Jeff Welker has been studying Arctic plant & ecosystem ecology, biogeochemistry and biosphere-atmosphere interactions since his research activities at NyAlyesund, Svalbard and Abisko, Sweden started in 1990. His research program focuses on four themes: a) tundra plant and ecosystem structure and function now and in the future using the ITEX (International Tundra Experiment) program; b) the Arctic Water Isotope Cycle and sea ice controls on shifting patterns, sources and distribution of precipitation; c) terrestrial and marine food web processes focused on diets and space-use of wolves, polar bears, brown bears, caribou and reindeer and d) herbivore and climate effects on greenhouse gas emissions, sources and ages. Dr. Welker serves on the US Arctic Icebreaker Coordination Committee (AICC), the NSF Office of Polar Programs Advisory Committee and as the Arctic Research Advisory to the Chancellor at the University of Alaska Anchorage. He is convening a UArctic Congress 2018 session on caribou-reindeer-cultural practices and is leading a new project titled: “Pan Arctic Water Isotope Network” which was granted INTERACT remote access to research stations. The project involves colleagues from Iceland, Denmark, Greenland, Czech Republic, Poland, USA, Finland, UK, Canada and Norway.