Earth surface processes are crucial components of the landscape system, as they are the primary mediators of changes in driving factors, such as climate, tectonic and human action. Accordingly, rigorous understanding of the often non-linear propagation of changed boundary conditions through Earth surface processes to landscape response is crucial to deliver useful and responsible information to the society. Whether the approach is through conceptual models, field studies, laboratory experiments or numerical data processing and modelling, a key question is which processes are important to consider in the complex system of earth surface processes. Two opposing fundamental concepts are either reductionism (larger-scale system behaviour can be predicted from measured lower-level characteristics) or synthesism (understanding across-scale interaction of processes and forms is vital to understand the system).

The following questions become important: What are the feedbacks between triggers and processes? How do feedbacks evolve to a complex, non-linear response? How do processes create a sedimentological record, and vice versa, how can they be interpreted from a record? How do we identify and measure the processes necessary to achieve a system understanding and an adequate system description? Is simplification of complexity a promising approach and, if so, how could this best be achieved?

This session brings together contributions from a wide range of disciplines and approaches. It focuses on the conceptual view rather than collecting case studies. We are delighted to host solicited talks by Chris Paola, Steven Wells and Tom Coulthard.