Evan Alderman
Pesticide Safety Education Program at Iowa State University

Evan Alderman, an Agricultural and Natural Resource Extension Specialist, serves as the Co-Coordinator of the Pesticide Safety Education Program at Iowa State University. Evan coordinates and produces all specialty crop pesticide continuing instruction courses for the state of Iowa. Evan’s background includes a MS degree from Kansas State University in Horticulture with an emphasis in Turfgrass Science, and a BS degree from Iowa State University in Horticulture with an emphasis in Turfgrass Management.





John Ball
South Dakota State University

John Ball is Professor of Forestry and Extension Forestry Specialist for South Dakota State University (Brookings, SD) where he offers courses in arboriculture and urban forestry, emergency medical technician training, and rock climbing.  John also serves as campus arborist.  John remains one of our most popular and requested presenters!






David S. Bienemann
Municipal Arborist/Utility Forester City of Hamilton, Ohio

David Bienemann is currently the Municipal Arborist and Utility Forester for the City of Hamilton, Ohio, where he oversees all aspects of tree management on city properties and rights-of-way, including coordinating the utility line clearance program for the City’s Electric Division. Before joining the City of Hamilton, David served as the Municipal Arborist for the City of Bowling Green, Ohio, and as the Manager of Forestry for Ohio Edison Company in Akron, Ohio. He holds degrees in Forestry from Iowa State and in Labor Economics from the University of Akron. With a long-standing commitment to his field, he has been a member of the International Society of Arboriculture (ISA) since 1993, earning certification as an ISA Certified Arborist in 2004 and becoming a Tree Risk Assessment Qualified (TRAQ) Arborist in 2018.




Scott Carlson

Based in Eldridge, Iowa, Scott Carlson is the lead instructor and consultant for Iowa Arborist Consulting. He imparts his expertise in tree care topics to various audiences, including tree care companies, municipalities, arboretums, and colleges. Scott’s contributions extend to assisting numerous individuals in achieving ISA Certified Arborist status.

Additionally, he provides consulting services, tree risk assessments, tree appraisal, inventories, and legal expert witness services.





Ryan Contreras
Oregon State University

Ryan Contreras is a Professor of Horticulture at Oregon State University. In this role, he teaches plant propagation, plant growth and development, and landscape plant identification. When it comes to research, his focus is on creating new cultivars of woody shrubs and trees with improved disease resistance, growth habits, and fragrance. His research blends fundamental and applied science, advancing our understanding of plant genetics and heritability of traits.

With his team, Ryan applies their discoveries to benefit the cultivar development program, which covers nearly 50 genera. The primary goal is to directly support nursery producers, landscapers, and consumers while contributing to scientific knowledge.




James Ellenwood
US Forest Service

James Ellenwood serves as the National Program Lead for Monitoring Remote Sensing and Geospatial Analysis Research for the US Forest Service in Washington, DC. His career within the Forest Service has encompassed a range of key roles, including Silviculturist, Forest Planning Specialist, Remote Sensing Manager, and Geospatial Analytics Specialist. James is a distinguished alumnus of SUNY College of Environmental Science and Forestry, holding both M.S. and B.S. degrees in Forestry.





Justin Glisan
Iowa Department of Agriculture and Land Stewardship – Climatology Bureau

Dr. Justin Glisan has extensive expertise in atmospheric and climatological research, particularly in the analysis of extreme temperature and precipitation events. He earned his B.S. (2005) and M.S. (2007) in meteorology, focusing on droughts and heatwaves, at the University of Missouri. In 2012, he completed his Ph.D. in Atmospheric Sciences at Iowa State University, with a research concentration on the dynamical mechanisms of precipitation and temperature extremes.

As State Climatologist of Iowa, Dr. Glisan’s responsibilities include ensuring the quality of Iowa’s weather observations, providing weekly recommendations to the U.S. Drought Monitor, and delivering both weekly and monthly climate summaries for state stakeholders. A crucial aspect of his role involves examining trends in precipitation and temperature and applying these analyses to the agricultural sector. Dr. Glisan serves as an advisor to the Secretary of Agriculture on climatological matters affecting agriculture.



Ted Hildebrant
Coldwater Pond Nursery

Ted Hildebrant, a third-generation nurseryman and accomplished propagator and along with his life partner Elly Keyel, proudly own and operate Coldwater Pond Nursery in Phelps, NY, a renowned specialty woody plant propagation nursery. Ted’s passion lies in the art of plant propagation, a craft he enthusiastically shares through teaching sessions for both professionals and gardening enthusiasts. His expertise also extends to consulting for nurseries, both new and established.

Coldwater Pond Nursery is a distinguished establishment that focuses on providing rare and unique nursery stock to gardeners, nurseries, and garden centers across the eastern United States.




Nick Kantola
Rainbow Tree care

Nick Kantola, an Arborologist hailing from Minnetonka, Minnesota, is a key figure at Rainbow Tree care. In his capacity, he plays a pivotal role in training both new and seasoned arborists and technical staff, ensuring the highest standards of service for clients. Nick’s formal education includes a Bachelor of Science degree in Biology with a field emphasis from the University of Wisconsin-River Falls. With a career spanning back to 2013, he brings a wealth of experience to the tree care industry.





James L. Komen
Class One Arboriculture Inc.

James Komen, a consulting arborist based in California, specializes in risk assessment and tree appraisal, providing invaluable assistance to clients seeking informed management decisions for individual trees and tree inventories. His noteworthy contributions have been featured in publications like Arboriculture & Urban Forestry, Arboricultural Consultant, Palms, Ontario Arborist, and Western Arborist. In addition, James is an ISA TRAQ instructor and shares his expertise by leading workshops on tree appraisal throughout the United States and Canada





Mike Kintner
Iowa Department of Agriculture and Land Stewardship

Mike serves as the EAB and Spongy Moth Outreach & Regulatory Coordinator with the Iowa Department of Agriculture & Land Stewardship. In this multifaceted role, he works with the Nursery Stock Grower and Dealer Inspection Program, insect trapping surveys, and vital biological control efforts.

Before his current position, Mike was an International Society of Arboriculture (ISA) Certified Arborist for six years.





Steve Marien
Eastern Area Coordination Center/National Park Service

Steve Marien grew up in Madison, Wisconsin. He graduated with a degree in Atmospheric Science from the University of Wisconsin-Madison in 1992. He worked as a forecaster for the National Weather Service in Madison, Wichita, and Louisville from 1993 to 2001. In 2001, he became the Eastern Area Fire Weather Program Manager at the Eastern Area Coordination Center (EACC). The EACC is a unit that coordinates resources for different types of emergencies, both in and outside the Eastern Area. It mainly focuses on supporting wildland and prescribed fires.






Fredric Miller
The Morton Arboretum, Lisle, Illinois

Dr. Fredric Miller holds the position of Senior Scientist – Entomology at The Morton Arboretum in Lisle, Illinois. Additionally, he currently serves as the acting Illinois DNR Forest Health specialist.

Dr. Miller earned his B.S.F. in Forest Management from the University of Missouri, an M.S. in Forest Entomology from the University of Arkansas, and a Ph.D. in Urban Forest Entomology, with a minor in Plant Pathology, from Iowa State University.

He is an active member of the Illinois chapter (IAA) of the ISA (International Society of Arboriculture) and the National Walnut Council (NWC).

His applied research primarily focuses on insect pests, pathogens, and abiotic factors that impact both urban and rural forests, with a specific emphasis on Emerald Ash Borer (EAB) population dynamics.


William Moomaw
Tufts University

Bill Moomaw is Professor Emeritus at Tufts University and Distinguished Visiting Scientist at Woodwell Climate Research Center in Massachusetts. He holds a PhD from MIT in Physical Chemistry and has been a lead author of 5 Intergovernmental Panel on Climate Change reports addressing technological means for reducing emissions of carbon dioxide and other heat trapping gases. In recent years, his research has been to develop Natural Climate Solutions that will remove additional carbon dioxide from the atmosphere and store the carbon in forests and urban trees, wetlands and soils.





Chris Olson
Olson Tree Care

Board Certified Master Arborist Chris Olson provides unique insights into the many faceted world of arboriculture. His strengths lie in visual perception analytics and a childhood connection with trees. Coming from a family of arborists, his entry into the industry was seamless, as was his exit. Problem identification led to research, study and the advocacy of trees. Still practicing, his focus revolves around plant health care, education, experimentation, awareness and advancement.





Robin Pruisner
Iowa Department of Agriculture

Robin Pruisner has been the State Entomologist for the Iowa Department of Agriculture and Land Stewardship since 2003. She oversees an eclectic array of topics from seed, noxious weeds, hemp, apiary, and emergency management for the department. In her spare time Pruisner and her husband keeps a few bees, tend a few flowers, and cheer on the Cyclones.






Andy Schmitz
Brenton Arboretum

Andy Schmitz is the Director of Horticulture and General Manager at the Brenton Arboretum in Dallas Center, Iowa. For the past 25 years, he has overseen all horticultural aspects of the 148-acre arboretum which was established in 1996, including planting and curating over 6,000 woody accessioned plants. He’s growing almost all the future tree additions to the arboretum from seed he has collected around Iowa and the Midwest. His favorite trees are the Kentucky coffee tree, Gymnocladus dioicus and the Osage-orange, Maclura pomifera both of which have been planted extensively at the arboretum. In his spare time, he likes to make predictions on how long newly planted urban trees will live.





Amanda Snodgrass
Bureau of Land Management

A native of Iowa, Amanda holds both a Bachelor of Science and a Master of Science degree in Horticulture from Iowa State University. Her professional journey began in 2012, and she has since dedicated the last 11 years to resource management on public lands throughout the United States. Amanda’s career has spanned various roles with prestigious agencies, including the National Park Service, US Forest Service, and the Bureau of Land Management.

Her experience is as diverse as the landscapes she’s worked in, ranging from her role as an invasive species management technician in Everglades National Park to being a native seed ecologist for Lake Mead National Recreation Area, spanning the Mojave Desert. She’s also served as a horticulturist managing the historic orchards of Capitol Reef National Park, led native plant materials programs at Grand Teton National Park, and worked as a botanist with the Klamath National Forest in Northern California. Presently, Amanda holds the position of a botanist with the Bureau of Land Management in Southern Oregon.



Guy Sternberg
Starhill Forest Arboretum

As the co-founder of Starhill Forest Arboretum, Guy Sternberg has played a pivotal role in creating the most extensive oak research collection in the United States, housing approximately 250 taxa and six globally endangered species.

Guy’s dedication to conservation is exemplified by his roles as a founding member of the Illinois Native Plant Society and past president of its central chapter, as well as his lifelong memberships in prominent organizations such as the International Dendrology Society, International Society of Arboriculture, and the International Oak Society, which he also founded.

In addition to his academic roles as adjunct faculty in Biology at Illinois College and adjunct research associate in Botany at the Illinois State Museum, Guy is an ISA-certified arborist, a retired licensed landscape architect, and a consultant to several state and federal agencies, along with numerous communities. He further serves as a tree consultant and tour coordinator for Oak Ridge Cemetery, home to President Lincoln’s Tomb and designated as Illinois’ National Living Memorial site due to its historic tree collection.


Adam Thoms
Iowa State University

Adam Thoms is an Associate Professor in the Iowa State University Department of Horticulture, with a specialization in commercial turfgrass management. Adam earned his B.S. degree from Iowa State University, and both M.S. and Ph.D. degrees from the University of Tennessee. His research interests include golf, athletic field performance and safety, residential, commercial, and municipal turf applications, and sustainable turfgrass management.






Todd Rounsaville
USDA-ARS, US National Arboretum

Dr. Todd Rounsaville leads the US National Arboretum Germplasm Program as Curator for the USDA-ARS National Plant Germplasm System Woody Landscape Plant Germplasm Repository (WLPGR) in Washington DC. His research program includes genetic and phenotypic characterization of woody plants, seed ecophysiology and dormancy breaking, and germplasm cryopreservation.  The WLPGR maintains an active plant exploration, collection, and distribution program in order to increase and improve the woody plant genetic resources available for plant breeding, conservation, and research.





Mark Vitosh
Iowa Department of Natural Resources Wildlife Bureau

Mark Vitosh has been a forester since the fall of 1988 and has worked in Oklahoma and Iowa.  He has been a District Forester with the Iowa DNR Wildlife Bureau since 2000, and he assists private landowners in managing their forest resources in eastern Iowa.






Suzanne Wainwright-Evans
Bug lady Consulting

Suzanne Wainwright-Evans is a horticultural entomologist with a specialization in integrated pest management. With over three decades of experience in the Green Industry, her primary focus has been on the effective use of biological control and pesticides. Suzanne is a graduate of the University of Florida, holding degrees in Entomology and Environmental Horticulture. She is the founder and owner of Bug lady Consulting, a thriving business that has been serving clients for 23 years.






Liz Westberg
Growth Solutions

Liz Westberg, with a formal education in Wildlife Ecology and a B.S. degree from the College of Natural Resources at the University of Wisconsin – Stevens Point, has successfully transitioned into the Utility Arboriculture industry. Since her entry in 2018, she has earned credentials as an ISA Utility Specialist and Tree Risk Assessment Qualification holder. In her role at Growth Solutions, a utility tree growth regulator application company, Liz takes charge of managing training, quality assurance, and safety programs. She has also served as a member of the Safety Council for Rainbow Companies over the past three years.





Fred Whitford
Purdue University

Fred Whitford is the Clinical Engagement Professor and Director of Purdue Pesticide Programs. He has served as the Director of the Purdue Pesticide Program since 1991. With a prolific career, Fred has authored over 300 publications, including 8 books and 120 extension bulletins. He’s an accomplished speaker, having delivered more than 6,500 presentations.

Fred’s remarkable contributions to Extension outreach have earned him several prestigious awards, such as the Frederick L. Hovde Award of Excellence in Educational Service to Rural People of Indiana, and the Honorary Master Farmer by Indiana Prairie Farmer and the Purdue University College of Agriculture.




Ed Zaworski
Iowa State University

Ed Zaworski works as a plant diagnostician in the Iowa State University Plant and Insect Diagnostic Clinic. In the clinic Ed works with tree diseases of all sorts but has a special interest in conifer diseases. Ed earned his Master’s Degree in plant pathology in 2010.