist, mixed stands and those with elk sedge. You’ll get an increase in forage, a bump in dietary quality, and likely some different species of plants coming up, and elk will respond to those features.” So far, RMEF has helped fund prescribed burns across well over a million acres of elk habitat, including beetle-ravaged forests. 72 • BUGLE • MAY/JUN 2014
have ransacked 1.5 million acres here, leaving an ocean of red needles and dying trees. The Medicine Bow National Forest saw 80 to 90 percent mortality in some areas. Lodgepoles are now toppling over by the tens of thousands. “Makes good bedroom habitat,” says Irwin. “It’s sure hard to sneak up on an elk in those conditions.” Tony Mong, Wyoming Game and Fish senior wildlife biologist for the region, wonders what this will mean for elk movements and how hunters will respond. Will elk shift to new routes and haunts? How will hunters negotiate the forests and haul out their game? If hunter success or the number of hunters drops, how will that affect the agency’s ability to manage the herd and bring it closer to the agency’s population objective of 4,200 animals—half the current population? In 2011, Mong launched a long-term study in the Sierra Madre, seeking answers to these questions with partial funding from RMEF.
Standing tall for the So far RMEF has helped reinvigorate forests across nearly 2 million acres of prime elk country.
o say the mountains surrounding Troy, Montana, are forested is an understatement. This is the deepest, darkest woods you’ll find in the state, the sort of doghair that repels most elk hunters. It takes an uncommon level of dedication to chase elk here, but it comes with a distinct reward: this area, Region 1 as it’s known to hunters, grows some big, old bulls. It has a proud history of elk hunting that is reflected on the walls of stores and saloons, and in the pages of the Boone and Crockett records. Yet there is another proud history here—that of the Rocky Mountain Elk Foundation. RMEF opened its doors in Troy in 1984, or more precisely opened its door—the foundation began in a single-wide slouched beneath towering Douglas firs. Considering that a primary challenge for elk here is finding enough to eat under the dense canopy, it is fitting if not really surprising that RMEF’s very first habitat project endeavored to open things up. It helped to fund an 1,100-acre prescribed burn not far from Troy, and so launched what has become one of the hallmarks of RMEF’s mission work: to
improve forest health for wildlife. Why should humans even need to mess with the woods to improve it for wildlife? Partly because forests by their very nature are in a constant state of flux. They burn. Windstorms lay them flat. Floods undercut them, droughts parch them, and as the surrounding article graphically illustrates, bugs eat them. Yet forests keep on renewing themselves, day to day, century to century. Historically this has almost always worked in elk’s favor. Flux means food to a species that thrives on new growth. But with stagnation, forests clog like the heart of a portly couch potato. Very few species thrive in such circumstances. Over the course of the past century, the system has experienced a blockage of sorts in the form of people trying to keep life in the forest on an even keel. We try to avoid the forest fires that destroy our homes, cabins and roads, marring our landscapes and skylines with blackened trees and clouds of smoke. By necessity, many forests now require a helping hand to balance the desires of man with the needs of wildlife. RMEF has helped to make this happen since that first prescribed burn in 1986
on the Kootenai National Forest in Montana. Before the year was out, RMEF helped sponsor another burn across the border in Idaho on the Nez Perce National Forest. Now 28 years later, the Elk Foundation has gone on to partner with the U.S. Forest Service and other federal and state land management agencies to improve forest health everywhere elk roam. That includes more than 2 million acres spread across 55 national forests and scores of other public elk hunting havens. Through prescribed fires, aspen enhancements, forest thinning and many other methods, RMEF has vastly improved available forage for the West’s most celebrated elk herds. Places like Colorado’s Grand Mesa, New Mexico’s Gila and Idaho’s Clearwater. And elk have responded. There are now twice as many wild elk on the hoof as when RMEF opened its door. It’s a never-ending effort, of course, but with time and good science, it can get more manageable with each passing season. And come fall, we hunters reap the dividends. —Paul Queneau MAY/JUN 2014 • BUGLE • 73
By placing GPS collars on cow elk, Mong will get an idea whether their movements and habits change in areas of heavy deadfall. He is also asking hunters to voluntarily carry a GPS unit for one day of their hunt: their track for the day is recorded and all of the data is kept anonymous. So far hunters have been very willing to help. “I’m not after their secret hunting spots,” Mong says. “Hunters are super interested in the project, and they’re already telling me that they are altering where they hunt due to deadfall.” The deadfall itself may protect tree seedlings from browsers, enhancing regeneration of a new forest over time. The beetle epidemic may lead to a much more diverse landscape in the long run. More definitive results will take a few years, but Mong’s research will help Wyoming Game and Fish continue to adapt their game management strategies.
A New Trajectory?
It appears the bark beetle epidemic has begun to taper off in the past three years. Aerial surveys across the West show that the cumulative “footprint” of mountain pine beetles and other bark beetle species has peaked. Time will tell whether the December 2013 cold snap that sent thermometers close to 40 degrees
below zero from Colorado to Montana will have an effect, but the fact is beetles are running out of steam in many places simply because they are running out of suitable trees. In some regions, though, plenty of mature potential hosts remain. Mountain pine beetles have also shown themselves to be particularly adaptable, jumping to other host species. They’re currently afflicting mature ponderosa pine in Montana and Colorado. They’ve laid waste to whitebark pines already endangered by a disease called blister rust. And for the first time on record, they have leapt north and east into Canada’s jackpine and boreal forests. Elk may well prosper in more open forests, but we humans will need to adapt our expectations: what our favorite ground “should” look like, where to find that honey hole in the fall, and what we may need to go through to get there. “We, our parents and our grandparents, who grew up between 1940 and 1980—our forests were green,” reflects Barry Bollenbacher, ecology specialist for the Forest Service. “But that’s not how our western forests operate. What we should expect is a combination of red, green and black. That is normal.” Christine Paige lives, writes and wanders the wilds in Wyoming.