Forest debris could shelter mountain huckleberry from climate change

Mountain huckleberries

Treasured by Native nations and sought by hikers and foragers, the mountain huckleberry is an iconic western fruit that faces habitat loss from climate change.

Washington State University scientists are at work in northwest forests, studying how fallen logs and other woodland debris could shelter the huckleberry from a hotter, drier future.

“Woody debris is a critical structure in the natural forest ecosystem,” said Mark Swanson, associate professor with WSU’s School of the Environment. “It’s a legacy of the older forest that benefits the next generation of shrubs and trees.”

A critical food and cultural resource

Found in the highlands of the Rockies, the Cascades, and other western ranges, the mountain huckleberry establishes itself after forest fires and other environmental disturbances.

Native Americans have long relied on huckleberries for food, traditional medicine, and their role in ceremonies and festivals. Hikers often pick them as a treat, while artisans sell the berries in everything from jam to soap.

“Culturally and ecologically, the mountain huckleberry is a very important plant,” said Margaret Magee, a master’s student in the School of the Environment. “It produces a very desirable berry.”

Hand with huckleberries, butterfly
Huckleberries are an ecologically important species, colonizing land disturbed by wildfire and providing a critical summer food source for bears.

Black bears and grizzlies feast on the fruit to pack in calories for their yearly hibernation.

“Huckleberries are a critical late-summer food resource for bears,” Swanson said.

Compounded by climate change, the dry summers of the Inland Northwest pose a challenge to the survival of huckleberry seedlings as well as other shrubs and conifers. As the climate warms, huckleberry habitat could shrink as it’s pushed to higher elevations.

Survival shelters

At the private Crane Creek Forest, a teaching site near Potlatch, Idaho, Swanson, Magee, and partner scientists are studying the effects of woody debris on the survival and growth of huckleberry seedlings. A similar project at WSU’s E.H. Steffen Center, a research site at Pullman, looks at the same effects on young conifers.

Along rows of logs, cut to standard timber-harvest sizes, they planted seedlings at set intervals to north and south, then measured the seedlings and environmental conditions. Early results show debris creates zones of shade and higher soil moisture, giving the seedlings an edge.

“At zero distance, we see better growth, survival, and vigor than in seedlings planted further out,” Swanson said. “We’re showing that you can improve survivorship by using logs to create a cooler, shaded, high soil moisture zone.”

Magee and Swanson at fallen log.
Swanson and Magee examine conifer seedling survival at a debris experiment at WSU’s E.H. Steffen Center.

Logs trap snow, boosting soil moisture for the young plants and creating a significant effect. While the sheltering debris aids the plants in most cases, a few conifer seedlings were gobbled up by voles who found cover from predators.

“We’ve known for a long time how important logs and woody debris are for animal habitat,” Swanson said. “Now, we’re realizing that plants also respond strongly to these structures.”

The project draws on the work of several collaborators. WSU forestry scientists Henry Adams and Arjan Meddens will study how seedlings respond to stress and use drones to characterize conditions at the microsites. University of Idaho scientist Andrew Nelson provided huckleberry seedlings and is partnering in research. The study is funded by the WSU College of Agricultural, Human, and Natural Resource Sciences Emerging Issues in Agriculture grant program.

This spring, the team will plant additional huckleberry study sites on the lands of the Coeur d’Alene Tribe (Schitsu’umsh) and at the Priest River Experimental Forest near Sandpoint, Idaho, in partnership with the U.S. Forest Service. Analysis will continue over the next two years, with Magee also studying huckleberry microsites that had a controlled burn.

While people have always been aware of the shelter effect, the research provides a better understanding of its benefits.

“We’re emphasizing its importance, especially in a time of warming climate and increased moisture stress,” said Swanson.

“Helping the Coeur d’Alene Tribe establish thriving huckleberry fields in places where elders can easily access them would be a huge triumph,” he added.

Magee at Steffen Center.
Margaret Magee, graduate student in the School of the Environment, examines a debris experiment site at WSU’s E.H. Steffen Center.

Media Contacts

Mark Swanson, Associate Professor, School of the Environment, (509) 335-1349