Data from: Effects of forest plantations on the genetic composition of conspecific native Aleppo pine populations

Afforestation is a common and widespread management practice throughout the world, yet its implications for the genetic diversity of native populations are still poorly understood. We examined the effect of Aleppo pine (Pinus halepensis) plantations on the genetic composition of nearby conspecific native populations. We focused on two native populations in Israel with different levels of isolation from the surrounding plantations and compared the genetic diversity of naturally established young trees within the native populations with that of local native adults, using nine nuclear microsatellite markers. We found that the genetic composition of the recruits was significantly different from that of local adults in both populations, with allelic frequency changes between generations that could not be ascribed to random drift, but rather to substantial gene flow from the surrounding planted Aleppo pine populations. The more isolated population experienced a lower gene flow level (22%) than the less isolated population (49%). The genetic divergence between native populations at the adult-tree stage (Fst = 0.32) was more than twice as high as that of the young trees naturally established around native adults (Fst = 0.15). Our findings provide evidence for a rapid genetic homogenization process of native populations following the massive planting efforts in the last decades. These findings have important implications for forest management and nature conservation and constitute a warning sign for the risk of translocation of biota for local biodiversity.

造林是全球范围内普遍且广泛应用的森林经营措施，但其对本地种群遗传多样性的影响仍未得到充分解析。本研究以阿勒颇松（Pinus halepensis）为研究对象，探讨了其人工林对邻近同种本地种群遗传组成的影响；我们选取以色列的两个本地种群，二者与周边人工林的隔离程度存在差异，并利用9个核微卫星标记（nuclear microsatellite markers），对比了本地种群内自然更新幼树与本地成年个体的遗传多样性。研究发现，两个种群的自然更新幼树的遗传组成均与本地成年个体存在显著差异，代际间的等位基因频率变化无法归因于随机遗传漂变，而是源于周边人工阿勒颇松种群的显著基因流；隔离程度更高的种群其基因流水平（22%）低于隔离程度更低的种群（49%）。本地种群成年个体间的遗传分化系数（Fst=0.32）是自然更新幼树间遗传分化系数（Fst=0.15）的两倍以上。本研究结果证实，近数十年大规模造林活动后，本地种群正经历快速的遗传同质化过程；这些发现对森林经营与自然保护具有重要指导意义，同时也为以提升本地生物多样性为目的的人为生物迁移活动所带来的生物多样性风险敲响了警钟。