The International Society of Arboriculture (ISA) has served the tree care industry for over eighty years as a scientific and educational organization. ISA certified Arborists are individuals who have achieved a level of knowledge in the art and science of tree care through experience and by passing a comprehensive examination developed by some of the nation’s leading experts on tree care. They must also continue their education to maintain their certification and adhere to a Code of Ethics. Therefore, they are more likely to be up to date on the latest techniques in arboriculture.