OAK RIDGE, Tennessee, May 17 (TNSper) -- The U.S. Department of Energy's Oak Ridge National Laboratory issued the following news release: Colleen Iversen, ecosystem ecologist, group leader and distinguished staff scientist at Oak Ridge National Laboratory, has been named director of the Department of Energy's Next-Generation Ecosystem Experiments Arctic, or NGEE Arctic, a multi-institutional project studying permafrost thaw and other climate-related processes in Alaska. Iversen has worked as a  more