abstractTime series records are crucial to understand the dynamical processes that occur within phytoplankton communities. This is even more important in the context of the current global change that is already forcing alterations of unprecedented nature and might have unknown consequences for multiple ecosystem processes. Here we present time series analyses of the biogeochemical trends that occurred in the shelf of the Galician coast (station 2 off A Coruña, NE Atlantic) since late 1980s. Upwelling strength and sea temperature in the area have not changed substantially during the last decades. However, while nitrate fertilization from upwelled waters has remained relatively stable, phosphate concentration has increased leading to a negative trend in the N:P ratio. Those trends have impacted the phytoplankton resource use efficiency jointly with the evenness of the community. Phytoplankton used resources more efficiently at higher values of upwelling strength and at lower values of nutrient concentration and evenness. Phytoplankton communities that were more even had higher dinoflagellate diversity contrasting to dominance of diatoms that used resources more efficiently. Moreover, variability in resource use efficiency increased with evenness.IEO (RADIALES-11
