The Betula pendula Roth. seeds used in this study were collected from three different natural populations in the province of Lugo (NW Spain). Three samplings were obtained from each population during the dispersal period of the species. The objective of our research was to assess the germination response of the seeds from each population and sampling when exposed to some of the most important effects of fires: high temperatures, ash and their joint effect. Significant differences have been found in the germination percentages of the seeds from the different populations and also from the three samplings. However, the tested effects of fire: heat, ash and their joint effect did not significantly affect the germination percentage of this species.