The International Society of Arboriculture (ISA) enjoys a rich heritage as a scientific and educational organization with a primary mission to disseminate information and knowledge in the care and preservation of trees. The Ontario Chapter sits consistently at 600-700 members, while the international membership is over 20,000, divided into almost 50 chapters and associate organizations worldwide – the world’s largest such organization. There are currently over 500 ISA Certified Arborists in Ontario and more than 25,000 worldwide.
