Monthly Archives: August 2019

Fire season safety tips for smoke-sensitive persons, drivers

Smoke blowing over a roadway nearly obscures USDA Forest Service wildland fire truck (WA-OWF E644) and a wildland firefighter from the camera's view.

While the “fire season” is off to a slower-than-normal start in many parts of the Pacific Northwest, fires like the Milepost 97 are here and ready to remind fire isn’t the only seasonal hazard to watch for. There are also two, other, closely related risks faced by our firefighters and our community during the season: smoke and motor vehicle traffic.

Even small fires can send a lot of smoke into nearby roadways. Sometimes, even smoke drift from distant fires can create enough haze to reduce visibility. That reduced visibility is a risk to pedestrians, other motorists (including those in or responding to disabled vehicles along the road shoulder), and even firefighters working nearby.

If you’re traveling in areas with nearby fire activity, be careful and use extra caution. In addition to reduced or poor visibility, you may encounter heavy equipment and firefighting trucks on the road. Drive carefully, slow down, and give plenty of space to firefighters and fire vehicles. Use extra caution when driving in smoke-filled conditions; debris, disabled vehicles and pedestrians may be concealed from view until you’re vehicle is just a few feet away.

Follow these tips to keep yourself and others, including firefighters and smoke-sensitive loved ones, safe!

  • If your travel plans require you to drive on routes that are impacted by fire or firefighting activity, consider alternate travel dates and/or routes.
  • If you must drive, pay close attention to road closures and warnings.
  • Be alert! Fire activity and subsequent operations can change quickly.  Adapt driving patterns accordingly and always yield to emergency responders.
  • Navigation applications on smart phones or other devices (GPS / maps) may not accurately reflect changing conditions. Watch out for changing local conditions and detours.
  • Plan ahead. If you live in a fire-prone area (which is all of us, in the Pacific Northwest!), keep your gas tank filled at least 3/4 full at all times. Maintain a clean air filter, and carry paper map or road atlas to assist you in travelling in areas with limited cell phone reception. Bring an extra cell phone charger (and battery back-up); make sure you have a spare tire and jack; and carry extra water, food, a first aid kit and a blanket in your vehicle at all times.
  • Remove unnecessary flammables from the vehicle, such as containers of gas and oil.
  • Stay calm and focus on driving tasks. Drivers should not be texting, taking photos or video footage, no matter what is unfolding around them!
  • Keep headlights “on” for safety when driving.
  • Keep vehicle windows closed when travelling through smoke, and close all exterior air vents; set air conditioning to the “recirculation” setting.
  • Smoke-filled air can also impact health at home, particularly for young children, the elderly, and for people with chronic heart or lung conditions such as asthma, emphysema, and COPD. If possible, maintain a “clean room” at home in which air can be filtered by an appropriately-sized filtration system; ideally, a True HEPA filter rated to remove 99.97% of particles of .3 microns or larger, paired with an activated charcoal filter to trap volatile organic compounds. (An air ionizer may also be helpful, but discuss your plans with a doctor as not everyone is a good candidate. Those with sensitive lungs should only run an ionizer while away from home to avoid breathing ionized particles, and people who are sensitive to ozone should not use ionizers).
  • Plan ahead! It’s important for everyone to have an emergency evacuation plan, but it is especially important for those with special needs, pets, or who do not have access to a motor vehicle to plan ahead. Find advice on emergency preparedness planning at RedCross.org and at Ready.gov.

Planning travel, and need the latest traffic, smoke and safety updates? These websites can help!

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/