Roger Cousen's work combines modelling, fieldwork, experimentation and, increasingly, molecular methods (with collaborators) to answer specific questions about the mechanisms behind spatial and temporal species dynamics.
His current research is primarily on coastal invasive plants and in particular the dynamics of two invasive sea-rockets - in many ways a plant analogue of the Neanderthal story. But he has very broad interests in plant population biology, dynamics and photography.
John is an author of two books: Dynamics of Weed Populations (1995) and Dispersal in Plants - A Population Perspective (2008). Roger organises biennial international debates on applied ecology topics, in various mountainous regions.