by Patrick Fonti & Ute Sass-Klaassen
As humans and animals, trees also perceive their environment. However, differently than humans and animals, trees cannot escape unfavorable situation and thus have to have good mechanisms to face them to survive over decades and centennials. Our COST Action STReESS (Studying Tree Responses to extreme Events: a SynthesiS) focused the attention on understanding how trees respond to a changing environment and on how to collect, use and interpret this information to early and directly assess the impact of extreme climate events on forests. This approach, called the “tree-centered approach”, basically let the trees tell us how strong they perceived a given climatic extreme and how this is affecting them over the following years. With today’s current techniques, this can be monitored in near real time, opening also the possibility to create early-warning systems to assess the health status of our forests.
Automatic dendrometers, i.e., devises that allow to measure stem size changes over time at high temporal resolution, are one of these tools that provide detailed information about the tree’s current water status and growth.
Dr Marcus Lindner and Laura Nikinmaa from EFI’s Bonn office have hosted 14 scientists from 8 countries to further developed a pilot study aimed at using dendrometer data from all over Europe to ask trees about how they have perceived the 2018 summer heatwave. By letting the trees tell us their stories, the researchers hope to qualitatively, temporally and spatially improve the assessment of forest resilience to extreme events.