In April 2004, the German Research Foundation (DFG) and the National Science Foundation (NSF) co-organized a meeting for US and German junior geoscientists in Washington DC. As an outcome of this Research Conference titled ‘Earth, Fire, Water, Air and Life’, a follow-up workshop took place in May 2005 at the Eberhard-Karls University of Tuebingen in Germany. This workshop covered new aspects of research to improve the understanding of steep biogeochemical gradients covering pH changes, redox zones, as well as solute and particulate concentration variations in aqueous systems. Detailed understanding of biogeochemistry in this context delivers new fundamental aspects in interdisciplinary research. Such work is also urgently needed to control ever-increasing scarcity of water that is to large parts driven by decreasing water quality. Research ideas on gradients in a biogeochemical context that were discussed by a subgroup of biogeochemists during that workshop are summarized and presented here.