This is how in Italy, thanks to genomics, we are studying trees to save ourselves
Thanks to the combination of fossil data and data on genetic diversity, the Institute of Biosciences and Bioresources of the Italian National Research Council (CNR) is discovering the secrets of the migration and adaptation of forests
Where do trees go? How do they move and how do they adapt to the fast-paced climate change? Thanks to their thousand-year-old history, combined with genomics and molecular studies, we can now find out. Knowing how trees react to global warming means being able to protect them better and acquire fresh knowledge on their incredible genetic diversity. The way molecular tools are already helping us to monitor how forests tackle climate change was the focus of a digital speech by Giovanni Giuseppe Vendramin, the director of the Institute of Biosciences and Bioresearch of the CNR, at Expo 2020 Dubai.
Italy is playing a prominent role in the “Climate and Biodiversity Week”, during which experts from around the globe are debating virtually on biodiversity protection and the impact of global warming. In addition, the country is also spearheading new studies which, thanks to genomics, are gradually unravelling the way forests react to global warming. Although it may not be clearly evident, Vendramin recalls that trees “migrate. They have always done so. Over millennia, the trees of our forests have always exhibited the same behaviour in the face of climate crises: they either migrate or adapt to changes or go extinct”. That’s why knowing how they are reacting to the present climate crisis, which is developing fast, is crucial for us: for protecting biodiversity, preserving species, but also for simply planning the cities and green areas of the future, given the importance of trees in absorbing CO2 and their decisive role in the fight against global warming.
“Trees have very long-life cycles,” explains Vendramin, “and we know that Italy too has trees that are thousands of years old. Compared to people and animals, trees move slowly, but they definitely move, by dispersing their seeds and pollen – they are moving in Europe, for example. But how do they defend themselves against global warming? They either use forms of migration, for example when the terrain housing them is no longer suitable for their survival, or they adapt to climate change. If they are unable to complete any of these two processes, they basically go extinct. That’s why we of the CNR and several other European projects are using new tools to study their behaviour”.
The main tool for understanding how they behave is “genomics. We observe and analyse the genetic diversity of trees and compare it with that of the past, thanks to fossils. We hope this will help us understand how and if trees have adapted to climate changes in the past and if and when they were compelled to shift”. The director recalls, for example, that “in the aftermath of the glacial period, many tree species that presumably lived in our lands, and in the so-called glacial refugia, began to shift. This explains why from Northern to Southern Europe we can find species that weren’t there before. Thanks to genetic markers and fossil data, we are reconstructing these movements to understand exactly how and why they shifted”.
Knowing the routes will be fundamental for preserving the species and already now we are recording “evident changes in the areal distribution of the species. Let’s take red fir, oak and beech trees: they now grow where they didn’t before, and perhaps disappeared from other zones”. One such example is the Aleppo pine. “Due to significant precipitations and droughts, it has recently adapted in some cases to extreme conditions, while elsewhere it has shifted”. The same applies to beech. “For example, they shifted from areas in Southern Europe that had become too dry for them to the mild climates of Northern Europe. We could say that the beech has migrated northwards”.
All the information that researchers are collecting on the genetic diversity of plants and on their ability to migrate and adapt will then be fed into calculators to produce, by means of modelling techniques, models that can be used to predict how trees will react, so that we can intervene in an effort to preserve them and plan the cities of the future.
“Trees have an extraordinary longevity: more than anything else they can explain to us a lot about climate change and their ability to adapt thanks to their extremely rich genetic diversity. Understanding how they respond to the crisis is crucial to understanding how we can design the future world: for example, knowing where to plant trees and which ones to plant, knowing whether some of them must be transferred, acquiring new tools for managing forests. We require all this information to preserve plants, but also for ourselves, given the decisive role trees play in absorbing CO2” concluded Vendramin.