Landforms constitute boundary surfaces between different components of the earth system (atmosphere, hydrosphere, biosphere, pedosphere, lithosphere). At these locations most of the human activity on earth takes place. This central position evokes a bi-directional interaction with the other spheres of the earth system. S- tial landform structures strongly affect processes of other earth system components. At the same time, the land-surface is shaped by the in uence of these processes impacting geomorphologic processes and landform morphometry. These interactions are the focus in the Research Training Group 437 "Landform - a structured and variable boundary layer" at the University of Bonn in Germany. Funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) the Research Training Group is a multidisciplinary research programme for postgraduate studies. Disciplines involved in this programme include: biology, c- matology, computer sciences, geodynamics, geology, geomorphology, geophysics, hydrology, mathematics, meteorology, pedology, and remote sensing.
These diff- ent disciplines offer various scienti c approaches, theories, methods and data for the study of landforms within their speci c paradigms. Over a period of ten years (1998-2008) more than 25 PhD projects have been completed. Dedicated to ongoing and completed research activities of the Research Training Group an international symposium titled "Landform - structure, evolution, process control" was held at the Department of Geography, University of Bonn, in 2007.