Plane trees in cities have an important cooling effect even in extreme heat, according to a new study by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). This challenges earlier assumptions that the cooling effect of trees reaches its limits at 30-35° degrees Celsius. + Get the most important news from Switzerland in your inbox Even in extreme heat above 39°C, plane trees continue to evaporate large amounts of water, thereby cooling their surroundings, the study published on Monday found. This is good news for urban areas. Days with temperatures above 30°C are becoming more frequent. The next important step is to find out how effectively other tree species transpire in extreme heat. Trees in cities cool their surroundings by evaporating water through their leaves. This process works like sweating: evaporation draws heat from the environment, causing the air temperature to drop. If leaf temperatures rise above 30-35°C photosynthesis no longer works - the ...
