CEU: 0.5
ISA Members: $9.95
Non-Members: $11.95
We tested the robustness of the assay using benchtop equipment with naturally infected samples. We then tested the assay directly in the field using a portable device. Results: The assay successfully detected R. lauricola directly from symptomatic wood tissue using crude DNA extracts. Furthermore, the assay readily allowed users to distinguish between symptoms caused by R. lauricola infection and similar symptoms caused by other agents. In-field, we assayed wood samples from symptomatic redbay (Persea borbonia [L.] Spreng) and sassafras (Sassafras albidum [Nutt.] Nees) across the Southeast and successfully detected R. lauricola-infected trees in less than an hour.
Conclusion: Results of this study confirmed that the field-deployable LAMP assay is robust and can rapidly and accurately detect R. lauricola in infected trees directly on-site. LAMP technology is well suited for in-field implementation, and these results serve as an incentive for further development and use of this technology in the field of forest pathology.
0.5 CEU (A, U, M, Bs, Bp)
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
The objective of this study was to identify and quantify the hazards present during arboricultural operations. The Occupational Safety and Health Administration Fatality and Catastrophe incident database and other Bureau of Labor Statistic sources were analyzed for arboricultural operation incidents within the 17-year period from 2001 through 2017.
There were 865 fatal and 441 nonfatal incidents reviewed from this period. The leading four fatal incidents, from the largest to the smallest number of fatalities, were climber falls, workers struck by a falling tree, workers making indirect contact with an electric current, and workers struck by a falling branch. Climber falls were also the leading incident for severe nonfatal injuries, followed by ground workers struck by a falling branch, workers struck by a chain saw, and falls by aerial device operators.
The American National Standards Institute Z133 American National Standard for Arboricultural Operations—Safety Requirements establishes safety requirements and recommendations for arboricultural operations in the United States. It addresses common hazard sources and has guidelines to avoid, eliminate, or reduce them. Safety training programs should emphasize the most common hazard sources for fatal and nonfatal incidents and follow the ANSI Z.
1 CEU (A, U, M, T, L, Bp)
CEU: 0.5
ISA Members: $9.95
Non-Members: $11.95
CEU: 2.0
ISA Members: $12.95
Non-Members: $15.95
Note: The accompanying publication is no longer sold by the ISA. You should only purchase this CEU Quiz if you already have prior access to the book.
This 40-question CEU quiz is based on the book The ABCs Field Guide to Young and Small Tree Pruning (©2012).
2 CEUs (A, U, M, T, L, Bp)
A score of 80% or higher is necessary to earn the CEUs.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
This study outlines a framework for creating urban-forest scenario models and reports the results of a case study conducted to highlight the ways in which decisions made at each stage of the scenario-development process impact its outcomes and application. Our case study focused on a neighbourhood in Vancouver, Canada, that is simultaneously undergoing urban densification and aiming to significantly increase canopy cover by 2050.
Our study demonstrates that a salubrious, resilient, and diverse urban forest can be created via a strategic program that complements extant trees in the public domain with planting programs along blue-green streets and on private property.
1 CEU (A, U, M, T, Bs, Bm)
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
1 CEU (A, U, M, T, L, Bp, Bs)
CEU: 1.0
ISA Members: $0.00
Non-Members: $13.95
An Analysis of Electric Distribution Tree-Caused Outages: Retrospective Case Series CEU Quiz. Article published in the July 2026 issue of Arboriculture & Urban Forestry.
Electric utilities spend billions of dollars annually clearing trees around power lines, while vegetation remains the leading cause of power outages at many utilities. Limited research exists to determine the cause of most power outages due to trees, particularly distribution-level outages. A team of utility urban foresters at a Mid-Atlantic electric utility in Virginia, USA, investigated over 1,104 outages caused by tree failures to identify characteristics of failed trees. Using an observational retrospective case series approach, data from afflicted (naturally fallen) trees directly involved in power outages were collected on a mobile phone application for each individual outage, including tree type (hardwood, softwood), genus, size (both diameter and height), tree defects and health status prior to the failure, and the type of failure—root, stem, or branch. After exclusion of incomplete or duplicated records, statistical tests on 844 outages evaluated simple associations using Chi-square and Cochran-Mantel-Haenszel (CMH) test, as well as probabilities using multiple (more than one factor), polytomous (more than two levels of response), nominal (categorical response levels), and logistic regression, with the main objective to identify factors associated with frequency of failed tree parts. This study found that most tree-caused power outages (TCOs) were the result of live trees failing at the trunk, and 46% of the failures had no visible defect prior to failure. While hardwood trees had more branch failures than softwood trees, overall, there was a low likelihood of branch failures. Some hardwood species were more likely than others to have branch failure; specifically, yellow poplar and maple, while pines were less likely, which was unexpected. Defects prior to failure were observed in only half of TCOs; however, of all trunk failures (n = 450), dead trees were 47.11%. This study highlights the importance of implementing the Utility Tree Risk Assessment Best Management Practices (BMPs) and expanding on existing methods to identify trees with either an elevated likelihood of failure and/or likelihood of impact. Purposefully managing an urban forest at a landscape scale requires knowledge of the species composition, size class, and how trees react to biological and physical factors in the environment. https://doi.org/10.48044/jauf.2026.016
1 CEU (A, U, Bm)
CEUs for this quiz may be earned only once during the life of your certification.
After purchasing, launch the quiz by visiting the Online Learning Center.
Arboriculture & Urban Forestry quizzes are available free online to members for one year after the date of publication; a maximum of six free quizzes are available at any time. CEU quizzes for older articles may be purchased by both members and non-members.
We recommend installing browser and device updates for the best experience. Google Chrome is the preferred browser.
Arboriculture & Urban Forestry is ISA’s bimonthly, peer-reviewed journal. This Open Access scholarly publication serves as ISA’s main outlet for disseminating new and original research findings centered on the care and management of trees in urban environments. Read more at https://auf.isa-arbor.com.
CEU: 0.5
ISA Members: $9.95
Non-Members: $11.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 0.5
ISA Members: $9.95
Non-Members: $11.95
The results of numerous pulling tests may be used to improve the quality of visual inspection through a better understanding of the biomechanical background and the actual performance and strength of trees.
The presentation accompanying this quiz illustrates what arborists who do not apply the pulling tests method themselves may learn for their own practice from the large number of tests carried out by consultants and researchers in the past decades.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 3.0
ISA Members: $14.95
Non-Members: $17.95
This 55-question online quiz is designed to accompany the book, Arboriculture & the Law. Do not purchase this quiz without having access to the book, which can be purchased on the ISA webstore here.
Read case examples and refer back to the text to find the correct answers to legal situations.
Earn 3 CEUs toward ISA recertification by completing this 55-question online quiz, which goes hand-in-hand with Arboriculture & the Law.
CEUs (A, U, T, M, L, Bm)
A score of 80% or greater is necessary to earn the CEUs. (©1992)
Please Note! This is a 55-question quiz, and currently there is no "Save Button", closing the quiz without finishing it and clicking "Submit" will erase all work! It is suggested that the pdf file of the quiz be printed, and filled out, so you can then transfer the answers online in a single session.
CEU: 3.0
ISA Members: $31.95
Non-Members: $39.95
Armored and Soft-Scaled Insects
Learn about the biology, life cycle, identification process, and management techniques of armored and soft-scaled insects.
This self-paced and interactive course supplements the Arborists' Certification Study Guide with a glossary of key terms, definitions, and pronunciations, and quiz questions that simulate certification exams.
Purchase of this course provides access for a three-year subscription period with unlimited attempts at completion. Eligible ISA credential holders will only receive CEUs for the first successful completion of the course within the three-year period. After three years, course access expires and the course may be repurchased, allowing for new completions.
3 CEUs (A, U, T, M, L, Bs). CEUs can be earned from this course once per recertification cycle.
After purchasing, launch the course by visiting the Online Learning Center.
Online courses are for individual use only.
We recommend installing browser and device updates for the best experience. Google Chrome is the preferred browser.
To help mitigate any potential connectivity issues, we ask that you take a screenshot/picture of your score; if the score does not save, or your CEUs do not apply, you may email the screenshot to our Customer Service Team at isa@isa-arbor.com so that your results can be input manually.
Any educational or preparatory material, whether published by ISA or not, should NOT be considered the sole source of information for an ISA certification examination. This publication and the ISA certification program exams are developed through separate processes and entities.
CEU: 0.5
ISA Members: $9.95
Non-Members: $11.95
CEU: 0.5
ISA Members: $9.95
Non-Members: $11.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 2.0
ISA Members: $26.95
Non-Members: $33.95
Bark Beetles
Learn how to diagnose, prevent, and respond to bark beetles with the industry's best management techniques. This course covers: bark beetle biology, tree vulnerability, diagnosis, and management.
This self-paced and interactive course supplements the Arborists' Certification Study Guide with a glossary of key terms, definitions, and pronunciations, and quiz questions that simulate certification exams.
Purchase of this course provides access for a three-year subscription period with unlimited attempts at completion. Eligible ISA credential holders will only receive CEUs for the first successful completion of the course within the three-year period. After three years, course access expires and the course may be repurchased, allowing for new completions.
2 CEUs (A, U, T, M, L, Bp). CEUs can be earned from this course once per recertification cycle.
After purchasing, launch the course by visiting the Online Learning Center.
Online courses are for individual use only.
We recommend installing browser and device updates for the best experience. Google Chrome is the preferred browser.
To help mitigate any potential connectivity issues, we ask that you take a screenshot/picture of your score; if the score does not save, or your CEUs do not apply, you may email the screenshot to our Customer Service Team at isa@isa-arbor.com so that your results can be input manually.
Any educational or preparatory material, whether published by ISA or not, should NOT be considered the sole source of information for an ISA certification examination. This publication and the ISA certification program exams are developed through separate processes and entities.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
This article explores the various ecosystem services insects provide, differentiate between "beneficials" and "pests," and discuss the use of biocontrol for the suppression of urban landscape pests.
1 CEU (A, U, M, T, L, Bs, Bp)
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
This quiz corresponds to BMP—Integrated Vegetation Management, Third Edition (2021). Do not purchase this quiz without having access to the BMP, which can be purchased on the ISA webstore here.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
ISA has developed a series of Best Management Practices (BMPs) for the purpose of interpreting tree care standards and providing guidelines of practice for arborists, tree workers, and the people who employ their services.
1 CEU (A, U, M, T, L, Bp)
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
1 CEU (A, U, M, T, Bm, Bp)
CEUs for this quiz may be earned only once during the life of your certification.
ISA has developed a series of Best Management Practices (BMPs) for the purpose of interpreting tree care standards and providing guidelines of practice for arborists, tree workers, and the people who employ their services.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
1 CEU (A, U, T, M, L, Bp, Bs)
ISA has developed a series of Best Management Practices (BMPs) for the purpose of interpreting tree care standards and providing guidelines of practice for arborists, tree workers, and the people who employ their services.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
This 2nd edition print contains 11 full-color images, including updated and brand-new illustrations.
1 CEU (A, U, M, Bs, Bp)
CEUs for this quiz may be earned only once during the life of your certification.
ISA has developed a series of Best Management Practices (BMPs) for the purpose of interpreting tree care standards and providing guidelines of practice for arborists, tree workers, and the people who employ their services.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
1 CEU (A, U, M, T, L, Bm)
CEUs for this quiz may be earned only once during the life of your certification.
ISA has developed a series of Best Management Practices (BMPs) for the purpose of interpreting tree care standards and providing guidelines of practice for arborists, tree workers, and the people who employ their services.
CEU: 1.0
ISA Members: $10.95
Non-Members: $13.95
It also serves as a companion publication to the ANSI A300 Part 9: Tree, Shrub, and Other Woody Plant Management—Standard Practices (Tree Risk Assessment a. Tree Failure) (©2020, softcover, 95 pp., glossary, appendices).
1 CEU (A, U, T, L, Bp, Bm)
ISA has developed a series of Best Management Practices (BMPs) for the purpose of interpreting tree care standards and providing guidelines of practice for arborists, tree workers, and the people who employ their services.