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

气候变化预计将导致全球野火发生频次攀升，进而对生物多样性与生态系统功能造成严重影响。本研究采用简单序列重复（simple sequence repeat, SSR）与单核苷酸多态性（single nucleotide polymorphism, SNP）分子标记，探究了火制度对伊比利亚半岛东部两种火适应性相近的针叶树种——海岸松（Pinus pinaster）与阿勒颇松（Pinus halepensis）的遗传多样性、种群历史动态及精细尺度空间遗传结构（spatial genetic structure, SGS）的影响。分别选取冠火发生高频（HiFi）与低频（LoFi）生境下的林分进行分析，结果显示两个物种的两类林分均具有相似的遗传多样性水平与种群历史动态，且所有林分均检测到遗传瓶颈信号。高频冠火种群并未出现遗传多样性耗竭的情况，这表明诸如由闭鳞松果形成的多样冠层种子库、早花习性与高基因流等适应性特征，可有效缓冲遗传多样性可能出现的下降。对于阿勒颇松这一对火敏感的火后更新型（seeder）物种，其高频冠火种群的SNP标记空间遗传结构显著强于低频冠火种群，这提示火相关的扩散模式改变，或结合微环境选择共同作用于该物种。与之相对，海岸松的SNP标记空间遗传结构与火制度并无关联，这可能源于该物种具有更强的耐火性，部分成年个体可在火灾中存活，从而降低了对火后更新的依赖。本研究结果表明，即便生活史特征相似的物种，野火的影响也存在显著差异。因此，需开展物种特异性研究，以明晰野火在未来森林演化中的作用。