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1 Square miles known to be infested with EAB: 5.7 (unchanged) In this issue: • ODA begins checking trap trees around Forest Grove for EAB • Multiple agencies map out Mediterranean oak borer response • Cornelius prepares for EAB response by inventorying its ash trees • Tigard plants alternatives to ash in natural areas • DEQ now has results from air curtain incinerator emissions test ODA begins checking trap trees around Forest Grove for EAB larvae In October ODA staff and contractors finished felling and collecting branch samples from 117 EAB trap trees located in a ring around Forest Grove. Funding appropriated to ODF through the federal Infrastructure Investment and Jobs Act (IIJA) was spent on contract to remove 72 of those girdled trees on private property. Back in May these trees were girdled, causing them to slowly die, and release an organic compound. This compound, while harmless to people, pets, and crops, draws any EAB in the area to the girdled tree where the females lay their eggs. Several 1-meter long (3.3 feet) branch samples were collected from each tree, labeled with a unique identifier, and taken to a central location. Once all the samples are collected, ODA staff and colleagues from local agencies will begin carefully peeling the bark from each sample and looking for EAB larvae underneath. This information will provide a clearer picture of how far and in what directions EAB is spreading from Forest Grove and how dense the population may be. This information will be used by local land managers as they decide how to prepare for and respond to EAB. ODA thanks Metro, Clean Water Services, Tualatin Soil & Water Conservation District, the Oregon Department of Forestry, USDA, the cities of Hillsboro and Forest Grove, Washington County, and dozens of local property owners for allowing them to conduct this study on their properties and for providing funding and logistical support. Agencies plan Mediterranean oak borer response Staff from multiple agencies in Oregon, Washington and California met in October to determine a plan of action for responding to the arrival on the West Coast of the invasive pest Mediterranean oak borer. The pest has been found so far in a number of counties in Northern California. In Oregon, it has been ---PAGE BREAK--- 2 identified in about 30 Oregon white oaks in Wilsonville in Clackamas County and one in Troutdale since felled) in Multnomah County, as well as in traps in Linn, Marion and Washington counties. The response agencies agreed upon includes: • monitoring via traps and ground reports to map where MOB has spread so far • research/monitoring to support potential management strategies • outreach messaging to landowners and the public about appropriate response e.g. slow the spread by not moving firewood, know the signs and of MOB, etc. • seeking funding opportunities Forest Entomologist Christine Buhl measures the diameter of an oak infested with MOB in Wilsonville. Forest Entomologist Christine Buhl is spearheading the Oregon Dept. of Forestry’s response to MOB She said, “We won’t have any new guidance or information on impact to oaks for a while since that research is still happening. ODF and the Oregon Dept. of Agriculture are investigating sites where we can test out some response strategies. We are writing a guide to management strategies we think will be effective, but also a nod to strategies that landowners may want to test at their own discretion. We’ll also state what responses are known not to work, and list resources for things like tree removal and wood waste disposal. We hope to complete this soon but it will be a living document as we learn more.” To learn more about this pest, please go to sheet-mediterranean-oak-borer.pdf After reviewing the signs and reports of suspected MOB presence can be made to the Oregon Invasives Species Council at Cornelius inventories its ash trees EAB was found in Cornelius in Washington County earlier this year. Ash trees make up a large number of the trees in that community and are common in yards, parks, and along streets. The city did not exactly how many they had, so ODF Urban and Community Forestry staff lent a hand and helped inventory the ash trees in Cornelius, giving the city of 13,500 a clearer picture of what they need to plan to treat or remove. While EAB is here to stay, we can slow its spread if people don’t move firewood more than 10 miles from where they buy or collect it. A few other steps to take include: ---PAGE BREAK--- 3 • Learn if any trees on your property are ash: ash-trees-oregon-washington-northern-california • Learn how to manage ash trees for EAB: selling/what-do-about-emerald-ash-borer-recommendations-tree-protection-eab • For more information on the statewide EAB response, please visit: Tigard on track to plant 80,000 replacements for ash and declining cedars Western red-cedars in Tigard’s natural areas were already dying from climate-related changes when a new threat emerged to the city’s ash trees in the form of EAB, discovered only 25 miles away in Forest Grove in 2022. “We realized it's not if but when we will lose our ash and it's not some but potentially all our ash trees," said Rick Gruen, Tigard Parks, Recreation and Green Infrastructure Divisions Manager. Wanting to get ahead of needed replacements for both species, the City of Tigard began working with Ash Creek Forest Management to do pre-emptive restoration plantings in the city’s largest parks. Ash Creek had received a grant to buy 80,000 trees and shrubs so Tigard only had to cover the planting costs, not the cost of the plants. Some 40,000 plants have already gone in the ground at Derkzen Nature Park and Cook, Summerlake and Woodard parks. Another 40,000 will be planted next year. In addition to shrubs native to the area like red osier dogwood, Pacific ninebark and Oregon grape, a variety of native trees were chosen, including cascara, western crabapple, bigleaf maple, black hawthorn and choke cherry. Right: Two workers during planting of some 40,000 native trees and shrubs in Tigard natural areas this year. The plantings anticipate the eventual loss of the city’s ash trees. ---PAGE BREAK--- 4 DEQ now has test results for air curtain incinerator emissions The Oregon Department of Environmental Quality, along with the Oregon Department of Forestry, Oregon Department of Agriculture, Clean Water Services and Montrose Environmental Services, completed an Air Curtain Incinerator Emissions Testing Project in spring 2023 and the results are now available. Data collected shows significant reductions in particulate matter and carbon monoxide emissions when compared to emission factors from various open burning studies. Also, results demonstrate potential health risks from toxic air pollutant emissions are much lower than previous estimates used by DEQ’s Cleaner Air Oregon program when evaluating the risk from ACIs. The test used ash wood removed as part of Oregon’s emerald ash borer response efforts. For more details on the ACI test and to read the Report Summary and Full Source Test Report, visit the DEQ's Air Curtain Incinerator Emission Testing web page. Publications Alternatives to Ash in Western Oregon: With a Critical Tree Under Threat, These Options Can Help Fill Habitat Niche. G. Kral, and D.C. Shaw. 2023. OSU Extension EM 9396. Oregon Ash: Insects, Pathogens and Tree Health by Oregon State University Extension (also available in Spanish at this same website) Wood Decay Fungi Associated with Galleries of the Emerald Ash Borer by the University of Minnesota and Uruguay’s Instituto Nacional de Investigación Agropecuaria Forests I Free Full-Text I Wood Decay Fungi Associated with Galleries of the Emerald Ash Borer (mdpi.com) Useful links for more information Mediterranean oak borer fact sheet Above: A worker tosses an ash log into an air curtain incinerator during an emissions test last May in Forest Grove. Results of the test are now available. ---PAGE BREAK--- 5 EAB monitoring guidance Oregon Dept. of Agriculture Oregon Dept. of Forestry OSU Extension Emerald Ash Borer Information Network, a collaborative effort by the USDA Forest Service and Michigan State University www.emeraldashborer.info USFS Forest Health Protection ---PAGE BREAK--- 6