Who We Are

ISA is a credentialing body that offers an internationally-recognized portfolio of professional arboriculture and urban forestry credentials designed to help improve tree care practices, advance tree worker safety, and enhance the professional image of credential holders. 

The ISA Credentialing Council is responsible for the development, review, evaluation, and administration of all policies and procedures as they relate to the credentials offered. The Council’s oversight of the various credentials helps to ensure they remain impartial, valid, technically accurate, and fair while being administered in accordance with approved and accepted credentialing standards and best practices. 

The activities of the Credentialing Council are managed by the ISA Executive Director and Director of Credentialing and monitored by the ISA Board of Directors. The structure of the Credentialing Council includes 7 to 10 voting members with a minimum of four ISA credential holders and two non-credential holders. The composition of the Credentialing Council is designed to ensure that a balanced diversity of subject matter experts with both industry and non-industry perspectives from a variety of geographic locations is included in its membership.  For more information, please view the Certification Program Policy and Procedure Statement.


  • Russell Ball, Chair
  • Adrienne Cadle, Vice-chair
  • Lucy Cohn-Still
  • Brandon Haley
  • Jamie King
  • Natalie McNeill
  • Pedro Mendes Castro
  • Colleen O'Sullivan
  • Aaron White
  • Simon Yu