Purcell’s latest book covers all relevant aspects of arboriculture based on current research and best practices, says reviewer Steven Pregler.

As readers of TCI Magazine, we should all recognize the name Lindsey Purcell. Among the many articles he has authored in this magazine, his book, “Arboricultural Practices: A Science-Based Approach,” first came to my attention when an excerpt entitled “Planting Protocols for Challenging Urban Sites” was published in the November 2023 issue. When I saw this, I could hardly wait for the book’s publication. I immediately knew that this book would be of exceptional quality based on my familiarity with the publications he produced as an urban-forestry specialist and teacher at Purdue University.

I can’t help but compare this book to other well-established arboricultural texts in my personal library. It’s been more than two decades, however, since these books were published. As you can imagine, our industry has continued to evolve and change.

Purcell’s latest book covers all relevant aspects of arboriculture based on current research and best practices.

When, excitedly, I open a new textbook for the first time, I like to flip through it. First impressions are important to me. They tell me if it is going to be an easy read, how well it is illustrated and if its content is going to be over my head. As I paged through Purcell’s book, I liked what I saw.

The first thing you encounter in this book is the table of contents. There are 13 chapters listing the various topics covered. Each chapter is further broken down into exactly what is covered and which page it can be found on. This makes it a quick and easy reference for later use. A big plus!

Relevant for all
The book was written to teach students of arboriculture. The contents, however, are relevant and essential for all arborists, urban foresters, consulting arborists, plant-health-care specialists, landscapers and anyone managing trees. For students and instructors, each chapter begins with a shaded box of “Learning Objectives.”

What also jumped out at me were the many, and I emphasize many, illustrations by Jeff Harris, photographs and tables. An illustration/picture is worth a thousand words, especially if it furthers one’s understanding.

“A Science-Based Approach” in the title should not scare readers away thinking its technical aspects will be difficult to understand. On the contrary, the science involved makes it easier to understand a more technical concept.
In Chapter 2, Tree Biology and Physiology, you will learn that conifers have tiny “check valves” on the ends of each tracheid (xylem cell) to prevent the spread of air bubbles (embolisms) that cause broken water columns and disrupt water transport. These check valves – “torus” individually or plural “tori” – are membranes that enhance a tree’s survival under winter and summer drought conditions.

These sketches of planting in compacted soil are among many illustrations by Jeff Harris that are in the book. Sketch and book-cover image courtesy of Lindsey Purcell.

Needs of trees
In Chapter 3, The Basic Needs of Trees, Purcell does an excellent job of explaining some of the more complicated soil chemistry involved in tree nutrition. Soil pH and cation-exchange capacity are made easier to understand using some great illustrations.

Risk management
Chapter 9 discusses Tree Risk Management and Assessment, which has continued to evolve over the years. Its coverage in this chapter includes coverage of diagnostic tools and decay detection devices.

Storm and weather damage
With climate change an undisputed reality, Chapter 12, Dilemmas, Remedies and Reparations, discusses, among other things, trees and storms, flood damage to trees and the effects of heat and drought. In this chapter, you will find winter watering recommendations to reduce the likelihood of winter burn when winter drought conditions begin to develop.

Terminology and online resources
Alex Shigo stressed that we need to use correct terminology when communicating with our colleagues and peers. Purcell’s book has a comprehensive, 29-page glossary to help us do just that. Additionally, the book has four pages of references and citations for resources that can be accessed online for further reading, as well as a listing of more than a dozen of Purcell’s past publications.

Conclusion
As one who occasionally follows Facebook pages and other online arborist resources, one thing is clear. Many people who offer advice noticeably don’t have a clear understanding of the topic they are advising on. A little bit of knowledge can be dangerous and misleading. What are we telling our clients? Are we doing them a disservice?

There is a saying, “You don’t know what you don’t know.” “Arboricultural Practices” can remedy that situation. It is a great read and guaranteed to increase your knowledge base!

Author’s note: For those contemplating taking the ISA Certified Arborist exam, this is one excellent additional resource for your preparation.

“Arboricultural Practices: A Science-Based Approach,” by Lindsey Purcell. Soft cover, 362 pages. Available at www.lpconsultinggroup.org.

Steven F. Pregler is an ISA Certified Arborist and retired City Forester for the city of Dubuque, Iowa.