VPDrought
Charlotte Grossiord, Jonas Gisler
Project staffPetra D'Odorico, Arthur Gessler, Jonas Gisler, Charlotte Grossiord, Christian Hug, Stefan Hunziker, Katrin di Bella Meusburger, Richard Peters, Andreas Rigling, Volodymyr Trotsiuk, Roman Zweifel
2022 - 2028
Cooperation FinancingA novel approach to disentangle atmospheric and soil drought ¶
High evaporative demand (i.e., vapor pressure deficit or VPD) is an important factor influencing plant transpiration. VPD has increased in the context of global warming in recent decades, and can be referred to in highly simplified terms as "air dryness".
We aim to apply a scale-spanning approach to disentangle the processes affected by atmospheric (i.e., VPD) and soil droughts in mature Scots pine trees (Pinus sylvestris).
VPDrought is the first atmospheric humidity and soil moisture manipulative experiment worldwide in a mature natural forest. Under the tree canopy, we use rain shelters to divert 50% of the natural precipitation, thereby increasing soil dryness. In the canopy, a dry misting system increases air humidity, thereby reducing the VPD.
The system will be installed at the long-term Pfynwald irrigation experiment, a pivotal monitoring and experimental site in a pine forest in Valais, where the effects of soil drought have been studied since 2003 (see map). The site benefits from extensive data series, including more than 120 parameters collected at the tissue, tree, and ecosystem levels.
- Exhaustive information and access to data: vpdrought.wsl.ch