Kees van Leeuwen conducts research on the concept of terroir in viticulture, including the effect of environmental constraints (water and nitrogen), phenology modeling and the impact of climate change in viticulture. The output of this research can help growers to optimize terroir expression and to adapt to a changing environment. Kees van Leeuwen is the founder and editor in chief of the viticulture section of the international peer reviewed open access journal OENO One.