Why trees grow at night
It is a common misconception that trees grow in the daytime, when photosynthesis produces carbohydrates from CO2. However, growth not only requires carbohydrates, but also highly depends on tree water tension. A study led by the Swiss Research Institute WSL has now shown that tree growth takes place primarily in the dark, mainly because in daylight, it is inhibited by dry air, even in moist soil conditions. Therefore, trees only grow for a small number of hours per day and per season. This finding may change the way we look at the impact of climate change on forests, in particular for predicting the carbon sink of forests.