We are pleased to announce that the Swiss National Science Foundation (SNSF) will support a new project in our group. The project, CoolRoots, builds on our recent work on how low root temperatures affect the hydraulic functioning and growth of temperate trees, and how these processes may shape species-specific upper elevational and latitudinal distribution limits. Led by Günter Hoch, in collaboration with colleagues from WSL (Birmensdorf) and SLF (Davos), the four-year project will support one PhD student and one postdoctoral researcher in the PPE group.

Project overview

Temperature is a key determinant of species distributions, underpinning widespread expectations that climate warming will shift species ranges. However, the ecophysiological mechanisms that define species-specific temperature limits remain poorly understood. A particularly striking case is the low temperature limit of tree species, which determines their high elevation and latitude distribution limits. One hypothesis is that the cold limitation of tree growth is driven by tree hydraulic constraints induced by restricted root water uptake (RWU) at low soil temperatures. Yet, the role of cold soils in shaping tree productivity and distribution is still insufficiently understood and is not well represented in current tree hydraulic models. CoolRoots addresses this gap by combining controlled experiments with field observations to quantify how low root temperatures influence water relations and growth in common European temperate tree species.