Tree Architecture and Morphophysiology Symposium
Royal Botanic Gardens, Kew: 7–8 April 2025
Tree morphophysiology can be defined as ‘the study of tree shape and structure in relation to function to achieve the goal of sustaining life’.
Morphophysiology introduces an arboricultural language which enables users to communicate in a clearer way, with more predictable outcomes, that is designed to help promote the condition and prolong the lifespan of a tree. Using this language and its models, arborists and those specifying pruning operations can understand each other’s objectives, resulting in better tree work.
We’re pleased to provide an opportunity to delve into this refreshing view of tree growth, response and behaviour, above and below ground, with implications for managing trees at all stages of life:
- Tree nursery production and establishment
- Formative pruning
- Maintenance pruning
- Mature and veteran tree management
Confirmed speakers currently include:
Giovanni Morelli
and
Stefania Gasperini, Italy
Tom Joye,
Belgium
Jeanne Millet,
Canada
It is hoped that the symposium will also be the platform to launch the English translation of Jeanne’s seminal work on tree architecture: The Architecture of Trees in Temperate Regions: Its History, Concepts and Uses.
Further speakers have been invited and the detailed programme, and opportunities for booking, will be announced soon. The programme is designed to include lecture presentations and discussions as well as outdoor demonstrations and walking tours.
Further background on tree morphophysiology
Tree morphophysiology provides a framework for understanding the developmental strategies of trees. The discipline sets out a coherent approach that helps interpret the historical development of the tree whilst also providing a vision for its future development. Such insights enable arborists to manage trees in a way that collaborates with natural developmental processes while alerting us to the subtle cues that trees express as they interact with their environment and other organisms. In simple terms, the framework offers a method of classifying the sequence of growth, branch shedding and regeneration stages in trees, from simple architectural units under the strong influence of hormonal balance during early stages, through the building of the crown structure for bio- mechanical resilience, to managing their energy in the later stages, as trees develop complex interconnecting functional units and reorganise their crown and roots, with the potential to regenerate new, young architectural units.
Using this ‘blueprint’ framework, it is possible to assess which life stage a tree is in, how it may be responding to external influences, what degree of hollowing, crown shedding and reiterative growth should be expected and whether active intervention is necessary. If intervention is required, the principles guide the process of pruning and other management practices, described as ‘accompanying arboriculture’. Morphophysiology introduces an arboricultural language which enables users to communicate in a clearer way, with more predictable outcomes, designed to help promote the condition of and prolong the lifespan of a tree. Using this language and its models, arborists and those specifying pruning operations can understand each other's objectives, resulting in better tree work.
Tree morphophysiology study tour – October 2024
The study tour group in front of St Francis of Assisi’s cypress at the Villa Verrucchio, near Rimini.
At the end of October, the Association’s Senior Technical Officers led a study tour to Ferrara, Italy. The aim was to gather a diverse group of UK arboriculturists with an interest in tree architecture and morphophysiology, and to provide an intensive course of study, discussion and observation of trees managed using the morphophysiological approach.
The hosts and presenters for this study tour were Giovanni Morelli and Stefania Gasperini, who have developed this approach to tree management, based on the principles of tree architecture which originated in France from proven research over the last half century.
Giovanni and Stefania studied for many years with Pierre Raimbault, who worked with Francis Hallé and others in France.
The resulting ‘morphophysiological approach’ introduces a number of interesting and novel principles which, although not contradictory to how tree biology, anatomy and physiology are currently taught in the UK, lead us to understand tree behaviour from a new and refreshing perspective. Recognising the growth and crown organisation that have developed over time allows us to gain a much deeper understanding of a tree’s history, its current condition and its ability to respond to future treatment or external natural events.
The group of 16 attendees included arboricultural and ecological consultants, contracting arborists, educators, VETcert trainers and examiners, Association Trustees including a tree officer, and representatives of the Ancient Tree Forum, Woodland Trust, City of London Corporation, Forestry Commission and Royal Botanic Gardens, Kew. Ages ranged from 27 to 69. The range of expertise in the group was impressively broad and members scrutinised the information presented with extensive discussion and debate. However, by the last day all were enthusiastically engaging in practical application in the field and planning how they can incorporate the morphophysiological approach into their professional lives.
What next?
There is relatively little established English-language reference material for this subject, as much of it has been developed outside of the UK and was not translated, although some of Hallé’s work on tree architecture is available in English. There are many others, in Europe, the UK and around the world, who have explored these ideas in different ways and so there is a huge opportunity to collaborate and find agreement in approach. One of the most important books on tree architecture is written by Dr Jeanne Millet, a French Canadian researcher who first published her work L’architecture des arbres des regions tempérées: son histoire, ses concepts, ses usages in 2012. We’re delighted to announce that this has now been translated into English as The Architecture of Trees in Temperate Regions: Its History, Concepts and Uses and we understand it will be available early next year.
In order to take this exciting project forward, the Association is presenting a symposium at Kew in April next year, and we hope to bring together these various voices to establish a coordinated expression of this new aspect of UK arboriculture.