Professor Fremier is an ecologist with a specific focus on understanding how biotic communities are structured by physical forces and how biota can significantly alter physical processes at local and landscape scales. He tends to work in riparian areas, as they are a tractable study system to research feedback mechanisms. His research aims to answer applied questions with a basic understanding of physical process and ecological insight.  The nature of his research lends itself well to quantifying the influence of stream restoration on stream and riparian habitat.  In addition, because of a process-based focus and the associated quantitative skill set, he has been able to explore other realms of related research, including landscape genetics and community phylogenetics.