James Clark, Ph.D., RCA #357

HortScience | Bartlett Consulting

Dr. Jim Clark has been a principal with HortScience, Inc. since 1991. He holds bachelor’s and master’s degrees from Rutgers University and a Ph.D. from the University of California, Davis. Dr. Clark is co-author (with Nelda Matheny) of several prominent books, including Arboriculture—The Integrated Management of Landscape Trees, Shrubs and Vines (also with Dick Harris).

He served on the ASCA board of directors from 2009 to 2013 and has been an instructor at the Consulting Academy since 2013. He is currently ASCA’s representative to, and chair of, the Council of Tree and Landscape Appraisers. Dr. Clark is an ISA Certified Arborist (WE-0846), a Registered Consulting Arborist (#357), tree risk assessment qualified, and an Honorary Life Member of both ISA and the Western Chapter, as well as a self-described all-around good guy.

Mark Duntemann, RCA #656

Natural Path Urban Forestry Consultants

Mark Duntemann is the owner of Duntemann Urban Forestry, LLC. He is an internationally recognized expert in tree risk management policy development. Mr. Duntemann is an ISA Board-Certified Master Arborist and an ISA Tree Risk Assessment Qualification instructor. He also maintains the tree assessment certification from the Arboriculture Association (UK).

Mr. Duntemann has a master’s degree in urban forestry from the University of Wisconsin–Madison. He received a post-graduate certificate in risk assessment methods from Harvard’s Chan School of Public Administration and completed the Public Risk Management Association’s course on Enterprise Risk Management. He is enrolled in a post-graduate certificate program in risk management at Boston University.

Mr. Duntemann has served as an expert witness in over 50 tree-related injury and fatality cases. He is currently developing a book on tree risk management and researching tools for identifying tree risk thresholds.

E. Thomas Smiley, Ph.D., RCA #635

Bartlett Tree Research Laboratories

Dr. Tom Smiley is a senior arboricultural researcher at the Bartlett Tree Research Laboratories in Charlotte, North Carolina, and an adjunct professor of urban forestry at Clemson University.

Dr. Smiley is active in the arboriculture industry and has co-authored many of ISA’s Best Management Practices. His research has led to improved methods of increasing sidewalk longevity near trees, protecting trees from lightning damage, improving tree root growth, and reducing tree risk.