Phylogeography and species distribution models (SDMs) were integrated to test the hypothesis that the current disjunct distribution of Podocarpus lambertii, a cold-tolerant species, preserves the signature of Quaternary climatic oscillations, revealing historical barriers to gene flow. Twenty-five populations (286 individuals) of P. lambertii were screened for sequence variation at three intergenic cpDNA loci. We characterized the genetic diversity, constructed a haplotype network, identified population groups based on genetic divergence among populations and putative refugial areas, and tested the association between genetic and geographic distances. For SDMs, we used an ensemble approach based on five algorithms to estimate climatically suitable areas for the species during the Last Glacial Maximum (LGM), Holocene (HOL), and the present-day (PD). For all populations, haplotype and nucleotide diversity were 0.676 and 4.8 × 10⁻⁴, respectively. Neutrality tests indicated a recent expansion for the species. Analysis of molecular variance revealed genetic divergence among populations (F_ST = 0.1385), significantly correlated with geographic distances (r = 0.524, p < 0.01). Bayesian analysis suggested the formation of a Southern Group (SG) and Northern Group (NG), separated by a barrier to gene flow, with high differentiation among groups (F_CT = 0.6458). The SDMs showed temporal changes in an area suitable for P. lambertii, mainly present at high altitudes and cold temperatures. The main occurrence area of P. lambertii now resides in SG, owing to a colder climate when compared with NG and the expansion of Araucaria angustifolia, a nurse plant that may have created better microclimatic conditions for P. lambertii expansion.

整合了系统学和物种分布模型（SDM），以检验以下假说：当前的耐寒物种罗汉松（Podocarpus lambertii）的离散分布保留了第四纪气候振荡的特征，揭示了基因流动的历史障碍。兰伯氏疟原虫的25个种群（286个个体）筛选三个基因间cpDNA位点的序列变异。我们表征了遗传多样性，构建了单倍型网络，根据人群和推定避难区之间的遗传差异确定了人群，并测试了遗传距离与地理距离之间的关联。对于SDM，我们使用了基于五种算法的整体方法来估计上次冰河期（LGM），全新世（HOL）和当今（PD）期间该物种的气候适宜区域。对于所有种群，单倍型和核苷酸多样性分别为0.676和4.8×10 ^-4。中性测试表明该物种最近有所扩展。分子变异分析显示了种群之间的遗传差异（F _ST = 0.1385），与地理距离显着相关（r  = 0.524，p  <0.01）。贝叶斯分析表明形成了南方群（SG）和北方群（NG），被基因流的障碍所分隔，各群之间差异很大（F _CT  = 0.6458）。所述SDMS显示在一个区域适合的时间变化P. lambertii，主要存在于高海拔和低温。现在，兰伯氏疟原虫的主要发生地区位于SG，这是由于与NG相比气候更冷以及南洋杉（Araucaria angustifolia）的扩大，该植物可能为兰伯氏疟原虫的扩展创造了更好的微气候条件。