Save the Butternut: The University of Bologna Has Launched a Special Project for the Care of its Monumental Tree

The University of Bologna will take care of its most majestic tree, the butternut (Juglans cinerea). With its 32 metres in height and 471 centimetres in circumference, it is the defining feature of the Botanic Garden of Bologna.

The large butternut of the Botanic Garden, recently included in Italy’s monumental trees list, is the fourth monumental specimen of the historic centre of Bologna, together with plane trees in Piazza Minghetti and Piazza Malpighi and the ginkgo in Piazza Cavour.

However, age is starting to take its toll on it, along with changes in the environment and climate. For this reason, the University of Bologna has launched a project dedicated to the care, health and preservation of this monumental tree.

Alberto Minelli (Department of Agricultural and Food Sciences), who will lead the initiative, works as a researcher and lecturer in this field in Italy and Europe. He takes care, among others, of the monumental trees at the Royal Palace of Caserta.

“This project is a unique case at European level for what concerns the complexity of the interventions and the quality of the results envisaged”, said Minelli. “We want to use all available tools and skills to give an impetus to the conservation of tree specimens, particularly in this case, as we are dealing with a tree of great value”.

The project will last for five years and will be included in the renovation of the Botanic Garden, which is part of the University Museum Network.

“Although it has survived to this day thanks to its strength, and some help from the gardeners of the Botanic Garden, our monumental butternut now finds itself in a condition of delicate balance with the surrounding environment”, says Umberto Mossetti, curator of the Botanic Garden and Herbarium of the University of Bologna. “The tree has reached an advanced ageing phase that is now irreversible, impairing its physiological functions, increasing its susceptibility to pests and diseases, and putting its survival at risk”.

An information panel will be installed next to the butternut, providing details about the unique characteristics of Bologna’s monumental tree and the experimental interventions that will be performed.

“The butternut is quite an uncommon tree in the urban environment, so much so that our specimen is the only one of its species on Italy’s monumental trees list, which today includes more than 4,500 specimens”, adds Mossetti. “The butternut, native to the North American Atlantic coast, is a slow-growing species typically found in the humid environments of valleys and slopes. It is rarely cultivated as an ornamental plant and is becoming increasingly rare in nature due to a fungal disease, usually fatal”.

Together with the Department of Agricultural and Food Sciences, which will deal with arboriculture, the project will also involve the Department of History and Cultures, for traditional and multi-spectral survey techniques, and the Department of Civil, Chemical, Environmental and Materials Engineering, for the structural part and laboratory analysis.

“This tree once again testifies to the importance of Bologna’s Botanic Garden, one of the oldest in the world, which will hopefully thrive in the future, thanks to the presence of a natural monument such as the butternut”, says Juri Nascimbene, prefect of the Botanic Garden of the University of Bologna (Department of Biological, Geological and Environmental Sciences). “In this historical moment, university botanic gardens play a key role. They help convey to students and the general public scientifically correct information about the natural world, in particular about the importance of plant biodiversity for life on our planet”.