Years of drought coupled with extreme temperatures indicative of climate change is stressing our local forests. Continuing decades of stewardship on 1,100 acres of community forests governed by the Ashland Forest Plan and the 2023 Climate Change Adaptation Addendum, the City and Ashland Parks and Recreation are planning work this winter that will ease the transition to species adapted to drought and heat. A recent report summarized the extent of dead and dying Douglas-fir trees, showing at least 20% have been impacted. With more die-off anticipated, proactive planning and action will ease the anticipated shift in species and lower wildfire risk to the community and Ashland’s watershed.
The City of Ashland commissioned an aerial survey of approximately 800 acres of community-owned forests located within and adjacent to town after a significant wave of tree die-off became apparent late this spring. The survey, completed by local company Rogue Reconnaissance, used a combination of technologies to quickly assess tree and forest health. This gives a snapshot in time to help anticipate developing wildfire risk and further plans to help our forests adapt to climate change.
The results of the survey show an overall die-back of approximately 20% of all Douglas-fir over the areas surveyed, which includes popular trails like Bandersnatch, BTI, White Rabbit, and Wonder. The 20% number includes dead from recent years, trees that just died this year (red needles), and trees showing signs of crown decline like dead branches that are a sign of the beetle called Douglas-fir flatheaded borer, the primary mortality agent. The number of "healthy" trees in the report may significantly underreport conditions on the ground.
“From recent research, work with forest insect scientists and foresters, and walking the ground, this aerial survey shows us the geographic extent of die-off but very likely underestimates how many trees are dying. Many trees that appeared green and healthy in the survey have signs of beetle attack and decline when you look at them from the ground,” said Ashland Fire & Rescue Forest Officer Chris Chambers.
Data being collected by local scientists also confirms that many more trees are dying than were captured via aerial surveys.
“We’ve been advised by researchers to anticipate high rates of Douglas-fir die-off under 3,000 feet elevation in the next five years, which is most of the area between Reeder Reservoir and Lithia Park including Siskiyou Mountain Park just east of the Ashland Watershed. Adapting our forests to the changing climate is a huge task that demands we act quickly not only to curb developing fire danger, but to do everything we can to keep forests intact for as long as possible. Some areas of the west are already losing forests for good, and we can avoid that if we are proactive,” Chambers added.
Reeder Reservoir is the City’s municipal water collection point, located 2 miles above the swimming reservoir at Glenview Dr and Granite St intersection.
Douglas-fir die-off is not a new issue, but it has intensified. In 2004, after three years of drought, the City removed thousands of dead and dying trees via helicopter. The most recent Douglas-fir mortality has been dubbed a “decline spiral” by Oregon State University and U.S. Forest Service researchers in a recent paper documenting the effect of drought combined with extreme temperatures, both made worse by climate change.
“In southwestern Oregon, forest management that steers toward oaks, pines and other more drought-tolerant species may be warranted in places with less than about 40 inches of average precipitation a year,” retired Oregon State University Extension Forester Max Bennett said. “But some individual trees and patches of Douglas-fir will likely persist on these dry sites at least for a time, so it’s important not to use an all or nothing approach.”
The survey shows patches of dead trees up to five or more acres that are expanding along with scattered dead on many more acres. Siskiyou Mountain Park at the top of Park Street and west of Oredson-Todd Woods has extensive die-off bordering neighborhoods. Of 191 acres surveyed there, about 30% is dead in total, with localized areas having over 70% dead and dying.
City staff, consulting company Small Woodland Services, and the Forest Lands Management Advisory Committee submitted a “Climate Change Adaptation Addendum to the Ashland Forest Plan” that was approved unanimously by the City Council in April. The result of a year and a half of work, the Climate Change Addendum anticipated the kinds of changes now evident, and set objectives for adapting municipal forests to climate change, some of which has already been employed for years such as thinning trees, controlled burning, and planting drought tolerant species.
Work to mitigate increasing fire risk from dead trees has already been ongoing, with projects co-managed by Ashland Parks and Recreation and Ashland Fire & Rescue on the Lithia Park hillside, Hald-Strawberry Park, and at the Red Queen trailhead at Terrace Street and Ashland Loop Road.
“The forest we see and know is not the same forest we’ll see in five to ten years, and certainly not in 25 years. We want to maintain intact forests through periods of intense heat, drought, and fire and being open to change is critical. Guiding change is much more desirable than having it forced on us,” Chambers concluded. A guide for the public and forest landowners was recently published by Oregon State University Extension Service.