Tuesday, 5/9/2023, 9:15AM, General
Basque Arborglyphs
Presenter: Iñaki Arrieta – Baro, University of Nevada, Reno, Reno, NV
The presentation will introduce the tree carvings or arborglyphs created by Basque sheepherders during the late 19th century and until the 1980s to express their inquietudes while alone in the mountainous areas of the West, leaving us a living legacy of their experience. Ongoing projects by the Basque Library and others on preserving this legacy will be presented.

Bio: Since 2015 leads the Jon Bilbao Basque Library, a unit that serves researchers from around the world interested in Basque Studies. He has focused the library on the Basque Diaspora, strengthening relationships with the Basque community to partner in everything connected to preserving its documentary legacy. He has coordinated the transfer of Basque digital collections to the preservation repository and organized workshops and conferences on Basque topics and digital humanities.
Tuesday, 5/9/2023, 10:30AM, General
“Elderflora and Chronodiversity”
Presenter: Jared Farmer, University of Pennsylvania, Philadelphia, PA
Big trees, old trees, and especially big old trees have always been objects of reverence. From Athena’s sacred olive on the Acropolis to the unmistakable ginkgo leaf prevalent in Japanese art and fashion during the Edo period, our profound admiration for slow plants spans time and place as well as cultures and religions. At the same time, the utilization and indeed the desecration of ancient trees is a common feature of history. In the modern period, the American West, more than any other region, witnessed contradictory efforts to destroy and protect ancient conifers. Prize-winning historian Jared Farmer reflects on our long-term relationships with long-lived trees, and considers the future of oldness on a rapidly changing planet.

Bio: Jared Farmer is the Walter H. Annenberg Professor of History at the University of Pennsylvania. A former Andrew Carnegie Fellow, he is the award-winning author of four books, including “Trees in Paradise: A California History” and “Elderflora: A Modern History of Ancient Trees.” He lives in Philadelphia.
Tuesday, 5/9/2023, 1:30PM, General
Digging into how we make tree care decisions.
Presenter: Nelda Matheny, HortScience | Bartlett Consulting, Berkeley, CA
Additional Presenter(s): Jim Clark, HortScience | Bartlett Consulting, Berkeley, CA
Arborists make tree management decisions based on assessment of the situation. Assessment is a thinking process that involves our judgment and knowledge. In this session we will explore how to think through our options to arrive at the best recommendations for the trees and our client. Thinking processes include considering judgmental heuristics that enable us to form quick assessments, our knowledge, ethics, uncertainty, and our personal feelings about risk. We will explore the process through scenarios and interaction with the audience.
Bio(s):
Nelda Matheny is Consultant and Advisor with HortScience | Bartlett Consulting. She received her degrees at University of California, Davis. Nelda has worked as a consulting arborist in the SF Bay Area for 40 years.
Jim is Managing Consulting Arborist with HortScience | Bartlett Consulting. He received degrees from Rutgers University and the University of California, Davis.
For the last 30 years Jim and Nelda worked together at their consulting company HortScience, Inc. Nelda and Jim have authored many technical articles and five books together. They are currently working on the 2nd edition of Trees and Development. They are on the long and winding road to retirement.
Tuesday, 5/9/2023, 2:15PM, General
Botany For Arborists: A new tree biology reference for arborists
Presenter: James Downer, Ph.D., University of California, Ventura, CA
The presentation will cover each chapter of the Botany for arborists book. We anticipate the book will be published and available for sale and signing at the meeting. The lecture can be coupled with a book signing. Check back for details!

Bio: Dr. Downer has over 37 years’ experience working for UC cooperative Extension as an environmental horticulturist. His degrees are in plant pathology, botany and horticulture. He is a past president of WCISA and still serves on the Education committee. Dr. Downer also serves on the board of the John Britton Fund as the research advisory committee chair.
Tuesday, 5/9/2023, 3:30PM, General
Utility-Caused Wildfire Mitigation
Presenter: Randall Miller, CNUC, West Des Moines, Iowa
Utility-caused wildfires are a cause of increasing concern in western North America. This presentation reviews factors that contribute to utility-caused wildfire ignition and how they can be mitigated.

Bio: Randall Miller holds an MS in Urban Forestry from the University of Wisconsin – Stevens Point. He is an ISA Board Certified Master Arborist and Certified Utility Specialist. He retired in 2017 after 23 years in vegetation management at PacifiCorp. He currently serves on the International Society of Arboriculture Board. In addition, he served as a Chair of the TREE Fund Board of Trustees and President of the utility Arborist Association among other volunteer leadership roles.
Tuesday, 5/9/2023, 4:15PM, General
New tools from the Urban Forest Ecosystem Institute.
Presenter(s): Camille Pawlak, Cal Poly- San Luis Obispo, San Luis Obispo, CA; Jenn Yost, Ph.D., Cal Poly State University, San Luis Obispo, CA; Natalie Love, Ph.D., Cal Poly, San Luis Obispo, CA
Moderated by: Matt Ritter, Ph.D., Cal Poly, San Luis Obispo, CA
Camille will discuss two common strategies thought to create resilient urban forests are planting native species and having high diversity. When assessing a species’ native status, scale is an important consideration. To understand what role California’s native trees play in urban environments, we have identified California’s native trees and ranges, created city-specific native species lists, and assessed how native trees contribute to urban tree diversity. This presentation will go over how to access and use our data.
Dr. Yost will discuss the neural network created by the team at Cal Poly SLO that automatically detects and counts trees in urban environments using aerial imagery. Using this method, we created tree counts for all cities within California, and created a spatially explicit point file that has a point for every urban tree in the state. We estimate that there are 43 million urban trees in California. In this talk, we present this inventory, and discuss patterns in tree density across the state.
Dr. Love will continue the conversation helping us how their team utilized data from the California Urban Forest Inventory and occurrence data from each species’ native range to understand the climatic requirements of urban tree species. We used these data to (1) characterize each species’ climatic niche, (2) compare climatic niche of urban and native tree populations, and (3) develop region- and species-specific climate suitability scores for current and future climatic conditions in California. The results from this study can help guide species selection and planning for resilient urban forests.

Bio(s): Camille Pawlak is a graduate student in the Biological Sciences Department at Cal Poly in San Luis Obispo, California, where she studies the California’s urban forest. She has a B.S. in Environmental Science from U.C.L.A. Camille’s research interests include urban forests, remote sensing, and California’s trees. She enjoys ceramics, hikes with her dog, and summertime tomato harvests.
Dr. Jenn Yost is an evolutionary biologist who focuses on the botany of California and is a Professor at Cal Poly, San Luis Obispo. She studies urban trees, the genus Eucalyptus, and the invasion potential of tree species. Jenn’s research also focuses on the ecological differentiation, speciation, and reproductive isolation. She is also a tree planter and regularly teaches arborists botany, tree ID, and evolutionary biology.
Natalie Love is a postdoctoral researcher at the Urban Forests Ecosystem Institute at Cal Poly in San Luis Obispo with Dr. Matt Ritter. Her research focuses on the intersection between ecology and urban systems. Her research addresses urban forest structure and function, urban tree and bird interactions, and tree species suitability in California’s urban forests. She also teaches botany classes at Cal Poly.
Wednesday, 5/10/2023, 8:00AM, Break out 1
Trees and Construction BMPs
Presenter: Ryan Gilpin, Nidus Consulting, Portland, OR
Additional Presenters: Richard Hauer & Nelda Matheny
Many communities are asking for more trees to be preserved on construction sites connecting arborists with design and construction teams. The International Society of Arboriculture has updated the Best Management Practices regarding trees and construction. This presentation will review the Best Management Practices and the important changes in the new version. The authors will discuss the science behind the recommendations and their experiences that have been successful when consulting on construction projects.

Bio: Ryan Gilpin is Principal Consultant of Nidus Consulting based in Portland, OR. Ryan has been a consulting arborist working on tree preservation projects since 2011. Ryan’s M.S. is from Georg-August-Universität, and B.S. from University of California Davis.
Wednesday, 5/10/2023, 8:50AM, Break out 1
Digging Into Tree Losses for Insurance Reporting
Presenter: James L. Komen, Class One Arboriculture Inc., Glendale, CA
When disaster strikes, consulting arborists are called upon by insurance adjusters to assess and value the damage done to trees. This presentation shows case studies of collaboration between consulting arborists and insurance professionals, focusing on claims from the Thomas and Woolsey fires, the Santa Barbara mudslides, and the Phoenix monsoonal windstorms. See the techniques an arborist can use to inventory trees that have been completely obliterated by disaster.

Bio: James Komen is a consulting arborist in California specializing in risk assessment and tree appraisal. He helps clients make informed management decisions for individual trees and for tree inventories. His work has been published in Arboriculture & Urban Forestry, Arboricultural Consultant, Palms, Ontario Arborist and Western Arborist. He is an ISA TRAQ instructor and has taught workshops on tree appraisal around the U.S. and Canada.
Wednesday, 5/10/2023, 10:20AM, Break out 1
Are CODIT and Compartmentalization the Same Thing
Presenter: Kevin T. Smith, Ph.D., USFS Northern Research Station, Durham, NH
Compartmentalization in trees is one of the most significant concepts developed in forest pathology in the 20th Century. Introduced by Dr. Alex Shigo while he was a research scientist with the USDA Forest Service, the concept integrated processes of tree growth, passive protection, and induced defense. Most researchers and practitioners such as arborists were introduced to compartmentalization through a series of richly illustrated and simply worded booklets that described the CODIT model for compartmentalization -of decay in trees. In CODIT, the conceptual walls that resisted the spread of infection were associated with anatomical features such as tyloses and other plugging materials, wood rays, and tree rings. Although adopted quickly as a teaching tool for practitioners, many researchers criticized CODIT and the underlying concept of compartmentalization as inadequate or even irrelevant to explain patterns of infection and decay in living trees. This presentation will explore whether CODIT and compartmentalization are still useful concepts to understand tree growth, protection, and defense.

Bio: In 1977, Dr. Kevin T. Smith began his research work in the USDA Forest Service lab of Dr. Alex Shigo. Since that time, Kevin has investigated the role of stress, disease, and beneficial fungi on tree health and productivity through more than 130 research and educational articles. His personal research topics include compartmentalization in living trees, environmental signatures within the tree-ring record, and the role of wood decay fungi in biogeochemical cycles. Kevin has published more than 130 research papers and educational articles and has received the Chapter’s Awards for Arboricultural Research and for Education.
Wednesday, 5/10/2023, 11:10AM, Break out 1
The Use of Logical Fallacies in Tree-Related Conflicts
Presenter: Mark Duntemann, Duntemann Urban Forestry, South Royalton, VT
Logical fallacies are statements of fact that contain errors in reasoning. When provided as an opinion, they often lack necessary context, rendering the opinion suspect. Logical fallacies may be an intentional instrument to present a specific argument, such as in a debate, or may stem from a less than full understanding of the topic. Several types of tree-related conflicts that have an adversarial element to them may include logical fallacies. These include conflicts between neighbors, residents, and municipalities, and most significantly, litigation. While several hundred types of logical fallacies exist, a dozen or so present themselves in tree-related conflicts. The ability to identify and challenge logical fallacies is critical for those in the arboriculture and urban forestry profession. Logical fallacies tend to mischaracterize an individual, organizations, or companies’ program and policies. The relevance to practitioners is that unchallenged, the fallacy can become a fact for the purposes of litigation and arguments. The session will detail the primary types of logical fallacies encountered in tree-related conflicts and measures to challenge them.
Bio(s): Mark has been a consulting arborist for over thirty years. His current practice focuses on developing reasonable, practical and proportionate tree risk management policies for tree care companies and government agencies within the United States and abroad. He has served as an expert witness in over eighty tree-related cases. His lectures are informed by these experiences.
Wednesday, 5/10/2023, 1:00PM, Break out 1
Reaching Greater Heights for Reforestation
Presenter: Jimi Scheid, CAL FIRE, Davis, California
Additional Presenter(s): Denia Troxell, CAL FIRE
California, and the greater West, has seen its forestlands ravaged due to wildfire, pests, disease, poor management and the impacts of climate change. Demand for materials to rehabilitate affected lands immensely outweighs supply. When coupled with workforce and infrastructure capacity, cooperative efforts are necessary and only recently beginning to coalesce to make a change. From climber to land manager to academic, this talk looks to expand our collective horizons toward improved reforestation.
Bio(s): Jimi Scheid is the Reforestation Services Program Manager for the California Department of Forestry & Fire Protection (CAL FIRE) out of the reforestation center in Davis, CA. An ISA Certified Arborist – Municipal Specialist, a State Registered Professional Forester and former supervising urban forester, Jimi looks to foster collaborative approaches to solving large-scale environmental concerns that plague our natural resources. He holds a BSc in Forest Resources Management from SUNY-ESF and is a graduate of both the Municipal Forestry Institute (2017) and the Green Communities Leadership Institute (2022). He previously served the WCISA Board from 2013-2022.
Denia Troxell serves as the State of California’s Seed Bank Manager for the California Department of Forestry & Fire Protection at the Lewis A. Moran Reforestation Center in Davis, CA. Prior to CAL FIRE, she worked in the private seed industry for 8 years under Research and Development programs. She obtained her B.S. in Plant Science from the University of California, Davis and is obtaining her M.S. in Plant Breeding from Iowa State University.
Wednesday, 5/10/2023, 1:30PM, Break out 1
Tree risk evaluation prior to and during tree care operations (from a 25 year veteran climber and 15 plus year business owner/employer perspective)
Presenter: Fredrick Frey, Vintage Tree Care Inc., Santa Rosa, CA
Taking over 25 years of daily tree care experience (with over 15 of those years as a business owner/employer) and combining that with the articulation skills taught in TRAQ to demonstrate how to effectively execute a preclimb/prework tree risk evaluation. This evaluation will include methods of risk detection from the ground level, as well as an ongoing evaluation as the canopy is accessed. An emphasis will be placed on how load dynamics applied during the course of the project can impact a given risk within the tree. Methods of risk mitigation prior to and during the work will be touched on to offer attendee an opportunity to walk away with tangible information. I will discuss the value in a repeat method of evaluation and having a site safety form to be filled out for improved accuracy.

Bio: Fred Frey is a Certified Arborist with over 27 years of daily field experience in the tree care industry as a climber and business owner. Fred has served ten of his 27 years in the municipal sector as an Arborist for the City of Santa Rosa. Fred has been a presenter and coordinator of innumerable climbing workshops and competed in Chapter level climbing competitions for ten years. Having been a business owner and employer for over 15 years of his career, he brings a unique perspective to tree risk evaluation as it pertains to the work process on a given tree.
Wednesday, 5/10/2023, 2:20PM, Break out 1
Working the tree the easy way
Presenter: Robert W. Phillips, Self Employed, Santa Rosa, CA
Tree climbing skill advancement for all ages and genders. Learn methods that will assist a climber to make the working in trees easier. Blending the methods of yesterday with todays updated tree climbing techniques. Unravel the systems approach to safe tree climbing techniques. Obtain correct body positioning to have control when making the cut in a tree.

Bio: Robert began working in trees professionally in 1974. He began competing in the Tree Trimmers Jamboree in 1975 and finished his Tree Climbing competitive years in the 2005. He attended the Cal-Poly University in San Luis Obispo, Ca. He is currently working as a climbing Arborist in the commercial field. Robert served on the WCISA Board starting in 1998 and was Chapter President in 2004. He currently serves as the Western Chapter Historian
Wednesday, 5/10/2023, 3:30PM, Break out 1
Sonic Tomography Case Studies: Using Results to Guide the Clients & the Climbers
Presenter: Nick Araya, TreeCareLA, Inc., Los Angeles, CA
Additional Presenter: Julian Urbina, TreeCareLA, Inc., Los Angeles, CA
Our presentation will look at how to integrate sonic tomography into your arborist toolkit. We will look at the trees and scenarios best suited for decay detection technology, including species, size, and age, as well as client risk tolerance, liability, and budget.
Case studies of tested trees, along with tomography images and analysis, will help you learn when to advocate for tree preservation and when it’s time to start up the chainsaw! Results may surprise you.

Bio(s): Nick Araya has been caring and advocating for trees for over 20 years. He’s the co-owner of TreeCareLA which manages large and old trees in Los Angeles. He loves how advancements in arborist technology can allow him to listen less to his “gut” and more to the data in order to preserve large trees. Nick is an ISA Board Certified Master Arborist and has the ISA Tree Risk Assessment Qualification.
Julian began his arborist career working for the Conservations Corps in both Arizona and California. He joined TreeCareLA in 2019 and is an experienced climber and ISA Certified Arborist. He is most passionate about the tree you can’t see – parts of the tree beneath the bark and under the soil – which is why he loves Airspade work, sonic tomography testing, trunk injections, and other work beyond just pruning and removal.
Wednesday, 5/10/2023, 4:20PM, Break out 2
Looking at Roots – Digging in Arboriculture
Presenter: Gordon Mann, CalTLC and Mann Made Resources, Auburn, CA
Trees growing where people live are often growing outside of their normal environment. Understanding how the roots grow in the different soils and the challenges of growing trees in places where people live and build is important to making decisions. We will look at how successful and unsuccessful root impacts have occurred. We can use this information when performing inspections and mitigation treatments, and performing design and construction around trees.

Bio(s): Gordon is a consulting arborist in Auburn CA, and co-owner of CalTLC, owner of Mann Made Resources, and co-founder of TREES ROI. He has over 44 years of experience managing trees where people live from the municipal, non-profit, and private tree care perspectives. He is a current Director on the California Urban Forests Council, and a Trustee on the TREE Fund. He is passionate about helping others grow quality trees where people live.
Wednesday, 5/10/2023, 8:00AM, Break out 2
Tree Demographics for Arborists: or, “how long do trees live?” and how to use that information in your projects
Presenter: Lara Roman, Ph.D., USDA Forest Service
Additional Presenter(s): Igor Lacan, Ph.D, UC Cooperative Extension
A common question about urban trees – “How long do trees in the city live?” – actually requires a somewhat complex research process to answer. Yet, the fundamental idea of “annual mortality rate” is both simple and very important for anyone involved in managing groups of trees, and understanding tree demographics is absolutely critical for arborists involved in tree planting programs. In this presentation, Lara will review recent research on demographics of urban trees, both dispelling some old myths (“the average urban tree lives only 7 years”) and clarifying the basic demographic concepts. Igor will then present examples of how to use demographics in tree management projects, from managing groups of trees, to estimating the planting needs (and removal needs) from tree inventories. We will conclude with a discussion of how demographic concepts can help us ensure sustainable urban tree populations.
Bio(s): Dr. Lara Roman is a Research Ecologist with the USDA Forest Service. Her research centers on the temporal dynamics of urban forests, including tree mortality, canopy cover and species composition change, historical legacies, citizen science, and tree planting in diverse urban neighborhoods. Recognized with an Early-Career Scientist Award from the International Society of Arboriculture (ISA), she has coauthored over 50 publications. She received a PhD at the University of California, Berkeley, and a Bachelors in Biology and Masters of Environmental Studies from the University of Pennsylvania.
Dr. Igor Lacan is a University of California Cooperative Extension Advisor specializing in urban forestry. Igor’s research projects explore emerging issues in urban landscapes such as optimizing tree growth in stormwater facilities, as well as contribute to mitigating longstanding problems such as wood decay and failure in urban trees. Igor produces extension and outreach materials that transfer findings from the University to practicing arborists. Igor’s academic training includes urban forestry (PhD), aquatic ecology (MS) and ecology (BS) all from the University of California, Berkeley.
Wednesday, 5/10/2023, 8:50AM, Break out 2
Digging In To Native Trees: Finding the appropriate species to grow our future urban forests
Presenter: Ian Kesterson, City of Berkeley, Oakland, CA
Native tree species are often held as the solution to the slew of climate-change and other human-caused problems we face. In this discussion, we’ll dig in into the idea of native trees, attempt to find a working definition, and consider their limitations in growing our future urban forests. We will also learn how to speak to our customers about the strengths/limitations of natives and where other options may provide the answers we seek.

Bio(s): Ian Kesterson runs the tree planting program for the City of Berkeley. After working for a tree company in San Diego to get through university, Ian doubled down as a lifelong arborist after graduation. Through the WCISA’s classes, climbing competitions, and conferences, he’s collected a strong network of tree friends, experience, knowledge, and volumes of journals full of questions that come in useful when growing the future urban forest for the City of Berkeley.
Wednesday, 5/10/2023, 10:20AM, Break out 2
Urban Forest Planning and the Wildland Urban Interface
Presenter: Scott Eckardt, Dudek, Auburn, CA
Additional Presenter(s): Dana Link-Herrera, Dudek
In many areas, community development is occurring within or adjacent to wildland areas – the Wildland Urban Interface (WUI). The WUI presents unique challenges around wildfire hazard and risk to communities. Planning and managing urban forests in the WUI require consideration of wildfire risk to communities. This presentation will explore the factors that comprise the fire environment (physical and regulatory) and how these components need to be considered in urban forest planning and management.

Bio(s): Scott Eckardt is a Registered Professional Forester and ISA Certified Arborist specializing in forest management, mitigation planning, wildfire and fuels management, and urban forest management. He routinely prepares forest and resource management plans, wildland fire and vegetation management plans, and wildfire hazard and risk and assessments. He holds a BS in Forestry and Natural Resources Management from California Polytechnic State University, San Luis Obispo, and an MA in Geography from California State University, Long Beach.
Dana Link-Herrera is an Urban Forestry and Wildfire Planner with a background in environmental and urban planning. She specializes in long-range planning for the urban forest and wildfire resilience, though preparation of urban forest management plans, community wildfire protection plans, fire protection plans, and wildfire analyses in accordance with CEQA. She holds a Master’s in Urban and Regional Planning from California Polytechnic State University, Pomona and a BA from University of California, San Diego.

Wednesday, 5/10/2023, 11:10AM, Break out 2
Sticks and Smoke: Simplifying Prescribed Burning in CA
Presenter: Cordi Craig, Placer Resource Conservation District, Grass Valley, CA
Fire has become a feared element in California. We close National Forests, keep evacuation bags in our cars, or leave the state entirely to avoid wildfires. Yet our forests and wildlife depend on and are adapted to low-intensity fire. Today, we face suffocating red tape, overwhelming fuels buildup, and narrow burn windows. This presentation will address recent changes in the law surrounding prescribed fire and community success stories on how education leads to implementation.
Bio(s): Cordi Craig is the Prescribed Fire Program Manager at Placer Resource Conservation District. In the last 2 years, Cordi has created and expanded the prescribed burn program, secured nearly $500,000 in grants, and helped train 200 landowners to use safe, legal, and ecologically beneficial prescribed fire for wildfire resilience and forest stewardship. Before joining Placer RCD, she worked as a firefighter for the NPS and USFS and earned an MS in Natural Resources and Environmental Science from the University of Nevada, Reno.
Wednesday, 5/10/2023, 1:00PM, Break out 2
Dermotology for Arborists
Presenter: Dr. John Hiebler, D.O.,
Dr. Hiebler will discuss the structure and function of the skin covering types of skin cancer and how we as arborists can take precautions to prevent skin cancer. Naturally Arborists spend quite a bit of time outside – chronic exposure is one of the causes of skin cancer. He will discuss the different types of sunscreen and other preventative measures (i.e. SPF clothing, etc.). He will also cover self skin examinations and the importance of annual skin exams with a dermatologist.
Bio: Dr. J. Hibler completed his medical and Dermatology training at Ohio University College of Osteopahtic Medicine in Athens, Ohio. Prior to and after this, he worked at his fathers dermatology private practice, and has devoted much of his time to expanding access to dermatology care in rural East Africa. As an osteopathic physician, Dr. Hibler believes in treating the whole person, not just a specific ailment or symptom. As the saying goes, “it’s all connected”. He does specialize in medical, pediatric, surgical and cosmetic dermatology and uses the most advanced biologic medications as well as traditional, holistic, and natural remedies. Dr. Hibler lives in North Lake Tahoe with his wife and two adorable kittens where he enjoys spending his spare time doing anything outdoors, cooking, and tinkering with projects in the garage. He is active in the community, notably as an active member of the Tahoe Nordic Search and Rescue team.
Wednesday, 5/10/2023, 1:30PM, Break out 2
Managing Tree Failure-Related Utility Wildfire Risk
Presenter: Niel Fischer, JH Land Consultants, Reno, Nevada
Additional Presenter(s): Eric Brown, Sacramento Municipal Utility District (SMUD)
Utilities must reduce wildfire risk, made up of ignition risk – or a fire caused by the utility, and carry risk – where fire threatens infrastructure while being, “carried,’ by fuel and weather.
Utilities have the ability to control tree-caused ignition risk and vegetative fuel near infrastructure, a two-pronged benefit. Decisions to manage the vegetation are based upon qualitative information and risk tolerance. To achieve zero risk, all vegetation within strike height is removed.

Bio(s): Niel Fischer is a Registered Professional Forester and Attorney at Law with 35 years’ experience in private forest management, utility vegetation management, law and policy. From July 2019 – July 2022, Niel managed operations on 191,000 acres in California and Oregon and sourced two sawmills. Niel spent 13 years at PG&E where he developed its hazardous tree rating system and authored its vegetation management rate cases. Niel is also a co-author of the ANSI A-300, Part Nine, Hazardous Tree Arboriculture Standard.
Eric Brown, SMUD’s Vegetation Management leader has 24 years’ experience in Utility Vegetation Management. Eric is a Certified Arborist and is Tree Risk Assessment Qualified. He is the immediate past president of the Utility Arborists Association, and is an advisor on the North American Transmission Forum in its vegetation management group. Eric is a Director of the El Dorado County Fire Safe Council and although Eric has his Bachelor’s Degree in Forestry and Range Management from the University of Nevada, Reno, he is a native Californian, with deep ties to the Gold Country. Eric has worked in the UVM industry in California his entire career and is a recognized thought leader in Utility VM Risk Management.
Wednesday, 5/10/2023, 2:20PM, Break out 2
Root Pruning Tips and Tree Preservation Solutions for Sidewalk, Curb, and Gutter Repairs
Presenter: Daniel Pskowski, City of Sacramento, Sacramento, California
Dan’s power point presentation will focus on root pruning for sidewalk, curb, and gutter repairs. The environmental and tree criteria to consider when severing roots. Tree preservation solutions when the amount of root removal warrants tree removal. The goal is to help arborists overcome their anxiety in making root pruning decisions. His Western Arborist articles: Root Pruning for Sidewalk, Curb, and Gutter Repairs – A 30-Year Perspective (Spring 2022) Root Shaving ( Summer 2022) Diamond Plate for Sidewalks(Fall 2022) are snapshots of the information that will be presented. In addition to upcoming articles Rubber Sidewalks (Winter 2022) and TERREWALKS (Spring 2023).

Bio: BS Degree Landscape Horticulture – Colorado State University, Post Graduate Study – Forest & Shade Tree Pathology, Applied Entomology – Colorado State University, ISA Certified Arborist WE-0964A, Tree Risk Assessment Qualified, City Arborist (29.5 years) City of Sacramento. Grounds Foreman, Campus Arborist (10 years) – Colorado State University. In these positions he was able to touch trees every day. His tenure in Sacramento allowed long term monitoring of root pruning and if sidewalk modifications, root shaving, alternative sidewalk products were effective.
Wednesday, 5/10/2023, 3:30PM, Break out 2
What counts as a tree?
Presenter: Darya Barar, HortScience Bartlett Consulting, Berkeley, CA
Additional Presenter: Ryan Suttle, HortScience Bartlett Consulting, Berkeley, CA
During this presentation, Darya & Ryan will go over what the standards are for measurement of a tree. How the standards approach measurement of multi-stemmed trees. They will then look at how municipalities in the Bay Area approach tree measurement. We will see that these small changes in city codes can make a big difference in what is included and what is mitigated. This topic is particularly interesting since no two cities are the same and many are not using the standards.
Bio(s): Darya Barar manages the HortScience | Bartlett Consulting (H|BC) office of 11 employees, nine of whom are Certified Arborists with three are Registered Consulting Arborists. During her tenure with H|BC Darya worked with the City of East Palo Alto on the urban forest master plan and companion tree ordinances, with the City of Menlo Park on their Heritage Tree Ordinance update, and is an on-call Arborist for the City of Berkeley. Darya specializes in urban forestry management with 14 years of experience in the municipal setting. She has particular experience in disaster management. Darya has extensive experience working with community groups, state and local agencies on tree ordinances, master plans and large-scale tree replacement projects.
Ryan Suttle is a consulting arborist & urban forester at HortScience | Bartlett Consulting (H|BC) in Berkeley, CA. He specializes in tree risk assessment and tree preservation projects. Prior to joining H|BC, Ryan worked in utility vegetation management throughout the Bay Area and in New England. He holds an M.Sc. in Arboriculture and Urban Forestry from UMass Amherst. There, his research largely focused on assessing the function, value, and risk of trees along utility rights-of-way in Massachusetts as well as the use of emergent artificial intelligence infrastructure in tree risk assessment.
Wednesday, 5/10/2023, 4:20PM, Break out 2
Planting For The Future With A Sister Climate City Analysis
Presenter: Alex Hancock, PlanIT Geo, St. Petersburg, Florida
Urban forest managers must do their best to ensure the species we recommend for planting today can live long, healthy lives, even as the climate changes. This presentation discusses how the City of Fremont, CA prioritized climate resilience and tree diversity by completing a “sister climate city” analysis, which uses forecasted temperatures, precipitation, and other variables to match modeled conditions of the client city 60-70 years in the future with a sister city’s conditions today.
Bio: Alex is an ISA Certified Arborist with a background in urban planning, urban forestry, and sustainability. She is experienced in tree canopy cover analysis, climate action planning, zoning and land use planning, public policy, and community development. At PlanIT Geo, Alex supports the development of urban forest management plans and policies. Specifically, she directs the integration of urban forestry with sustainability, resilience, and equity-based planning through public engagement, staff consultations, policy analysis, and plan development.
Thursday, 5/11/2023, 8:30AM, Break Out 1
Bark Beetles in California Conifers: Are your trees susceptible?
Presenter: Daniel Cluck, US Forest Service, Susanville, CA
Presentation will address general bark beetle biology and ecology with an emphasis on current bark beetle-caused tree mortality related to drought and declining forest health conditions in California. Site specific factors in individual tree susceptibility to bark beetles in both wildland and urban locations as well as management and treatment options will be discussed.
Bio: 30 years with US Forest Service in northern California. Experience in all aspects of forest management with an emphasis on forest insects and diseases. BS in Biology from Humboldt State in 1992.
Thursday, 5/11/2023, 9:15AM, Break Out 1
Advancements in Tree Injection Research and Technology
Presenter: Richard Hauer, University of Wisconsin-Stevens Point, Stevens Point, WI
Join us for an interdisciplinary journey using lessons learned with tree injection. See how science has led to effective treatments based on tree size and health as reliable predictors at preventing tree loss. We will explore Emerald Ash Borer decision making by using sustainability constructs. What do we know about tree treatments to prevent ash loss? Finally, practical findings from field studies and will further help with your short- to long-term decisions with tree populations.

Bio: Richard Hauer is a Professor of Urban Forestry at the University of Wisconsin – Stevens Point teaching courses in urban forestry, nursery management, woody plants, dendrology, and introduction to forestry. Rich has conducted research in tree biology, urban forest management, emerald ash borer management, trees and construction, tree risk management, and ice storms. He was honored as the 2018 L.C. Chadwick Award for Arboricultural Research. He is also the Director of Urban Forestry at CNUC.
Thursday, 5/11/2023, 8:30AM, Break Out 2
Creating a Culture of Success
Presenter: Jessika Mitchell, Davey Resource Group, Los Angeles, CA

Bio(s): Jessika Mitchell is a Project Coordinator for Davey Resource Group’s Geospatial and Software Support Services Team. She is an ISA Certified Arborist and Tree Risk Assessment Qualified (TRAQ). Jessika serves as the Chair of the WCISA Women in Arboriculture Committee and was the recipient of the Young Professional Award from WCISA in 2020. Jessika has contributed within the nonprofit, commercial, and research sectors of urban forestry since 2014. She feels a deep sense of personal responsibility for the success of the people and projects that she supports. Jessika believes that the secret to building a profitable team is understanding and harnessing individual strengths and allowing each team member to instinctively put their best foot forward. She is committed to fostering a culture of respect and dignity within the tree care industry.
Thursday, 5/11/2023, 9:15AM, Break Out 2
The Service Provider Contract
Presenter: Derek A.Simpson, The Law Offices of Derek A. Simpson, P.C., Valencia, CA
Arborists and tree-service contractors routinely enter into service agreements with their clients. This presentation will discuss provisions that may assist the tree-related service provider’s in meeting their risk management goals.
Bio: Derek Simpson’s practice focusses on tree-related matters: trespass-to-timber cases, nuisance-tree case, and all wide range of other cases involving trees and tree law. He has worked on tree cases for about the past 20 years.
Thursday, 5/11/2023, 10:30AM, General
Energy Flow from Sun to Soil
Presenter: Kevin Smith, Ph.D., USFS Northern Research Station, Durham, NH

Bio: In 1977, Dr. Kevin T. Smith began his research work in the USDA Forest Service lab of Dr. Alex Shigo. Since that time, Kevin has investigated the role of stress, disease, and beneficial fungi on tree health and productivity through more than 130 research and educational articles. His personal research topics include compartmentalization in living trees, environmental signatures within the tree-ring record, and the role of wood decay fungi in biogeochemical cycles. Kevin has published more than 130 research papers and educational articles and has received the Chapter’s Awards for Arboricultural Research and for Education.
Wednesday, 5/11/2023, 11:15am
The Last Arborist Standing
Presenter: Kelaine Ravdin, Urban Ecos, Amherst, NH
We’ll close out this year’s conference with another exhilarating and educational “WCISA Battle”—this time you’re one of the contestants! The conference room will be our coliseum, and we’ll battle it out to see whose arboricultural knowledge is the greatest. The Last Arborist Standing will be crowned the 2023 Champion. Along the way, expect challenging questions, chances to learn, mixed battle metaphors, cool pictures of trees, and a fight to the finish!

Bio: Kelaine Ravdin is an urban ecology and urban forestry consultant whose work focuses on making our cities greener, more sustainable, and more environmentally sound. She has a background in forestry and landscape architecture, and advises cities, nonprofits, and corporations on how they can use trees to reduce greenhouse gases, conserve energy, support wildlife, and clean our air and water. And once a year, Kelaine steps away from her computer and spreadsheets and i-Tree software and moonlights as a referee at WCISA conference battles.