In the present volume, resulting from the fifth ‘Panmediterranean meeting’ held in Montpellier, special emphasis is given to water constraints and responses of biota at different scales. Overall, 25 authors contributed to 14 chapters, arranged under four sections: (i) Time-scale interactions in physiological processes; (ii) Consequences of interannual rainfall variability; (iii) Evolutionary responses to summer drought; and (iv) Past and future mediterranean climates. The first section deals with physiological processes. I do not understand why a volume about mediterranean biota starts emphasizing studies on water stress in Spinacia oleracea (chapter 2). More adequate is the modelling approach (chapter 3), aiming at understanding how instantaneous fluxes of water flow and storage in plants produce slower daily processes, as well as the problem of upscaling from daily transpiration to a seasonal water balance (chapter 4).