Types of Arborists

Below are some of the credentials available alongside regulatory agencies in-charge ordered by increasing hierarchy and designation.


Arborist Apprentice – Department of Labor

An arborist apprentice is an employee who is learning the Arborist trade from a skilled Journeyman. The program requires three years of training or 5,440 hours of paid on-the-job (OJT) training and classroom study. See breakdown of OJT below.

On-the-Job Training (OJT) – 5000 Hours

Apprentice will learn various work processes and competencies on the job.

Areas of OJT

  • Tree Trimming
  • Tree Climbing
  • Tree Disease, Diagnosis, and Treatment
  • Arborist skills
  • Equipment fundamentals
  • Aerial tree work
  • Rigging and tree removal
  • Tree biology and identification
  • Plant health care
  • Leadership in tree care operations
  • Communication skills

Classroom Study/Self-Study – 440 Hours

Using one-on-one approach and self-study, an apprentice will learn specific competencies required for the program.

Certified Tree Worker Climber Specialist – International Society of Aboriculture (ISA)

This certification is for tree workers who specialize in climbing work. To become certified as an ISA Tree Worker Climber Specialist, you must have the skill and endurance to climb trees, demonstrate strong knowledge of safe work practices, and be able to get the job done off the ground. A Tree Worker Climber has proficiency in the following:

– Climbs trees using specialized techniques to conduct tree pruning and removal;
– Knowledgeable in tree biodynamics for climbing and rigging procedures;
– Operates several sizes of chainsaws; and
– Able to work with equipments for dismantling larger or complicated trees.

Tree Risk Assessment Qualification (TRAQ) – International Society of Aboriculture (ISA)

The Tree Assessment Qualification (TRAQ) is a voluntary qualification program designed to train and assess candidates in a specialized field of arboriculture. When a professional earns the ISA TRAQ credential, they have specialized knowledge in tree risk assessment and proficient in these areas:

– The fundamentals of limited-visual and basic tree risk assessment. as defined in ISA Best Management Practice;

– understand the principles of advanced diagnostic techniques for assessing tree risk;

– know how to gather and synthesize information needed to assess tree risk; and

– can make reasoned judgements and recommendations for mitigating identified risk.

Certified Arborist – International Society of Aboriculture (ISA)

To earn an ISA Certified Arborist credential, you must be trained and knowledgeable in all aspects of arboriculture. ISA Certified Arborists must also adhere to the Code of Ethics that strengthens the credibility and reliability of the workforce. In addition before taking the exam the following requirements must be met:

– Three or more years of full-time, eligible, practical work experience in arboriculture; or
– A degree in the field of arboriculture, horticulture, landscape architecture, or forestry from a regionally accredited educational institute.

Journeyman Arborist – Department of Labor

A Journeyman Arborist is an experienced arborist having proficiency in all areas of tree care and must have completed a minimum of three years of training or 5,440 hours of paid on-the-job training and classroom study.

Member Arborist – American Society of Consulting Arborists (ASCA)

An ASCA member arborist has demonstrated higher skills in certain technical areas related to trees and tree care, providing objective, independent opinions with improved communication and presentation skills


Consulting Arborists are the authoritative experts on trees and bring an objective, comprehensive viewpoint to their clients—ensuring the safety, health, and preservation of trees. Consulting Arborist provide the following types of services:

– Contract Preparation and Supervision
– Diagnosis of Tree and Landscape Problems
– Expert Witness and Litigation
– Forensic Investigation
– Tree Assessments and Surveys
– Insect and Disease Identification and Management
– Municipal Ordinance Development
– Plant Health Care Programs
– Training and Education
– Tree, Landscape, and Nursery Appraisals
– Tree Management for Arboreta, Golf Courses, and Nurseries
– Tree Plant Inventories
– Tree Planting Programs
– Tree Protection for Construction Projects

Board Certified Arborist – International Society of Aboriculture (ISA)

The ISA Board Certified Master Arborist® credential is the highest level of certification offered by ISA. This credential recognizes ISA Certified Arborists® who have reached the pinnacle of their profession. 

Registered Consulting Arborist (RCA) – American Society of Consulting Arborists (ASCA)

An RCA has demonstrated higher skills in certain technical areas related to trees and tree care, providing objective, independent opinions, with training for higher communication, presentation, and/or report writing skills.

THIS SITE CONTAINS INFORMATION ON TREE CARE, LAWN CARE, AND PLANT CARE