Holden Staff Instructors

Rick Belding, horticulturist at Lantern Court. Belding earned his bachelor's in aeronautical science from Embry-Riddle Aeronautical University and his master's in horticulture from the Univeristy of Wisconsin-Madison. Prior to joining Holden, Rick designed and installed residential landscapes, was a fruit and vegetable horticulturist at the renowned Chicago Botanic Garden. Belding was alsodirector of the garden at a historic gentleman's farm on the north shore of Chicago.


David Burke, PhD, holds a bachelor's degree in environmental science from Rutgers University, a master's degree biology from East Stroudsburg University and a doctorate in biology, with concentration in ecology and evolution, from Rutgers University.Burke is a plant biologist whose research focuses on the interactions between plant roots and soil organisms with a particular emphasis on mycorrhizal ecology.He is the chairman of the Research Department at The Holden Arboretum and has an adjunct position in the Department of Biology at Case Western Reserve University.


Tere Cole-Lang, lead horticulturist at The Holden Arboretum, graduated from Ohio State University with a bachelor's degree in golf course management and plant pathology and a master's degree in integrated pest management.Cole-Lang is currently working on a masters in primary science education.Shebegan her career in the green industry more than 20 years ago on a golf course, spent two years in the PeaceCorp, worked at Longaberger Golf Club gaining Audubon Certification status, was superintendent at Springfield Country Club, managed the plant care department and designed landscapes at Scarff's nursery and, most recently, was groundskeeper for Laurel School.


Toby Davidson, horticulture supervisor for the Display Gardens, earned his associate's degree in forestry from Hocking College. He spent the first eight of his 12 years at Holden caring for the trees in the outer collections. He enjoys pruning trees and designing garden spaces.


Julie Dougherty, the assistant manager of guest relations, is a certified interpretive guide from the National Association for Interpreters. She earned her bachelor's degree from Cleveland State University, her master's degree in sports psychology from West Virginia University and her master's in education administration from Ursuline College. She taught outdoor education at Hiram House Camp for 10 years, physical education at St. Vitus for 12 years and served as principal at St. Louis Elementary for seven years.


Natalie Gertz-Young, has been a public programs seasonal employee since 2010 and a Growing Students in Science instructor since 2010. While she has many interests her main effortsi at Holden are managing and developing new features at Buckeye Bud’s Adventure Woods, Holden’s nature play area; and getting children and families more engaged in Holden’s gardens and natural areas. She earned a bachelor’s degree in psychology from the College of Wooster in 2008 and a master’s degree in environmental science with an environmental education specialty from Antioch University New England in 2010.


Roger Gettig, director of horticulture and conservation.Gettig began his career at Holden in 1988 as a native plant intern before becoming full-time staff as natural areas foreman.He left Holden to attend the University of Wisconsin, where he majored in ecological restoration while earning his Master's degree in landscape architecture. He returned to Holden in 1996 as landscape consultant and then assumed the role of land conservation manager.


Lori Gogolin earned an associate's degree in horticulture from Kent State University in 1998.She is a horticulturist at The Holden Arboretum and is responsible for the Arlene and Arthur S. Holden Jr. Butterfly Garden.


Sharon Graper, manager of formal education, began her relationship with Holden in 1981 as a student at Hawken High School, working on her senior project in the Myrtle S. Holden Wildflower Garden. She came back as an intern in 1984 and as a summer employee teaching children’s classes in 1991. Since 1994, she has managed school and youth programming at Holden. She earned her undergraduate degree in environmental science from the University of Virginia and her master’s degree in science education from the University of Delaware.


Clement W. Hamilton, president and CEO. Hamilton grew up in Wisconsin and Ohio, where he developed his three primary passions for nature, baseball and music.He earned a bachelor's degree in geology at Harvard, and a doctorate in ecology and evolutionary biology at Washington University and the Missouri Botanical Garden.He has conducted botanical research and fieldwork in Thailand, Panama and Chile, as well as the United States.He was assistant and associate professor in the Center for Urban Horticulture at the University of Washington, 1985-99, directing the center from 1992-99; executive director of Rancho Santa Ana Botanic Garden in Claremont, Calif., 1999-2004; and vice president for arboretum programs and director of research at the Morton Arboretum in Lisle, Ill., 2004-08.In the spring of 2008, Hamilton became president and CEO of The Holden Arboretum, where he seeks to maximize Holden's contribution toward creating a more livable, diverse and ecologically sustainable world by promoting the planting and conservation of trees and forests.


Ethan Johnson, plant records curator, earned his associate's degree from Paul Smith’s College, N.Y., in forestry and his bachelor's degree in environmental horticulture from the University of Connecticut.He has been Holden’s plant records curator since 1989. As curator he documents the history, growth, phenology, and condition of cultivated plants in the living collection as well as produces plant accession, labels and collection maps.


Stephen Krebs, PhD, started at David G. Leach Research Station in 1992 and has been the director of the Leach Research Station since 1998. He received his bachelor's degree in history at the University of Chicago and his doctorate in plant breeding and genetics/horticulture from Michigan State University. Work at the Leach Station centers on the development of ornamental rhododendrons that are adapted to difficult conditions. Research in support of this goal includes investigations of cold and heat tolerance, identification and transfer of disease resistance, and adaptations to brighter (sunnier) growing conditions.


Sarah Kyker, PhD, is a microbial ecologist interested in the influence of human and natural environmental changes on microbial communities and their function. Kyker received bachelor's degrees in botany and secondary education from Miami University (Ohio) in 2003.Her graduate work was conducted in biology at Case Western Reserve University and resulted in a master's in 2006 and a doctorate in 2010.Sarah has been with The Holden Arboretum since 2007, where shecompleted her doctoral research under the advisement of Research Department Chairman David Burke.She is currently a postdoctoral scholar at Holden working with Burke and scientist Kurt Smemo.


Sheryl Petersen, PhD holds a bachelor's biology from Hiram College and an master's and doctorate in biology from Case Western Reserve University. Peterson is a plant ecologist whose research focuses on the roles natural and human-generated disturbance play in shaping vegetation patterns. She is particularly interested in how understanding the effects of disturbance can help provide a scientific basis for restoration of plant communities. She is currently a post-doctoral research associate at The Holden Arboretum and Case Western Reserve University


Ann Rzepka, horticulturist at The Holden Arboretum since 2008.Rzepka maintains the Myrtle S. Holden Wildflower Garden, collects and propagates seed for use within the garden, assists conservation staff with the heritage species monitoring program, and helps maintain Holden’s commitment to the Center for Plant Conservation and the preservation of rare and endangered plant species.She was previously employed by the Geauga Soil and Water Conservation District where she served as their Natural Resources Specialist.She earned a bachelor's degree in environmental studies from Hiram College.


Kurt Smemo is an ecosystem ecologist at The Holden Arboretum and an adjunct assistant professor at Case Western Reserve University and Michigan State University.His studies involve how soil microorganisms control organic matter decomposition and nutrient availability in forest and wetland ecosystems, and how those organisms respond to environmental change. Smemo has earned his bachelor's degree in forestry at the University of Montana, his master's in environmental science at the University of Illinois and his doctorate in ecology from Cornell University.


Susan Swisher, Holden's librarian, is a Northeast Ohio native who received her master's in library science from Case Western Reserve University. She began her career as a reference librarian at the Cuyahoga County Public Library. She spent several years in San Diego managing a cooperative library system before returning to Ohio.


Rebecca Thompson, Growing Students and Science program coordinator, has been with the Education Department at Holden since 1999 and has worked in environmental education for many years. She coordinates the Growing Students and Science Program, a community partnership to build interest and ability in the sciences in public school systems, and leads Holden’s Junior Birders Club for children and teaches a number of children’s classes. She received her bachelor's degree in biology at Kent State University.


Charles Tubesing, chief horticulturist, is a graduate of Purdue University. Tubesing has been with Holden since 1986. He is responsible for the development of Holden’s plant collection, having extensive experience and interest in the selection of appropriate woody plants to fit specific landscape criteria and in plant propagation with a special interest in magnolias.


Michael Watson, conservation biologist, started at Holden as a conservation seasonal three years ago. He earned his bachelor's degree in biology from the College of Wooster and his master's in ecology and evolutionary biology from the University of Michigan.He spends most of his time on the deer browse project, a large-scale, long-term study attempting to measure the impact of deer on Holden's forests. He is also the coordinator for Holden's Bluebird Project, which relies on 50 volunteers to monitor and band bluebirds, tree swallows and other secondary cavity nesting birds that use more than 200 nest boxes on the Holden properties.


Marian Williams, manager of public programs, has been with Holden since 1987 and is responsible for Holden’s public programs and interpretation of the gardens and natural areas as well as a variety of other special projects. She received her undergraduate degree from Earlham College and her master’s degree from Purdue University.


Greg Wright, nursery supervisor, is in charge of plant propagation at Holden. He earned his bachelor's degree in horticulture at Brigham Young University and his master's degree in landscape architecture at Utah State University. Wright has been with Holden for eight years and teaches a variety of classes on horticulture and landscape architecture.


Non-Staff Instructors

Ian Adams is an environmental photographer, writer, and teacher specializing in natural, rural, historical and garden areas in Ohio. Since 1985, more than 6,000 of his color photographs have been published in books, posters, calendars, magazines and other publications. Ian has published 18 photography books and conducted more than 175 photography workshops and seminars.His books include The Holden Arboretum (University of Akron Press, 2000), Backroads of Ohio (Voyageur Press, 2006), Our First Family's Home: The Ohio Governor's Residence & Heritage Garden (Ohio University Press, 2008), Missouri Botanical Garden: Green For 150 Years (Missouri Botanical Garden Press, 2008) andA Photographer'sGuide to Ohio (Ohio University Press, 2011) He lives in Cuyahoga Falls with his tabby cat, Fuji.


Denise Brown is a registered yoga and tai chi instructor with many years of experience as well as personal practice. She truly believes everybody can benefit from yoga and tai chi regardless of body type or experience level. Hailing from Surrey England, she picked up her first yoga book at the age of thirteen. As she moved around the world she continued to follow her love of yoga. Landing in Cleveland Heights, Ohio, Brown studied with the American Light of Yoga Society and Alice Christensen where her teaching roots were developed. She then pursued her formal teacher training with Joseph le Page, founder and director of Integrative Yoga Therapy (IYT) in 1999.


Pat Biliter comes from a long line of eastern Kentucky coal miners and broke family tradition to become a geologist. After completing his undergraduate and graduate studies at the Ohio State University and UCLA, and Airborne and Ranger training at Fort Benning, Georgia, Biliter spent the next 30 years overseas working for the Army Corps of Engineers.Among other assignments, he served as the Deputy District Engineer of the Europe District in Wiesbaden, Germany, where he was responsible for military construction, humanitarian relief and host nation assistance in 90 European, African, Middle Eastern and southwest Asian countries.After retiring from federal service in 2001, he settled in Cleveland, Ohio, and within a year became a school guide at the Holden Arboretum.Inspired in high school by the writings of John Muir and Rachel Carson, Pat quickly realized that the Holden Arboretum was a perfect setting to share his lifelong love of natural history and conservation with coming generations of young Americans.Biliter is also an Ohio Certified Volunteer Naturalist.


Pierluigi (Enrico) Bonello's primary research interest is in the ecological role of tree pests. He completed a M.Sc. in Forest Sciences at the University of Padova, Italy and a Ph.D. in Forest Pathology from the University of Oxford, U.K. Most of Bonello’s current work focuses on understanding molecular and chemical mechanisms of tree resistance to both indigenous and alien invasive pathogens and insects, including the model systems represented by (1) Austrian pine (Pinus nigra) and the shoot blight and canker pathogen, Diplodia pinea; (2) coast live oak (Quercus agrifolia) and the causal agent of sudden oak death, Phytophthora ramorum; and ash (Fraxinus spp.) and the emerald ash borer (Agrilus planipennis).He has trained 11 Ph.D. and Masters students and 3 postdocs and has published over 60 peer-reviewed papers, several book chapters, many abstracts, and several reports for the lay public.He has presented his work all over the world.


Jean H. Burns, PhD, holds a bachelor's degree from the College of Idaho in biological science and mathematics and a doctorate from Florida State University in ecology and evolution.She is an assistant professor at Case Western Reserve University in the Department of Biology.Her research focuses on experiments and phylogenetic comparative approaches to ask how proximate, ecological mechanisms interact with ultimate, evolutionary mechanisms to govern plant community assembly.She has received numerous grants including a grant from the National Science Foundation entitled EAGER: The role of demographic stochasticity in community assembly.


Judy Churchill, AYT, RYT, CYT, an accredited yoga teacher of Satyanada Yoga and registered as an RYT at the 500-hour level with Yoga Alliance.In 2001, she received formal initiation in India from Swami Niranjanananda Saraswati and given the spiritual name, Jayasri. She later earned a level two accreditation from Satyananda Yoga Academy, Mangrove Mountain, NSW, Australia. Churchill maintains a website with book reviews and articles on yoga at www.yogic-wisdom.com


Joshua Clark, a self-taught nature and wildlife photographer specializes in avian photography and resides in Northeast Ohio. Clark has taken wildlife images within Ohio and other regions of the United States since 2005.He presents programs to local photography and nature groups and is the group coordinator for MPEG (Midwest Photographers Enthusiasts Group).

Dan Donaldson is the district administrator of Lake County Soil and Water District. Having earned his bachelor's degree in environmental management from Cleveland State University, he assists local governments, landowners, and partner agencies with natural resource planning objectives, including special projects, ordinances, programs, conservation easements, program planning, administration and grant writing.


Denise Ellsworth, directs the honey bee and native pollinator education program through the OSU Department of Entomology on the OARDC campus in Wooster. In this outreach position, she supports and teaches beekeepers, farmers and gardeners through a variety of workshops, written materials and electronic resources. She earned her master's at Ohio School of Natural Resources and bachelor of science from Ohio State University's Department of Plant Pathology. She is also a garden writer for the Akron Beacon Journal.


Bob Faber has been a consultant to conservation and environmental organizations throughout the region. He leads natural history programs across the United States.


Susan Kalisz is a plant evolutionary ecologist. Growing up in Michigan, Dr. Kalisz developed a deep appreciation for the diverse habitats of the Great Lakes region and now uses basic research to aid in the conservation of the regions’ flora and fauna. One facet of her research explores how current interactions among native plant species, overabundant herbivores, and exotic plant invaders are shaping forest understory community diversity. Dr. Kalisz holds a Bachelors of Science degree from the University of Michigan and Masters and Doctoral degrees in Ecology and Evolution from the University of Chicago.Prior to her current position as Professor in the University of Pittsburgh’s Department of Biological Sciences, Dr. Kalisz held Assistant and Associate Professor ranks at Michigan State and the Kellogg Biological Station.She has served as a Program Director at the National Science Foundation Population and Community Ecology Program, and as an Associate Editor for the journals Evolution, Plant Ecology and American Naturalist, lead working groups at the National Evolution Synthesis Center (NESCent) and is currently an Editor of the American Naturalist.Dr. Kalisz presents her work to public and scientific audiences nationally and internationally and is an author on numerous journal articles on the ecology and evolution in wild plant populations (for more details see her website: http://www.pitt.edu/~kalisz/).


Lisa Rainsong holds a doctorate of musical arts in composition from the Cleveland Institute of Music, is a member of CIM’s music theory faculty and is also a professional soprano as well as a teacher and composer, She also earned a naturalist certificate from the Cleveland Museum of Natural History, where her study focused on field experience.  She records bird songs and the songs of crickets and katydids as part of her field research and presents programs on bird song and insect song across the state.  Her recordings and photos – including birds and insects found at Holden - can be found on her blog, Listening in Nature at listeninginnature@blogspot.com.


Bryant Scharenbroch, soil scientist at the Morton Arboretum, Bryant received a doctorate in soil science from the Univeristy of Wisconsin-Madison, a master's in plant science from the University of Idaho, and bachelor's degrees from University of Wisconsin - Stevens Point in urban forestry and forest management. His current research interests pertain to anthropogenic impacts on soil quality, tree health, and ecosystem function. Bryant is an associate editor for Arboriculture and Urban Forestry. He is the vice-chair of the Urban Tree Growth and Longevity Working Group and the incoming chair for Urban and Anthropogenic Division of Soil Science Society of America. He received the Early Career Scientist Award from ISA in 2013.


Barbara Tercek, RYT, a certified yoga instructor and social worker is studying for her certification in yoga therapy.


Wendy Wasman has a bachelor's in cultural anthropology from Oberlin College and a master's in library science from Kent State University. Wasman was the librarian at the Cleveland Museum of Natural History and served as the science librarian at Haverford College. She and her family moved back to the Cleveland area in 2000. After holding various part-time library positions for eight years, Wasman is happy to be back as the librarian at the Cleveland Museum of Natural History.