Washington DNR 2016 Forest Health Report

The Washington State Department of Natural Resources and USDA Forest Service conduct annual aerial surveys to identify, map and monitor the impacts of insect and diseases on forest lands throughout the state. Aerial survey data are verified with ground-based observations and are compared against the results of other forest health research happening throughout the state.

Survey results are compiled into an annual report called Washington’s Forest Health Highlights. This year marks the 70th anniversary of cooperative aerial survey work between the Washington Department of Natural Resources, the Oregon Department of Forestry and the USDA Forest Service.

Due to the time required to collect and analyze the survey data, then verify and publish the results, the Forest Health Highlights outlines forest health conditions observed in the previous year. Nonetheless, these reports provide critical benchmarks for the presence or absence, scope, and severity of insects, diseases and other environmental conditions that adversely affect the health of trees and forests in Washington state.

Care to know what types of insects and diseases are affecting forest lands where you live? Download a copy of the recently released Forest Health Highlights in Washington–2016

Originally published in DNR Tree Link.

PNW-ISA ATC 2017 Keynote Speaker Announced

PNW-ISA Annual Training Conference
Lynnwood, WA
September 24–27, 2017

Trees are a vital link in achieving a variety of environmental and social changes that are urgently needed. We are witness to an ever faster pace of change in social and environmental conditions that affect trees in return. This year's conference promises a program filled with outstanding speakers and vital topics for addressing the challenges facing trees and the people who care for them.

Aligning with this year’s theme of People and Trees: Adapting to Change, our chapter is pleased to announce that we’ve confirmed Dr Jim Clark to deliver the Keynote address as well as a special session by local environmental reporter Lynda Mapes.

Keynote: Managing Mature Trees in a Changing Environment

Dr. James Clark, Vice President, HortScience, Inc.

Dr. Clark is an inspirational educator and mentor to many green industry professional in Pacific Northwest Chapter going back to the 1980's when he was on the faculty at the University of Washington Center for Urban Horticulture and a board member of the Pacific Northwest Chapter. He is co-author of A Photographic Guide to the Evaluation of Hazard Trees in Urban Areas, Trees and Development, Arboriculture - Integrated Management of Landscape Trees, Shrubs and Vines (4th ed.), and Structural Pruning - A Guide for the Green Industry, in addition to numerous articles in the Arborist News and several research journals. A recipient of the ISA Alex Shigo Award for Arboricultural Education, he lectures in arboriculture and urban forestry worldwide and is recognized internationally by the ISA.

Witness Tree: Seasons of Change with a Century-Old Oak

Lynda V. Mapes, Seattle Times Environmental Reporter

Lynda Mapes is a longtime reporter for the Seattle Times, covering the environment and natural history, including the removal of the Elway River Dams. She is author of four books, Elwha- A River Reborn, Breaking Ground: The Lower Elwha Klallam Tribe and Unearthing of Tse-Whit-Zen Village, Washington: The Spirit of the Land, and most recently, Witness Tree: Seasons of Change with a Century-Old Oak. In her new book Witness Tree, Lynda tells the story of climate change through the life of a single 100-year-old red oak tree in the Harvard Forest. She will share the story of what she learned during the year she spent at there as a Bullard Fellow in forest research in residence, exploring the human and natural history of a single tree.

More Speakers to Be Announced

These and many more great speakers will be providing attendees with thought provoking ideas at the conference this year! A full speaker program will be announced later this summer.

What's Next

The PNW-ISA Tree Climbing Championship will take place right before the conference. Will you compete this year? Join the Regional competition in Portland and find out!

ISA Announces New Executive Director



ISA Members and Credential Holders:

The ISA Board of Directors has completed its search and selection process for the Executive Director position, and we are pleased to announce the outcome of that process. We have selected Caitlyn Pollihan to be the next Executive Director for ISA. To learn more about Caitlyn’s background and the ISA Board’s decision, please see the press release.

The ISA Board of Directors and the Executive Director Transition Committee are dedicated to a smooth transfer of leadership for our members, credential holders, and staff. As such, we anticipate the transition to begin on July 1, 2017, when Caitlyn officially takes over as the ISA Executive Director. At that time, Jim Skiera will proceed as a Senior Advisor until his retirement later this year to assist in a smooth change in leadership for the organization.

We would also like to take this moment to acknowledge and thank Jim for his multiple decades of service, passion, and leadership in serving ISA and the industry. Jim has served the organization well, and we are better as a result of his service.

ISA looks forward to Caitlyn Pollihan’s new role as Executive Director as we continue to serve our members, credential holders, and other professionals throughout the industry.

Warm regards,

Michelle Mitchell
President, ISA Board of Directors

Annual Training Conference 2017 Logo

This Year's Theme: People & Trees Adapting to Change

Trees are increasingly recognized as a vital link in bridging environmental, social, and policy issues. Professionals from a broad range of disciplines are paying more attention to the role of trees in their collective efforts for environmental conservation. The working arborist’s role is to keep current with the science and practice of tree care and effectively convey that information to a broad audience in a rapidly changing world.

Effective collaboration between professions and disciplines results in more successful solutions than any one group can achieve on their own. Linking our expertise and efforts may be our most vital tool for adapting to change.

ATC 2017 Logo

In developing our logo this year, we wanted to honor the locale. Conference attendees will be converging in Snohomish County; an ecological and societal delta where the mountains, estuaries, and sound come together with big cities and big trees. Through our artistic rendering of the location we hope to inspire attendees to see more solutions than obstacles when adapting to change.

The logo was provided and developed by local artist/photographer Sabina Burd.


Ian Scott

Ian Scott, Chair, ATC 2017
Photo courtesy of Sabina Burd Photography (

My membership with the ISA began when I became a certified arborist in 2000. This was the same year that I moved to the PNW and joined the Chapter. At the time, my involvement was limited, but then the international conference was being hosted in Seattle so I volunteered to help. The networking and comradery with my peers was so enjoyable that I’ve stayed an active volunteer with the Chapter ever since.

My current volunteer position is the planning chair for the 2017 Annual Training Conference being hosted nearby in Lynnwood, Washington. Over the years, I’ve gained tremendous leadership experience through my volunteer efforts with the ISA, and this position is another opportunity I couldn’t pass up. Early on in my career, I learned from the example of my mentors at Puget Sound Energy, how volunteerism within the PNW-ISA creates even more opportunities to learn and grow professionally than just our daily work on its own. Read More "Ian Scott"

Your Market Value

What is your market value as an employee or a potential employee looking to be hired or working with a professional tree care company?

I recently had a conversation with several of my non-certified production arborists regarding attaining the ISA Certified Arborist Certification. Many are trained “in-house” and others are hired from the outside. All with different skill sets and experience. All of them are motivated to improve and take the opportunity to be moved up from production, whether they were climbers or plant health care technicians looking for new opportunity. Read More "Your Market Value"

News from ISA – Spring 2017

Visit Washington, DC for the ISA Annual International Conference

ISA is partnering with MAC-ISA (ISA Mid-Atlantic Chapter) to bring you the 2017 ISA Annual International Conference and Trade Show, July 29 – August 2 ... the premier event “where arboriculture meets.” Besides offering educational opportunities for professionals from all areas of arboriculture, this year’s event rejoins the International Tree Climbing Championship and the TREE Fund’s STIHL Tour des Trees.

The educational programming includes pre-conference workshops on the weekend, multiple educational sessions Monday through Wednesday, the trade show, and Climbers’ Corner demonstrations on the trade show floor. And the International Tree Climbing Championship will kick off the conference this year at the United States National Arboretum, July 28-30. Read More "News from ISA – Spring 2017"

Hot Off the Press!

PNW-ISA member Christina Pfeiffer of Seattle, WA has recently published an updated edition of her book, Pacific Northwest Month-by-Month Gardening: What to Do Each Month to Have a Beautiful Garden All Year.

Notes Christina: “This practical guide has been updated with current information for maintaining beautiful and healthy gardens, tuned into important regional issues such as water conservation, and protecting pollinators. Arranged by month, each chapter cues into the seasonal rhythms and life cycles in the garden and the timely tasks that go along them. When we can work in sync with nature, caring for the garden becomes more of a pleasing journey, and less of a battle. And as with the first edition, this book offered me an opportunity to include accurate and up-to-date information on tree care and hiring Certified Arborists that is so often missing in general garden guides for the public.”

In Memoriam: Cass Turnbull and Mike Bowman

Cass Turnbull

February 7, 1951 – January 26, 2017

In late January, we were all saddened to learn of the sudden and unexpected death of well-known PlantAmnesty founder Cass Turnbull. While vacationing in Hawaii with her husband, she suffered a fatal heart attack after a swim. Cass was the power, the energy, the humor, and the magic behind PlantAmnesty, a long-time member of ISA and the PNW Chapter, and she will be missed by all who knew her.

PlantAmnesty is organizing a public celebration of her life called “The Life and Times of Cass Turnbull” at 1 PM on Saturday, March 25, 2017 at Shoreline Community College Theater in Shoreline, WA. Further information can be found at

Read More "In Memoriam: Cass Turnbull and Mike Bowman"

Silver Linden Tilia tomentosa

Linden trees, especially American, Tilia americana and littleleaf, Tilia cordata, have been widely planted in urban areas because they are drought tolerant, durable and beautiful, and thrive is some of our toughest locations. However, aphid infestations on these lindens can be incredibly messy and a real nuisance. The “honeydew” under a street tree can appear as if it rained just beneath the canopy. Except in this case, the shiny area you see is sticky like glue, excretions from the aphids. This glaze of honeydew can be horrible for cars, sidewalks, and outdoor furniture.

A perfect solution to avoid this malady is to select a close relative, the silver linden, Tilia tomentosa, which does not attract aphids. As the species name implies, tomentosa is used to describe a woolly coating on the leaf formed by the tomentose hairs. Apparently, it is the hairs or woolly coating on the leaves that repel the little critters. So, there is no need to blacklist all lindens because of the aphids. Read More "Silver Linden Tilia tomentosa"