The International Society of Arboriculture (ISA) has served the tree care industry for over eighty years as a scientific and educational organization. ISA continues to be a dynamic medium through which arborists around the world share their experience and knowledge for the benefit of society. ISA, aligned on many fronts with other green organizations, is working hard to foster a better understanding of trees and tree care through research and the education of professionals as well as global efforts to inform tree care consumers.

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. Certified Arborists must also continue their education to maintain their certification. Therefore, they are more likely to be up to date on the latest techniques in arboriculture.

The Illinois Arborist Association is a non-profit organization that educates our members in proper tree care. We support research on trees. Our mission is to "Foster interest, establish standards, exchange professional ideas and pursue scientific research in Arboriculture.

The Tree Care Industry Association is a 72-year-old public and professional resource on trees and arboriculture. Our members recognize stringent performance standards for quality and safety. They maintain trained, professional arborists on staff and are dedicated to ethics and quality in business practices.