Category Archives: Pacific Northwest Research Station

Seeking ground less traveled: how elk respond to recreation

A female elk wearing a telemetry collar in the Starkey Experimental Forest and Range, Ore. The collar enabled scientists to track the animal’s movements in response to different types of recreation by volunteers wearing GPS units while riding all-terrain vehicles, mountain bikes, horses, or on foot. Courtesy photo by Leslie Naylor; Confederated Tribes of the Umatilla Indian Reservation, Department of Natural Resources.

Recreation on public land is increasingly popular in the Pacific Northwest. But recreation management requires balancing opportunities for people to enjoy the outdoors with mitigating the effects on wildlife and other natural resources.

Recreation and wildlife managers who are grappling with these issues asked scientists to quantify the impacts of motorized and non-motorized recreation on elk.

In Science Findings # 219, the USDA Forest Service – Pacific Northwest Research Station explores recent research in Oregon that sought to measure how elk respond to various human, and especially recreation-based, activities.

Elk are highly valued for hunting and viewing by the public. As large herbivores, they also play a critical role in many ecosystems of the Intermountain West.

A large fenced area within the Starkey Experimental Forest and Range in eastern Oregon provided a unique setting for assessing how a wide-ranging species like elk respond to four types of recreation.

Real-time data recorded by telemetry units worn by people and elk alike allowed scientists to establish a cause-effect relationship between human movements and activities and elk responses.

Scientists found that elk avoided areas where humans were recreating. All-terrain vehicle use was most disruptive human-initiated activity, followed by mountain biking, hiking, and horseback riding.

When exposed to these activities, elk spent more time moving rather than feeding and resting.

The findings build on earlier studies, which suggested that frequent disruptions and movement to avoid human contact increase mortality rates for newborn elk.

Researchers also found that such disruptions effectively reduce the total amount of usable habitat available for elk herds.

Land managers can use this information to assess trade-offs between multiple, and often competing, land uses. When combined with planning efforts that include stakeholder engagement, this research may offer a clearer path forward on balancing human and wildlife needs on National Forests and other public and privately-held lands.


Source information: Science Findings is published monthly by the USDA Forest Service – Pacific Northwest Research Station. To search past issues, visit: https://www.fs.usda.gov/treesearch/.

Engineering answers for Spirit Lake

An aerial view to the south of Mount St. Helens in 1982 as another lahar—melted snow and volcanic rock (think wet cement)—occurred. When the lahar encountered the debris blockage from 1980, part of it flowed into Spirit Lake (bottom left), while the rest flowed west into the Loowit Creek drainage that flows into the upper North Fork Toutle River. USGS photo by Tom Casadevall.

In Science Findings #218, “The Spirit Lake Dilemma: Engineering a Solution for a Lake with a Problematic Outlet,” USDA Forest Service – Pacific Northwest Research Station writers explore new research into the future repair or replacement of an outflow tunnel at Spirit Lake, on Mount St. Helens.

The eruption of Mount St. Helens on May 18, 1980 fundamentally transformed the surrounding landscape, triggering geophysical processes that are still unfolding.

Spirit Lake, with Mount St. Helens, Washington, in the background (2015). A debris avalanche triggered by a volcanic eruption on May 18, 1980, blocked the lake’s natural outlet. A tunnel was built to safely remove water from the lake and minimize the risk of catastrophic flooding to communities downstream. Maintaining the tunnel is expensive, so long-term solutions are being explored. USDA Forest Service photo by Rhonda Mazza.

Among them was a debris avalanche caused by the eruption, that blocked the outlet from Spirit Lake to the North Fork Toutle River.

To prevent the rising lake level from breaching the blockage and potentially flooding communities downstream, the U.S. Army Corps of Engineers built an outlet tunnel to maintain safe lake levels.

However, the tunnel must be periodically closed for repairs, during which time the lake level rises.

Prolonged closures, combined with increased volume from melting rainfall and snow in the spring, could allow the water level to rise high enough to breach the natural dam.

In 2015, the Gifford Pinchot National Forest commissioned a study to assess risks associated with alternative outlet options.

A team consisting of researchers from the U.S. Forest Service Pacific Northwest Research Station, the U.S. Geological Survey, and Oregon State University authored the study.

At the team’s request, the U.S. Army Corps of Engineers conducted a dam safety risk-assessment of long-term solutions: maintaining the existing tunnel, rehabilitating the tunnel, creating an open channel across the blockage, or installing a buried conduit across the blockage.

The assessment determined that there is no risk-free way to remove water from Spirit Lake, but the likelihood is generally low that these solutions will fail.

With this information, the Forest Service is moving forward with developing a long-term solution to managing the Spirit Lake outlet.


Source information: Rhonda Mazza is a public affairs specialist for the USDA Forest Service – Pacific Northwest Research Station, which publishes Science Findings. Find past Science Findings at: https://www.fs.usda.gov/treesearch/.

Animation tells story of fish and fire

Fire and Fish: Habitat and History in the Northwest is a 5-minute animated video featuring two Forest Service research biologists that illustrates the complex relationship between fire and fish in Pacific Northwest rivers and streams. This screen capture from the video depicts juvenile fish finding shelter within a fallen log that has become submerged in a stream channel, providing refuge from both predators and strong currents.

An animated video recently released by the Pacific Fire Science Consortium explores and illustrates the complex relationship between fish and fire in the Pacific northwest United States.

The video, “Fish and Fire: History and Habitat in the Pacific Northwest,” was produced by the University of Oregon School of Journalism.

It features interviews two Forest Service research fish biologists, Rebecca Flitcroft and Gordon Reeves, both assigned to the USDA Forest Service – Pacific Northwest Research Station.

The scientists explain how some fish species in the Pacific Northwest have adapted to benefit from the impact of intermittent forest fires:

  • Fire adds silt and small rocks or gravel, which replenish materials needed to for some fish to create spawning beds.
  • Dead trees may fall into streams, creating complexity in the stream’s flow, which can reduce stress on fish by providing refuge from strong currents.
  • Log jams especially benefit juvenile species by creating broad flood plains, further diffusing rapid currents and offering many nooks and crannies in which to evade predators while nourishing the insect larvae, worms, beetles, and other organisms they may feed on.

The University of Oregon, the university’s Ecosystem Workforce Program, the Oregon State University and its Extension Service, The Nature Conservancy, Sustainable Northwest, the Center for Natural Lands Management, and the USDA Forest Service – Pacific Northwest Research Station are members of the Northwest Fire Science Consortium, one of fifteen regional science information exchanges funded by the Joint Fire Science Program.

From FireScience.gov:

In the Pacific Northwest, native salmon and trout (family Salmonidae) are some of the toughest survivors on the block. Over time, these fish have evolved behavioral adaptations to natural disturbances, and they rely on these disturbances to deliver coarse sediment and wood that become complex stream habitat. Powerful disturbances such as wildfire, post fire landslides, and debris flows may be detrimental to fish populations in the short term, but over time they enrich in-stream habitats, enhancing long-term fish survival and productivity.

LAND MANAGEMENT IMPLICATIONS

Forest management activities, such as enhancing river network connectivity through fish passage barrier removal and reducing predicted fire intensity and sizes, may increase the resilience of bull trout (Salvelinus confluentus) in the face of disturbances such as climate change and wildfire.

Natural disturbances, along with sound riparian management and road management practices that allow natural flood plain functioning, are important in maintaining healthy change in aquatic habitats. Connected, complex aquatic habitats benefit from ecosystem management practices that are analogous to the spatial extent of wildfires and bridge human-imposed divides such as land ownership boundaries.

Fire planning that includes aquatic issues such as habitat quality, stream network connectivity, and fish population resilience offers resource managers the opportunity to broaden fire management goals and activities to include potential positive effects on aquatic habitats.

WATCH the video here (or find it on YouTube):

More information:

Science Findings #198 (July, 2017): https://www.fs.usda.gov/pnw/publications/adaptation-wildfire-fish-story

“Wildfire may increase habitat quality for spring Chinook salmon in the Wenatchee River subbasin, WA, USA” (submitted 2015, published 2016): https://www.fs.fed.us/pnw/pubs/journals/pnw_2015_flitcroft001.pdf


Source information: The USDA Forest Service – Pacific Northwest Research Station is a leader in the scientific study of natural resources. We generate and communicate impartial knowledge to help people understand and make informed choices about natural resource management and sustainability. The station has 11 laboratories and research centers in Alaska, Oregon, and Washington, and manages 12 active experimental forests, ranges, and watersheds.

Why are bark beetles attracted to heat-stressed trees? Alcohol, new study says

Close-up image of a red turpentine beetle (Dendroctonus valens).

Foresters have long known that trees under stress from fire injury are vulnerable to bark beetle attacks. Now, Rick Kelsey and Doug Westlind, researchers with the Pacific Northwest Research Station, have developed a model that explains how physiological changes cause heat stress in woody tissues, even after exposure to less-than-lethal fire temperatures, and produce a chemical signal that attracts some bark beetles.

When heat disrupts normal cell functions, the tree produces ethanol as a short-term survival strategy.

And if enough ethanol accumulates, mixes with volatile organic compounds in the tree’s resin, and is released to the atmosphere, the combination has proved to be a strong attractant for red turpentine beetles.

A man in protective hat, vest inspects a tall, hanging series of cones.
Retired Forest Service scientist Rick Kelsey collects bark beetles captured in funnel traps following a prescribed fire in Oregon. Understanding the interplay between tree response to heat stress and certain insects can help forest managers design fuel-reduction treatments to achieve specific outcomes. USDA Forest Service photo.

Kelsey and Westlind showed that ethanol interacts synergistically with 3-carene, a dominant ponderosa pine resin monoterpene. In a trapping study, red turpentine beetles were more attracted to lures combining ethanol and 3-carene than lures with ethanol or 3-carene alone.

Understanding ecosystem responses to fire can help managers characterize forest health and plan for post-fire management.

The results also hold promise for developing simple ethanol detection methods for monitoring tree stress.

Real-time feedback on ethanol levels could help forest managers quickly assess which trees to cull after a fire, and which to leave in place.

Learn more in the USDA Forest Service Pacific Northwest Research Station’s Science Findings 217, at https://www.fs.usda.gov/treesearch/pubs/58195.

Ethanol dissipation mechanisms: diffusion, sapflow, and metabolism with relative rates at ambient conditions. Ethanol is metabolized by alcohol dehydrogenase to acetaldehyde (Zanon et al. 2007), which is converted by aldehyde dehydrogenase to acetate, which is converted by acetyl-CoA synthase into acetyl-CoA (MacDonald and Kimmerer 1993, Gass et al. 2005). The latter can enter the tricarboxylic acid or glyoxylate cycles or be used to synthesize lipids depending on heat damage to membranes and enzymes. Ethanol dissipation mechanisms: diffusion, sapflow, and metabolism with relative rates at ambient conditions. Ethanol is metabolized by alcohol dehydrogenase to acetaldehyde (Zanon et al. 2007), which is converted by aldehyde dehydrogenase to acetate, which is converted by acetyl-CoA synthase into acetyl-CoA (MacDonald and Kimmerer 1993, Gass et al. 2005). The latter can enter the tricarboxylic acid or glyoxylate cycles or be used to synthesize lipids depending on heat damage to membranes and enzymes.
As ethanol accumulates in the tree, it immediately begins to dissipate via (1) diffusion, (2) sapflow, and (3) metabolism. Each process is affected differently by the heat-stress mechanism the tissues and whole tree experience. USDA Forest Service illustration (originally published at https://academic.oup.com/bioscience/article/67/5/443/3746565).

Source information: USDA Forest Service Pacific Northwest Research Station (Science Findings 217). The research station – headquartered in Portland, Ore. – generates and communicates scientific knowledge to help people make informed choices about natural resources and the environment. The station has 11 laboratories and centers located in Alaska, Washington, and Oregon and about 300 employees. Learn more at https://www.fs.usda.gov/pnw/