Certified Arborists are specialists that have achieved a recognized professional level of knowledge in the art and science of tree care and have passed a comprehensive examination developed by the nation’s leading experts in the industry, the International Society of Arboriculture. Certified Arborists must also continue their education to maintain their certification and adhere to a stringent Code of Ethics. Certification is the process through which professionals can measure the knowledge and the competence required to provide proper tree care.