In order for trees to grow, they need to control their water balance meticulously.
In order for trees to grow, they need to control their water balance meticulously. A study by the University of Basel shows how trees react to drought – and revises previous perceptions.
Plants have small pores on the underside of their leaves, known as stomata. When the sun rises, these pores open and the plants absorb carbon dioxide (CO2) from the atmosphere, which they need, in addition to sunlight and water, for photosynthesis. At the same time, water evaporates through the open stomata; for a tree, this may be several hundred liters per day.
When water is scarce, plants can close their stomata and thus prevent it from evaporating too much water. The fact that plants have this protective mechanism at their disposal is nothing new. Until now, however, it has not been clear when this closure occurs and what the trigger was. Researchers at the Department of Environmental Sciences at the University of Basel have provided new findings in the scientific journal Nature Plants. Most of the measurement data comes from the University of Basel’s forest laboratory in Hölstein, in the canton of Basel-Landschaft, where a crane makes it possible to study processes in the crowns of mature trees.
Read more at University of Basel
Image: Researchers aboard a cable car that lifts them into the canopy of their forest lab with the help of a crane. This allows them to study processes in the crowns of mature trees. (Photo: University of Basel, Christian Flierl)
