For her dissertation, Rebecca Sheridan, who recently received her Ph.D. in sustainable forest management, studied Douglas-fir seedlings. Her research on this famous tree is specific and based on the latest technology available in the Western world, but the Oregon native says one of the essential parts of her graduate school experience takes place 6,500 miles away in Armenia.

“When I started graduate school, I wanted to do research that could be applied and helpful in solving restoration and reforestation issues,” she says. “The work I’ve done in Armenia is a reminder of the tangible outcomes research can have. It helps me stay grounded.”

Sheridan’s major professor was Interim Dean Anthony S. Davis, who has collaborated with the International Programs office of the U.S. Forest Service and other organizations to complete seedling-related projects. In 2016, Sheridan joined him for the first time in Armenia.

During Sheridan’s first visit, the U.S. team worked with a nonprofit organization to build a greenhouse and start the first growing season for seedlings with the goal of restoring the depleted landscape.

Sheridan says understanding Armenian culture, the history of the country and the greater region is important when it comes to the forestry and natural resources industries. For example, after the collapse of the Soviet Union, there was an oil and gas blockade, so tree harvests increased to supply heat to homes.

“Deforestation rapidly increased during that time,” Sheridan explains. “I’m not sure what the landscape looked like before the blockade, but these days, it looks like Eastern Oregon with rolling hills and lots of juniper trees. It’s higher and dryer there, and the goal of this project is to reintroduce native species to the land.”

Sheridan says many of those species are wild versions of edible plants like pear, apple and almond.

“It’s cool to work with species that are familiar to us as food, but are native, wild plants in another region of the world,” she says.

Culturally, Sheridan says Armenia is an exciting fusion of West and East with diverse food and kind people.

During her three trips to the country, Sheridan relied heavily on local knowledge while gathering materials and planning her workshops. The first growing season in 2016 yielded about 200 plants, while during the
2018 season, production increased to about 5,000 seedlings. Now, Sheridan says, the greenhouse is at capacity.

“The biggest challenge is working in such a rural, agricultural community,” she says. “People there have experience with food crops and orchards. We do our best to be respectful of the knowledge of our in-country partners while also highlighting how and why we’re training them to grow container seedlings for restoration in a different way than they might be used to.”

Sheridan says they will plant the seedlings in challenging environmental conditions, without irrigation or long-term maintenance of competing vegetation, so they need to be ready for the conditions they will face. Wildfire is also becoming prevalent in the area, adding a new twist to the project, as Sheridan and her in-country partners consider whether the landscape is fire adaptive.

Sheridan says the international work experience inspired her, and even though she’s not sure what her future holds, she hopes to continue visiting Armenia.

“It doesn’t matter if I understand every detail about how plants grow,” she says. “But, if I don’t understand how fertilizer gets shipped into different parts of the world or the cultural norms that influence what time of day you
can get people to water at our greenhouse, I’ll be less effective in helping solve these problems.”

A version of this story appeared in the fall 2019 issue of Focus on Forestry, the alumni magazine of the Oregon State University College of Forestry. Learn more about international programs within the College of Forestry here.

Conventional timber harvesting has no effect on carbon levels in the mineral soils of the western Pacific Northwest for at least 3 1/2 years after harvest, according to recently-published research by Oregon State University and Weyerhaeuser Company.

The study is important because soils contain a large percentage of the total carbon in forests – generally about half of it – and understanding soil carbon response to clear-cuts and other forest management practices is vital in determining carbon balance in any given stand as well as the overall landscape.

Stable carbon levels in the ground means less carbon dioxide in the atmosphere. An important greenhouse gas, carbon dioxide’s concentration in the atmosphere has risen 30 percent since the start of the Industrial Age.

Historic in its scope, this collaborative and long-term effort between Jeff Hatten of the OSU College of Forestry and Scott Holub of Weyerhaeuser monitored nine managed Douglas-fir forest stands in Oregon and Washington, before and after conventional timber harvest and replanting, and involved more than 50,000 soil samples from 2700 sample points, thus far.  Continued monitoring of soil carbon with additional rounds of sampling is planned at these sites for decades to come.

“Our original hypothesis that timber harvesting would decrease soil carbon in the short term was disproven,” said Hatten, a soils researcher in the college’s Department of Forest Engineering, Resources and Management. “And I think it’s fair to say this has been the most extensive sampling ever conducted to determine if harvesting has an impact on soil carbon.”

“The no-result was remarkable,” he said. “Even where you have the highest soil temperatures and the highest soil moistures – the strongest environment for decomposition that releases carbon dioxide into the atmosphere – harvesting doesn’t seem to have an impact in the areas we studied. And the results likely extend to similar areas, probably totaling many millions of hectares in the Northwest.”

Across all the sites combined, after harvest, the scientists found negligible change (+2%) in mineral soil carbon content and a 184 percent hike in forest floor carbon, the result of harvest residue.

Modern harvest methods are designed to cause minimal soil disturbance, and the stable soil carbon would seem to reflect that, the researchers said.

“Concern about rising atmospheric carbon dioxideconcentrations has heightened interest in the role that forests play in carbon sequestration, storage and cycling,” Hatten said. “Living trees sequester and store carbon, but less recognition has been given to soils’ role. We have plans to resample these sites in coming years and decades to look at the longer-term impacts.”

Citation:

Holub, S.M. and Hatten, J.A. 2019. Soil Carbon Storage in Douglas-Fir Forests of Western Oregon and Washington Before and After Modern Timber Harvesting Practices. Soil Science Society of America Journal 83(1):S175-S186.

Abstract available here: https://dl.sciencesocieties.org/publications/sssaj/abstracts/83/s1/S175

Carbon dioxide emitted into the atmosphere from the burning of fossil fuels is causing the Earth to warm, oceans to acidify and climates to change. Because tree growth captures atmospheric carbon, some scientists and environmental advocacy groups promote massive tree planting as a solution to climate change.

A group of 46 scientists from around the world, led by Joseph Veldman of Texas A&M University, are urging caution regarding plans to address climate change through massive tree planting.

These scientists teamed up with Veldman, whose research focuses on the fire ecology of savannas and forests of Texas and Tropical America, to publish a message of concern in the journal Science.

 “While tree planting can be good in some deforested areas, tree planting in Earth’s natural grasslands destroys plant and animal habitat and will not sequester enough carbon to compensate for fossil fuel emissions,” Veldman says. “Few people realize that planting trees in the wrong places can actually damage ecosystems, increase wildfire intensity and exacerbate global warming.”

The new publication is a critique of another recent paper in Science, which claimed global, large-scale tree planting could capture 205 gigatons of carbon, or one-third of the carbon dioxide emitted since the industrial revolution.

 “Because the estimate of 205 gigatons of carbon was so large, in July 2019, headlines around the world declared tree planting to be the best solution to climate change,” Veldman said. We now know those headlines were wrong.”

In their critique, Veldman and his collaborators write that serious methodological flaws led to a five-fold overestimate of the potential for new trees to mitigate climate change. Among the problems, they point out that the original study assumed that soils in ecosystems without trees contain no carbon, when in fact many ecosystems such as savannas and peatlands, contain more carbon in soils than in the above-ground vegetation.

The study also neglected the fact that coniferous forests in boreal and high mountain regions absorb more sunlight and emit more heat than treeless areas, and actually exacerbate rather than mitigate global warming.

Finally, Veldman and his collaborators argue tree planting in grasslands and savannas, as proposed by the original article’s research team, is damaging to the environment.

“Ancient grasslands and savannas contain immense biodiversity and provide services to humanity, such as livestock forage and groundwater recharge,” Veldman says. “We worry that a myopic focus on tree planting will reduce the capacity of people to adapt to climate change while distracting from efforts to conserve intact ecosystems and reduce fossil fuel consumption.”

Co-author Christopher Still of the Oregon State University College of Forestry, adds,  “Careful and targeted afforestation and reforestation can help with the climate crisis, but only if done in certain regions and with appropriate safeguards for biodiversity, water availability, and in concert with local communities. ”

While earning his master’s degree at Oregon State, Preston Green conducted research on cable-assisted harvesting, a safer way to harvest timber, on the McDonald Forest. The McDonald Forest is owned and operated by the College of Forestry. Just minutes from Corvallis, the forest is often utilized as space for graduate, undergraduate and faculty research. It’s also a living classroom for students conducting labs and a recreation resource for the public.

Preston says, “The College Forests, to me, are a place that epitomizes the potential a forest can have. A forest can provide for so many different uses and when the right management and stakeholders are brought together, everybody can truly win. My research was a great example and why I particularly enjoyed the opportunity to work on the College Forest – not only for the generation of wood products that help support the College of Forestry and the local community but also for the forest health and scientific knowledge that has reached audiences worldwide.”