Elected world President of the International Society of Arboriculture (ISA), past President of the Southern Chapter of ISA (9 states), past President of the international Arboriculture Research &
Education Academy (AREA), and founding member and past President of the Georgia Urban Forest Council.
Appointed to the USDA-Secretary’s NUCFAC (National Urban & Community Forestry Advisory Council), advising on urban and community forestry issues representing the nation's educational institutions.
First person to receive four of ISA’s competitive world awards – the Shigo, Harris, Lilly, and Merit awards.
Granted the Arbor Day Foundation’s highest award -- the J. Sterling Morton award.
Author of over 500 technical publications and articles.
International lecturer and consultant to private citizens, corporations, attorneys, and communities
on tree biology & health care, tree risk, tree appraisal, abiotic tree stress, lightning & tree protection, storm damage, biomechanics, climate change & trees, and community forest ecology.
Outreach programming and educational product development in tree health care, technical arboriculture, abiotic tree & site stress, tree morphology, taxonomy & physiology, tree biology, lightning & tree protection, storm damage & risk assessment, tree biomechanics / structural mechanics, tree risks and hazards, tree appraisal & asset assessment, essential element diagnosis & life-staged based fertilization, climate change & tree impacts, and community forest ecology.
- PhD, Forest Ecology, Iowa State University
- MS, Tree Physiology, Iowa State University
- BS, Forest Management, Iowa State University