Session Descriptions

Monday, 3:00:00 PM, Field Experience

Build confidence in risks and defects detection

Presenter: Alby Thoumsin, Sperry Tree Care, Eugene OR, Eugene, Oregon

This presentation is designed to help new Arborists interested in becoming TRAQ qualified or simply more at ease with tree risk assessments, and for any seasoned professional in need of a refreshing field course.

Bio(s):

Forestry Technician 1983 graduate from Belgium with experience from forestry, landscaping and arboriculture since 1984 (the last 26 in arboriculture). ISA Certified since 97 and sales/consultant since 99. Became ASCA RCA in 2007 and part of the first group certified with TRACE that became TRAQ later. I am actively working on becoming a TRAQ instructor and love sharing the knowledge I accrued over the past decades from my passion for trees.

I recently started a group called Elder Trees Forum designed to raise the awareness of the importance of veteran trees whether historically, culturally or ecologically. The forum welcomes professional arborists as well as the general public since the perception of veteran trees in the US and in urban areas is far too often associated with risks. My experience with tree risk assessment helps putting the notion of risks in perspective and hopefully change minds in an objective matter.

Tuesday, 8:45:00 AM, General

Re-establishing caretaking practices to restore black oak cultural landscapes

Presenter: Irene Vasquez, Great Basin Institute, Mariposa, CA

This presentation explores restoring black oaks and cultural landscapes in Yosemite Valley through partnerships with Tribal crews guided by Traditional Ecological Knowledge (TEK). The work focuses on balancing ecological and cultural goals—reducing hazardous fuels, protecting heritage values, and revitalizing traditional stewardship. It also addresses the practical realities of setting achievable objectives within the complexities of park management, politics, and funding, highlighting collaboration as key to sustaining resilient landscapes and living traditions.

Bio(s):

Irene Vasquez is a Cultural Biologist and Research Associate with Yosemite National Park, specializing in Tribal partnerships and Traditional Ecological Knowledge (TEK) integration. Her work focuses on restoring black oak woodlands, protecting cultural landscapes, and supporting Indigenous stewardship practices. Irene collaborates with Tribal crews to balance ecological resilience and cultural values in park management, fostering community engagement and intergenerational learning through hands-on restoration, education, and applied research across Yosemite’s diverse natural and cultural resources.

Tuesday, 9:45:00 AM, General

KEYNOTE – Harnessing the generative power of disturbance for our lives, forests, and our planet

Presenter: Nalini Nadkarni, University of Utah

Disturbances in the systems around us are increasing in frequency, intensity, and impact, As a forest ecologist who has studied tree canopy biota for four decades, I have gained many insights about the nature of disturbance and recovery from my scientific perspective. However, to broaden and deepen my understanding, I have invited input from a wide range of academic disciplines and societal sectors. I share some emerging principles that transcend disciplines: to seek knowledge from diverse sources; to foster webs of relationships, and to be open to a “third state” that is neither the pre-disturbance state, nor the newly disturbed state, but something that differs from both. By integrating these insights, we can reimagine the study and management of forests to better navigate change – and disturbance — across personal, social, and ecological domains.

Bio(s): Nalini Nadkarni is a Professor of Biology at the University of Utah. Her unique academic career interweaves her scientific research on rainforest canopy biota with innovative public engagement. She has written 150 scientific papers and tree scholarly books on forest canopy-dwelling communities, supported by the National Science Foundation. She also engages with those who do not or cannot gain access to science education, including faith-based groups, artists, corporations, and the incarcerated. In 2016, she created the “STEM Ambassador Program” to train academic scientists to carry out public engagement events in community venues. Her work is featured in journals ranging from Science to Playboy, and in public media such as Science Friday, Wait, Wait, Don’t Tell Me, and RadioLab. She writes and broadcasts a weekly public radio program, called “TreeNote,” about the wonder of trees. In 2024, the National Geographic Society named her as one of their ten “Explorers at Large.” Her awards include a Guggenheim Fellowship, the National Science Foundation Award for Public Service, The Rachel Carson Award for Conservation, and The Wilson Award for the Advancement of Social Justice.

Tuesday, 1:15:00 PM, General

Giant Sequoias in a Changing World

Presenter: Wendy Baxter, Ancient Forest Society, South Lake Tahoe, California

Giant sequoias are the largest trees on the planet and among the oldest. They are a testament to resilience and adaptability. In the face of climate change and after more than a century of fire suppression, giant sequoias are now vulnerable to threats like severe drought, wildfire and bark beetle attack. This presentation will share insights from ongoing giant sequoia research and management techniques that are being used to help these iconic trees.

Bio(s):

Wendy Baxter is Program Director and Co-Founder of Ancient Forest Society, a non-profit dedicated to the conservation of ancient forests. She received a MSc in Environmental Science from Wageningen University. Following her studies, she spent more than a decade researching giant sequoia and coast redwood forests at UC Berkeley in collaboration with Dr. Anthony Ambrose and other scientists. Building on these years of research experience, Ancient Forest Society was founded in 2020.

Tuesday, 1:45:00 PM, Field Experience

Arborist assisting science in old growth forests

Presenter: Lawrence Schultz, Ancient Forest Society, San Rafael, California and Ben Fisher, Cristian Garcia Arcos

Presenters will explain the hurdles encountered and the adaptations of traditional arborist techniques resulting from those conditions. A live demonstrations of each step will be performed to further detail the aforementioned talking points.

Bio(s):

Lawrence Schultz has been in the industry for over 20 years. Starting off on the east coast, he’s gone on to migrate to the Bay Area where he’s contracted climbed for the past 10 years. In recent years he’s expanded his efforts in to training other arborists and working with non profits like the Ancient Forest Society.

Ben Fisher is a Certified Arborist working on Tree Preservation, Advocacy, Planting and Growing in the Long Beach, California area. He has been running his own Licensed D-49 Tree Service, LB Holistic Tree, since 2016. Educating the public so they know good tree care is the foundation of his work. He has been working in Sequoia research and cone collection with the Ancient Forest Society since 2021.He has been teaching Arboriculture, Climbing and Cone Collection since 2023 and collecting cone with SEGI Reforestation during the same timeframe. He teaches with SEGI, Arboleros, the Western Chapter of the ISA, at elementary schools, garden clubs, neighborhood associations and any time a person has questions and a genuine interest in trees.

Cristian Garcia Arcos is a passionate arborist and advocate for trees, community, and environmental justice with five years of professional experience. He serves as Co-Chair of Arboleros, supporting Spanish-speaking arborists through education and resources, and as Commissioner for Parks and Community Services in Costa Mesa, where he champions green spaces and equitable park access. Cristian is also active with the Hispanic Arborist Association and collaborates on conservation projects protecting ancient forests, including cone collection, sap flow monitoring, core sampling, and sequoia treatments. An avid tree climber and lifelong tree lover, he enjoys time with his family, his German Shepherd Bella, and finding perspective among the branches.

Tuesday, 3:30:00 PM, General

Wildfire Risk Reduction Qualification: Western Chapter Launch

Presenter: Jeff Spohn, Mohawk Environmental

This session introduces the Wildfire Risk Reduction Qualification to the ISA Western Chapter. Attendees will gain an overview of how the program prepares arborists to address wildfire risk through vegetation-focused assessment and mitigation. The presentation highlights the growing role of arborists in fire-prone communities and outlines how this qualification supports professional growth and field application across the West.

Bio(s):

Jeff is the President and owner of Mohawk Environmental arboriculture and utility consulting firm specializing in Arboriculture, Forestry, Utility Vegetation Management and Fire Mitigation. Jeff brings more than 25 years of experience in the field including utility operations and advanced grid technology. Jeff graduated from West Virginia University with a BS in Forestry and holds a Master Certificate in Business Improvement from Auburn University. He is an ASCA Registered Consulting Arborist (#391), and an ISA Certified Arborist/Utility Specialist (WE-3506-AU). Jeff serves on the Western Chapter Board as Treasurer.

Prior to Mohawk Environmental, Jeff was Director of Distribution Operations and Maintenance with Arizona’s largest electric utility provider, Arizona Public Service, where he held various roles over the course of his career with a focus on Distribution Operations, Construction and Maintenance, Fire Mitigation Distribution Automation and Vegetation Management. Jeff has lead teams in the United States Forest Service, Private and Commercial Business, and the Electric Utility Industry as well as serving as an instructor at the University of Wisconsin Stevens Point, Yavapai Community College, and the Arizona Wildfire and Incident Management Academy.

Tuesday, 4:00:00 PM, General

Forest Ecology: Science and Management of the Mariposa Grove

Presenter: Garrett Dickmann

Science offers a foundation for how to manage giant sequoias but translating science into on-the-ground action is rarely straightforward. The Mariposa Grove of giant sequoia offers an example of how ecological understanding, management constraints, and wildfire intersect. Giant sequoias evolved in frequently burned forests, yet a century of fire suppression around the Mariposa Grove altered forest structure and fuel conditions, increasing the risk of high-severity fire, which occurred during the 2022 Washburn Fire. Recent wildfires across the Sierra Nevada have confirmed that these altered conditions can overwhelm even highly fire-adapted species. While emergency wildfire response can reduce impacts to individual trees, it is an imperfect substitute for ecological restoration. Using the Mariposa Grove as a case study, this talk examines how prescribed fire, fuel reduction, and large-scale ecological restoration, have reshaped the grove. Together these efforts illustrate how integrating science, management, and visitor experience can lead to a landscape that is more resilient to fire and drought while improving how people experience and move through this famed forest.

Bio(s): Garrett Dickman is the forest ecologist for Yosemite National Park. He has helped pioneer treatments to prevent giant sequoia mortality during wildfires. He works on implementing landscape level forest restoration treatments to help prepare Yosemite for fire and climate change

Tuesday, 4:30:00 PM, General

A Powerful ‘WHY?’: An Introduction to the Practice of Forest Bathing, for Wellness and Wonderment in the Profession of Arboriculture

Presenter: Josh Gevertz, Cypress Lawn Arboretum, Colma, California

Forest bathing is a practice rooted in the Japanese culture of ‘shinrin-yoku’. At its heart, this healing modality is a sensory, noticing practice of connecting with the ‘more-than-human world’. For the intellectual arborist, an intention of slowing down, and just being with trees, versus managing them or mitigating their hazards, may serve as a grounding way forward of restoring purpose, passion, even wonderment and awe in our connection with trees.

In this session, ISA certified arborist and ANFT certified forest therapy guide Josh Gevertz will share a personal anecdote of the value of the forest as therapist and healer, where the guide simply opens the door into a powerful ‘WHY?’ for our professional community of arborists. Join in for an interactive dialogue of meaning in the practice of tree care, for lessons in the fostering of kinship between people and trees.

Bio(s):

Josh Gevertz serves as Arboretum Director at Cypress Lawn Arboretum and Memorial Park in Colma, CA, managing care for nearly 4000 trees representing approximately 150 woody taxa, including original plantings dating back to Cypress Lawn’s founding in 1892. As co-chair of the WCISA Education Committee, Josh coordinates and hosts many educational programs. Josh’s diverse academic background includes a Biological Sciences BS from UC Davis and a master’s degree from UC Berkeley’s College of Environmental Design. Josh is also a certified guide through the Association of Nature and Forest Therapy.

Wednesday, 8:00:00 AM, Science

Lifestyles of urban fungi: beyond disease and risk assessment

Presenter: Kevin T. Smith, USDA Forest Service R & D, retired, Portland, ME

Fungi are part of our everyday urban and community landscapes. Traditionally the province of forest pathology, fungi are often viewed as a nuisance at best and as a death sentence at worst. Mortality may come through fungal disease or through prescribed removal. An expanded view of neutral and beneficial urban and community fungi allows the arborist to focus on useful treatments for tree health and community safety. The expanded view challenges arborists to better understand the dynamics of the landscape in their care. Specific topics will include mulch and turf fungi, slime molds, as well as frequently encountered arboreal macrofungi.

Bio(s):

Kevin T. Smith, Ph.D. is a tree and forest pathologist with a special interest in how trees respond to injury, infection, and environmental variability. Retired from a 40-year career in the USDA Forest Service, Smith applied botanical tools of anatomy, physiology, and mycology to inform forest management, US environmental policy, and practical arboriculture. A frequent lecturer in the US and abroad, Smith has received numerous awards for his original research from governmental and technical organizations.

Not applicable

Wednesday, 8:50:00 AM, Science

Tiny Wonders: Lichens of the Sierra Nevada

Presenter: Ruth Williams, Community Forest Solutions, Portland, OR

Lichens grow in every terrestrial biome on Earth, and are often nestled in our community trees. They play a role in nutrient cycling, support wildlife, and are first foods for indigenous people. Lichenologists are still exploring their diminutive world, and discovering surprises along the way. Learn about these tiny tufts and how to recognize a few Sierra Nevada species.

Bio(s):

Ruth Williams is an ecology enthusiast with degrees in Environmental Horticulture & Urban Forestry and Landscape Architecture from UC Davis. As an ISA Board Certified Master Arborist based in Portland, Oregon, she helps preserve trees for future generations. She teaches nature illustration and guides interpretive hikes on a wide variety of ecological subjects.

Wednesday, 9:30:00 AM, Science

Irrigation effects on the cooling potential of urban trees

Presenter: Ursula Schuch, University of Arizona, Tucson, AZ

Trees in southwestern landscapes are planted for their cooling potential of the urban environment to reduce air temperatures and providing shade. This presentation reviews how deficit irrigation affects the cooling potential of trees. Canopy growth and physiological function are influenced by the frequency and amount of water trees receive. To realize the potential benefits of cooling environments through tree canopies, minimum irrigation requirements need to be established to promote a functional urban canopy.

Bio(s):

Dr. Ursula Schuch is a Professor and Extension Specialist for Environmental Horticulture in the School of Plant Sciences at the University of Arizona. She earned a M.S. degree in Forest Science and a Ph.D. in Horticulture. Dr. Schuch has worked to support the green industry in Arizona through research, conference presentations, workshops, and seminars. Her work includes research on irrigation practices of landscape plants, witches broom of palo verde, and production of pomegranates.

Wednesday, 10:30:00 AM, Science

Retrenchment Pruning of AncientTrees: Anecdote or Science?

Presenter: Linda Chalker-Scott, Washington State University, Tacoma, WA

Retrenchment pruning is promoted as the preferred method of managing aging trees. However, there is no peer-reviewed experimental evidence to support this practice. This seminar will present the state of science on the physiology of aging trees, which can predict the impacts of conventional and retrenchment pruning on tree health. It will also help arborists to understand the consequences of unnecessary and improper pruning.

Bio(s):

Dr. Linda Chalker-Scott is an Emerita Professor in the Department of Horticulture at Washington State University. She holds ISA credentials as a Certified Arborist and TRAQ; additionally, she is an ASCA consulting arborist. Linda conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. She is also the editor of the Western Arborist.

Wednesday, 11:20:00 AM, Science

Battling the Bark Beetle

Presenter: Nathan Wilson, ArborVista, LLC, Oakhurst, CA and Ryan Joseph

This presentation examines the ecological mechanisms driving bark beetle outbreaks across western coniferous forests, emphasizing California and Arizona. Speakers will discuss the interplay between prolonged drought, elevated temperatures, and forest structural conditions that amplify beetle success and disrupt ecosystem balance. Topics include outbreak progression, host defense failure, and management approaches integrating silvicultural, chemical, and biological strategies aimed at restoring forest health and mitigating future infestation severity.

Bio(s):

Nathan Wilson oversees consulting utility forestry operations for Pacific Power in Oregon and Washington and leads pre-inspection programs for PG&E in California. An ISA Certified Utility Arborist, TRAQ Qualified, Licensed Timber Operator, and HAZWOPER certified professional, Nathan brings over a decade of experience in vegetation management, urban forestry, and consulting. He is recognized for his data-driven approach, responsive leadership, and ability to deliver efficient, high-quality results

Ryan Joseph brings over 15 years of arboriculture experience, including leadership of utility vegetation pre-inspection operations for Pacific Gas and Electric in California. An ISA Certified Arborist, TRAQ Qualified, and Certified Treecare Safety Professional (CTSP), Ryan specializes in tree permit review, risk assessment, and municipal code compliance. He leads arborist teams with a focus on public safety and practical, field-based decision-making.

Wednesday, 1:15:00 PM, Science

Mulch: Its not just the carbon, its the ENERGY!

Presenter: James Downer, University of California, Ojai, CA

Trees require soil for anchorage, minerals and water as well as for interaction with its many microbial partners that support healthy root functioning. Trees evolved to drop copious amounts of litter on the ground which in the built/urban environment can be lacking. Organic inputs have long been recognized by many scientists as vital inputs for tree health. The focus over many decades has been on litter and mulch as a carbon source. Gunina and Kuzyakov (2021) presented a compelling argument that soil microbes use organic matter not for its carbon per se but for its energy. This changes everything about how litter and mulch is viewed, not for carbon but as a soil energy source. In this presentation I will navigate the complicated path of carbon into soil from litter and mulch. The presentation has important knowledge for understanding how the soil microbial support systems that trees utilize are affected by carbon sources and its various qualities.

Bio(s):

Dr. Downer is retired from the University of California where he worked as a plant pathologist and horticulturist. As an emeritus, he continues to conduct research and education about trees, mulch and soil microbiology. Dr. Downer is a past president of WCISA and an avid horticulturist.

Wednesday, 2:20:00 PM, Science

Leveraging Soil Biodiversity for Plant and Ecosystem Health in Urban Landscapes

Presenter: Joshua Garcia, PhD., University of Merced

Soil microorganisms play an important but understudied role in regulating plant and soil health in urban landscapes. In this presentation, Dr. Joshua Garcia will provide an overview of his research work examining how soil biodiversity can be leveraged to support urban soil health and sustainable agriculture and forestry in the San Francisco Bay Area.

Bio(s): Dr. Joshua Garcia is an Assistant Professor in the Department of Life & Environmental Sciences at the University of California, Merced. He received his BS in Biological Sciences from UC Davis and his PhD in Plant Science from Cornell University. His research broadly investigates how soil organisms can regulate plant traits and their effects on ecosystem-level processes using a diverse range of research methodologies.

Wednesday, 3:30:00 PM, Science

Beneficial arthropods: insects relevant for potential arthropod pest management on trees

Presenter: Joanie King, PhD., New Mexico State University

Beneficial arthropods play an important role in managing pest populations on trees by providing natural biological control. These organisms, including predators and parasitoids, help suppress harmful insects and other arthropods such as aphids, borers, caterpillars, scales, and mites. Predatory arthropods, including lady beetles, lacewings, spiders, and predatory mites, actively feed on pest species, reducing their numbers and limiting damage to trees. Parasitoid wasps contribute another form of control by laying their eggs in or on pest insects; as their larvae develop, they ultimately kill the host. By naturally regulating pest populations, beneficial arthropods reduce the need for chemical pesticides, which supports integrated pest management (IPM) strategies— promoting healthier, more resilient tree ecosystems. Through the lens of IPM, we can better understand, conserve, and enhance these natural enemies. Encouraging habitat diversity, minimizing the use of broad-spectrum insecticides, and providing flowering resources are key practices that help sustain their populations and effectiveness.

Bio(s): Dr. Joanie King is an Assistant Professor and Extension Entomology Specialist in the Departments of Extension Plant Sciences, and Entomology Plant Pathology and Weed Science at New Mexico State University. She received her B.Sc. in biology from the University of Central Florida, M.Sc. in entomology from The University of Georgia and a Ph.D. in entomology from Texas A&M University. Dr. King is interested in Integrated Pest Management (IPM), ants, beneficial insects and other arthropods (e.g., natural enemies, pollinators), and entomology outreach. In addition to her work as an entomologist, she enjoys climbing, running, and macro photography.

Wednesday, 4:15:00 PM, Science

Relating Tree Responses to Extreme Drought to Arboriculture

Presenter: Edward Bobich, Cal Poly Pomona, Pomona, California and

Since the beginning of the 21st century, western North America has experienced periods of extreme drought, leading to crown dieback and mortality of hundreds of millions of trees. The mortality of a species typically depends on its water-use strategies and its ability to modify its canopy during the drought. By applying the knowledge gained from scientific studies on these tree responses, we can determine how to increase the success of arboriculture in a changing climate.

Bio(s):

I am originally from Illinois, but I grew up in Colorado. I earned a bachelors degree in Organismal, Population, and Environmental Biology at the University of Colorado. I moved to California in the mid 1990s to attend UCLA, where I earned my Ph.D. in Biology. I did postdoctoral research at Biosphere2 Center on climate change and at the University of Arizona in plant physiological ecology. I am in my 21st year at Cal Poly Pomona.

My research combines the fields of plant physiological ecology and anatomy. Currently, I primarily study the responses of perennial plants, including trees, to drought, but I have also performed research in plant biomechanics and population ecology.

Wednesday, 8:00:00 AM, Practice

Modern Tree-Safety Assessment and Evaluation

Presenter: Frank Rinn, RINNTECH, St Charles, Illinois

Combining the results from research on tree allometry and cambial mechanoperception allows to understand the main principles of the biomechanical growth concept of trees and this allows to create a method for assessing and evaluating the relative change of the tree-breakage safety factor – as the most important parameter determining the probability of failure (in consequence of defects).

Bio(s):

Studied physics and developed technical devices for inspecting trees, timber and tree-rings since 1986, such as resistance drilling, sonic tomography and tree-ring-density measurements.

Wednesday, 8:50:00 AM, Practice

Zone 0 and the implications for trees in Wildland Urban Interface areas

Presenter: Jeremy Cawn, Dudek, Oakland, CA and Yana Valachovic

Regulations for Zone 0, the area within 5 feet of a structure, are coming to California’s WUI areas. This presentation will summarize the intent of the regulation, where it applies, where Zone 0 fits in with existing defensible space requirements, and what the specific requirements related to tree care. The threat of wildfire is not exclusive to California, so the presentation will summarize the current industry best practices and the science behind defensible space requirements for tree care.

Bio(s):

Jeremy Cawn is an urban forestry and wildfire mitigation specialist with 12 years’ experience as a wildfire risk assessor and hazardous vegetation management program manager. Jeremy’s wildfire mitigation experience includes wildfire risk assessments, fire protection planning, defensible space inspections, and vegetation management plans. Jeremy previously worked as a fire prevention inspector for the Glendale Fire Department and as an arborist and forester for New York City, the City of Claremont, and the City of Glendale. Prior to his work experience in urban forestry and vegetation management, Jeremy spent 11 years working as a wildland firefighter and a prescribed fire specialist.

Coming Soon

Wednesday, 9:30:00 AM, Practice

Wildfire Mitigation Strategies for Utilities

Presenter: Amanda Smith, ArborWorks, LLC, Scottsdale, AZ and

Wildfire risk is expanding beyond the western U.S., requiring utilities to proactively plan and adapt. This session provides a practical framework for developing and implementing wildfire mitigation strategies, including targeted pole clearing, hazard tree removal, and fuels management. Attendees will learn how to assess system vulnerability using the wildfire triangle and strengthen organizational preparedness through cross-department collaboration, response planning, and data-driven vegetation management practices that protect infrastructure and communities.

Bio(s):

Amanda has over 17 years of experience in the utility transmission and distribution industry, with a proven track record of delivering innovative solutions. She has previously held leadership roles in the utility industry, where she successfully implemented strategic initiatives to drive growth and operational excellence. Amanda has an MBA in management strategy & entrepreneurship from Rutgers Business School.

Wednesday, 10:30:00 AM, Practice

Full Circle Training: Sustaining Safety, Skill, and Standards Across Generations

Presenter: Dane Jensen, WCA, Huntington Beach, California

This session explores how effective tree worker training sustains safety, skill, and professionalism across generations. Participants will examine evolving industry standards—including ISA BMPs, TCIA guidelines, and the forthcoming ANSI Z133 update—and how these shape modern training and policy. Emphasizing mentorship, accountability, and a culture of personal responsibility, the session highlights workforce development as both a compliance requirement and a sustainable investment in the long-term health, safety, and success of the arboriculture industry.

Bio(s):

Dane Jensen is an ISA Certified Arborist, Utility Specialist, and Urban Forest Professional, as well as a TCIA Certified Treecare Safety Professional. A former U.S. Marine, he brings discipline and leadership to his role leading workforce development and safety initiatives for West Coast Arborists, Inc., supporting more than 1,200 employees across multiple states. Dane is dedicated to advancing a culture of accountability, professionalism, and sustainability within the tree care and vegetation management industry.

Wednesday, 11:20:00 AM, Practice

The Slack Trap: How Small Gaps in Safety Can Lead to Big Consequences

Presenter: Justin Morejohn, UC Davis, Davis, California

While data-driven decision making is an increasingly popular business topic, rarely do production climbers have data about how their decisions can impact their safety. This presentation provides data for climbers and bucket truck operators as it relates to their climbing and work positioning systems. The classroom presentation will show forces on the arborist when slack is in the system and accidents occur. We will then provide solutions for how to decrease or eliminate slack for safe and preventative work.

I will conclude the presentation with how to eliminate slack (such as properly fitting your harness, properly anchoring your fall arrest lanyard in a bucket, using an adjustable bridge, and climbing SRS).

Bio(s):

Justin is an ISA Board Certified Master, Utility and Municipal Arborist who is passionate about teaching all aspects of arboriculture. He works at the University of California, Davis, supervising the tree team in caring for the 26,000 trees of the campus urban forest. An ASCA Registered Consulting Arborist and TCIA Certified Treecare Safety Professional, he is dedicated to continuing education and safety in everything tree related. He has been climbing rocks for thirty years, climbing trees for twelve years, climbing ice for three years, and is a SPRAT certified Rope Access Technician. Whenever possible, he is exploring the Sierra Nevada Mountains with his family, and camping under the stars.

Wednesday, 1:15:00 PM, Practice

The Our-Trees Initiative: Using storytelling to raise awareness about and incite protection for trees around the world

Presenter: Nalini Nadkarni, University of Utah

Because of their connections to diverse human values, trees evoke from and tell stories to people of all kinds. In 2024, we started “The Our-Trees Initiative” to gather, curate, and disseminate tree stories, and to then create modules to inform and incite actions that help protect trees among public groups such as schoolchildren, seniors, indigenous groups, faith-based communities, and people who are incarcerated. This presentation will guide audience members to post their stories, and to solicit tree stories from others to expand and extend this effort.

Bio(s): Nalini Nadkarni is a Professor at the University of Utah and a National Geographic Explorer at Large. She has written 150 scientific papers and three books on forest canopy communities, supported by the National Science Foundation. She engages with non-academic groups, including faith-based communities, artists, and people who are incarcerated. Her work is featured in public media such as RadioLab and Science Friday. She broadcasts a weekly NPR program, called “TreeNote,” about the wonder of trees. Her awards include a Guggenheim Fellowship and The Rachel Carson Award for Conservation.

Wednesday, 2:20:00 PM, Practice

Trees and Insurance: Understanding Vegetation Risk

Presenter: Paul Brady, Green Shield Risk Solutions

Wildfire risk is reshaping the property insurance landscape throughout the West. This session explores how vegetation influences insurability and how arborists can better understand and communicate wildfire risk to clients. Participants will gain perspective on how properties are evaluated and how thoughtful vegetation management plays a role in today’s wildfire environment.

Bio(s):

Paul Brady is an NFPA Certified Wildfire Mitigation Specialist, ISA Certified Arborist TRAQ/WRRQ – WE-15457A , and former U.S. Forest Service Hotshot with more than 15 years of experience in wildfire risk reduction, vegetation management, and insurance focused mitigation. He has led wildfire programs for major insurance carriers, trained hundreds of underwriters and fire personnel, and guided high value commercial clients across the United States and Canada.

As SVP and Head of Wildfire Insights and Mitigation for Green Shield Risk Solutions (GSR) / Property Guardian, Paul oversees wildfire strategy, loss control, and InsurTech integrations for Fortune 100 partners and GSR’s own MGA. His expertise bridges field operations, advanced wildfire technology, wildfire mitigation management, and client education. Paul brings a rare combination of firefighting experience, arboricultural knowledge, and insurance industry insight to help communities and professionals reduce wildfire risk.

Wednesday, 3:30:00 PM, Practice

Data-Driven Decision Making: Turning Urban Forest Data Into Informed, Equitable, and Actionable Policy

Presenter: Drue Epping, American Forests, Seattle, WA and Jake Simon

This session will explore how cities can use data and community priorities as a strong foundation for urban forest policies, action, and tree protection codes that advance long-term resilience. See how decisions that aren’t grounded in data can lead to friction in the community and even expose cities to legal vulnerabilities. Without an informed basis, urban forestry efforts often struggle to meet their stated goals, especially around equity, climate readiness, and canopy protection. We’ll walk through examples of municipalities in the Pacific Northwest and Southwest that have translated data into action and leveraged adjacent planning efforts and coalition building to strengthen their urban forestry programs. Through this collaborative approach they’ve enacted policy and codes that are both evidence-based and community-driven.

Bio(s):

Drue Epping is the Director of PNW & West Coast Urban Forestry at American Forests and an ISA Board-Certified Master Arborist. In her role she advances Tree Equity across the region, connecting partners with tools and strategies to grow healthy, resilient, and inclusive urban forests. She also serves on the PNW-ISA board, teaches Arboriculture at South Seattle College, and chairs Seattle’s Urban Forestry Commission.

Jake Simon is the Director of Southwest Urban Forestry with American Forests and works across the Southwest to improve Tree Equity at the community, city, county and state level. Jake has been an ISA certified arborist for more than 10 years and specializes in enhancing urban forestry programs through technical assistance, coalition development and community engagement. He has previously worked in the utility vegetation management and forest conservation sectors.

Wednesday, 4:15:00 PM, Practice

Join our “FAM” – the science and regulatory issues of Fresh Arborist Mulch

Presenter: James Downer, University of Caliornia, Ojai, ca and Daniel Mahoney

A consequence of tree trimming operations is “waste” or trimmings often sent through a branch chipper at the trimming site. Once the job is done tree companies often haul this material away from the job site, often paying for its disposal. What happens next defines corporate environmental sustainability and profitability. Instead of considering trimmings “waste” they can be considered green resources that have value. We introduce here the term FAM or Fresh Arbor Mulch. This presentation will lay out the science of its use around landscape trees, the opportunity it presents tree care companies to add a revenue stream, and the regulatory environment that is surrounding its use by the tree care industry. Downer and Mahoney will present the science, marketingm and regulation of FAM in an concert with new research-based information on its environmental sustainability.

Bio(s):

Danny Mahoney has been immersed in the tree care industry his entire life. As part of the Mahoney family, he began working at the West Coast Arborists nursery at just 13 years old, planting trees and developing an early appreciation for the urban forest. After earning his degree from California State University San Marcos, Danny returned to West Coast Arborists and became a Certified Arborist at age 22, opening the door to new opportunities to support sustainable urban forestry. He spent several years with Street Tree Revival, WCA’s urban wood recycling program, where he learned the importance of salvaging this vital bioresource from the landfill. Today, Danny serves as Recycling Manager at WCA, overseeing the company’s daily output of more than 800 tons of green waste. His focus is on creating circular solutions that repurpose this material for the highest value, leading efforts to transform it into sustainable products that give back to our communities and the environment.

Miércoles, 29 de abril de 2026 a las 8 AM, Spanish

Círculo completo – comunicación relacional en la gestión del arbolado urbano, Cecilia Michea

“En arboricultura, “Full Circle” invita a entender el ciclo urbano de los árboles y a reconocer que un proyecto ambiental solo perdura si la comunidad se apropia de él, trascendiendo así los ciclos administrativos. Desde esta perspectiva, la comunicación relacional, capaz de generar vínculos emocionales duraderos entre la comunidad y la infraestructura verde, resulta clave, pues los mensajes que integran información + emoción se fijan con mayor fuerza en la memoria de las personas y favorecen la sostenibilidad del proyecto.

Las ciudades deben concebir los árboles como parte esencial de una infraestructura ecológica integrada. Esto requiere articular ciencia, gestión, comunicación y comunidad para valorar el arbolado urbano desde un enfoque de triple impacto. Esta presentación examina el papel de la comunicación estratégica en ese proceso a partir de dos experiencias que he liderado y los aprendizajes obtenidos: la campaña que dio origen a Red Árbol Urbano y su aporte al proceso del proyecto de ley de arbolado urbano en Chile, y la iniciativa de difusión Árbol Urbano 360°, dedicada a visibilizar la naturaleza urbana. Porque, si aspiramos a infraestructura verde resiliente, necesitamos relatos que inspiren compromiso y cuidado.

Biografía(s): Cecilia Michea es especialista chilena en fortalecer la presencia digital de marcas desde una mirada estratégica que integra branding, marketing y diseño. Desde Red Árbol Urbano impulsó la campaña comunicacional que contribuyó al proceso detrás del proyecto de ley de arbolado urbano que estuvo en el Senado de Chile entre 2021-2025. Fue ponente en el Foro “Bosques y árboles urbanos como derecho humano.” México 2025 y en el IV Foro Latinoamericano y del Caribe sobre Bosques Urbanos Brasil 2024, donde destacó el rol del branding y la comunicación estratégica en la formulación de políticas públicas. Actualmente desarrolla Árbol Urbano 360°, iniciativa de difusión que ha causado gran interés.”

Miércoles, 29 de abril de 2026 a las 8:50 AM, Spanish

Relevancia de la gestión y recuperación de los bosques y del arbolado urbano en Acapulco después de los huracanes Otis y John, Gabriela López Daman

Tras el impacto devastador del huracán Otis en octubre de 2023 y posterior John en 2024, que afectó más del 80% del arbolado y los bosques en los municipios de Acapulco y Coyuca de Benítez, Reforestamos México implementó un proyecto de restauración integral que articula esfuerzos de la sociedad civil, gobierno, iniciativa privada y ciudadanía.

Biografía(s): disponible pronto

Miércoles, 29 de abril de 2026 a las 10:30 AM, Spanish

Importancia del Trasplante de Árboles Nativos en Zonas Urbanas, Sotero Garcia
Se presentan las experiencias de más de 15 años en el trasplante de árboles nativos provenientes de zonas que son impactadas. El origen normativo del por qué ese lleva a cabo la recuperación de especies de diversos árboles y estos son integrados al paisaje en áreas verdes de la ciudad con la oportunidad de conservar sus servicios ambientales mostrando los procedimientos y los resultados con la implementación de estas prácticas así como la oportunidad de trabajo que representa para los trabajadores de la industria de la arboricultura.

Biografía(s): Sotero Garcia Valdez, Ingeniero forestal. Representante de la empresa Asesoría Agropecuaria y Forestal Integral, especialista en consultoría y servicios ambiental, con amplia experiencia en estudios de impacto ambientales, manejo forestal, planes de manejo de arbolado urbano y servicios por más de 25 años ha implementado acciones de mitigación ambiental, especialista en trasplante de árboles en áreas naturales con impacto, su establecimiento, manejo y conservación en zonas urbanas. Es miembro de la ISA y socio de la AMA. Arborista certificado.

Miércoles, 29 de abril de 2026 a las 11:20 AM, Spanish

Círculo completo: Deja que la Tierra respire de nuevo, Cosijooji Montero

A pesar de encontrarse en una de las regiones de mayor diversidad biológica de México, donde en pocos kilómetros se puede encontrar desde bosques de pino y encino hasta paisajes desérticos, esta biodiversidad no se aprovechó para crear un patrimonio forestal a largo plazo, ya que la historia y la cultura locales impulsaron únicamente la industria y la mano de obra calificada.

Años después, la ciudad enfrenta numerosos desafíos ambientales debido al abandono de la idea de tener una ciudad arbolada, con muchas consecuencias adversas para la salud y la calidad de vida de sus habitantes.

Ahora es el área urbana mexicana donde, en los últimos ocho años, se han plantado más árboles que desde su fundación en 1596. También es la ciudad mexicana donde se plantan más árboles diariamente gracias a la acción de una asociación civil sin fines de lucro que ha logrado posicionar la cultura del árbol como un tema central en la recuperación de un entorno saludable para la población.

Literalmente, en Monterrey el bosque urbano está resurgiendo de las cenizas de su cultura industrial hacia un nuevo bosque urbano.

Biografía(s): Cosijoopii Montero Sánchez es Director de Reforestación Extrema A.C. Su trabajo está centrado a lograr los objetivos de Monterrey Bosque Urbano Metropolitano, para que el Área Metropolitana de Monterrey (AMMty), sea considerada la urbe más y mejor arbolada de México, poniendo en práctica, las mejores prácticas de la industria de la arboricultura a nivel internacional. Es Board Master Arborist certificado por la International Society or Arboriculture (ISA). Cuenta con la certificación Municipal Arborist y Utility Arborist, también por la ISA haciendo de él, el primer y único mexicano y el primer y único latinoamericano en obtener estas tres certificaciones. Está certificado como Tree Worker Arborist (ISA). Tiene la calificación como Tree Risk Assessment Qualified también por la ISA. Cuenta con la certificación Certified Tree Safety Professional (CTSP)por la Tree Care Industry Association (TCIA). Cuenta con las calificaciones de la Tree Care Industry Association (TCIA) para: Aerial Lift Specialist, Aerial Rescue, Chainsaw Specialist, Crane Operator Specialist, Crew Leader, Ground Operator Chipper Specialist, Ground Operator Specialist, Tree Care Safety Specialist, Tree Care Specialist y Tree Climber Specialist. Es autor del libro Gestión Integral del Arbolado Urbano y Áreas Verdes (Manual Operativo, 2022) para el Municipio de San Pedro Garza García (Nuevo León) y Gestión Integral del Arbolado Urbano y Áreas Verdes (Manual Operativo, 2023) para el Municipio de Zapopan (Jalisco), derivado de una investigación de 12 años (2010). Estos manuales son el documento técnico más completo alguna vez publicado para mejorar los procesos de gestión de infraestructura verde urbana, en los municipios en México. El objetivo último de este esfuerzo es convertirlo en una norma a nivel nacional con una reforma legislativa para declarar el arbolado urbano como parte del capital natural nacional y profesionalizar las prácticas de conservación y creación del patrimonio forestal urbano en México.

Miércoles, 29 de abril de 2026 a las 1:15 PM, Spanish

Construyendo puentes entre los servicios públicos y la Junta de Demostración de Seguridad Pública, Jessica Henderson, Julius Uehlein, Brock Navarro, Clinton Curtis, Jesus Nava-Murillo, y Felix Morales

Únete a nosotros para conocer cómo Pacific Gas & Electric está trabajando para mantener a los arboristas seguros mediante la difusión de información sobre seguridad eléctrica y los recursos que ofrecemos. El contacto no intencional con las líneas eléctricas puede tener consecuencias catastróficas. Los colaboradores de PG&E se han estado reuniendo con diversas empresas para proporcionar información de seguridad y tender puentes entre las compañías eléctricas locales y los proveedores de servicios de cuidado de árboles residenciales. Juntos podemos reducir el contacto no intencional con las líneas eléctricas y construir una industria más segura.

Aprende qué sucede cuando los árboles, las escaleras y los vehículos entran en contacto con las líneas eléctricas. Esta presentación energizada incluye una red eléctrica en miniatura que transporta 12,000 voltios. La presentación abordará cómo funciona la electricidad, la infraestructura eléctrica y qué hacer en caso de emergencias. Mantener distancias de trabajo seguras con respecto a las líneas eléctricas es esencial para proteger a los trabajadores forestales y a las comunidades.

El equipo de Inspección de Operaciones de Vegetación supervisa a los contratistas de Manejo de Vegetación de PG&E. Este equipo se enfoca en la seguridad, el cumplimiento y la eficiencia de las cuadrillas que realizan actividades de reducción de incendios forestales. PG&E llevó a cabo medidas de mitigación de riesgo en más de 1.5 millones de árboles en 2024. Estas actividades mantienen seguras a las comunidades y garantizan que proporcionemos energía segura y confiable. El trabajo que realizan estas cuadrillas respalda la postura de PG&E de que los incendios forestales catastróficos deben terminar.

Biografía(s): disponible pronto

Miércoles, 29 de abril de 2026 a las 2:20 PM, Spanish

Podando Raíces, Steve Jimenez y Jasmine Lopez

Poda básica de raíces. Técnicas, herramientas y un estudio de caso. Raíces enmarañadas, raíces circulares y raíces estrangulantes.

Biografía(s): Steve Jiménez: Arborista Maestro Certificado por ISA TRAQ y Profesional Certificado en Bosque Urbano. Candidato a doctorado en la Universidad Estatal de Misisipi, con más de 20 años de experiencia en paisajismo, incluidos 4 años en Disneyland.

Jasmine López: Licenciatura en Ciencias Vegetales por Cal Poly Pomona, con más de 7 años de trabajo en el Disneyland Resort como arborista certificada por TRAQ y experiencia en evaluaciones de ISHB.

Miércoles, 29 de abril de 2026 a las 3:30 PM, Spanish

Fundamentos Técnicos Básicos del Riego: Aplicaciones Prácticas en el Cuidado de los Árboles, Ian Campbell y Michael Madewell

Esta sesión introduce a los participantes a los fundamentos de los sistemas de riego residenciales y comerciales pequeños, con un enfoque particular en su aplicación a los árboles. Los asistentes aprenderán los aspectos esenciales del diseño de riego, los componentes del sistema y los métodos de diagnóstico, y luego conectarán este conocimiento con la salud de los árboles, la eficiencia en el uso del agua y la ampliación de los servicios ofrecidos. Al combinar instrucción técnica con estudios de casos reales, esta sesión brindará a los profesionales del cuidado de árboles herramientas prácticas para incorporar el conocimiento de riego en sus operaciones comerciales diarias, ampliando los servicios y aumentando la rentabilidad.

Biografía(s): Ian Campbell CEO, IC Trees LLC – Arborista Maestro Certificado por la Junta, Arborista Consultor Registrado, CTSP, QAL – Con 24 años en la arboricultura, Ian ha trabajado en todos los puestos de la industria, incluidos 16 años con Bartlett y Davey Tree Experts. Como CEO de IC Trees, integra el cuidado de árboles, el riego, el cuidado de la salud vegetal y la construcción. Ian ofrece una perspectiva del mundo real sobre cómo los servicios de riego amplían la oferta comercial y mejoran los resultados de salud de los árboles.

Mike Madewell Contratista de Paisaje / Irrigador / Viverista – Con más de 40 años en la industria verde, Mike se desempeña como Representante de Agencias Públicas para Hunter Industries, un fabricante global de productos de riego e iluminación. Ex contratista con licencia C-27, con amplia experiencia en operaciones de vivero, diseño, construcción y mantenimiento. Especialista en diseño de riego, diagnóstico y mejores prácticas (BMPs), impartiendo cursos en Estados Unidos y México en inglés y español.

Miércoles, 29 de abril de 2026 a las 4:15 PM, Spanish

Evita se el Vector: maneja los residuos verdes y detén la propagación de plagas, Beatriz Nobua Behrmann, PhD

Los desechos verdes son una parte inevitable del cuidado de los árboles, pero la manera en que se manejan determina si las plagas invasoras se propagan o se contienen. Esta sesión explica los requisitos para las plagas reguladas y las mejores prácticas para las plagas no reguladas, conectando la biología de las plagas con estrategias de manejo. Los asistentes aprenderán enfoques eficaces para el triturado, almacenamiento temporal, transporte y disposición final, y obtendrán herramientas prácticas (incluyendo lenguaje para contratos y estrategias de educación para clientes) que apoyan el cumplimiento y protegen nuestros bosques urbanos.

Biografía(s): La Dra. Beatriz Nobua-Behrmann es Asesora de Recursos Naturales y Silvicultura Urbana para la Extensión Cooperativa de la Universidad de California en los condados de Los Ángeles y Orange. Obtuvo su doctorado en Biología en la Universidad de Buenos Aires, Argentina, donde estudió las interacciones insecto–planta. Desde que se unió a UC ANR en 2017 (Asesora desde 2019), su programa de investigación y extensión se ha centrado en plagas invasoras de árboles, desarrollando estrategias de manejo y apoyando la salud de los bosques urbanos mediante divulgación, investigación aplicada y educación.

Thursday, 8:45:00 AM, General

Fungal partners in tree and forest development

Presenter: Kevin T. Smith, USDA Forest Service R & D, retired, Portland, ME

Bio(s):

Thursday, 10:05:00 AM, General

Identity: A Conversation on Diversity and Inclusion

Presenter: Natalie Krug, San Mateo County, Sunnyvale, California

Equity, Diversity and Inclusion have become highly controversial terms with the acronym “DEI” being a triggering buzz word for some. Within the Arboricultural industry there is opportunity to recognize the importance of identifying and celebrating Diversity within the work force and clientele, understand the importance of being equitable, learn how empowering inclusivity can be for people who feel ostracized through a dynamic narrative discussion and storytelling.

Bio(s):

Natalie has dedicated much of her career to taking thoughtful approaches to managing trees. With nearly 20 years in the Arboricultural industry, the majority as an ISA Certified Arborist, her enthusiasm for trees is something she enjoys sharing with others. She began her career as a residential consulting arborist in Chicago before relocating to California to becoming the first Arborist/Urban Forester for San Mateo County in California.

Thursday, 10:40:00 AM, General

Mentorship in Arboriculture, A Full Circle Journey

Presenter(s): Grayson Keating, TreeCircus, Sapphire, NC, et al

Mentorship connects experience to potential, strengthening resilience and continuity within arboriculture. This session offers actionable strategies to build effective, inclusive mentorship relationships that support safety culture, equity, and professional growth. Participants will reflect on their own mentorship journeys and learn how investing in others sustains arboriculture’s living network of knowledge, ethics, and community, bringing the profession full circle.

Bio(s):

Coming Soon

Thursday, 11:30:00 AM, General

The 6th Annual Battle of the Trees: The 24/7 Lectures

Presenter: Kelaine Ravdin

Didn’t make it to every talk? Disappointed that one of your favorites didn’t present this year? Think 45-minute talks are too long? Well, here’s your solution to all of that! Bringing this conference full circle (and inspired by the Ig Nobel Prize ceremony), we’ve invited a dozen of our presenters and guests to tell us what arboricultural topics are top of their minds these days. The gimmick? They only get 24/7, that is: They have 24 seconds to provide a complete description of their chosen topic. They must present a clear summary, that anyone can understand, in 7 words. You’ll be out there cheering for the speedy ones and drowning out the ones who take too long. We’ll end with a vote for the audience favorite. So stick around for this quick romp through the hottest ideas in arboriculture!

Bio(s): Kelaine Ravdin is an 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 moonlights as a referee at WCISA conferences.