The War Between Trees and Grasses by Howard Thomas: The Book I wished I’d had as an Undergraduate.

The cover of "The War Between Trees and Grasses"

What drives the author to spend time on the piano to re-establish calm or why did the song The Teddy Bears’ Picnic leave an unsettling feeling as a child? These comments are just some of the fascinating thoughts which make this biological history of an ‘edgy relationship’ so personable.

Howard Thomas’s recent book The War Between Trees and Grasses is a fantastic biological history of these two great groups, how they evolved through time, and shaped our planet. This slim book conveys an important message in its pages; that the tree-grass battle has been raging for millions of years and continues to this day.

The Setup of the Intra-plant War

The War Between Trees and Grasses sparked my interest because it covers two of my botanical passions. My undergraduate degree was in Environmental Conservation at Bangor University surrounded by foresters and botanists. Many of the course modules included a plant biology, agricultural or forestry aspect. The Forestry Society was a big part of my life during that time as well, so trees were at the root of my plant biology studies. In the past few years of my career, I have crossed sides in the war so to speak and now work with grasses, namely black-grass (Alopecurus myosuroides), the biggest weed problem in UK agriculture. Hence, I found it a particularly interesting point Thomas makes about grasses having become so important to mankind “but it also turned agricultural weeds loose on the world”.

The book is neatly split into three parts; Part 1. Tree, Part 2. Grass and Part 3. Human. Each part has five chapters chronologically describing how trees and grasses have evolved, then introducing humans into the midst of the conflict between them. There is also one appendix, a nice summary of geological timelines, showing some of the notable time points discussed in the book and a fantastic mnemonic for remembering the order of the geological periods. The many publications cited in this book are listed at the end along with the sources of the publications.

Part 1 introduces the world hundreds of millions of years ago to relate the birth of trees and how they dominated and defined the ancient skyline through their ability to produce wood. The end of this section briefly discusses herbs before introducing the next episode of the story “the arrival of angiosperms and the rise of the grasses”. The book flows perfectly onto the grasses, firstly describing angiosperms and gymnosperms. It then briefly describing the distinguishing features of monocots and dicots before capturing how grasses filled niches that trees couldn’t through adaptation by being “anti-trees”. The trade-off was that grasses were left vulnerable to grazing by mammals and the subsequent domestication of a few vital genera by early humans.

Part three describes the human element to this war. There’s a paradox between needing trees for firewood as early settlers but then finding them a hindrance to creating areas to cultivate vital grasses required for food. People then worried about a ‘timber famine’ as ship building and the industrial revolution took hold.

Balancing Trees, Grasses, and Humans

The ‘war’ is always going to be a tricky issue for people to resolve. A few species of grass are vital for feeding the growing human population as well as its leisurely importance of providing humans with football pitches and parks. Conversely, trees are also used in recreation, for building, furniture, and books. Trees also have cultural significance. For instance, Christmas trees in our houses remind us of the greenery of spring, and there is research supporting that seeing trees out a hospital window can improve recovery. These ideas of the trees returning can be seen in the growing re-wilding movement. Howard Thomas, in his overview of Part 3, surmises that “there is no doubt whose side Homo sapiens is on,” but the definition of victory is not so clear cut.

A Useful Botanical Book

The War Between Trees and Grasses is a concise, easy to understand scientific work. The author’s personal comments throughout the book made me feel more connected to the points being made. Excellent pictures come at the end of each chapter and are used to neatly illustrate what has just been discussed. The Index is useful as it includes definitions of the scientific terms.

This book would have been useful as an undergraduate to provide a fundamental understanding of the major differences between the two groups and I highly recommend it as a plant biology text for students. It certainly helped refresh my memory of C3 and C4 photosynthetic pathways for instance. However, I believe that anyone with an interest in the botanical world and/or our socio-interactions with it would enjoy this book.

And if you’d like to know how Betty Boop, the UK Conservative Party and amusing cat videos all fit into the The War Between Trees and Grasses, get this great book to find out.