The Gray Ghosts Of Change: Can The Grizzly 'Bear Tree' Be Saved?
The whitebark pine tree is receiving federal protection at same time states are pushing to remove grizzlies from imperiled list. A story about how fate of trees and bears is intertwined
Much of a grizzly's life between coming out of the den and heading back in focuses on finding food. Here, a griz moves through a Northern Rockies forest in search of nutritional sustenance. Photo courtesy NPS
by Laura
Lundquist
Last August was
hot, but not too hot for a backpacking trip on the 40-mile Teton Crest Trail
along the western edge of Grand Teton National Park. Rarely descending below
8,000 feet, the route affords views of rugged mountain peaks and the Snake
River valley that are worth the climb. But having been a Forest Service
silviculturalist, Liz Davy was usually preoccupied with the trees.
“All of the
sudden, we were in an area of whitebark pine right at tree line, and I was
like, ‘Oh, look at those beautiful trees,’” Davy said. “And then I was like,
‘Whoa, wait a minute.’”
Walking closer,
she winced as she saw pitch tubes in the tree trunks and small piles of boring
dust on the ground below, classic signs of mountain pine beetles hitting the
trees. She’d seen it while working on the Bridger-Teton National Forest, right
before the last beetle outbreak in 2009. The resulting devastation of whitebark
stands unraveled parts of the high-elevation ecosystems that depend on pine
seeds and the retention of snowpack. Back home in Driggs, Idaho, Davy called
Nancy Bockino, another whitebark pine expert in Jackson Hole. Yes, Backino had
seen similar indications of beetles during her travels.
It turns out
several people had been seeing increasing signs of beetles in the Greater
Yellowstone region, with the earliest warnings starting in the south. These harbingers and the disappearance of a once-thriving whitebark pine forest prompted the U.S. Fish and Wildlife Service to list the species as threatened under the Endangered Species Act in 2022. What to do next opens the door to provocative questions looking at both short-term and long-term horizon lines as we venture deeper into a century that is turning warmer drier overall in the West.
° ° ° °
Whitebark pine is
an important focal point for thinking about the real effects of climate change
and the role that different biological parts play in holding an ecosystem and
the animals that inhabit it together. It's been a topic of intense research focus and one of the leaders out front has been Dr. Diana Tomback, professor of integrative biology at the University of Denver. Not long ago, before the Fish and Wildlife Service was persuaded to list whitebark, Tomback delivered a gripping overview at the Draper Museum of Natural History in Cody and she has been an advisor to a pair of new short videos, one focused on the Clark's nutcracker, that recently premiered at the National Press Club in Washington, D.C. You can watch the one on whitebark below.
Adapted to high altitude and colder
temperatures, whitebark pine is a five-needle pine, similar to limber pine,
that once dominated the slopes of the Northern Rockies. Although slow growing,
some bushy whitepark pine matriarchs tower over their progeny, producing cones
with seeds that feed squirrels, Clark’s nutcrackers and most famously, grizzly
bears. Sadly, many stands are now just gray ghosts, their wooden skeletons a
glaring warning of climate change and the mistakes men make enable invasive
species.
Biologists like
Dr. David Mattson, a wildlife ecologist by training, a former member of the
prestigious Yellowstone Interagency Grizzly Bear Study Team and a researcher
whose dozens of peer-reviewed journal articles on grizzly bear nutrition are
widely cited, has for years pointed out of the importance of whitebark pine.
Mature trees
produce cones which are chock full of nuts. Red squirrels gather and cache the
cones for ready eating later. Grizzlies come upon the caches and gorge
themselves on the nuts which are rich in fat and protein.
Mattson has
noted that grizzlies which have had access to these staples are able to put on
weight needed to get them through the year, and through winter hibernation.
Female bears able to take advantage of abundant cone years tend to be healthier
and that translates into mothers having successful pregnancies. It’s no
coincidence that Greater Yellowstone’s grizzly recovery, in which numbers of
bears grew, happened when the whitebark pine forest of the region was still
healthy.
Former Forest Service Climate Change researcher Jesse Logan and colleague Polly Buotte observe a smaller whitebark pine hit by mountain pine beetles near Island Lake in the Absaroka-Beartooth Wilderness. Photo by Laura Lundquist
Because of
where the trees grew, their draw as a food center also pulled bears away from
populated human areas. In previous years, when the whitebark cone nuts were few
and far between, bears roamed over larger areas looking for food and sometimes
those navigations brought the into greater conflict with people. Whitebark pine
trees had many benefits besides those imparted to grizzlies. Clark’s
nutcrackers eat them and disperse the nuts which result in more trees growing.
Trees also helped hold snowpack longer during summers. Many hikers who
encounter the strange, contorted trunks of whitebark probably had no idea of
how important they’ve been.
Bear researcher
Kerry Gunther, lead grizzly bear biologist in Yellowstone, put together a paper
that identifies all of the natural things grizzlies eat. The lost tops more
than 200 different items. Mattson contends that whitebark pine, in terms of its
high value, has ranked in the top four. Uncertainty over just how important whitebark is to sustaining a viable bear population in Greater Yellowstone is one of the reasons a federal judge ordered grizzlies to be placed back under federal protection after they were temporarily delisted in 2007.
The findings of an
analysis on whitebark was carried out by grizzly bear researchers and
published in the journal Yellowstone Science in 2015. There remains a debate about the
loss of whitebark pine means for the ongoing health of the Greater Yellowstone
grizzly population, as it also contends with unprecedented development pressure
on private lands, more recreationists moving through public lands displacing
wildlife, and the onset of climate change that is disrupting the food and water
chain.
° ° ° °
Today, the
federal government agrees with conservationists that the whitebark pine needs
to receive protection under the Endangered Species Act and listing brings with
it a different kind of lens. Whitebark are threatened by a number of factors—an
exotic fungus that came to North America from Asia known as blister rust, the
rising frequency of wildfires being hastened by climate change, drought and
outbreaks of beetles that experts also link to warmer temperatures and trees
becoming stressed by elemental forces and more vulnerable to infestation.
National Park Service ecologist Erin Shanahan first noticed more
beetles becoming active in 2019 on the southern end of the Bridger-Teton
National Forest. Shanahan has surveyed whitebark pine on Commissary Ridge
almost yearly since she took over as lead of the Interagency Whitebark Health
Monitoring Program in 2004. After the pandemic forced her to cancel that trip
in 2020, she was looking forward to getting up there again the following year.
But her
excitement dimmed as she approached the site and saw that the trees for miles
along the ridge were now dotted with a rusty orange. The needles were dying.
She too checked in with Bockino, who that year found similar conditions in the
Wood River drainage east of Commissary Ridge.
“The beetles do
appear to be hitting them hard again, way earlier than I thought I’d see, based
on all that predictive modeling. I know we’re always going to see beetle
activity in localized cases but what I’m seeing has me concerned that this may
be a little bigger than that. It could trend northward similar to the pattern
that the last epidemic had,” Shanahan told the Whitebark Pine Ecosystem
Foundation in a presentation a year ago. The National Park Service denied
access to interview Shanahan for this story.
Whitebark pine enthusiasts are a tight bunch with grapevines that thread throughout the Northern Rockies. For the past year, emails have bounced back and forth within a portion of the group that’s vigilant about beetles, comparing past observations and planning for more.
University of Montana forest entomology researcher Diana Six confirmed Shanahan’s worries about the future.
“[Beetles are] building right now, in Wyoming and other places,” Six said. “Others are seeing buildups that are pretty indicative that it’s going to be bad, starting this year, in some areas that haven’t been hit before.”
A new beetle outbreak in the Greater Yellowstone region could be devastating. The epidemic that peaked in 2009 wiped out an estimated 75 percent of the mature, seed-producing whitebark pine, according to Shanahan’s inventories. Some, including retired Forest Service entomologist Jesse Logan, put the estimate as high as 80 percent. Sadly, another wave of beetles could decimate the remaining few.
Logan has been watching the slow-motion onslaught of threats to whitebark pine happening in the interior West for decades. Having retired to Paradise Valley, Montana, he has witnessed it in all of Greater Yellowstone’s major mountain ranges, including the Absarokas and Gallatins that rise beyond his front and back doors.
“The threat to whitebark is a three-legged
stool: you’ve got climate change, you’ve got beetles and you’ve got blister
rust. You can’t fix just one leg only. You’ve gotta fix all three or the stool
will fall over.”
–
Diana Six, entomology researcher at the University of Montana
The 2009 outbreak was one of the drivers that prompted whitebark pine lovers to push the U.S. Fish and Wildlife Service to list the tree under the Endangered Species Act. After a few delays, the Service finally granted the species federal protection in December. Most were happy with the ruling, but some scientists question a couple details.
For one, the Fish and Wildlife Service declined to designate critical habitat for the tree, a step normally required by the Endangered Species Act unless it’s unknown or imprudent. Critical habitat are areas that are critical to a species’ survival but its designation puts restrictions on those areas, limiting what forest managers can do. Joe Szuszwalak, acting deputy assistant regional director of communications for the Fish and Wildlife
Service Mountain-Prairie Region, said in an email, “the Service is not designating critical habitat for this species because habitat loss is not a threat to the species’ continued survival; disease from white pine blister rust is the primary threat.”
That illustrates the other problematic detail, which isn’t part of the ruling, but some worry that current pressures could make it de facto guidance: the priority on fighting white pine blister rust above all other threats.
“We’re all hoping for a future for whitebark pine. It’s not like grizzlies or wolves where you have the two factions fighting,” Logan said. “But it seems that the dominant narrative is just looking at blister rust and saying, ‘We’ve got a cure for blister rust, give us enough money, problem solved.’ But that’s clearly not the case, particularly here in the Greater Yellowstone.”
° ° ° °
Whitebark pine are long lived, some of the oldest reaching 1,000 years old. Trees don’t produce cones until they are 30 to 50 years old and cone profusion holding lots of nuts doesn’t happen until trees are between 60 and 80 years old. That’s why any whitebark reforestation efforts are not likely to begin paying dividends until a half-century later. Researchers with the U.S. Forest Service have been at work trying to develop disease-resistant whitebark and trees that could potentially grow faster.
When whitebark pines mature, that’s typically when mountain pine beetles attack. Scientists have learned that historically pine beetles persist at low levels in many regions. Then a few years chain together characterized by drought and longer, hotter summers, similar to what we’ve experienced for the past few years. Those conditions, along with a vast food resource, led to a population explosion in the late 2000s by allowing beetles to reproduce annually instead of biennially.
The outbreak might have continued but for a decreasing food supply—dead trees—and an abnormally cold October that is believed to have killed many larvae. At that point, many thought the beetle threat was past and wouldn’t return for another 60 years or so. That time interval was based on the previous outbreak documented in the central Rockies occurring in the 1930s. But that was before the onset of climate change.
In the meantime, other researchers were focused on white pine blister rust first kills the needles on a branch and then works its way down the branch, growing 5-6 inches a year, to the trunk, eventually girdling and killing the branch and later the whole tree.
After peeling back the bark of a whitebark pine tree, former Forest Service Climate Change researcher Jesse Logan points to the mountain pine beetle larvae growing in the tree. Photo by Laura Lundquist
White pine blister rust was introduced to the U.S. in the early 1900s when foresters used European nurseries to raise white pine for replanting overlogged areas. And it’s another bold example of how exotic species, whether aquatic, flora or fauna, represent major threats to natural ecosystems. Blister rust had already invaded Europe from Asia, and it hitched a ride to the U.S. on a small number of the white pine seedlings planted along the West Coast. From there, its spores slowly spread east to infect nearly all western forests, hitting not only white pine but also whitebark.
That threat prompted the nonprofit American Forests to start an effort to replant whitebark pine in the early 1990s, said Libby Pansing, American Forests Director of Forest and Restoration Science. At that time, they were harvesting all available seed to grow into seedlings that they’d then plant back in the same area.
That changed after U.S. Forest Service geneticist Mary Frances Mahalovich identified about 180 whitebark pine trees in the early 2000s that appeared to be resistant to blister rust. Using seeds from those individuals, she developed seedlings that carried the resistant trait. Since 2012, the Forest Service and American Forests have planted tens of thousands of blister rust-resistant seedlings in burned areas of the Greater Yellowstone and in other regions.
The American
Forests plan is to plant thousands more to counter what Pansing calls the
“existential threat” to whitebark pine. In the Crown of the Continent and
Glacier National Park, where Pansing has done research, the mortality rates can
be upwards of 80 percent because blister rust attacks not only mature trees but
also the upcoming generation of small seedlings.
Recently,
American Forests and the Whitebark Pine Ecosystem Foundation have worked with
federal, state and tribal land managers to develop a National Whitebark Pine
Restoration Plan. While previous planting efforts were fairly opportunistic,
depending on where enough passionate volunteers and seedlings were available,
the plan will make restoration efforts more standardized and coordinated,
Pansing said.
The idea is
that each jurisdiction—a national forest, tribal reservation or Bureau of Land
Management district—would identify 30 percent of the whitebark pine range under
its control to be a “core area” where a suite of restoration activities will be
applied. The majority of those activities would likely involve planting
rust-resistant seedlings.
“The good news
is we have the tools, we have the knowledge, and we can restore the species,”
Pansing said. “This is an infinitely solvable problem, we just need to mobilize
to get the work done.”
Biologists stand in a grove of "faders"—whitebark pine trees turning red after being invaded by mountain pine beetles—near Island Lake in the Absaroka-Beartooth Wilderness. Photo by Laura Lundquist
After hearing
that similar attitude from others, Logan is worried for Greater Yellowstone.
“We need to
shift that narrative to something more reasonable, particularly here in the
Greater Yellowstone and I think all across the southern distribution of whitebark
pine,” Logan said. “The whole scenario that American Forests and the Whitebark
Pine Ecosystem Foundation is working on is up in the Northern Rockies. But it
doesn’t hold here.”
° ° ° °
It doesn’t hold
in Diana Six’s study areas in Idaho either, where the trees are breaking the
mold by breaking their branches. Blister rust is present and it eventually does
kill big branches. But then they just fall off the tree, removing the
infection.
“We haven’t
done the actual research yet but it doesn’t seem to be killing the big trees.
They seem to just shed these infected big branches and go on just fine,” Six
said. “Until the beetles show up.”
While the
branch-shedding trees may have evolved one sort of defense, Six has found some
trees that survived the 2009 outbreak appear to have another defense: beetle
resistance. When comparing several traits between trees that died and those
that survived, Six discovered that the beetle survivors tend to be slower
growing. And slower growing trees tend to have xylem—tree tissue that
transports water from the roots to the treetops—with narrower channels, which
help draw water up using capillary action. That makes them less vulnerable to
drought and related stress, two factors that enable beetle attack.
“The threat to
whitebark is a three-legged stool: you’ve got climate change, you’ve got
beetles and you’ve got blister rust. You can’t fix just one leg only. You’ve
gotta fix all three or the stool will fall over,” Six said. “If slow growing
trees are resistant to beetles but they’re also resistant to drought, that’s
about as good as it gets.
Six is
continuing her research to see if such resistance is heritable. If so, maybe
beetle-resistant trees can be developed. She’s found genetic differences but doesn’t
know if they are related to the xylem.
“The good news is we have the tools, we have the knowledge, and we can restore [whitebark pine]. This is an infinitely solvable problem, we just need to mobilize to get the work done.” – Libby Pansing, director of forest and restoration science at American Forests
Meanwhile, Six
is frustrated that American Forests has been lobbying the BLM district that
oversees her study site to plant blister rust-resistant trees. If they plant
large numbers of blister rust-resistant seedlings in those areas, the
seedlings’ genes could swamp out the genetic diversity of surviving
populations, perhaps eliminating advantages such as beetle resistance.
Producers that breed for a single desired trait have often set a species up for
disaster when it no longer has the genetic diversity to respond to novel
threats. History is replete with such examples.
When it comes
to beetles, American Forests says on its website that pheromone patches can
protect whitebark pine. Beetles use the scent to signal other beetles that a
tree is fully colonized, so patches trick beetles into avoiding a tree. But
during outbreaks, pheromone patches are basically useless, Six said.
When asked if
American Forests would consider planting beetle-resistant trees, Pansing said
the organization was interested in all potential tools.
“It’s just a
matter of whether those tools are sufficiently developed and whether it’s
appropriate for a given location,” Pansing said. “One of the challenges of
having a listed species that covers such a large geography is that the nature
of the threat is variable, depending on where you are. In some locations, in
certain years, mountain pine beetle becomes a greater threat than white pine
blister rust, even though I will reiterate that blister rust is the existential
threat.”
—
The big push
for focusing restoration primarily on controlling blister rust irks beetle
people, who have their hunches for why bias might exist.
Logan said part
of it might be that agencies would have to reverse their priorities, which they
also don’t do easily. Or that federal
agencies would have to acknowledge the effects of climate change, something
they are still reluctant to do. Blister rust isn’t worsened by climate change
while beetle outbreaks are. Accelerating climate change means that, except for
food availability, the conditions for beetle outbreaks will occur more
frequently.
Logan and his
Utah State University collaborator, Wally Macfarlane, had to lobby for research
funding and then fought the U.S. Forest Service for three years to publish
their study documenting the 90 percent whitebark mortality that occurred in the
Greater Yellowstone during the 2009 beetle outbreak.
“The issue at
that time was climate change; the reluctance of agencies to admit it. I was a
scientist working for the Forest Service on a climate-change issue, and I was
not allowed to use the terminology when presenting a paper at a scientific
conference,” Logan said. “Scientists have a worldview, it’s linear thinking.
It’s easy to get blinders. Some are so convinced that blister rust is the whole
story. They’re trying to avoid any criticism of that narrative.”
Logan, along
with his bear researcher friend, Mattson, and Mattson’s wife, Louisa Willcox, a
legendary conservation figure in Greater Yellowstone, have pointed out that
even if the plight of whitebark could be miraculously reversed, it would be
decades before recovery of that species could again become an abundant food
source for grizzlies. Grizzlies have also been impacted by the loss of access
to spawning cutthroat trout in Yellowstone Lake caused by the introduction of
lake trout that have decimated the cutthroat trout population. In turn,
grizzlies have been forced to find other food sources in the spring and it has
led to higher predation on elk calves.
° ° ° °
In her 2022
presentation, Shanahan said all the threats, worsened by climate change and
spread over a broad landscape, are happening faster than we can find effective
solutions to resist them. So a combination of efforts is required, perhaps a
sort of triage.
She suggested
the Resist-Accept-Direct framework that Stephen Jackson, advisor on biodiversity
and climate change for the U.S. Geological Survey, recently developed to help
managers make choices about how and where to do projects based on future
changes due to climate change.
With whitebark
pine, trying to keep everything the way it is by planting trees falls under the
“Resist” mode, which resists change. That may be appropriate in some places.
But in southern regions or lower elevations, rising temperatures might doom
whitebark seedlings. In such areas, the “Accept” mode is more applicable, where
people must accept that changing conditions soon won’t favor whitebark pine.
The final mode, “Direct,” requires finding new regions or elevations where
future conditions would support whitebark pine and moving seedlings there. All
three modes would require climate change modeling to predict the areas where
each mode is most applicable.
“The issue at
that time was climate change; the reluctance of agencies to admit it. I was a
scientist working for the Forest Service on a climate-change issue, and I was
not allowed to use the terminology when presenting a paper at a scientific
conference.” –Jesse Logan, retired Forest Service entomologist
Because they’re well established, large whitebark pine with deep
roots can still endure in “Accept” regions where no future generations will
follow. Scientists call them “dead glades walking” because the stand is
essentially extinct except the individuals are still living. But that’s where
Six has seen people planting seedlings, and she shakes her head.
Six agrees linear
thinking might play a role, but it could also be a bit of a turf struggle.
After some dedicated people have worked so hard for decades to develop the
blister-rust program, the idea that beetle resistance might also be important
can be seen as a bit of a threat.
“It’s scary to
some people. They’ve said, ‘we don’t want this to make us stop planting.’ But
there’s also this need to step back and think about what are you planting where,
and is it appropriate?” Six said.
Some of those
details should be addressed in the Whitebark Pine Recovery Plan, another step
required by the ESA listing now being fleshed out by the Fish and Wildlife
Service. Recovery plans provide guidance on how to minimize threats and provide
criteria by which to judge recovery.
Former Forest Service Climate Change researcher Jesse Logan clambers down scree to get to whitebark pine stands along Packsaddle Peak in the Tom Miner Basin. Photo by Laura Lundquist
Pansing said
American Forests has “had conversations” with the Service about incorporating
its Restoration Plan into the federal Recovery Plan, but she didn’t know where
things stood.
Being a beetle
person, Six was a little surprised when Fish and Wildlife Service Listing and
Recovery Specialist Julie Reeves asked her a few weeks ago to sit on the
advisory board for the team writing the recovery plan. The board will also have
experts on blister rust, birds and plant ecology. It was encouraging because
Six doesn’t think she would have been asked a few years ago. The U.S. Fish and
Wildlife Service denied access to interview Reeves for this story.
An initial
draft of the recovery plan should be complete within the year. By then,
observers across Greater Yellowstone will have a better idea of what’s
happening with pine beetles. Some people hope that this winter might have
knocked beetles back since it’s been colder and longer than in recent years.
But beetles can withstand the cold unless there’s a snap in the late fall or
early spring when their “antifreeze” isn’t as effective.
After the past
two to three summers of heat domes and pervasive drought, all signs point to an
outbreak so it’s going to be a critical year. A lot of people are on pins and
needles, Logan said.
Davy still
remembers the sinking feeling she got last year seeing the rust-colored needles
on Teton Ridge. She’s hoping against hope that it won’t have worsened.
“We’ll have to
see what happens this summer,” Davy said. “I’m going to cry. But it will be a
good reason to go backpacking.”
Greater Yellowstone has been touted as a place that still retains all
of its biological parts—strands so important in holding together its unrivaled
mosaic of large mammal species. The decline of whitebark pine is just one data
point indicating that a fraying is happening. Logan has said we must not take
the region’s intactness for granted and said everyone needs to work together,
doing all we can to hold it together.
EDITOR'S NOTE: Also read the essay, below, by entomologist Dr. Jesse Logan that appeared at Mountain Journal in 2017.
Laura Lundquist earned a journalism degree from the University of Montana in 2010, and has since covered the environmental beat for newspapers in Twin Falls, Idaho and Bozeman, in addition to a year of court reporting in Hamilton. She's now a freelance environmental reporter with the Missoula Current Online Journal.
