Arborist News

Urban environments and tree species composition affect the species diversity of urban decay fungi. The common and important decay fungi of urban trees in North America have similar characteristics that lend themselves to decaying and fruiting on urban trees. For arborists, this is an important point, as urban conditions potentially reduce the number of important fungi that they are likely to encounter. In this article, the “Big Five” common and important decay fungi of urban trees are reviewed. 1 CEU (A, U, M, T, L, Bs, Bp)

Support systems are installed to mitigate risk associated with certain defects, such as weakly attached and overextended branches. There are four main types of support system: cables, braces, guys, and props. The systems can be used alone or in combination to optimize support for trees while minimizing physiological stress. This article will focus on two support systems: cabling and bracing. It will describe the situations in which cabling and bracing systems may be appropriate; objectives and types of systems; hardware, tools, and techniques used to install them; and their limitations. 1 CEU (A, U, M, T, L, Bp, Bm)

Urban trees often struggle to survive, reducing their ability to provide the shade and ecosystem services needed in our cities. One of the key limitations of tree health is the poor quality of urban soils. While soil compaction is often cited as the primary challenge for urban trees, a wide variety of other factors contribute, including salinity, alkalinity, water scarcity, poor drainage, and altered biological activity. Active soil management both at time of planting and for existing trees is a powerful tool for arborists and urban foresters in their quest to cultivate a healthy urban forest. 1 CEU (A, M, Bs, Bp)

Sonic tomography is an advanced technology used to detect internal defects in trees which cannot be seen from the outside without having to resort to invasive drilling. It produces a two-dimensional image called a tomogram that can be interpreted to estimate the size of defects within the tree. The technology is used in Level 3 Tree Risk Assessments to supplement other observable conditions and to help provide a more complete understanding of the risk associated with a tree, along with better informed options for mitigating risk. 1 CEU (A, M, T, L, Bs, Bm)

IVM control methods include biological, chemical, cultural, prescribed fire and physical. Integrated vegetation management (IVM) best management practices (BMP) are to select the control method best suited to vegetation and site conditions and most often multiple control methods should be integrated for best results. Whenever possible biological methods should be implemented to establish plant communities that will never interfere with management goals and maintenance objectives. 1 CEU (A, U, M, Bp, Bs)

As arborists and urban foresters, we make management decisions that take minutes to enact, yet may have impacts on our community for decades. In doing so, we effectively decide what trees future generations will have to enjoy. Shoddy planting, an affinity for monocultures, and an underappreciation for the rarity of large, established trees have all diminished today’s urban forests to some extent. This article draws on past research to offer new insights into a familiar topic while dispelling a few myths that continue to persist within the tree care industry. 1 CEU (A, M, T, Bp)

Trees require soil for support, water, and nutrients. Soil quality is a concern for arborists and urban foresters because it directly influences tree and shrub establishment, stability, growth, health, and longevity. High-quality soils enable trees to grow and thrive, while poor-quality soils hinder establishment, slow growth, and shorten longevity. In order to recommend soil modifications, develop management or soil conservation recommendations, and provide information to match plant species with site conditions, it is important for arborists to perform a soil assessment. 1 CEU (A, U, M, T, Bp, Bs)

With the spotlight in the United States and elsewhere focused on invasive insects such as Asian longhorned beetle, emerald ash borer, and spotted lanternfly, it has been easy to overlook native insects that are also key pests in ornamental landscapes and urban forests. Native woodborers, in particular, can be very devastating and difficult to manage. By consuming vascular tissue under the bark of the trunk and main branches, borers sever the vital pipeline between the canopy and the roots, disrupting the essential movement of nutrients, water, and carbohydrates. In this article, author Daniel Herms discusses how wood-borer feeding impacts the health of infested trees and provides strategies for monitoring, preventing, and managing infestations of flatheaded and clearwing borers. 1 CEU (A, U, M T, Bs)

This is the second of a two-part article series based on the newly released Tree Climbers’ Guide, 4th Edition. Part 1 of this article series contrasted moving and stationary rope systems while explaining many of the advantages and limitations associated with stationary rope system (SRS) climbing. Part 2 discusses strategies for ascending and navigating a tree, as well as some tips for SRS climbing. 1 CEU (A, U, M, T, L, Bp)

This is the first of a two-part article series based on the newly released Tree Climbers’ Guide, 4th Edition. Part 1 of this series contrasts moving and stationary rope systems while explaining many of the advantages and limitations associated with stationary rope system (SRS) climbing. Though many aspects of the two climbing systems are similar, including much of the equipment, there are different considerations for tie-in points, gear selection, rope constructions, and other factors. (A, U, M, T, L, Bp)

Trees are an important asset in our landscapes, providing many benefits. Yet we must understand that all trees present some level of risk. However, it is important to realize that the benefits trees provide far outweigh the risks. We don’t want to remove trees unnecessarily, but rather should aim to reduce risk and the potential for failure by identifying, analyzing, and evaluating risk and performing the appropriate mitigation. The key component of that process is the ability to identify common defects. (A, U, M, T, L, Bs, Bp)

Urban foresters recognize that species diversification is essential to safeguarding the urban forest and the benefits it provides. However, increasing the diversity of the urban forest does more than just improve resilience to pests. More diverse trees and plants also provide habitat for more diverse bacteria and fungi. This is important, because exposure to these microbes can stimulate the human immune system, leading to surprising health benefits for the people who live among them. (A, U, M, Bm, Bs)