Science of Arboriculture: Recent Episodes
International Society of Arboriculture
No matter where you are, keep up-to-date with the latest research-based information on tree care by listening to this podcast! Science of Arboriculture was developed by the International Society of Arboriculture to provide easily accessible educational talks by the world’s top researchers, educators, and practitioners. Subscribe to this ArborPod™ series to keep up with the fast-paced and evolving research!
If you have comments or a favorite topic in arboriculture that you would like to learn more about, please contact us at isa@isa-arbor.com.
This presentation, led by Charles Cannon, will introduce the basic concepts of sap flow, the factors that influence it, and how it is measured, and then delve into collaborative research programs in long-term monitoring and experimental trials, ending with prospective uses of the data and technology. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, M, T, Bs)
Lignotuberous and epicormic buds are stress adaptations which can grow 4 m per annum and 300 mm per week using the capabilities of mature stem and root systems. Lignotuberous shoots are well-attached to root systems, but heavy, rapidly-growing epicormic shoots can fail. Both can be used to manipulate canopies. In a study conducted and discussed by Greg Moore, seedlings of Eucalyptus obliqua were heat stressed and decapitated in order to understand shoot production. In stressed trees, regeneration is from epicormic buds higher in the canopy, then lower branch epicormic buds, buds on the trunk, and finally lignotuberous buds, which are a last-resort survival mechanism. Understanding these shoots can be the difference between life and death for urban forest managers. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, M, T, Bs)
When trees are damaged during storms, they typically respond through the production of sprouting branches. Referred to as epicormic sprouts, these branches are a critical component in replacing the tree crown and photosynthetic capacity. Unfortunately, there is little empirical data to guide industry best management practices with respect to crown restoration pruning. In this presentation, Jake Miesbauer discusses results from a long-term study on the growth response of damaged trees to different pruning treatments and how these results can help guide practitioners to improve their methods for restoration of storm damaged trees. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, M, T, Bp)
In this presentation, Alessio Fini discusses an experiment that began in 2011 to evaluate the effects of different pavements on the growth and health of two urban tree species: Fraxinus ornus (Manna ash) and Celtis australis (European hackberry). Biometric and physiological measurements have been made since 2012. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, M, T, Bp)
In this presentation, James Downer examines the post-apocalyptic zone in Pripyat, Ukraine and the survival of an extant population of horsechestnut trees. Comparisons are made between similar age populations in Kiev, Ukraine. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, M, T, Bs)
Wire baskets helped to industrialize the transplanting process for field-grown nursery stock. However, their use is not without controversy, and while opinions abound, actual research on this topic is relatively scarce. Join Andrew Koeser as he discusses past and recent research findings in an effort to offer an impartial view on one of arboriculture’s more controversial issues regarding cultural practice. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, M, T, Bp)
Tree health and vitality influence a wide range of physiological processes including pest/disease susceptibility and water stress resilience. Dr. Banks will introduce the concept of tree vitality and how it can relate to pest and disease resilience, as well as tree establishment and survival within the landscape. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge (A, U, T, M, Bp)
This presentation by Dr. Ruark covers some of the current “state-of-the-art” tools and techniques used by urban foresters in determining nutrition sampling, risk assessment, and lab diagnostics for plant pathogens. Plus, a compiled list of mobile device apps currently used by diagnosticians. Listen to the Science of Arboriculture podcast and then take the accompanying CEU quiz to check your knowledge. (A, U, T, M, Bp)
When planning new green spaces, it is necessary to remember that the urban environment is very different from the natural environment where the species evolved. Which trees native or exotic should be planted in order to maximize carbon sequestration and pollutants removal? Which species can better face the temperature increase foreseen for the next decades? Discover theses answers and more with Dr. Francesco Ferrini by listening to the Science of Arboriculture podcast and then taking this accompanying CEU quiz to check your knowledge. (A, U, M, T, Bp)
What conditions give trees the best chances of living a healthy long life? What systems do trees use to defend against insects? Go in depth with Chadwick Award Winner Dan Herms by listening to the Science of Arboriculture podcast and then taking this accompanying CEU quiz to check your knowledge. (A, U, T, M, Bp)
What are the effects of pruning on mature trees? Linda Chalker-Scott presents the current state of science on the physiology of aging trees, which can be used to predict the impacts of conventional and retrenchment pruning on tree health. (A,M,T,L,Bs)
Taking care of an urban forest doesn’t mean you don’t have to deal with wildlife, and whether it’s protected species, or just ecological common sense, knowing how to retain wildlife will benefit the environment, and everyone in it. (A,T,L,Bp)
Falls are a constant danger for arborists working at height, and understanding the limitations and differences between fall protection, fall arrest, and fall restraint systems can be the difference in going home safe, or taking a trip to the hospital. Ed Carpenter explains in this month’s Science of Arboriculture.(A,M,T,L,Bm)
Using a tree inventory to list the species, health, age, and maintenance needs of a specific tree is easy, but when you’re dealing with an urban forest of thousands of trees, that’s where the science of Geomatics map making comes into play.(A,M,Bs)
As arborist it's easy to forget not everyone loves trees, in fact some people claim to hate them. In this episode of Science of Arboriculture, Francessco Ferrini examines the public misconceptions that can lead to this short sited view.(A,M,Bm)
A small dedicated group of researchers, tree climbers, and photographers set out to capture a singular image from the Waipuoua forest; a complete unobstructed picture of a full grown forest conifer. Their efforts became the New Zealand Tree Project, compositing the final picture from thousands of individual shots, and producing a documentary video of this towering project.(A,M,Bm)
Species diversity is an urban forest is vital to surviving a disease threat. In this month’s Science of Arboriculture, we look at the efforts in Sweden to learn from painful lessons and create a cooperative template between arborists, municipalities, and universities in promoting species diversity.(A, M, Bp)
In 2012 an ambitious project brought together arborists, municipal managers, and university researchers from three different countries to help establish standards for the young and growing arboricultural practice in the Baltic Sea region. Lina Juisoo explains the challenges and successes of Project Green Man (A,M,Bm)
Ever more detailed and complex tree inventories provide a wealth of information to urban forest managers, and can help identify potentially unsound trees before they fail. But just how much of that information should be made available to the general public? Is there a down-side to flagging potential risks? Jaroslav Kolarik reports on a program in the Czech Republic. (A,M,Bm)
The destructive potential of a medium to large falling branch is commonly acknowledged by arborists, but just how much force can a me branch deliver to a target? John Goodfellow recaps a study for the utility industry attempting to answer that question in this month’s episode of Science of Arboriculture (Original presentation by John Goodfellow)(A,U,M,T,L,Bs)
A three day freeze with temperatures well below zero decimated the urban forests of Chihuahua Mexico, leaving the city with tens of thousands of dead trees to remove and replace. Carlos Van Der Menden reports on the recovery efforts. (A,M,Bm)
The U.S. state of Florida covers thousands of square miles with climates ranging from temperate to tropical, Jason Smith, who specializes in emerging threats, takes a look at tree health issues in Florida, and beyond.(A,M,Bs)
Vegetation management under and around powerlines is a never ending struggle, but with today’s Satellite imagery and GIS, along with status reports from ground crews, near real time workload planning and cost forecasting is possible. Barry, Grubb of Florida Power and Light, and Chris Kelly of Clearion Software report on advances in this technology (A,UM,Bm)
Every tree care business has its own unique set of capabilities, customer expectations, and pest management philosophies. Joe Boggs, assistant professor with Ohio State University Extension and department of entomology examines a common sense approach in maximizing pest management strategies.(A,U,M,T,L,Bm)
Ecological and financial benefits of tree planting projects can be quantified through long and short term studies, but what about the social outcomes for the communities of people involved, and the neighborhoods they live in? Jess Vogt and Shannon Watkins report on a five city study of neighborhood and non-profit urban forestry projects. (A,U,M,T,L,Bm)
Trees and greenscapes provide a wealth of physical health benefits; cleaner air, shade and resulting lower temperatures, but what about physiological benefits? Dr. Ellen Vincent reports on a fascinating study targeting patient pain levels when provided with views of nature. (A,Bm)
Individuals and companies place a high priority on safety, as do government regulators, and over the years that’s driven training standards. Keith Norton and Bob Urban examine the history of training standards and industry safety playing a perpetual game of catch-up in this month’s edition of Science of Arboriculture. (A,U,M,T,L,Bm)
Look! Up in the sky! It’s a bird, it’s a plane, it’s an arborist with a drone! With the flood of unmanned aerial vehicles entering the commercial market, UAVs are already being put to use in agricultural, and arboricultural settings. From surveying and inspection, to pin-point spraying, Dan Staley and Alex Bilous takes a look at current and future use of drones in the green industry. (A,U,M,Bp)
Managing trees around utility power lines is a balance between maintaining a healthy forest, and guaranteeing uninterrupted power. Sara Sankowhich, system arborist with Unitil reports on a three year program that keeps the lights on, keeps utility customer’s happy, and maintains a thriving forest scape along right of ways. (A,U,M,Bm)
The struggles against the Asian Long Horned Beetle, and Emerald Ash Borer are just the latest battles against a history of imported pests. But as Joe Boggs explains, the challenge of dealing with non-native pests flows both ways between countries, and sharing information is the best weapon in turning the tide. (A,M,Bm)
Are the world’s urban forests losing their big trees? Is there an ideal distribution of tree size in an urban forest? Justin Morgenroth of the New Zealand School of Forestry looks at ten years of data and compares guidelines for urban forestry management in this edition of Science of Arboriculture (A,M,Bm)
Trees in the Northeast United States were hammered not once, but twice in the past few years, with hurricanes Irene and Sandy devastating both urban and rural forest areas. Richard Gibney, a landscape architect, examines some of the surprising reasons some trees survived and others didn’t. (A,M,Bm)
The Job isn’t finished until the paper work is done! Writing a report properly can mean the difference between winning and losing in a legal battle. Lori Ballard of Samnik & Ballard Tree Consulting walks us through the fine points of reports that follow industry standards, and hold up in deposition and court. (A, M, Bm)
Urban landscapes can be a hostile environment for trees, and when a major city plans sidewalk upgrades the situation often becomes worse. Lisa Hammer, horticulturist and arborist, and Aida Curtis of Curtis and Rogers Design Studio report on a Miami Florida project that takes the trees into account first. (A,M,Bm)
In the arboricultural industry mulching trees is a long standing practice, but is there really science to back up the beneficial claims? Dr. Bert Cregg presents the findings from several Michigan State University studies(A,M,Bp)
Rex Bastian, regional technical advisor with the Davey Tree Expert Company discusses the physiology of trees and how stress affects a tree’s ability to thrive. (A, Bs)
Joe Murray, former college biology professor and certified arborist takes a look at the symbiotic life cycle, and benefits of lichen in today’s forests (A,Bs)
How diverse should an urban forest be to reduce the risk of decimating pests like the Emerald Ash Borer, or Dutch Elm Disease? Dr. John Ball presents an eye opening talk on the dangers lurking in many diverse forests today (A,M,Bm)
Today’s arborists must often times balance the needs of the community against damage to the environment. Organic pesticides and herbicides are a choice, but just how effective are they? Dr. Linda Chalker Scott looks at the science behind rating their efficacy. (A,U,M,Bs)
Dr. Kim Coder, professor of tree biology and health at the University of Georgia presents an in depth look at the threat, mitigation, and recovery from lightning strikes in both urban and rural forests. (A,U,M,Bs)
More than two years after Super Storm Sandy pounded the east coast of the U.S., recovery efforts are still on-going. Including efforts to bring the rural and urban forests back from incredible storm damage. Join David Johnson of Asplund Tree Expert Company as he looks at the damage done, and recovery attempts made in the hardest hit areas. (A,U,M,T,L,Bs)
One of the unseen benefits an urban forest brings to a community is storm water management. A healthy diversified urban forest can extend the life of a cities gray infrastructure over decades. Dr. Peter Donagh looks at the incredible job trees perform in handling storm runoff in a city. (A,U,T,M,L,Bs)
Dr. Alexia Stokes discusses the many external stressors that affect a tree’s growth and mechanical stability, and how trees naturally adapt themselves to thrive in different environments
Urban trees have a substantially shortened life span due to a number of problems, not the least of which is limited access to uncompacted, aerated, fertile soil. The average 4’ X 4’ X 4’ tree pit has less than one tenth the rooting volume needed. L. Peter MacDonagh of Kestrel Design Group, discusses examples of minimum soil volume policies that give arborists the leverage they need to provide trees with adequate useable soil volume. (A,U,M,T,L,Bm)
As solar energy gains an increasing presence in the developing world, the arboricultural industry has a key opportunity to work hand in hand with installers in both pruning strategies and tree selection. Dan Staley discusses solar smart strategies for today’s urban arborist.(A,U,M,T,L,Bp)
Dr. Alessio Fini of Florence University explains his study into the growth, physiology, and uprooting resistance change experienced by two Urban tree species with different levels of root severance. 96 pre-planted trees were studied over two growing seasons to track the results (A,U,M,T,L,Bs)
Green cities are more livable cities, and yet the urban natural resources, and the means we have to manage them, are diminishing. Dr. Weston Brinkley takes a look at a current set of integrated Urban Forest Assessments looking for answers in today’s land management stewardship.(A,U,M,T,L,Bs)
How much soil is enough for a healthy tree? That question has plagued urban foresters for years when planning urban tree planting programs. Nina Bassuk, Ph.D. professor from Cornell University looks at new techniques and new technology being employed in the search for answers.
Biochar, a waste product from the anaerobic heating of biomass, has tremendous potential as a soil amendment for urban soils. Dr. Kelby Fite from the Bartlett Tree Research Laboratory, presents research data on this re-use of waste materiel improving urban soils.
Joris Veoten discusses a completely new structural soil for trees in the urban environment, made from recycled glass and recycled organic material. Experiments have shown Re-Soil maintains structural function and tree growth potential even when installed under pavement.
Dr. Zhu Ning discusses a recent study on the effects of elevated carbon dioxide levels on urban trees. Listen to this episode of Science of Arboriculture to learn more about the physiological processes of photosynthesis, transpiration, and stomatal conductance in Southern red oak and red maple.
Arborists are industrial athletes, challenged every day to keep their bodies operating at peak performance to do their job. Amanda Carpenter and Jessica Skiera discuss how nutrition, hydration, and sleep can help or impair an arborist’s performance.
Alessandro Pestalozza was inspired to study the effects a previous branch failure has on its wind resistance after a fatal injury occurred on a busy street in Italy. Learn about how tree fibers respond to the extreme tension exerted by static pull tests in this effort to make our urban forest a safer place.
Tree canopy assessments provide a better understanding of the urban forest than conducting an inventory, because these assessments include trees on private property. Ruth Williams discusses the change of canopy cover in Portland, Oregon, based on the results of her 10-year canopy study.
Henry King discusses the principles of effective project management as a vegetation management contractor. Learn how to communicate across disciplines and execute a plan.
Bryant Scharenbroch discusses the effects of compaction to top-soil in urban development, and potential remediation options. Learn about the study he conducted to determine what common practices improve the quality of urban soils.
Gregory Moore discusses the economic value of shade trees in the urban forest. Learn about the role of trees in the heat island effect and how the loss of tree cover affects public open spaces.
Ken James explains his study on the effects of wind loads on both urban and forest-grown trees. Learn how branches affect the movement of trees during heavy wind loads, and how pruning decisions affect urban trees.
Matthew Palmer explains how visual tree assessment (VTA) has impacted utility network performance at Energex. Learn how to apply the visual tree assessment method and prioritize maintenance for utility networks, on this episode of Science of Arboriculture.
Learn how the electric power line company and forest service in the province of Alberta, Canada, successfully reduced the frequency and severity of forest fires on this episode of Science of Arboriculture.
Learn more about how biological control methods work, as Francis Schwarze explains the process for identifying the proper antagonistic strain for a pathogen, on this episode of Science of Arboriculture.
Timothy Johnson, Donald Cameron, and Gregory Moore collaborate to investigate the relationship between tree root growth, architecture, and surface infrastructure permeability. Learn about their results on this episode of Science of Arboriculture.
Dean Simonsen explains the results of a case study in Canberra, which used an innovative survey approach for analyzing the composition of the public urban forest. Learn about the benefits and challenges of completing an inventory using this approach, on this episode of Science of Arboriculture.
Ian Shears talks about a series of ongoing projects in the City of Melbourne that are working towards a long-term healthy urban forest, while creating a more sustainable and livable community. Learn how art, science, and technology can be used in combination to improve the physiological, sociological, economic, and aesthetic benefits of trees, on this episode of Science of Arboriculture.
Daniele Zanzi explains how the Static Integrated Method (SIM) is used to provide reliable measurements for estimating the stability of urban trees with root damage. Learn more about the application of experimental field pull tests on this episode of Science of Arboriculture.
John Goodfellow discusses the potential conflicts between trees and electric utilities. Learn about the fundamental causes of electrical faults and the principles for analyzing and mitigating potential utility risks in the field on this episode of Science of Arboriculture.
Correctly diagnosing the causes of tree decline can make managing tree health more successful. Listen to Paul Barber discuss factors in the urban forest that contribute to tree decline and how taking the time to correctly diagnose a disease can make the difference between sustaining and removing a tree.
Wildfires can inflict billions of dollars in damage, but can also expose utility companies to significant liabilities. In this podcast you can listen to Nelson Money talk about the challenges of fire risk management in utility arboriculture. Learn about strategies that he believes will increase safety in utility vegetation management and reduce the threats posed by wildfires.
Jim Neeser talks about the use of tree growth regulators (TGRs) in integrated vegetation management operations. Learn about the development of tree growth regulators and their use in the arboriculture industry, on this episode of Science of Arboriculture.
Angus and Graeme McMahon manage the maintenance of large and mature trees. Learn about the struggles and strategies of working with trees that are over 328 feet (100m), and the impact human interference may have on the future of these trees.
Jeremy Barrell talks about legal implications for duty holders when a tree fails and causes harm. Learn about how the court could look at tree failures and how negligence and liability could be assigned.
Discover the diversity of over 900 eucalypt species by listening to Dean Nicolle’s talk on this episode of Science of Arboriculture. Dean Nicolle describes the cultivars, regeneration strategies, variety of uses, and economical importance of this dominant flora that is native to Australia but planted in landscapes across the world.
David Cashman divulges the depths of London’s soil by discussing the subterranean development and how it is related to city property and growth. Learn how engineers, designers, and arborists can work together to preserve trees in heavily disturbed construction sites.
Francesco Ferrini presents the results of a long-term project that investigates the impacts of mulch, compost, and fertilization on physical, chemical, and biological soil properties and resulting tree growth. Find out the most effective soil amendments and their potential to improve tree health and longevity.
In this month’s episode, Laura Mendiburu talks about the riveting results revealed by a comprehensive tree inventory conducted in Madrid, Spain. Learn how the inventory helped guide the strategic planning for tree care and maintenance in this European city.
How do porous pavements affect tree growth? Find out on this podcast as Dr. Justin Morgenroth shares the results of his experiment where he measured the impact of porous and impervious pavements on root abundance, soil moisture, aeration, pH, and nutrient availability around trees.
Do you know how long it takes on average to train a young tree? What about how much it costs? Learn from Dr. Gregory Moore and Cameron Ryder on how formative pruning can be an effective strategy in reducing long-term tree maintenance costs.
Want to catch-up on the most recent literature on tree risk assessment? Listen to this podcast to hear Nelda Matheny talk about her analysis of over 700 research papers focused on biomechanics, wind in trees, soils, wood decay, and other topics related to tree risk assessment.
Dr. Kim Coder, professor at the University of Georgia’s Warnell School of Forestry and Natural Resources in Athens, Georgia, United States, delves deep into the complex world of atoms, elements, and trees. He discusses the process for diagnosis of element deficiencies in trees, as well as the impact of different combinations of elements. Don’t miss this episode where you can learn more about the complex interactions of soil elements and trees!
Kelaine Vargas, studied ecology and landscape architecture and has pursued research in these fields as a Fulbright Scholar in Berlin and with the U.S. Forest Service. In this talk, she discusses the history of the Urban Forest Map Project as well as some of its applications and the partnerships that they have developed. Listen to this episode to learn about this exciting collaboration of government, non-profit organizations, and private companies to map trees in San Francisco. This presentation was given at the ISA 2011 Annual Conference in Australia.
Judy Fakes, first arborist appointed as full-time judicial officer in Australia, discusses the model in New South Wales for resolving disputes involving trees. This model focuses specifically on solving disputes about trees and property between neighbors and acts as a reference for future legislations in other territories. This presentation was given at the ISA 2011 Annual Conference in Australia.
ISA Certified Arborist Mark Bridge, a member of the Swiss Arborist Association and the international work safety committee, discusses the global development, manufacturing and quality assurance of personal protective equipment (PPE). Listen today as he touches on topics such as outsourcing, traceability, and regulations; and learn about the present-day challenges of inspecting climbing equipment and the implications for the end user. This presentation was given at the ISA 2011 Annual Conference in Australia.
In this episode of Science of Arboriculture, Daniel Burcham discusses the relationship between urban soil properties and street tree performance in Singapore. Burcham’s presentation focuses on a few tropical trees such as the raintree (Samanea saman), yellow flame (Peltophorum pterocarpum), Honduras mahogany (Swietenia macrophylla), and Senegal mahogany (Khaya senegalensis). Burcham is an arboriculture researcher at the Centre for Urban Greenery and Ecology in the National Parks Board, Singapore and this presentation was given at the ISA 2011 Annual Conference in Australia.
When repairing a sidewalk, how close can the roots of a nearby tree be cut? Dr. Tom Smiley discusses the important issue of how root cutting impacts tree stability at variant distances. Find out the optimal distance for root cutting and the difference dry or wet soil can make on a tree’s stability on this month’s episode of Science of Arboriculture.
Dr. Tim Newson analyzes the performance of tree structures in severe winds to better understand wind speeds and the Fujita scale. What critical wind speeds lead to failure for different tree species? Find out more about his inquiries and how they apply in arboriculture on this month’s episode.
What is good branch structure? And how does determining good branch structure affect our pruning standards? These are questions Dr. Gregory Dahle will discuss in this episode of Science of Arboriculture. Dr. Dahle focused his experiments on analyzing how the branching structure of decurrent trees change their form and function over time.
There has been much anecdotal evidence about the effects of aerated compost teas on soil, but there have been few peer-reviewed studies on the topic. In this episode of Science of Arboriculture, Dr. Bryant Scharenbroch, soil scientist at The Morton Arboretum, discusses his experiments with aerated compost tea. Topics in this lecture include what makes “good dirt” in the urban landscape, Dr. Scharenbroch’s process for making aerated compost tea, as well as his results in comparing aerated compost tea to other treatments.
In this episode of Science of Arboriculture we will hear from Lothar Göcke, about the use of tomography equipment to detect decay in trees. In his presentation, Lothar also talks about the technology behind the use of tomograms for tree inspection as well as how to interpret tomograms for different tree species.
Phytophthora cinnamoni and other species of Phytophthora are a common problem for landscape plants. Phytophthora and laurel oak ( Quercus laurifolia ) have lived simultaneously in the southeast United States for close to 200 years, but recently the fungi has become a serious issue among laurel oaks. Join us for this episode of Science of Arboriculture as Dr. Steve Jeffers discusses this problem, and treatment methods for preventing death among laurel oaks.
In this episode of Science of Arboriculture, we will hear Philip van Wassenaer, president of the consulting firm Urban Forest Innovations, Inc. His talk focuses on the use of pulling tests for real-world tree stability assessments. In this podcast you will learn about principles of tree statics and how they can be utilized to evaluate tree stability.
In this episode of Science of Arboriculture, John Goodfellow talks about his research on the biomechanics of small branches and how they may fail. He also discusses his work finding and defining good indicators of branch failure, as well as where small branches typically fail.
In this episode of Science of Arboriculture we will present an issue that gets many arborists “ticked off.” Dr. Wes Watson discusses an important issue for arborists working in the field: tick and tick-borne diseases. In this episode you will learn about the different species of ticks and their associated pathogens, as well as methods for preventing disease and localized control of tick populations.
In this episode of Science of Arboriculture, learn how wind and other loads affect tree stability and how urban trees’ branches aid in supporting trees dynamically. Our guest, Dr. Ken James, discusses dynamic systems versus static systems, and how we might apply this knowledge to the study of tree stability for urban trees.
In this episode of Science of Arboriculture Dr. Dirk Dujesiefken delivers a lecture on the CODIT Principle. Dr. Dujesiefken addresses the four phases of the defense reaction according to the CODIT principle, and shares his most recent experiments which have interesting implications for how, he suggests, the CODIT model should be expanded.
On this episode of Science of Arboriculture, Adriana Jacykewycz gives a presentation on "green streets" and stormwater capture in New York City. Adriana is the director of Greenstreets, a project in which she and her team are converting unused roadbeds into planting beds and stormwater-capture systems. Adriana discusses the various studies involved in the Greenstreets project, and the challenges and success they have encountered thus far.
Join us for this week’s episode of Science of Arboriculture in which Dr. Patricia Zungoli discusses fire and Asian needle ants. These two species of ants continue to dominate their surrounding habitats, and Dr. Zungoli delivers a compelling lecture regarding the nature of the problem as well as possible methods of treatment.
On this episode of “Science of Arboriculture,” Dr. Jim Clark discusses Manion’s “morality spiral,” and how this concept relates to a process of decline we see in many urban trees. Dr. Clark gives an in depth outline of the symptoms associated with the decline spiral, and discusses potential management prevention strategies to prevent premature tree death.
In this episode, join us as Dr. Christina Wells presents a series of experiments across the country testing a soil decompaction and amendment process designed to improve soil conditions for root growth and tree performance in urban trees. Listen to this episode to find out whether the results of Dr. Wells’ experiment indicate a value to a combination treatment approach to urban trees in compacted soil.
In this podcast, Mr. Philip Andreen delineates prevention tactics that the public entity litigator, the urban forester, as well as the private arborist can use to proactively defend his/her public entity, company or client in tree-related, personal injury litigation cases.
One means of de-polluting our soils, air, and water is through the use of living organisms, or bioremediation. If the bioremediation process uses plants to contain, degrade, eliminate, or accumulate these pollutants is called phytoremediation. Dr. Bonnie Appleton explains how trees and shrubs in the landscape were evaluated using Filterra®, a stormwater management system.
Starting with the National Arborist Association’s (TCIA) cabling standards in 1944, the industry standards have now expanded to include numerous aspects of tree care and safe work practices. Dr. E. Thomas Smiley explains the process of creating a standard and its corresponding Best Management Practice guide is discussed in this podcast.
Regardless of your stance on climate change, the consideration of how specific tree species could be either adversely affected or more effective in a changing urban environment provides a thought-provoking forum. Dr. Francesco Ferrini discusses the evaluation of tree species that have been traditionally planted in urban settings in various parts of the world to determine which species may be more adaptable and beneficial in the event of climate change.
For several years tree experts have tried to assess breakage and uprooting failure potential of trees based on technical measurements. Such calculations may seem reliable at first glance, but Frank Rinn explains how a more detailed analysis shows many ‘hidden’ problems.
Determining the necessary branch diameter to support a specific load is crucial for safety during tree climbing, cabling, and for appropriate tree risk assessment and mitigation. In this presentation, Andreas Detter talks about differences between tree species and other parameters affecting tree strength and stiffness during wind events in urban environments.
Trees are well suited to become a part of a city’s rainwater management system, but must have sufficient soil resources and large canopies that reduce the impact of rainfall by absorbing and retaining water and decreasing peak flows into regional water systems. James R. Urban explains how urban foresters and arborists are key initiators in the use of trees for rainwater management.
During which types of storms are tree failures most likely to result in human fatalities? Dr. Thomas Schmidlin discusses the unique characteristics of specific windstorms, such as thunderstorms, hurricanes, and tornadoes. Study results identify the numbers of human deaths from falling trees or tree parts in relation to each type of windstorm and the U.S. locations most affected
What are the results of root pruning on root ball quality and the stability of trees planted from containers? Dr. Edward F. Gilman presents two research studies that evaluate root pruning effects on root defects and tree stability of hardwoods.
Visual assessment of trees for signs of decay is essential, but it may not be enough. Once decay indicators help identify trees that require further testing, implementation of sounding, probing, and advanced assessment methods is recommended. Dr. Christopher J. Luley explains how following the “trail of indicators” and using testing devices in the proper locations on a tree can result in more accurate detection of the incidence and severity of decay.
An engineer identifies risk by asking: 1) what can go wrong? 2) with what likelihood? and 3) with what consequence? Dr. Guikema discusses how engineers measure risk, estimate probabilities, and choose risk management options.