Żukowska Weronika Barbara, Lewandowski Andrzej
Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, Kórnik, 62-035, Poland.
Sci Rep. 2025 Jan 23;15(1):3014. doi: 10.1038/s41598-025-86994-w.
Genetic diversity is crucial to secure the survival and sustainability of ecosystems. Given anthropogenic pressure, as well as the projected alterations connected with the level and circulation of water, riparian forests are of particular concern. In this paper, we assessed the genetic variation of black poplar - one of the keystone tree species of riverine forests. The natural habitats of black poplar have been severely transformed leading to a significant decline of its population size. Using a set of 18 nuclear microsatellites and geographic location data, we studied 26 remnant populations (1,261 trees) located along the biggest river valleys in Poland. Our main goal was to assess the overall genetic variation and to verify if range fragmentation and habitat transformation have disrupted gene exchange among populations. Genotyping revealed that 261 trees were clones. The level of clonality was higher in more transformed river sections. All populations have probably gone through a drastic genetic bottleneck in the distant past, and most of them have low effective population sizes. Still, the overall level of genetic variation remains high, but certain populations require attention due to their lower genetic variation, higher clonality and strong spatial genetic structure. Genetic differentiation was low, yet Bayesian clustering supported the existence of 11 genetic clusters. According to the results, gene exchange is most prevalent between adjacent populations. Relatively free gene flow occurs only along the Vistula, particularly in its middle section which is characterized by the highest genetic variation. Noticeable genetic structuring was observed along the Oder. Populations located at the range margin showed signs of genetic divergence and reduction of variation. We conclude that human activities have impacted the gene pool of black poplar in Poland by disrupting landscape connectivity and preventing the species from generative reproduction. The study provides practical guidelines on how to develop and implement the conservation program for the gene pool of black poplar in Poland. It also presents a strong case favoring river renaturation and genetic monitoring, particularly concerning keystone species.
遗传多样性对于确保生态系统的生存和可持续性至关重要。鉴于人为压力以及与水位和水流相关的预计变化，河岸森林尤其令人担忧。在本文中，我们评估了黑杨（河漫滩森林的关键树种之一）的遗传变异。黑杨的自然栖息地已被严重改变，导致其种群数量大幅下降。我们使用一组18个核微卫星和地理位置数据，研究了位于波兰最大河谷沿线的26个残余种群（1261棵树）。我们的主要目标是评估总体遗传变异，并验证范围破碎化和栖息地转变是否破坏了种群间的基因交换。基因分型显示有261棵树是克隆体。在受改造程度更高的河段，克隆性水平更高。所有种群在遥远的过去可能都经历了严重的遗传瓶颈，而且大多数种群的有效种群规模较小。尽管如此，遗传变异的总体水平仍然很高，但某些种群因其较低的遗传变异、较高的克隆性和强烈的空间遗传结构而需要关注。遗传分化较低，但贝叶斯聚类支持存在11个遗传簇。根据结果，基因交换在相邻种群之间最为普遍。相对自由的基因流动仅沿着维斯瓦河发生，特别是在其中段，该河段具有最高的遗传变异特征。在奥得河沿线观察到明显的遗传结构。位于分布范围边缘的种群显示出遗传分化和变异减少的迹象。我们得出结论，人类活动通过破坏景观连通性和阻止该物种进行有性繁殖，影响了波兰黑杨的基因库。该研究为如何制定和实施波兰黑杨基因库的保护计划提供了实用指南。它还有力地支持了河流生态修复和遗传监测，特别是对于关键物种。
