The 12th meeting on Frankia and Actinorhizal Plants that took place in Carry-le-Rouet, France in June 2001 was the opportunity for scientists to communicate about latest developments on this symbiosis that concerns a wide range of dicotyledonous plants, initiates ecological successions and is used in a number of countries to protect crops from winds or improve soil status. Selected papers on plant ecology, Frankia's genetics or physiology, and host plants' genetics or physiology are published in this special Plant & Soil issue.