The Certified Arborist Exam is administered by the International Society of Arborists (ISA) to assess your knowledge and skills in the field of arboriculture.
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Certified Arborist Exam Eligibility
In order to apply to become a Certified Arborist, you must fulfill at least one of the following requirements:
You must have at least three years of full-time experience in arboriculture. Some of the many eligible duties include cabling and bracing, fertilization, pruning, and the diagnosis and treatment of tree problems. Example employers include municipalities, landscape companies, tree care companies, and nurseries.
You can submit supervised volunteer work, as long as you can provide documentation providing the hours worked and responsibilities. To validate work experience, you must submit a letter of reference from previous or current employers. If you are self-employed, you must submit three letters of reference.
Education
You may fulfill the eligibility requirements by completing a university-accredited degree program with additional practical experience in arboriculture or by completing an assessment-based certificate program.
Certified Arborist Exam Outline
The Certified Arborist exam contains 200 multiple-choice questions, and you will have 3.5 hours to complete the exam.
The questions are split into ten domains. Each domain contains multiple tasks, and each task contains a set of knowledge-based and skills-based areas.
1. Tree Biology (11%)
TASK A:
Recommend and specify tree work based on knowledge of tree anatomy, biomechanics, and physiology.
Knowledge
- Anatomy and functions of roots, trunks, leaves, twigs, and branches
- Photosynthesis
- Respiration
- Energy allocation and storage within a tree
- Tree profiles
- Tree identification
- Mechanical stress and response growth
- Growth habits and stages
- Water movement within the tree
- Morphophysiology
Skills
- Identifying trees
- Making management and maintenance recommendations based on structural and physiological needs
- Making management and maintenance recommendations based on the developmental stage of the tree
TASK B:
Explain the life cycle of a tree and develop tree work recommendations based on developmental needs and tree growth.
Knowledge
- Vegetative growth
- Tree death
- Phenology
- Environmental effects and responses
- Propagation
- Reproduction
Skills
- Developing maintenance recommendations based on condition and life cycle
2. Identification and Selection (9%)
TASK A:
Describe the importance of proper tree identification when it comes to tree management.
Knowledge
- The relationship among tree species characteristics, accurate tree identification, and problem diagnosis
Skills
- Using tree identification reference materials
- Using tree identification systems
TASK B:
Explain tree classification systems and utilize appropriate nomenclature during tree identification and communication.
Knowledge
- General tree classification
Skills
- Using and notating plant-specific names in communication and report writing
TASK C:
Describe important physical and morphological structures used in the identification of tree species.
Knowledge
- Leaf anatomy, types, arrangements, and characteristics
- Root, branch, twig, and trunk anatomy
- Tropical and desert tree characteristics
- Fruits
- Seeds and seedpods
- Flower and inflorescence types
- Tree profiles
Skills
- Collecting tree samples that aid in identification of the tree
- Recognizing notable features in key anatomical structures
- Utilizing available tree identification resources and tools
TASK D:
Select trees appropriate for a given planting site and project needs, taking into consideration short-term and long-term requirements and maintenance goals.
Knowledge
- Tree species characteristics
- Considerations and potential vulnerabilities of specific species
Skills
- Collecting and analyzing soil samples
- Assessing site characteristics
- Selecting a tree species that will thrive at a given site
- Recommending tree species for the planting site
- Communicating tree requirements and site considerations
- Making recommendations based on tree requirements and site considerations
3. Soil Management (7%)
TASK A:
Assess the chemical, biological, and physical components of soil and its relationship in supporting tree development and growth.
Knowledge
- Industry standards for soil management
- Biological components of soil
- Chemical characteristics of soil
- Physical characteristics of soil
- Soil formation and horizons
- Relationship between root distribution and soil
- Soil sampling methods
- Urban soils
Skills
- Collecting and testing soil samples
- Interpreting test results
- Analyzing soil characteristics
TASK B:
Explain the interaction between soil and water and how it affects tree growth and development, list management options when needed, and assess site conditions.
Knowledge
- Water movement and drainage
- Supplemental water systems
- Water budgets
- Soil structure
- Water behavior in soil
- Local climatic conditions affecting availability and uptake of water from soil
- Relationship among soil characteristics, water, and drainage
Skills
- Assessing water-holding capacity and drainage
- Recommending methods for effective water management
TASK C:
Plant and transplant trees according to industry standards and best practices.
Knowledge
- Soil management and amendments
- Types of fertilizer
- Tree nutritional and uptake requirements
- Fertilization application timing and techniques
- Soil volume and structure requirements for trees
Skills
- Recommending soil management and development strategies to support tree growth and development in urban areas
- Recommending and applying fertilizer on a needs basis, according to applicable industry standards
- Identifying soil improvement and remediation strategies
4. Installation and Establishment (9%)
TASK A:
Plant and transplant trees according to industry standards.
Knowledge
- How the nursery industry propagates and grows trees
- Advantages and disadvantages of different nursery stock types
- Industry-standard planting and transplanting practices
- Planting timing
- Backfilling
- Root ball interaction with soil and planting hole
- Proper tree placement
- Impact of soil amendments
Skills
- Assessing the quality and health of planting stock
- Pruning roots and shaving root balls to prevent girdling
- Transplanting trees
- Handling planting stock
- Removing root ball package materials
- Preparing the planting site
- Backfilling and adding soil to support tree establishment
TASK B:
Provide care for newly planted trees to ensure growth, good structure, and survival.
Knowledge
- Tree species characteristics
- Trunk wrap and support systems
- Environmental and cultural requirements for different tree species
Skills
- Determining watering requirements
- Selecting and applying mulch
- Recognizing inappropriate planting techniques
- Pruning young trees for good structure
- Installing support for newly planted trees
- Recommending plant health care plans
- Including and engaging local stakeholders to ensure long-term maintenance
5. Pruning (14%)
TASK A:
Explain why pruning is undertaken and list the main industry-standard pruning systems, types of cuts, general practices, and objectives.
Knowledge
- Pruning practices and considerations in relation to optimal timing and quantity
- Pruning objectives
- Accepted industry standards for tree pruning
- Wound response
- Outcomes of tree pruning
Skills
- Communicating how tree pruning promotes good structure
- Assessing site and tree conditions that influence pruning decisions
- Explaining the difference between unacceptable and acceptable pruning techniques to a lay audience
TASK B:
List commonly used industry-standard pruning tools and their uses.
Knowledge
- Chainsaws
- Scissor-type tools
- Pruning saws
Skills
- Selecting the appropriate pruning tool for a given scenario
- Cleaning and maintaining pruning tools
- Handling pruning tool according to best practices
TASK C:
Recommend and execute tree pruning in a way that minimizes impact and promotes longevity.
Knowledge
- Compartmentalization of decay in trees
- Root and utility pruning
- Improper pruning techniques
- Safety standards and requirements for working near electrical systems
- Anatomy and physiology of tree parts, branches, and branch unions
- Types of pruning cuts
- Disinfection of tools
- ISO 11681-2:2011/AMD 1:2017
Skills
- Determining where the pruning cut should be according to the branch union anatomy and best practices
- Writing pruning specifications and objectives
- Sequencing cuts to facilitate the ease of handling removed materials
- Minimizing the potential for bark tearing beyond the point of branch attachment
- Predicting tree response to pruning cuts depending on the tree species, timing, age, wound size, and overall health of the tree
TASK D:
Explain pruning practices that are detrimental to tree health and longevity.
Knowledge
- Consequences of improper cuts on tree health and structure
- Harmful pruning practices
Skills
- Anticipating potential impacts of detrimental pruning practices to tree health and structure
- Explaining why certain pruning strategies, cuts, and wound dressings may be detrimental to tree health and longevity
6. Diagnosis and Treatment (9%)
TASK A:
Explain and implement diagnostic principles and practices.
Knowledge
- Tree identification
- Common biotic and abiotic stresses and disorders
- Diseases
- Difference between signs and symptoms
- Difference between biotic and abiotic disorders
Skills
- Identifying the causes of common tree health problems
- Identifying emerging regional problems and trends in plant pests and disease recognition and monitoring
TASK B:
Explain plant health care and integrated pest management principles.
Knowledge
- PHC and IPM principles
- Compounding factors
- Stress factors
TASK C:
Develop and implement a plant health care management plan that takes integrated pest management into consideration and a holistic view of the landscape and environmental needs.
Knowledge
- PHC and IMP principles
- Tree identification
- Standards and laws associated with chemical control use, proper waste management, storage, and application
- Tree diagnostics and treatment
Skills
- Developing and implementing a PHC management plan
- Communicating findings and associated management plans and recommendations
- Monitoring pest resurgence, treatment success, and follow-up care
7. Trees and Construction (9%)
TASK A:
Develop and implement tree protection plans for individual trees or tree populations that are on or near construction, development, or demolition sites.
Knowledge
- TPZ and CRZ
- Accepted industry standards related to trees and construction
- Species-specific resilience/vulnerability to construction
- Tree protection measures
- Site plans
- Construction phases
- Roles of developers and contractors withing a tree protection plan
- Methods for root and soil protection
Skills
- Interpreting a site plan
- Coordinating tree protection activities with contractors and developers
- Assessing the effectiveness of tree protection plans
- Recommending measures to protect trees from damage before and during construction
- Utilizing the site plan to aid in implementing the tree protection plan
TASK B:
Predict the impact of construction activities on tree health and stability.
Knowledge
- Construction practices and techniques
- The impact of construction activity on tree health and stability, trunk, branches, and root systems
TASK C:
Recommend treatments for trees that have been impacted during construction.
Knowledge
- Short-term and long-term impact of construction on a tree’s longevity
- Conditions w3hen tree removal and replacement is necessary
Skills
- Assessing risk related to construction injury to the tree
- Developing a treatment and mitigation plan
- Providing care to the tree to promote recovery
- Recommending short-term and long-term treatments to promote recovery
8. Tree Risk (11%)
TASK A:
Identify and communicate the roles and responsibilities of different parties involved in tree risk management.
Knowledge
- Roles and responsibilities of the risk assessor
- Roles and responsibilities of the tree owner/manager
- Roles and responsibilities of the arborist
Skills
- Communicating risk and risk management with a diverse audience
TASK B:
List the types of risk associated with trees.
Knowledge
- Tripping
- Slipping
- Whole tree vs. tree part failure
- Other potential risk sources
TASK C:
Perform a limited visual tree risk assessment of an individual tree or a population of trees near specified targets.
Knowledge
- Site analysis
- Assessment levels
- Tree stability
- Tree analysis
- Mitigation of tree risk
Skills
- Identifying obvious tree defects and conditions that may increase the likelihood of failure
- Determining the interval of inspections
- Determining which level of assessment is necessary under various circumstances
- Recommending measures to mitigate tree risk
9. Safe Work Practices (15%)
TASK A:
Explain and comply with industry safety standards, regulations, local laws, and directives for performing tree work and ensuring the safety of climbers, workers, and other persons near the work zone.
Knowledge
- Industry safety standards and requirements
- Industry safety standards and requirements regarding working near electrical systems
- ISO 11681-2:2011/AMD 1:2017
- Work-zone security, communication, and work planning best practices
- Fire safety
Skills
- Referring to relevant laws and regulations from all levels of government
- Accessing and maintaining reference materials
TASK B:
Develop safety protocols to mitigate risk present within the tree of interest, work site, or equipment being used.
Knowledge
- Command and response communication system
- Local plants and animals that are potential hazards to workers
- Signs and symptoms of trunk and root decay
- Species-related patterns of whole tree or tree part failure
- Fire safety
- Mechanical or physical damage done to a tree and/or root system
- Ergonomics
- Visual tree inspection
- Common defects in trees
Skills
- Reviewing documentation
- Determining if the tree can withstand the necessary work forces
- Securing hazardous materials when not in use
- Managing traffic hazards
- Assessing tree structure
- Preparing the work zone
- Visually identifying obvious tree defects and conditions
- Visually inspecting the immediate surroundings of the tree
- Developing and communicating a job briefing
TASK C:
Comply with safety standards when working near electrical hazards.
Knowledge
- Basic properties of electricity
- Common electrical systems and other services
- Minimum approach distances
- Sources of electrical shock
Skills
- Identifying what stage of electrical distribution the line is carrying
- Maintaining minimum approach distances
- Identifying electrical hardware and line features
- Wearing personal protection equipment
TASK D:
Utilize tools and equipment to safely conduct tree work.
Knowledge
- Pruning saws
- Large equipment and vehicle applications
- Scissor-type tools
- Chippers and stump grinders
- Aerial lifts
Skills
- Recognizing operational flaws
- Coordinating arboriculture work with large equipment vehicle operators
- Inspecting tools and equipment for sustainability
- Selecting the appropriate mechanical or hand tools to perform arboricultural work
- Using mechanical and hand tools in accordance with manufacturing specifications
TASK E:
Utilize appropriate personal protective equipment to protect the health and safety of the arborist.
Knowledge
- Head protection systems
- Eye protection systems
- Hearing protection
- Leg, foot, and hand protection
- Industry-standard tree-climbing saddle/harness, connecting links, and spurs/gaffs
- Other PPE according to local regulations
Skills
- Selecting and inspecting appropriate PPE
- Wearing, adjusting, and maintaining PPE
- Selecting tree-climbing equipment that is appropriate for project specifications and meets regulations and industry standards
TASK F:
Explain critical climbing tasks necessary to perform tree work safely.
Knowledge
- Climbing ropes and rope systems used in arboriculture
- Climbing techniques used for tie in and ascent
- Procedures for a safe and controlled ascent, descent, and tree work while aloft
- Knots or rope tools which provide safe entry and activity in the tree
TASK G:
Explain methods and techniques for tree-rigging used in arboriculture.
Knowledge
- Tree-rigging hardware, techniques, and systems
- Tree characteristics and strength in relation to anchor point and anticipated forces in use during rigging
TASK H:
Remove trees using appropriate techniques to ensure accuracy and safety as well as processing the tree parts.
Knowledge
- Techniques for felling
- Work positioning techniques to reduce repetitive strain injuries and minimize exposure to chainsaw kickback
- Chainsaw safety features
- Cutting techniques
- Techniques for aerial dismantlement
- Tree-removal safety hazards
Skills
- Developing a felling strategy
- Developing a felling escape route strategy
- Work positioning to maximize comfort and control and minimize exposure to kickback while handling a chainsaw
- Selecting and recommending appropriate tools to achieve directional control
TASK I:
Aid in providing care or oversight during emergency situations involving physical harm or hazardous conditions that pose a safety risk to the arborist, other workers, and other persons near the work zone.
Knowledge
- CPR
- Aerial rescue
- Emergency action plan
- First aid
Skills
- Communicating with emergency responders
- Assessing environmental hazards
- Documenting and communicating with stakeholders after an emergency
TASK J:
Promote the importance of safety and training of safety procedures and behaviors.
Knowledge
- Safety procedures
- Importance of safety training
- Relevant guidelines and standards for arboriculture work
Skills
- Communicating the benefits of safety training and procedures
10. Urban Forestry (6%)
TASK A:
Discuss the aesthetic, ecological, economic, environmental, social, and health benefits of urban forests and trees.
Knowledge
- Aesthetic benefits of trees
- Environmental benefits of trees
- Economic benefits of trees
- Sociological benefits of trees
- Health benefits of trees
- Benefit-cost ratio (BCR) and return on investment (ROI) associated with trees
Skills
- Discussing benefits, tradeoffs, and investment associated with trees with different stakeholders
- Recording appropriate tree attributes for calculating tree value
- Using established tree value calculators to determine the value of tree
TASK B:
Explain accepted plant appraisal principles and approaches.
Knowledge
- Appraisal approaches
- Community tree benefits
- Real estate value improvement
TASK C:
List possible regulatory ordinances and laws concerning trees.
Knowledge
- Regional laws concerning wildlife management and habitat protection
- Ordinances and tree preservation orders
- Potential local laws and regulations
- Regional permitting and licensing procedures
Skills
- Accessing and maintaining reference materials
- Referring to relevant laws and regulations from all levels of government
TASK D:
Utilize tools and equipment to safely conduct tree work.
Knowledge
- Sustainable initiatives
- Tree inventories
- Pests and diseases management
- Pruning/maintenance cycle
- Diversity of species management and planning
- Invasive species management
- Planting plans, initiatives, and canopy cover goals
Skills
- Collecting tree data onsite
TASK E:
Inform the public and various stakeholders regarding proper tree care and management practices.
Knowledge
- Industry-standard maintenance practices and tree care for trees in an urban environment
Skills
- Communicating with a diverse audience
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Certified Arborist Exam Registration
You may apply for the Certified Arborist Exam on the ISA website, through the “My ISA Dashboard.” After submission, you will receive an approval or denial email from ISA. In the approval email, there will be a link to sign up for the exam.
After enrollment, candidates who requested a pen and paper exam will receive a confirmation packet with the location, date, and time of the exam, as well as a contact person. Applicants who requested a computer-based exam will receive an email with a link to schedule the test.
Exam Fees
Members of ISA, an ISA chapter, or an affiliated organization pay $170 for the exam. The fee for nonmembers is $280 USD. If you request the computer-based exam, there is an additional $125 administration fee.
If you need an additional 90-day authorization period to reschedule the exam, there will be a $50 fee.
Test Day
Testing location depends on whether candidates are taking the exam through an ISA chapter, affiliate organization, or separately. Some of the common procedures and tips are listed below.
- Please arrive at the testing center 30 minutes before the start of the exam.
- Bring two forms of identification. One ID must have a photograph, while the other ID must have your signature.
- You are allowed to take bathroom breaks, but that time is considered your exam time.
- Food, beverages, reference materials, books, papers, cell phones, and other mobile devices are prohibited.
If you are taking the computer-based exam, you will receive your test results immediately after the exam. Applicants taking the paper-based exam will receive their results in six weeks.
If you pass the test, you will receive a certificate, score sheet, congratulatory letter, identification card, patch, and hard-hat decal. If you do not pass the exam, you have one year from the original test day to retake the exam. The first retake is free, and any retake after that is $75. If you retake the test after the one-year window, you are required to pay the full amount, including the $125 administration fee, if taking the computer-based exam.
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How to Study for the Certified Arborist Exam
How to Study Effectively
Your success on Certified Arborist test day depends not only on how many hours you put into preparing but also on whether you prepared the right way. It’s good to check along the way to see whether your studying is paying off. One of the most effective ways to do this is by taking Certified Arborist practice tests to evaluate your progress. Practice tests are useful because they show exactly where you need to improve. Every time you take a free Certified Arborist exam practice test, pay special attention to these three groups of questions:
- The questions you got wrong
- The ones you had to guess on, even if you guessed right
- The ones you found difficult or slow to work through
This will show you exactly what your weak areas are and where you need to devote more study time. Ask yourself why each of these questions gave you trouble. Was it because you didn’t understand the material? Was it because you didn’t remember the vocabulary? Do you need more repetitions on this type of question to build speed and confidence? Dig into those questions and figure out how you can strengthen your weak areas as you go back to review the material.
Answer Explanations
Additionally, many Certified Arborist practice tests have a section explaining the answer choices. It can be tempting to read the explanation and think that you now have a good understanding of the concept. However, an explanation likely only covers part of the question’s broader context. Even if the explanation makes sense, go back and investigate every concept related to the question until you’re positive you have a thorough understanding.
Comprehend Each Topic
As you go along, keep in mind that the Certified Arborist practice test is just that: practice. Memorizing these questions and answers will not be very helpful on the actual test because it is unlikely to have any of the same exact questions. If you only know the right answers to the sample questions, you won’t be prepared for the real thing. Study the concepts until you understand them fully, and then you’ll be able to answer any question that shows up on the test.
Strategy for Certified Arborist Practice
When you’re ready to start taking practice tests, follow this strategy:
- Remove Limitations. Take the first test with no time constraints and with your notes and Certified Arborist study guide handy. Take your time and focus on applying the strategies you’ve learned.
- Time Yourself. Take the second practice test “open book” as well, but set a timer and practice pacing yourself to finish in time.
- Simulate Test Day. Take any other practice tests as if it were test day. Set a timer and put away your study materials. Sit at a table or desk in a quiet room, imagine yourself at the testing center, and answer questions as quickly and accurately as possible.
- Keep Practicing. Keep taking practice tests on a regular basis until you run out of practice tests or it’s time for the actual test. Your mind will be ready for the schedule and stress of test day, and you’ll be able to focus on recalling the material you’ve learned.
FAQs
Q
How hard is the Certified Arborist exam?
A
The exam is not considered to be a difficult exam, especially if you study adequately before you take it.
Q
How many questions are on the Certified Arborist exam?
A
The exam contains 200 multiple-choice questions.
Q
How long is the Certified Arborist exam?
A
The time limit for the exam is 3.5 hours.
Q
What is a passing score for the Certified Arborist exam?
A
You need to score 76% to pass the exam. You need to respond correctly to 152 questions to maintain a 76%.
Q
How much does the Certified Arborist exam cost?
A
For ISA members, the exam costs $170. The general admission cost is $280.
