OPTMix has recently received foreign researchers for soil sampling (more details here), but OPTMix members also visit experimental sites in foreign country in order to promote international exchanges between researchers. It is with this goal of scientific exchanges that Jordan Bello (PhD student on OPTMix) went to Sweden, and more specifically to Umeå at SLU, Swedish University of Agricultural Sciences for one month (november 2017). He is working with Niles Hasselquist, a researcher working on soil-plant relationships and mainly on how climate change and resource management are changing energy and nutrient cycles. Jordan will take advantage of this exchange to analyse data from isotopic measurements taken in the soil and trees of OPTMix at the end of summer 2016 (more details here). The objective of these analyzes is to determine the depth of water uptake by trees during a period of water stress and to see wether this depth depend on tree species (sessile oak or Scots pine), tree size, and stand composition (pure or mixed). Jordan also visited their experimental site where isotope measurements of sap water are made in real time (see picture below).