Data from: Effects of fire regime on the population genetics of natural pine stands, in Genetic structure of forest trees in biodiversity hotspots at different spatial scales (Ph.D. thesis).

The recurrence of wildfires is predicted to increase worldwide due to
climate change, resulting in severe impacts on biodiversity and ecosystem
functioning. We used simple sequence repeat (SSR) and single nucleotide
polymorphism (SNP) markers to examine the effects of fire regime on
genetic diversity, demographic history and fine-scale spatial genetic
structure (SGS) of Pinus pinaster and P. halepensis, two conifers with
similar adaptations to fire in the eastern Iberian Peninsula. Stands
growing under high (HiFi) or low (LoFi) frequency of crown fires had
similar levels of genetic diversity and similar demographic history, with
bottlenecks detected in all stands in both species. HiFi populations were
not genetically depleted, suggesting that adaptations such as a diverse
canopy seed bank due to serotinous cones, an early age of first flowering
and high gene flow buffer against possible reductions of genetic
diversity. Significantly stronger SGS at SNPs in HiFi than LoFi stands of
P. halepensis suggested fire-related altered dispersal possibly combined
with microenvironmental selection in this fire-sensitive “seeder” species.
In contrast, SGS at SNP markers was unrelated to fire regime in P.
pinaster. This could be a consequence of more pronounced fire-resistance
in this species enabling some adults to survive fire, hence causing a
lower dependence on post-fire regeneration. Our results highlight that the
impact of fire differs in species with similar life-history traits.
Therefore, species-specific studies are needed to understand the role of
wildfires for the evolution of future forests