Amongst the waddling Gila monsters, speeding roadrunners and jutting cacti of the Arizona desert lies an unlikely centre of academic excellence – the Laboratory of Tree-Ring Research (LTRR). In Tree Story, Valerie Trouet invites us into this surprising world.
Trees possess a series of rings that correspond to annual cycles of growth, which are determined by atmospheric and climatic events. To the untrained eye, the rings of a favourite garden tree stump might elicit nothing other than childhood memories of laboriously counting. Yet, through Trouet’s trained eyes as a qualified dendrochronologist, this practice is a transcendental journey through time. Travelling the world to ‘core’ trees and collect samples, dendrochronologists have forged a timeline through which to examine complex climatic periods and events in Earth’s history. Trouet’s work in this field transports us to far-flung reaches of the planet, even if, as inexperienced arborists, we may need a bit of hand-holding.
The protagonists of this tale are the ancient pillars of our environments which, to some skilled researchers, harbour wisdom from aeons past. Trouet’s fascination with the treasures of her adventures brings out the character in each of her subjects. There is Adonis, the oldest dendrochronologically dated tree in Europe, towering atop the Pindos mountain range in northern Greece; there is Methusaleh, the 4,789-year-old sage of the Ancient Bristlecone Pine Forest; and countless other trees which have stood witness to the events in our history books.
Trouet paints a portrait of a scientific process. We learn how scientists think in order to solve seemingly insurmountable challenges; how they share information and meticulously plan their study. Descriptions of belaboured academic processes can leave one reeling, but there is a reverence to be found in Trouet's steady process and loyalty to her field. Dedication to accuracy is the essence of dendrochronology, and the reason for its authority in dating wooden archaeological finds, and in resolving disputes over the authenticity of historic artworks (experts can accurately date the frames).
Trouet is at her best when she weaves history and climate science, such as the dendrochronologically dated cold summer of 1816 – a byproduct of the Tombara volcanic eruption in Indonesia – which she claims forced Mary Shelley, holidaying at Lake Geneva, inside to swap stories about a young scientist and his monster.
For those that enjoy academia, or those who can get round it, Trouet’s Tree Story is a handy field-guide to study Earth’s climate; its dependency on orbital variations, its sensitivity to volcanic eruptions and to solar radiation. Through an unexpected lens, we learn how our climate has been shaped by natural forces, and how some of the most ancient living things bear the etchings of time immemorial.