Thursday, November 06, 2025

 

Wildfire risk making timberland less valuable, long harvest rotations less feasible



Oregon State University
Douglas-fir forest 

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Douglas-fir forest.

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Credit: Steve Lundeberg, Oregon State





CORVALLIS, Ore. – Rising wildfire risk in the Pacific Northwest combined with notoriously volatile timber pricing may lower forestland values by as much as 50% and persuade plantation owners to harvest trees much earlier than planned, a new analysis of Douglas-fir forests shows.

Under the worst-case scenarios, modeling by researchers at Oregon State University suggests harvesting trees at 24 years would make the most economic sense. Absent wildfire risk, the optimal age would be 65 years.

Generally, private landowners harvest between those two ages, but it’s not a surprise for the optimal rotation age to go down in these scenarios, the scientists say.

“Basically, under high wildfire risk that rises with stand age, every year you wait to harvest you’re rolling the dice,” said Mindy Crandall, an associate professor in the OSU College of Forestry.

Earlier harvesting reduces both long-term timber revenue and carbon storage potential, as well as impacting wood quality, adds study co-author Andres Susaeta.

“Our research highlights that traditional forest valuation methods, often based on fixed timber prices, fail to capture the financial uncertainty caused by fluctuating markets and growing wildfire danger,” said Susaeta, an assistant professor in the College of Forestry. “By integrating both wildfire risk and timber price volatility into forest management models, policymakers can design smarter tax systems, insurance programs and carbon market incentives that adapt to the changing conditions we are seeing and that are expected to worsen.”

Forests cover nearly half of Oregon’s 96,000 square miles, and Douglas-fir accounts for roughly 65% of the state’s timber stock. It’s the backbone of an $18 billion timber industry, and Douglas-fir forests also provide a range of ecosystem services including wildlife habitat and carbon sequestration, a key factor in mitigating climate change.

Susaeta, Crandall and doctoral student Hsu Kyaw, who led the project under Susaeta and Crandall’s supervision, say their findings point to several strategies for strengthening forest resilience and economic returns.

Fuel reduction programs such as thinning and prescribed burns, they note, can lower fire risk and help landowners extend harvest cycles, capturing higher returns from mature timber.

“Improved salvage logging operations and wildfire-adjusted insurance programs could also help recover postfire losses and stabilize landowner income,” Susaeta said. “It’s important to note that our study shows that higher carbon prices can encourage longer rotations and boost land values – but these benefits diminish under high wildfire risk. Expanding carbon offset programs to include wildfire mitigation and salvage credits could better align climate goals with economic incentives.”

The researchers say that reducing fire exposure while maintaining forest productivity requires a mix of adaptive zoning, cooperative fuel management and diversified forest composition.

Adaptive zoning refers to the flexible, dynamic allocation of management zones within a forest landscape based on changing environmental or socioeconomic conditions, and cooperative fuel management is a collaborative approach among multiple stakeholders to reduce fire risk by managing forest fuels across property boundaries.

Forests have a diversified composition when they feature a variety of tree species, age classes and structural features. The diversity enhances their economic value as well as their resilience and ecological function, Susaeta said. In addition, longer rotations improve the odds of having valuable material to salvage.  

However, the way financial risk is usually considered has an even bigger impact on landowners’ decisions than potential salvage value, he said. This is particularly important for landowners who are cautious about risk.

“Overall, our work underscores that managing forests under climate uncertainty requires integrating economic and ecological risks,” Susaeta said. “By balancing wildfire resilience with market adaptation, forest policies can better protect both the environment and rural livelihoods.”

Findings were published in Forest Policy and Economics.

 

Concussions linked to increased risk of a serious traffic crash



Institute for Clinical Evaluative Sciences




Toronto, ON, November 6, 2025 – Adults diagnosed with a concussion may be at about 50 per cent higher risk of a subsequent traffic crash, finds a new study from researchers at ICES and Sunnybrook Research Institute.

Concussions can temporarily affect brain function, with symptoms including insomnia, dizziness, depression, brain fog, and slowed reaction times that can linger for weeks. These symptoms could alter driving skills and increase the risk of a motor vehicle accident.

“I worry that sometimes a concussion requires more recovery time than most people realize,” says Dr. Donald Redelmeier, scientist at ICES and Sunnybrook Research Institute. “Rushing things might lead to another injury including a life-threatening traffic crash.”

Key findings: 

  • The increased risk of a traffic crash is particularly high during the first four weeks after a concussion.
  • The overall traffic risks increased further with repeated concussions.
  • The traffic risks also applied to pedestrians crossing the street.
  • Of the 425,158 adults diagnosed with a concussion in the study, one in 13 patients were injured in a subsequent traffic crash.
  • The increased risk accounted for 1,633 total ambulance calls59,978 days in hospital, and $835 million in medical costs.

Some limitations of the study include the lack of data on concussion severity, as well as other factors that predispose patients to concussions as well as contribute to traffic crashes. While the findings cannot establish cause and effect, concussions can lead to symptoms that increase the risk of a serious traffic crash.

“These results highlight the importance of traffic safety following a concussion as well as preventing concussions in the first place,” says Robert Tibshirani, a professor of statistics at Stanford University and also a co-author of the study.

The researchers recommend patients treat insomnia, headaches, depression, or substance misuse and also avoid high-speed trips during late-night hours in bad weather during the first month after a concussion. Clinicians should also warn patients about road traffic safety after a concussion.

The study “Concussions and risk of a subsequent traffic crash: retrospective cohort analysis in Ontario, Canada” is in the November issue of BMJ Open.  

 

ICES is an independent, not-for-profit research and analytics institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. ICES leads cutting-edge studies and analyses evaluating healthcare policy, delivery, and population outcomes. Our knowledge is highly regarded in Canada and abroad and is widely used by government, hospitals, planners, and practitioners to make decisions about healthcare delivery and to develop policy. For the latest ICES news, follow us on BlueSky and LinkedIn: @ICESOntario   
 

Sunnybrook Research Institute (SRI) is the research arm of Sunnybrook Health Sciences Centre, an internationally recognized academic health sciences centre fully affiliated with the University of Toronto. With well-established programs in basic and applied sciences which span across three scientific platforms and eleven clinical programs, SRI is developing innovations in care for the more than 1.1 million patient visits the hospital provides annually.  

FOR FURTHER INFORMATION PLEASE CONTACT:  

Charlotte Lam 
Communications Associate
ICES  
media@ices.on.ca  
437-317-8804 

Nadia Norcia
Communications Advisor
Sunnybrook Health Sciences Centre
nadia.norcia@sunnybrook.ca
416-480-4040

COVID-19 vaccination lowers long COVID risk in adolescents


Columbia University Irving Medical Center



Nov. 6, 2025--Adolescents who were vaccinated against COVID-19 were less likely to develop long COVID after their first SARS-CoV-2 infection than unvaccinated peers, finds a new study.

The study, led by the NIH-funded RECOVER Initiative, is the first to examine the potential benefits of COVID vaccination in adolescents beyond lowering the severity of initial COVID symptoms. 

“These findings provide evidence that COVID vaccination has an important secondary effect in helping to mitigate the risk of long COVID in adolescents,” says Melissa Stockwell, a pediatrician at Columbia University Irving Medical Center and clinical senior author of the study.

The RECOVER research team estimates that approximately 5.8 million youths have experienced long COVID which can include prolonged symptoms such as daytime fatigue, joint and muscle aches, and memory problems.

Previous studies have shown that vaccination against COVID-19 can reduce the risk of long COVID in adults. But evidence of a similar benefit among youths has been limited. 

The new study included over 1,200 adolescents from across the United States; 724 were vaccinated against COVID in the six months prior to their first infection and 507 were not vaccinated. 

The researchers found that the risk of developing long COVID was over 20% among unvaccinated youths and about 13% among those who were vaccinated—representing a 36% reduction in risk after vaccination. 

“Every day, our study sees young people who are unable to fully participate in the activities they enjoy while they deal with long COVID symptoms,” says Stockwell. “While our study did not look at the effects of COVID vaccination in adolescents with subsequent infections, our findings strongly suggest that getting vaccinated against COVID-19 could allow many more adolescents to live their lives normally after COVID infection.” 

Additional information

The study, titled “Preventive Effect of Vaccination on Long COVID in Adolescents with SARS-CoV-2 Infection,” by Tanayott Thaweethai, Rachel S. Gross, et al. https://doi.org/10.1016/j.vaccine.2025.127907, was published online Nov. 1 in Vaccine, Vol. 68 (Dec. 5, 2025).

All authors: Tanayott Thaweethai (Harvard University), Rachel S. Gross (NYU Langone), Deepti B. Pant (Harvard), Kyung E. Rhee (University of California  San Diego), Terry L. Jernigan (UCSD), Lawrence C. Kleinman (Rutgers University), Jessica N. Snowden (University of Tennessee), Amy  Salisbury (Virginia Commonwealth University), Patricia A. Kinser (Virginia Commonwealth), Joshua D. Milner (Columbia University), Kelan Tantisira (UCSD), David Warburton (University of Southern California), Sindhu Mohandas (USC), John C. Wood (USC), Megan L. Fitzgerald (Patient-Led Research Collaborative, Calabasas, CA),  Megan Carmilani (Long COVID Families, Charlotte, NC), Aparna Krishnamoorthy (Harvard), Harrison T. Reeder (Harvard), Andrea S. Foulkes (Harvard), and Melissa S. Stockwell (Columbia University).

The study was funded by NIH agreements OT2HL161841, OT2HL161847, and OT2HL156812. Additional support for the study is reported in the article.

Melissa Stockwell, MD, MPH, is chief of the Division of Child and Adolescent Health and professor of pediatrics at Columbia University’s Vagelos College of Physicians and Surgeons and professor of population and family health at Columbia’s Mailman School of Public Health. Dr. Stockwell is chair of the pediatric coordinating committee for RECOVER.

###

Columbia University Irving Medical Center (CUIMC) is a clinical, research, and educational campus located in New York City. Founded in 1928, CUIMC was one of the first academic medical centers established in the United States of America. CUIMC is home to four professional colleges and schools that provide global leadership in scientific research, health and medical education, and patient care including the Vagelos College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing. For more information, please visit cuimc.columbia.edu

Vaccine is the pre-eminent journal in the field of vaccinology. It is the official journal of The Japanese Society for Vaccinology and is published by Elsevier. Copies of this paper are available to credentialed journalists upon request. Please contact the Elsevier Newsroom at newsroom@elsevier.com.

 

Mathematicians model the menace of mosquitoes



Virginia Tech
Kyle Dahlin 

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Kyle Dahlin

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Credit: Photo courtesy of Virginia Tech




The wispy shadow at the corner of your eye emitted a high-pitched whine. It grew louder. You were chosen.

After landing gently, the mosquito fluttered briefly at your skin. Then, with a slight prickle, it slipped its needle-like mouth into your vein and sucked your blood. 

Host targeted. Skin pierced. Blood ingested.

Like a macabre game of choose-your-own adventure, every point in this nervy scenario is important when it comes to the transmission of mosquito-borne diseases such as malaria, Zika, West Nile, and dengue, which lead to nearly a million human deaths each year.

For starters, a mosquito can transmit pathogens at the probing stage, which happens before it starts feeding.

“It kind of spits some saliva into you, and this is one of the points where infection can take place,” said Kyle Dahlin, a postdoctoral associate in mathematics at Virginia Tech.

Other complicating factors include: What if you thwack it? What if you miss? What if it probes you but doesn’t bite? What if it goes for someone else instead and kicks off a new cycle of disease transmission?

“These looping possibilities can exacerbate disease transmission and multiply it,” Dahlin said.

To account for these contingencies, Dahlin led a team of mathematicians in the development of a model that can handle more complexity and open new paths for disease suppression. The work was recently published in the Bulletin of Mathematical Biology.

Once bitten, twice shy

Dahlin scaled up the mosquito-biting model to connect individual-level mosquito behavior to human diseases on a population level. The model is already offering up some surprising insights.

For instance, in terms of population-level disease transmission, the model shows that it’s actually better to let the mosquito bite you.

You might get sick. But somebody else may not. It represents less overall transmission,” said Lauren Childs, the Cliff and Agnes Lilly Faculty Fellow and associate professor in mathematics.

While the researchers don’t encourage this course of action, with proper parameterization, the findings point to more practical recommendations, such as which types of insecticides repel mosquitos before they land on you. 

“We hope that this will bring about additional ways to suppress disease,” said Dahlin, who came to Virginia Tech specifically to work with Childs and mathematician Michael Robert to build a better disease-transmission model. In this endeavor, he was supported by a Mathematical and Physical Sciences Ascending Postdoctoral Research Fellowship from the National Science Foundation.

“This won’t necessarily be the silver bullet but hopefully another tool in the toolbox,” Dahlin said.  

Orginal study DOI: 10.1007/s11538-025-01540-z