Christopher Still, a professor at the Oregon State University College of Forestry, studies forest ecology and the physiology of trees. His research spans from a singular leaf on a tree to entire ecosystems. He also studies carbon cycling and forest-climate interactions.

So, when the temperatures rose to unprecedented levels in the summer of 2021 and a heat dome descended upon Oregon, Still knew the scorching heat and intense energy from the sun would stress the trees, scorch the foliage and impact Oregon’s forests. Especially after two years of state-wide drought. But at what scale? And what would that mean for the long-term health of the trees?

“The ‘heat dome’ led to numerous reports of foliage scorch and leaf drop in westside forests of the Coast Range and Cascades,” Still said. “Western hemlock and western red cedar seemed to be impacted the most, but Douglas-fir and various alders and maples were affected, too. Notably, trees and saplings with direct solar exposure and on south-facing slopes seemed to suffer the worst foliage scorch.”

With help from citizen scientists, researchers like Still spent months documenting the heat dome’s effects on Oregon’s trees. Using a website created by the Oregon Department of Forestry, community members and researchers reported their observations to map and analyze the foliage scorch.

Still then organized a symposium to share information and begin piecing together what the heat dome event might mean for the long-term health of trees.

“Researchers do not know what the near- and long-term physiological causes and consequences of foliage scorch and heat stress will be, at either leaf or tree scales. The impacts could range from impaired metabolism on surviving leaves, to reduced stem diameter growth, to eventual tree mortality,” Still says.

The symposium served as a central place for tree experts like foresters, silviculturists and botanists to meet and discuss their findings and plan for the next steps to monitor the impacts of the heat dome.

“I think there are many challenges for forest management. The challenges range from trying to help forests become more resilient to climate change impacts, to working on assisted migration and planting of new genotypes and identifying species that can better handle a warmer and drier climate in the future,” Still says.

Still says we should expect more intense heatwaves in the future, and we should all work urgently to lower our carbon footprint to mitigate future climate change.

However, he said the data shows there is much to learn about heat stress physiology and how different genotypes, species and forest types will respond to future heat and drought extremes.

“I think the scale of the impacts – both the spatial scale and the range of species and forest types affected – was surprising. I think the resilience shown by some species and forests was also a pleasant surprise,” Still says.

A version of this story appeared in the Spring 2022 issue of Focus on Forestry, the alumni magazine of the Oregon State University College of Forestry.

When the Oregon State University (OSU) College of Forestry had to fill the knowledge gap created by the departure of emeritus professor Jeff Morrell, it turned to Gerald Presley, who joined the college in 2019 after earning his PhD at the University of Minnesota and completing postdoctoral research at Oak Ridge Laboratory.

“The opportunity at Oak Ridge gave me a chance to work in a new field, bacterial genetics, where I worked on a project aimed at making value-added chemicals from biomass. At Minnesota, my work focused on the biology of wood decay,” says Presley, assistant professor of forest-based bioproducts. “OSU has been a leader in wood durability research for years and I plan to continue that program now that I am in a position here.”

Since joining the college, Presley finds himself performing a wide variety of research, the bulk of which is related to his role as leader of the Utility Pole Research Cooperative and the Environmental Performance of Treated Wood Research Cooperative.

“The Utility Pole Research Cooperative focuses on research to improve the durability of utility poles,” Presley says. “Many of the studies we perform are designed to compare different treatments that can be done to utility poles to extend their service life and improve their resilience.

This research, Presley says, can benefit the treated wood industry and utilities by improving the durability of commodities produced and used by these industries. It helps make wood products more competitive with carbon-intensive alternatives such as steel, which is important in the overall effort to reduce carbon emissions across all sectors.

The Environmental Performance of Treated Wood Cooperative studies how preservative chemicals leach out of treated wood. The cooperative also looks at ways to prevent leaching into the environment and provides outreach to the broader public. Data collected from this research is used to model the impacts of treated wood on the environment which helps builders determine whether treated wood structures are appropriate for a specific environment.

“The cooperative has performed extensive validation efforts for treated wood best management practices, which are voluntary procedures for manufacturers that can reduce leaching from treated wood products,” Presley says. “We also are embarking on a significant research effort to measure the impact of treated wood used in agriculture and are developing an accelerated leaching and migration test to look at preservative movement from different types of treated wood with different types of water exposure.”

The research the cooperative pursues improves our understanding of these wood products’ environmental dynamics. The work provides insight into the pathways treated wood interacts with in the environment. The efforts can inform mitigation efforts that will improve products and reduce impacts to the environment.

The Creosote Council and several wood-preserving industry partners gave OSU a gift to study the environmental pathways of creosote-treated wood in recognition of Presley’s research capabilities and publication efforts.

The widely used wood preservative is used to preserve critical wood infrastructures such as utility poles, railroad ties, and marine pilings. It has a long history of practical use and is the oldest wood preservative originating from the industrial age.

This gift will fund a master’s student, Skyler Foster, for two years and support a mixture of lab-based and field research studying the migration of polyaromatic hydrocarbons from creosote-treated wood with an intent to quantify the environmental impacts.

“This generous gift will allow us to perform research that will improve our understanding of how creosote treated wood impacts the environment,” Presley says. “We all rely on creosote-treated wood in some capacity, whether it be for the delivery of goods by rail or pilings that support a pier. Knowing the impacts of these commodities on the environment is essential for ensuring their continued use.”

Moving forward, there are many questions on the horizon the research cooperative will address.

“Opportunities will develop in the utility pole market due to the looming loss of pentachlorophenol (penta) as a utility pole treatment and our cooperatives will play an important role in assessing the viability of alternatives for western utilities,” Presley says. “These changes will come with questions about the environmental impacts of penta substitution, something we will continue to investigate as these changes unfold.”

A version of this story appeared in the Spring 2021 issue of Focus on Forestry, the alumni magazine of the Oregon State University College of Forestry.