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  • Louisa Willcox

Warriors for Whitebark Pine: Fighting for an Imperiled Forest

Photo by Steven Gnam

This blog summarizes an essay in Grizzly Times’ new essay series, launched to provide more detailed analyses than can fit into the scope of a blog. At a time when most journalists offer ever-briefer and more sensationalized coverage of complex environmental issues, we opted to do the opposite: go deep.

I confess to a long love affair with the whitebark pine forests that define high peaks of the Northern Rockies. From their alpine summits, mountains recede to the horizon, hinting at the curvature of the earth. Here, whitebark pine feed and shelter species large and small, from 600-pound grizzlies to tiny voles.

My heart broke as healthy forests throughout the Greater Yellowstone ecosystem turned into an ocean of red dying trees in the blink of an eye, the result of a novel outbreak of native mountain pine beetles during the 2000s. Subsequent investigations have confirmed that whitebark pine has collapsed throughout North America due to the ravages of a nonnative fungal pathogen and an unprecedented outbreak of beetles unleashed by warming temperatures.

In response, the US Fish and Wildlife Service (FWS) proposed during 2020 to protect whitebark pine as a threatened species under the Endangered Species Act (ESA). A final decision is expected this spring.

The FWS proposal brought back memories of the remarkable people that precipitated this moment and their largely unsung efforts to document the catastrophic demise of whitebark pine. Perhaps more importantly, this seemingly obscure campaign for a little-appreciated tree offers important lessons for conservation at a time of unprecedented threats.

Whitebark Pine Gets its Due

A federal safety net for whitebark pine could not come at a more critical time. Over 50% of the whitebark pine forests in the US have died – and threats are mounting, not just to the trees themselves, but the high mountain ecosystems that they sustain.

So far, efforts to address these threats have been piecemeal. Because the tree has little economic value, its plight has not been a priority for the Forest Service that manages the lion’s share of whitebark pine forests.

The FWS’ listing proposal was the long-delayed result of a 2008 petition that I helped draft as Senior Wildlife Advocate for Natural Resources Defense Council (NRDC). Our concerns were reinforced by subsequent surveys of whitebark pine forests that I also helped lead. In 2011, the agency responded to our petition by concluding that whitebark pine deserved endangered species protections. But the agency dodged formally listing the species, claiming that the agency’s limited resources needed to be prioritized for protecting other more critically imperiled species.

A decade later, after updating their analysis and expanding upon our earlier work, the FWS agreed with our assessment that the tree was in urgent need of protection.

Painting by Larry Eifert

Creating Ecosystems: From Grizzlies to Trout

Scientists have long been fascinated with the whitebark pine trees that cling to wind-scoured outcrops at the highest elevations of any tree in the Northern Rockies, Sierra Nevada, Cascades, and much of interior Alberta and British Columbia. These trees endure bitter cold, icy winds, lightning strikes and poor soils – even as they create conditions within which other tree species and plants can flourish.

Whitebark pine functions as the lifeblood of the ecosystems where they grow. These trees play a surprisingly vital role in the hydrology of watersheds by shading the snowpack, slowing the melt of snow, reducing soil erosion and regulating stream flows. They sustain the region’s world-class trout fisheries, farms in the valleys below, and the human communities that depend on both. And their high fat-rich seeds feed a rich diversity of wildlife, including the Yellowstone grizzly bear. For more on the ecological role of whitebark pine, see this publication by David Mattson and others, and this overview by the Whitebark Pine Ecosystem Foundation.

Grizzly Threats

The threats to whitebark pine are numerous and complex but climate change looms largest of all. Some climate models project that we could lose 70% or more of the environments cold enough to sustain whitebark pine by the end of this century.

Climate change is also driving increasingly frequent and large wildfires that are killing whitebark pine faster than they can reproduce while at the same time promoting competitors such as Douglas-fir. And warming temperatures have been triggering unprecedented outbreaks of native mountain pine beetles in whitebark pine forests. Tragically for whitebark pine, it did not evolve defenses capable of weathering the beetle’s attacks, unlike lower-elevation pines that co-evolved with bark beetles.

Whitebark pine is also threatened by white pine blister rust, a deadly non-native fungus that was introduced from Asia to North America around the turn of the 20th century. Starting from where it had been introduced along the Pacific coast, the fungus’ spores traveled far, wiping out some forests entirely.

Making matters worse, trees weakened by blister rust become more susceptible to beetle attacks. Meanwhile, in some parts of the Northern Rockies whitebark pine are being crowded out by other conifers following decades of misguided fire suppression.

A Rag Tag Army Unites Around Whitebark

A massive outbreak of pine beetles in Greater Yellowstone’s whitebark pine during the 2000s changed the course of whitebark pine conservation by galvanizing scientists, citizens, nongovernmental organizations, and agency officials, including members of the government’s Whitebark Pine Working Group. The crisis precipitated a loose-knit coalition to form focused on assessing the damage and sounding the alarm.

"Sea of Red", Dying Whitebark Pine: Union Pass, Wyoming, 2009

This coalition could not have been more different from the testosterone-fueled government committees at the center of managing politicized species such as grizzly bears and wolves that I was used to – committees that assiduously excluded the concerned public. Without money or political agendas at play, this group tended to attract people who were genuinely curious and cared about the organism they had gathered around.

At the time, government managers were focused on blister rust -- collecting seeds from trees that show genetic resistance to the disease, and cultivating and planting them to propagate forests of less vulnerable trees. But the beetle outbreak demanded a new approach -- one that took the form of a collaborative effort among NRDC, the Forest Service, and the Park Service to aerially assess the damage caused by mountain pine beetles in the Yellowstone ecosystem. Key partners included myself, entomologist and ecologist Jesse Logan, geographer Wally MacFarlane, ecologist Willie Kern, pilot Bruce Gordon of Ecoflight, Liz Davy of the Bridger Teton Forest, and NRDC’s Gaby Chavarria. Our results showed that less than 20% of mature whitebark pine forests in Greater Yellowstone were healthy or nearly so – and that only about 5% were completely untouched by beetles. A shocking 80% of mature whitebark had suffered medium to high levels of beetle mortality.

NRDC also helped convene gatherings of scientists and managers, and host events that brought journalists together with lead scientists to tramp through dead and living whitebark pine forests. Although whitebark pine was an obscure part of a remote ecosystem, we were able to leverage media interest by connecting its plight with high-profile issues, including grizzly bears.

At the same time, backcountry skiiers, outfitters and other “citizen scientists” began to band together to collect data on the health of whitebark pine forests. Equipped with cameras, strong legs, and a sense of adventure, people who were often not trained as scientists collected information about damage to whitebark pine caused by blister rust and beetles. We began to call ourselves “Whitebark Warriors.”