Tree: A Life Story and . Allen & Unwin, Sydney, 2018. xiii + 208pp. Price AU $24.99. ISBN 9781760523770 (hardback, also available as Ebook).
Trees can seem a very ‘accessible’ part of the natural world. They are easily encountered in most cities, and easy to spot. Unlike many animals, they don't tend to hide, fly away or migrate for winter; most of us see them every day. But our daily encounters with trees are little more than brief ‘snapshots’ into their long lives, and superficial ones at that: we don't often see the full extent of their struggles (with each other, or with their pathogens) for example, nor much of the remarkable internal engineering that allows them to lift substantial quantities of water (without pumps).
The internal workings and external interactions of trees are explored in detail within the academic literature, but Tree: A Life Story aims to let the more general reader glimpse into the private lives of these super-sized plants. It does so by adopting one of publishing's most popular formats: biography. Tree tells the life story of just one individual tree – a North American Douglas Fir, Pseudotsuga menziesii – from its violent ‘birth’ (Douglas Firs re-generate after forest fire), through to maturity, then to its existence as an ancient tree and its after-life as a deadwood habitat.
Suzuki and Grady's decision to use the biographical format is clever, from a science communication perspective, and well-executed: they tell their tree's story evocatively and engagingly. Their account of the fire storm that began the tree's life is vivid and dramatic; their account of the tree's sex life, meanwhile, adopts a rather salacious tone when describing a pollen grain's ‘penetration’ of the ovule. The book's most moving sections are its final chapters, beautifully describing how the dying tree provides habitat for a hunting cougar and other creatures, before finally collapsing and becoming a nutrient-rich seed-bed for successor trees – sustaining life beyond its own. Each chapter of the tree's life is told clearly, and sheds light on matters that can sometimes be unclear to the non-specialist: how fire can be a force of creation as well as of destruction, or why Spotted Owls―whose protection under the U.S. Endangered Species Act has been a bone of contention―have such apparently fussy habitat needs.
While the book's narrative focuses on a single individual, Suzuki and Grady are careful to paint a broader picture around it. Discussion of the principal subject's sexual behaviours, for instance, also considers those of oaks, dipterocarps and bamboos: the ‘biography’ format is not allowed to get in the way of helping readers understand plant life more generally. Nor do the authors ignore the wider landscape in which their tree stands. Beautiful ‘word pictures’ are created, in which we learn of the salamanders that hunt for insects in its shade, and of the Douglas squirrels that feed upon its seeds and shelter within its hollows (sometimes being de-capitated by the owls who also like to haunt the tree). We also learn of unseen nutrient transfers going on underground between the tree and its mycorrhizal partners, and about how migratory salmon transfer nitrogen from the oceans to the forests (the mineral is released from the carcasses of fish that have been taken from the streams by local bears). The book therefore gives the reader a sense of how individual trees fit into their wider environments, and of some of the less obvious connections that help knit natural communities together.
Specialist readers will find irritations in some aspects of the book. The authors’ description of xylem tubes and the mechanism by which water moves through them, for example, seems to mis-represent prevailing scientific thought, as does their classification of fungi as ‘plant related organisms’. Given that this publication is an ‘updated’ edition of Suzuki and Grady's 2004 text (it has a new introduction by Peter Wohlleben), such gripes could have been avoided. Where the book's chapters draw on scientific studies (e.g. in relation to the nitrogen transfer by salmon), its list of ‘Selected References’ fails to clarify the sources – although it does find space to list several non-science works. This is unhelpful for anyone wanting to delve deeper into plant science or forest ecology.
However, the nature writing contained within Tree is compelling and highly readable. It will open many peoples’ eyes to the often-overlooked wonders of our charismatic mega-flora, and leave them with a realization that there is more going on within their neighbourhood's trees than immediately meets the eye. At a time when many of the world's habitat trees are under threat (whether they stand in cities, or in paddocks or in the wild), this matters. Tree: A Life Story is, therefore, a worthwhile book. It is an enjoyable one, too.
