"Trees’ spring awakening is becoming less sensitive to altitude differences"

Introduction: Researcher UAntwerp and his international colleagues conduct research on Swiss Alps forest species. In the Swiss Alps, the time lag between tree leafing at high and low altitudes has shortened dramatically since the 1960s due to climate change. This is the finding of an international study conducted in collaboration with the University of Antwerp, which has just been published in the journal PNAS (Proceedings of the National Academy of Sciences of the United States of America). Led by biologist Yann Vitasse, three researchers - among whom UAntwerp research fellow Dr Yongshuo H. Fu - analysed more than 20,000 observations recorded by volunteers in Switzerland and collected by MeteoSwiss since 1960. The records in question covered the dates on which leaves or needles appeared on four forest species: beech, spruce, larch and hazel. The study was conducted by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) and the University of Neuchâtel in collaboration with the Swiss Federal Institute of Technology Lausanne (EPFL), the University of Antwerp and Beijing Normal University. Five decades of citizen science bear fruit "These forest species are among the most widespread in Switzerland, especially in mountainous areas.