Severe bottlenecks significantly diminish the amount of genetic diversity and the speed at which it accumulates (i.e. evolutionary rate). They further compromise the efficiency of natural selection to eliminate deleterious variants, which may reach fixation in the surviving populations. Consequently, expanding and adapting to new environments may pose a significant challenge when strong bottlenecks result in genetic pauperization. Herein, we surveyed the patterns of nucleotide diversity, molecular adaptation and genetic load across hundreds of loci...

1. Forest decline under environmental stress is expressed by regeneration failure and accelerated mortality in all ontogenic stages at the population level. Characterizing functional traits and mechanisms that best capture species decline and mortality is essential to assess forest dynamics. 2. We analyzed sensitivity to increasing water stress in two species with different water-use strategies on a mixed Quercus pyrenaica - Pinus sylvestris forest where adult pines express vulnerability to climate change but oaks do...