PNW-ISA asks governments to consider public safety tree care “essential”

Cristina Bowerman Cristina Bowerman
Executive Director
Learn more about Cristina Bowerman.

The letter below was emailed and mailed to government officials in PNW-ISA's region.

(Tigard, OR, Monday, March 23, 2020) The Pacific Northwest Chapter of the International Society of Arboriculture (PNW-ISA) is a nonprofit organization representing over 2,000 arborists and tree care companies in Alaska, Idaho, Oregon, Washington and British Columbia, Canada. Due to the COVID-19 pandemic, we have experienced numerous federal, state, and local health or business closures affecting our members. While the jurisdictions, business activities affected, and length of time for the closure may differ, most will exempt essential businesses or essential business activities that directly relate to public safety. Read More "PNW-ISA asks governments to consider public safety tree care “essential”"

PNW-ISA Postpones Spring Education Workshops

Cristina Bowerman Cristina Bowerman
Executive Director
Learn more about Cristina Bowerman.

(Tigard, OR, Monday, March 16, 2020) PNW-ISA is postponing its March and April education programs to limit in-person contact. We are taking every precaution necessary to ensure our members remain healthy and safe. We have been in communication with instructors and facilities to determine rescheduling dates and will announce these dates as soon as they are finalized. When rescheduling, registrants will be notified and automatically moved into the new dates selected. If you are unable to attend the new date, you will be able to cancel your registration at that time and receive a refund.

To reduce exposure to COVID-19, PNW-ISA will be hosting conference calls/virtual meetings for its board and committees. We are doing everything possible to reduce exposure and adhering to recommendations for social distancing and isolation.

PNW-ISA will continue to monitor May activities such as our educational workshops and tree climbing competitions as we don’t want to put anyone at risk. We will continue to make informed decisions over the next few weeks and update members and registrants immediately.

We hope you and your loved ones remain healthy and safe as we navigate this time together.

Nominations Process Begins for Chapter Awards 

Each year, PNW-ISA recognizes the skill and dedication of our members through the Chapter Awards program and the Chapter Tree Climbing Championship. This year’s award winners will be recognized during the Annual Training Conference in Coeur d’Alene, ID, October 4-7, 2020.   Read More "Nominations Process Begins for Chapter Awards "

PNW Seeks Volunteers for Board & New Committee

PNW-ISA is currently seeking qualified volunteers for the positions below. To express interest, please click on the links below.

Editor, Pacific Northwest Trees Newsletter

This position serves under the Board of Directors, Advisory Committee. The Editor is responsible for all aspects of preparing the quarterly (Spring, Summer, Winter, Fall) Chapter newsletter which includes collecting content, editing submissions, preparing the layout, proofreading, etc. This position is supported by the Editorial Committee and is appointed by the Board of Directors with a three-year term. If interested in this position, please complete the board member interest form. Read More "PNW Seeks Volunteers for Board & New Committee"

Regional Plant Appraisal Guidebook 3rd Edition Scheduled for ATC 20 Publication

Zeb Haney Zeb Haney
Tree Resource
Learn more about Zeb Haney.

The last convening of the Regional Plant Appraisal Committee (RPAC) back in 2007 resulted in the publication of the Species Rating guidebook. If you haven’t purchased a copy of this tiny gem I believe there are still literally boxes of them available for sale through the chapter office. (Seriously. It’s time to reconvene.) Read More "Regional Plant Appraisal Guidebook 3rd Edition Scheduled for ATC 20 Publication"

What You Don’t Know Could Cost You

Cristina Bowerman Cristina Bowerman
Executive Director
Learn more about Cristina Bowerman.

If you are an arborist that is operating a tree services company in Oregon, are you aware of how many licenses you must maintain to plant and remove trees? No, this isn’t a riddle, it’s a serious question that could prevent your company from receiving hefty fines and possible civil penalties.
Read More "What You Don’t Know Could Cost You"

Updates from the Board of Directors

Phil Bennett Phil Bennett
More articles by Phil Bennett.

Transition Update

In February 2019, the Board of Directors reviewed the results of an Organizational Assessment completed by Loveall Price & Associates, a nonprofit transitional consulting firm. The Board accepted the recommendations in the assessment, including initiatives to update operational systems, and move towards a virtual office for the Chapter. Staff have been working diligently to implement those recommendations.

PNW-ISA has retained Loveall Price and Associates to assist with an Executive Director Search that will commence later this summer.  We will hire a new executive Director for the Chapter by the end of 2019.

PNW-ISA Board of Directors Positions Available

If you are interested in serving on the PNW-ISA Board of Directors, please complete the Board interest form.  A Board Position may be available prior to this year’s Annual Training Conference (ATC), and elections will be held for several positions at ATC.

TREE Fund Summer Update

Evan Sussman Evan Sussman
Board TREE Fund Liaison & Sonshine Tree Care, LLC
Learn more about Evan Sussman.

Greetings arborists! I wanted to write a brief update on the on goings at the TREE Fund. For anyone who isn’t familiar with the TREE Fund, they manage endowment funds that support research and education for arboriculture. A lot of the current and past research that we base our practices on has been funding in part or whole by the TREE Fund.


Webinars are in full swing. These are a great way to stay in the loop with current TREE Fund researcher’s works, and to get free CEUs. Upcoming this year are:

Remediating Compacted Soils Compromised by Urban Construction
Dr. Nina Bassuk, Cornell University
June 11, 2019, 11:00 am PST

Can We Vaccinate Trees to Protect Against Diseases?
Dr. Glynn Percival, Bartlett Tree Experts Research Laboratory, UK
August 29, 2019, 10:00 am PST

Health Benefits of City Trees: Research Evidence & Economic Values
Dr. Kathleen Wolf, University of Washington
November 19, 2019, 11:00 am PST

All of these webinars are good for 1 free CEU!  You can access the archive of previous webinars at Additionally, you can stay up to date on future webinar offerings at that link or by following our PNW-ISA Facebook page.

Read More "TREE Fund Summer Update"

Treasure Valley Tree Selection Guide: A Process of Transformation

Mary Jane Marlow Mary Jane Marlow
Canopi Design
Learn more about Mary Jane Marlow.

The Cities of Boise, Caldwell, Eagle, Kuna, Meridian and Nampa, Idaho are proud of their trees! It was with this sentiment of value and appreciation for our trees that the TV Tree Selection Guide was created. Based largely on the original version from the Boise Parks & Recreation Department’s Tree Selection Guide developed by the Urban Forestry Unit in 1995, the new guide was fashioned.

It was time…time to broaden tree species selections to include new cultivars. And, remove old ones that were not performing well. This was a labor of satisfaction for everyone involved. Read More "Treasure Valley Tree Selection Guide: A Process of Transformation"

Photos from October Tree Risk Assessment Workshop

Dylan Saito Dylan Saito
More articles by Dylan Saito.

The PNW class “Common Fungi Affecting PNW Trees and Implications for Tree Risk Assessment” was a classroom/outdoor course in tree diseases, and particularly anyone conducting risk assessment of trees with disease.  Led by Dr Julian Dunster and Professor Bob Edmonds.

The diseases covered included Phaeolus schweinitzii, Heterobasidion occidentale, Armillaria ostoyae, Porodaedalea pini, Kretzschmeria deusta, Phellinus sulphurascens, Neofusicoccum arbuti and others.

Morning lectures covered visual assessment techniques for disease, using a combination of signs and symptoms of common diseases in native PNW trees. Sonic tomography and resistance drilling will be discussed as examples of advanced risk assessment techniques.

The afternoon was spent outdoors examining diseases of Douglas-fir, western hemlock, western red cedar, bigleaf maple, and Pacific madrone. The types of wood decay, fungus fruiting bodies, as well as structural and risk implications will be covered.

The PNW is grateful to have Roger Barnett attend, to learn and capture moments on digital film for all to take a peek into this course.  Please see some of these moments on this flicker account below: