Science of Arboriculture Podcasts

In the presentation accompanying this CEU Quiz, Dennis Swartzell brings to light the extreme drought of the southwest USA and recent mandates to remove turf grass in nonresidential spaces. Unfortunately, trees located in these turf areas are subject to severe stress when the landscape conversion is conducted inappropriately. The presenter will highlight the best management practices for selection, retention, protection, and preservation of existing trees within an arid environment.

Watch the presentation here before taking this CEU quiz.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bs)

CEUs for this quiz may be earned only once during the life of your certification.

Veteran trees have great ecological value but above all are a cultural phenomenon. Veteran trees’ management cannot be limited to the arboricultural aspects; it must extend to the anthropological and social reasons that justify their existence. The Emilia-Romagna region has defined laws for veteran trees’ protection, management, and enhancement. The Great Mulberry (Morus alba L.)  of Cervia is an emblematic case of management of a veteran tree in full compliance with the law’s principles, and it is discussed in the presentation accompanying this CEU. More than ten years ago, after the tree experienced severe structural failures, the Municipality of Cervia decided to implement a program for the tree’s recovery, including rooting site protection, root activity promotion, implementation of a support and cabling system, and a long-term pruning plan. The mulberry tree, which can now be said to have been brought back to a condition of ordinary management, has become an emblematic case study, so much so that it has been included in training programs.

Watch the presentation here before taking this CEU quiz.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bm)

CEUs for this quiz may be earned only once during the life of your certification.

The terms girdling and ring-barking tend to be used synonymously in arboriculture, but in the presentation accompanying this CEU quiz, Dr. Greg Moore argues that these are two distinctly different processes, both in the actions taken by arborists and in the effects these processes have on trees. This presentation discusses research surrounding girdling and ring-barking, including tree responses, consequences of damage, and restorative measures. In discussing the two types of cuts, Dr. Moore shares how trees can often survive various levels of damage from either type of cut.

Watch the presentation here before taking this CEU quiz.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bs)

CEUs for this quiz may be earned only once during the life of your certification.

In the related presentation, Riley Rouse discusses modification methods for addressing root defects of container-grown trees. Growing trees in standard smooth-sided containers can lead to malformed root systems, especially circling roots. A great number of techniques are often suggested by industry professionals to remediate root defects prior to planting. In the discussed trial, three shade tree species commonly listed as “difficult to transplant” when lifted as bare-root stock (Carpinus caroliniana, Ostrya virginiana, and Liriodendron tulipifera) and one species that is “easy to transplant” bareroot (Platanus × acerifolia) were subjected to four root modification treatments: deep slicing, shaving, bare-rooting, and control. A subset of bare-root and control trees were subjected to compensatory pruning to investigate the potential to mitigate negative crown impacts following root treatments at planting. Bare-rooting reduced survival of the species that are commonly regarded as difficult to transplant as bareroot stock. Measurements of plant water relations suggest that mortality was related to increased moisture stress associated with root and substrate removal.

0.5 CEU. (A, U, T, M, L, Bp)

This presentation discusses the numerous benefits of setting tree cover canopy goals. Ground-level tree planting is relatively straightforward, but more tree planting opportunities exist on rooftops and other elevated structures, which comprise a significant percentage of urban impervious surface. The functionality of these rooftop oases can be dramatically increased when complimented with large maturing trees. However, growing and anchoring trees on elevated structures present many challenges, such as ensuring wind stability, managing weight and minimizing risk from multi-story branch drop. This presentation defines, explores, discusses, and addresses these challenges and increases your knowledge of horticultural systems specialized for high-elevation urban trees.

Watch the presentation before taking this CEU quiz. 0.5 CEU credits. (A, U, T, M, L, Bp)

CEUs for this quiz may be earned only once during the life of your certification.

This presentation discusses specifics of soil testing, including proper management practices and components to be aware of when testing. Increasingly, the importance of soil testing before prescribing use of fertilizers is recognized, but all soil tests are not created equally; agricultural soil metrics are not appropriate for use in landscapes. Moreover, relevant soil test data can be correlated with careful site observations to learn more about what constitutes sustainable levels of organic matter and nutrient levels. Learning how to interpret soil tests by ground-truthing with site conditions allows arborists and landscape managers to understand how rhizospheres are currently functioning and what, if anything, should be added.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bp)

CEUs for this quiz may be earned only once during the life of your certification.

While aging urban trees provide a wealth of benefits to the residents who live amongst them, they may also begin to pose more risk, and as urban centres become increasingly dense, trees, people and infrastructure often come into conflict. Balancing these competing interests while looking out for the trees can be a real challenge. Today’s arborists can choose from a wealth of methods to better manage and assess the risk of trees. The recently introduced ANSI A300 Part nine describes three levels of risk assessment. By presenting a series of case studies, this talk will focus on how advanced risk assessment methods (Level 3) are being used to better understand the likelihood of failure and to contribute useful information used in the development of conservation management strategies for aging and significant urban trees.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bm)

CEUs for this quiz may be earned only once during the life of your certification.

En esta presentación, Carlos Llanos habla de las intervenciones incorrectas, aplicadas a los árboles en las ciudades y en todas las latitudes, que dañan gravemente a los árboles adultos. A corto plazo, estos árboles no pueden reemplazar las funciones de soporte y nutrición que realizan sus raíces y, mientras el árbol permanezca abierto, hongos, insectos y otros patógenos pueden ingresar a través de los cortes. La improvisación hace que se produzcan varias podas de raíces en el mismo árbol y conduce al colapso del árbol con consecuencias que todos conocemos en algunos casos dramáticos.

Esta prueba vale 0.5 CEU. (A, U, T, M, L, Bs [0.25], Bp [0.25])

Las CEU de esta prueba pueden obtenerse sola una vez durante el período de certificación.

CEU quiz in Spanish. In this presentation, Carlos Llanos describes how the incorrect interventions applied to trees in cities and in all latitudes severely injure adult trees. In the short term, these trees are unable to replace the support and nutrition functions performed by their roots, and, as long as the tree remains exposed, fungi, insects, and a number of other pathogens can enter through the cuts. Improvisation can result in root pruning in multiple places on the tree, which can lead to the collapse of the tree with consequences we're all familiar with in some dramatic cases.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bs [0.25], Bp [0.25])

CEUs for this quiz may be earned only once during the life of your certification.

With the adoption of the newly revised ANSI A300 standard for managing trees on construction sites, the International Society of Arboriculture updated the best management practices. This presentation reviews the new standard and discusses both the science and practice behind the changes. The presentation is highly recommended for arborists who deal with construction protection for tree.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bm)

CEUs for this quiz may be earned only once during the life of your certification.

Kaitlyn Pike presents a follow-up to a study exploring the efficacy of a comprehensive tree preservation ordinance. Pike’s study details how surveyed homeowners view trees and nature on their private property and how these views may differ between types of homeowners. The results show that homeowners are largely uninformed about the home development process and its impact on the urban canopy, and that they are even removed from decisions about their own yard. The study covered in this presentation emphasizes the importance of an ordinance that requires tree preservation during construction.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bm)

CEUs for this quiz may be earned only once during the life of your certification.

Vegetation management is typically one of a utility’s largest budget items. Presently, identification of high-risk trees near utility lines is labor intensive, time consuming, and costly. In this presentation, Ryan Suttle and Nasko Apostolov share a study that describes a machine-learning approach which trains a novel convolutional neural network (CNN) to automatically classify trees, using only a single photograph and with a high degree of accuracy, into likelihood of failure categories. The CNN’s high degree of accuracy demonstrates the potential of artificial intelligence to automate risk assessment and consequently to reduce costs. Preliminary results are extremely promising for future study and improvement.

This quiz is worth 0.5 CEU credits. (A, U, T, M, L, Bm)

CEUs for this quiz may be earned only once during the life of your certification.