Content

Introduction - Welcome to UFOR 521
Readings
Fundamental Concepts
Self Check
Activities & Assignments
Summary
Self Review

Welcome to UFOR 521 - Advances in Arboriculture!

Imagine a sustainable urban forest, a forest that is built to last.

Imagine a city, where trees are carefully selected to grow and thrive in their environment. Imagine urban sites, consciously planned and adapted to meet the needs of these developing trees.

Over time, these trees are monitored as their size, health and condition evolve. Meanwhile, the use of land around these trees may shift, climate trends may fluctuate and pests and diseases may appear. Nevertheless, within this urban forest, specialized teams anticipate changes and generate action plans to retain trees amid these events. These trees are assessed and practices are implemented to mitigate the threats of environmental changes. Measures are put into place to ensure that trees reach maturity and continue to benefit communities. The potential risks associated with trees are consistently evaluated by knowledgeable specialists. When these risks can no longer be managed to prevent likely and severe damages or injuries, trees posing a high level of risk are removed. These trees are replaced. Replacement strategies are guided by state of the art knowledge and approaches. A mindful and adaptive cycle of urban tree management continues.

Utopia or possibility? Urban foresters, informed by the science and practice of arboriculture, can bring this vision to fruition.

Arboricultural knowledge is essential in creating, preserving and enhancing sustainable urban forests. This discipline is a critical component of urban forestry.

To successfully understand the science and practice of arboriculture in urban forestry, we need to situate this field in a wider context of urban development.

This course introduction will establish a working definition for "arboriculture" and "arborist." The main objectives of contemporary arboriculture will be discussed, bringing to light the tensions encountered when trying to promote healthy tree development within artificial and constantly changing urban environments. It is an endless balancing act.

This week's readings will offer perspectives of what arboriculture is, what it seeks to achieve, the challenges of the profession and opportunities to elevate the field.

Learning Objectives

By the end of this topic, you should be able to:

Define the function and main objectives of contemporary arboriculture
Explain why arboriculture is important in relation to urban forest strategic planning and operational management
Identify aspects of urban development that could benefit from a better understanding of trees

Topic Readings

This week, we look at how arboriculture has developed, as a discipline, in different parts of the world.

It is also fascinating to contemplate how arboriculture will evolve as society, technology and the environment face massive and accelerated change.

Required Readings

Hauer, R.J., Miller, R.W., & Werner, L.P. (2017). The history of trees in the city. Routledge
Handbook of Urban Forestry. Routledge, London, (pp. 17–32) (Course textbook).
Davison, A and Kirkpatrick, J. (2013) Re-inventing the urban forest: The rise of Arboriculture in Australia. Urban Policy and Research, 32 (2), 145-162. Re-inventing the Urban Forest The Rise of Arboriculture in Australia 2013-10.pdf
Bengston, David N. (2019). Scanning the horizon for the future of Arboriculture. Arborist News. 28(4), 26-31. Scanning the Horizon for the Future of Arboriculture 2019-08.pdf

Optional Readings

Looking to get up to speed? Consider this optional reading for more background context and terminology.

Harris, R.W., Clark, J.R., & Matheny, N.P. (2004). Arboriculture: Integrated Management of Landscape Trees, Shrubs, and Vines (4th edition). Prentice Hall, Chapter 1.

Want to dive a little deeper? Consider these optional readings to find out more.

On Professional Identity in Urban Forestry, the Role and Limitations of Arboriculture:

O’Herrin, K., PE Wiseman, SD Day, & RJ Hauer., (2020). Professional identity of urban foresters in the United States. Urban Forestry and Urban Greening. 54.

Professional identity of urban foresters in the United States 2020.pdf

On Women in Arboriculture:

Bardekjian, A., Nesbitt, L., Konijnendijk, C., Lotter,B. (2019). Women in urban forestry
and arboriculture: experiences, barriers and strategies for leadership. Urban Forestry and Urban Greening. 46, 1–13
Women in urban forestry and arboriculture 2019.pdf

Fundamental Concepts

Lecture 1 - Recorded Video (Uploaded September 10, 2021 - see Zoom link)

Lecture 1 Slide Show - Power Point Presentation Microsoft PowerPoint - 1.1 Striking a Balance Intro.ppt [Compatibility Mode].pdf

Key Ideas

Arboriculture

Arboriculture is the practice and study of the care of trees and other woody plants in the landscape. Unlike silviculture, traditional forestry or agroforestry, arboriculture developed as an industry to address tree-related issues involving gardens, residential properties, commercial and industrial lands as well as municipal and utility assets. Modern research identifies a distinction between arboriculture and urban forestry suggesting that arboriculture's scope is limited to the management of individual trees whereas urban forestry manages entire populations of planted as well as naturally occurring trees and vegetation in a specific urban environment (Davison and Kirkpatrick, 2014; Hauer et al. 2017; O'Herrin et al. 2020). Notwithstanding this distinction, arboriculture is a critical component of urban forestry. Whether they self-identify as arborists, urban foresters or other allied professionals, people assessing and making decisions about trees in cities need to understand how trees function in urban environments. They also need to be able to intervene effectively to resolve complex tensions between tree development and human activities.

Arboriculture: An Interdisciplinary Approach

Introducing trees to urban sites and ensuring their long term survival requires a holistic approach.

For tree planting and care to be successful in the built environment, professionals must be aware of multiple fundamental principles. For example, when incorporating new trees to a streetscape, practitioners must understand the biological requirements of trees to establish and grow. However, as new information becomes available and as environments change, people assuming responsibility for trees must also keep up to date with the latest knowledge and scientific consensus. When testing out theories and implementing new practices, observation is key to developing experience and confidence in one's approach.

Contemporary arboriculture attempts to reconcile a need for safe, healthy and resilient trees with the pressures that urban development exerts on these trees as well as on the environments in which they grow. Mediating between tree development and human development implies several objectives;

Creating urban sites that are conducive to tree growth and development, all while preventing detrimental and dangerous conflicts;
Identifying and selecting trees that are appropriate for a given planting site;
Prescribing and/or providing care after planting to establish new trees in the landscape;
Identifying physiological disorders and their abiotic and/or biotic causes;
Recommending and/or implementing measures to manage physiological disorders and promote tree health;
Intervening safely to resolve conflicts between trees and human activities, infrastructures and services while attenuating the effects of these actions on tree health and condition;
Educating clients and stakeholders on the requirements of trees in urban environments;
Assessing risks associated with trees in the urban environment and managing these risks diligently;
Contributing to the preservation of mature trees in the landscape;
Participating in the replacement of urban trees after removal;
Fostering safe work practices, in all tasks completed.

A holistic approach, centered on the care of trees and woody plants in the landscape, is needed to support and enrich the urban forest. In a context where urban foresters seek to manage tree populations for a maximum of benefits to communities, arboriculture can provide effective and sustainable practices to achieve that end.

Arborists are professionals who possess the technical competence gained through experience and related training to provide for or supervise the management of trees and other woody plants in residential, commercial and public landscapes. They can specialize in specific domains of arboriculture such as tree work, consulting, utility arboriculture (vegetation management), commercial arboriculture and even urban forestry.

Self Check Quiz

1.1 Practice Quiz

As you learn the course content, consider trying out this optional practice quiz to see how you're understanding course concepts and ideas.

Try out the quiz now.

Activities & Assignments

First Interaction: Course Calibration

To kick off this course, please complete the following 14 question survey. Your answers will help customize your experience with this course.

https://forms.gle/88k8AC6zeL8g5v8LA

Assignment 1: Connecting With the Content

Sharing Your Experience Reconciling Tree Development and Human Development in the Urban Landscape

This week's seminar will be devoted to framing arboriculture as a discipline within the wider framework of urban forestry. To connect with the course content, you are asked to share a photograph and prepare a rapid-fire 5 minute presentation on an issue that you've encountered with trees in the urban environment. This could be an experience in learning, work or volunteering that caused you to reflect and act to address and/or resolve a problem.

You are asked to identify the issue, discuss why it provoked you to reflect and act, explain your course of action and what you learned from the experience. From incorporating new trees to a barren space to preserving a mature tree or helping influence a policy change or elevation of practice, anything goes!

Topic Summary

Arboriculture is the practice and study of the care of trees and other woody plants in the landscape.

Urban forestry, as a discipline, manages trees and forest resources in and around cities, with intent, for the physiological, sociological, environmental and economic benefits for human society. Nevertheless, human societies can significantly alter or destroy the natural environments where trees grow. Moreover, humans create and modify artificial environments, where trees are then incorporated, often near the end of these development processes. As a result, human intervention is needed to establish and then preserve trees in the landscape. This is particularly a challenge when conflicts arise between urban infrastructure and trees. As a result, different sectors and approaches in arboriculture have developed over time such as utility arboriculture, veteran tree management and tree risk assessment. Yet, urban forestry puts benefits at the forefront of the pursuit for healthy city trees and forests. To yield maximum benefits while managing potential risks, arboriculture contributes scientific and operational knowledge to help achieve a sustainable vision of urban forestry.

To be proficient in arboriculture, practitioners, making recommendations and decisions about trees, must be able to understand the following topics as they relate to tree selection, establishment and care;

Tree biology and physiology
Environmental and nutritional requirements for tree growth and development
How trees interact with abiotic and biotic constraints in their environment
Tree identification (minimally in the practitioner's region of work)
Tree propagation and standards for nursery stock
Tree planting and care after planting
Plant health care and the integrated management of tree pests and diseases
Tree pruning
Tree biomechanics and supplemental support systems
Tree risk assessment
Managing trees effected by urban development (demolition, construction and land modification)
Tree risk assessment
Tree inspection and report writing

Other spheres of work in arboriculture may require additional competencies such as, but not limited to, tree work skills, tree climbing and worker safety as well as tree valuation, tree inventory management, utility vegetation management or providing testimony in tree-related litigation.

Arborists are professionals who possess the technical competence gained through experience and related training to provide for or supervise the management of trees and other woody plants in residential, commercial and public landscapes. They can specialize in specific domains of arboriculture such as tree work, consulting, utility arboriculture (vegetation management), commercial arboriculture and even urban forestry.

In many parts of world, tasks pertaining to urban tree management have been, and continue to be, performed by a multitude of professionals in an array of specializations ranging from forestry, horticulture, landscape architecture, agronomy and ecology to public works, engineering and urbanism - to name a few. The fundamentals of arboriculture as well as industry best practices can be learned. This is a promising opportunity for education and mentorship within the wider urban forestry community. However, if policies regarding trees do not consider arboriculture, the results could be untenable or outright disastrous for diligent urban forest management and good governance.

Topic Self-review

Consider the following questions as you undertake studies in arboriculture and urban forestry. You may find it interesting to reflect on these questions at the beginning of the course and document your answers. At the end of the course, or even at the end of the program, consider asking yourself these questions again. Has your perspective changed?

1- How are the disciplines of arboriculture and urban forestry connected? Can one discipline be successful without the other? Why or why not?

2- What skills, competences and knowledge areas are needed to make rational and responsible decisions about urban trees?

3 - Is the arboriculture industry in your area effective at maintaining and improving urban forests? Why or why not?

4- What changes do you expect to see in arboriculture in the next 20 years?

5- Arborist? Urban forester? Planner? Green industry professional? How do you self-identify when it comes to your current profession or future professional goals?

Meagan Hanna, 2021