Population dynamics of Arabis alpina in the French Alps: evidence for demographic compensation?

O_LIDue to its genetic proximity with Arabidopsis thaliana, Arabis alpina (Brassicaceae) is increasingly used as a perennial model species in studies of molecular evolution and adaptation.\nC_LIO_LIWe studied the demography of A. alpina in six natural sites widely differing in their degree of disturbance, slope and vegetation, and encompassing the full altitudinal range of the species.\nC_LIO_LIWe estimated three vital rates (growth, reproductive effort and survival) for individually-marked plants, studied for six years (2008-2014). We characterized the thermic conditions of each site with different thermal variables obtained using in situ continuous-time data loggers.\nC_LIO_LIAlthough A. alpina is described as a perennial species, the average life expectancy was only 1.82 years and most plants died before setting seeds. Plant size was a strong predictor of all three vital rates.\nC_LIO_LIMean daily temperature showed a positive effect on growth and a negative effect on survival. Furthermore, reproductive effort covaried negatively with survival, suggesting a mechanism of demographic compensation acting on an elevational gradient.\nC_LIO_LISynthesis. These results are informative of the selective pressures experienced by A. alpina in natural conditions and will help design experimental and molecular studies of local adaptation in this species.\nC_LI