Abstract Remnant riparian woodlands have an important landscape function, due to their ability to act as ecological corridors. In this study we used molecular markers to assess the genetic variation occurring within and between spontaneous white willow (Salix alba L.) riparian woodlands. Our main goal was to evaluate the extent to which the fragmentation of a woodland corridor along a heavily impacted river in northeastern Italy and stand structural conditions may have affected the population genetics. Although having different structures, the three examined white willow stands showed high estimates of genetic similarity, as well as low genetic differentiation between them, indicating that they shared a similar gene pool and that the stands could result from a common set of individual genotypes, and should be regarded as metapopulations. The magnitude of genetic diversity within each of the stands and genetic differentiation between them, despite their high sexual reproductive capacity associated with a highly marked gene flow, suggest that these stands are dynamic and capable of adaptive responses to possible changes in their fluvial environment. However, the factors influencing genetic diversity should be interpreted from a long-term perspective. Fluvial geomorphic patterns in regulated rivers may be modified to a degree that could lead to changes in dispersal processes, sexual reproduction vs. asexual propagation, and hence genetic diversity.

中文翻译：

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沿支离破碎的河岸走廊邻近白柳（Salix alba L.）种群的遗传多样性和林分结构：案例研究

摘要 残余河岸林地作为生态廊道具有重要的景观功能。在这项研究中，我们使用分子标记来评估自发白柳 (Salix alba L.) 河岸林地内部和之间发生的遗传变异。我们的主要目标是评估意大利东北部受严重影响的河流沿岸林地走廊的破碎程度和林分结构条件可能对种群遗传产生的影响。尽管具有不同的结构，三个被检查的白柳林显示出较高的遗传相似性估计，以及它们之间的低遗传差异，表明它们共享相似的基因库，并且这些林可能来自一组共同的个体基因型，并且应该被视为元种群。每个林分内的遗传多样性的大小和它们之间的遗传差异，尽管它们具有与高度显着的基因流相关的高有性繁殖能力，表明这些林分是动态的并且能够对其河流环境的可能变化做出适应性反应。然而，影响遗传多样性的因素应该从长远的角度来解释。受管制河流中的河流地貌模式可能会在一定程度上被修改，从而导致传播过程、有性繁殖与无性繁殖的变化，从而导致遗传多样性的变化。表明这些林分是动态的，能够对其河流环境中可能发生的变化做出适应性反应。然而，影响遗传多样性的因素应该从长远的角度来解释。受管制河流中的河流地貌模式可能会在一定程度上被修改，从而导致传播过程、有性繁殖与无性繁殖的变化，从而导致遗传多样性的变化。表明这些林分是动态的，能够对其河流环境中可能发生的变化做出适应性反应。然而，影响遗传多样性的因素应该从长远的角度来解释。受管制河流中的河流地貌模式可能会在一定程度上被修改，从而导致传播过程、有性繁殖与无性繁殖的变化，从而导致遗传多样性的变化。