Modified dispersal-related traits in disjunct populations of bird-dispersed Frangula alnus (Rhamnaceae):: a result of its Quaternary distribution shifts?
Modified dispersal-related traits in disjunct populations of bird-dispersed Frangula alnus (Rhamnaceae):: a result of its Quaternary distribution shifts?
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DOI：
10.1034/j.1600-0587.2000.230511.x
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发表时间：
2000-10-01
期刊：
影响因子：
5.9
通讯作者：
Bairlein, F
中科院分区：
文献类型：
--
作者：
Hampe, A;Bairlein, F
许多欧洲树种在地中海避难所的更新世冰川中幸存下来，并在之后迅速融入温带欧洲。冰间和冰后期的迁移过程被认为具有催化进化优化的传播相关的特征，但到目前为止，经验证据是缺乏脊椎动物分散的植物。我们调查，如果南伊比利亚冰川遗迹和中欧的“殖民者”人口的鸟类分散的树赤杨经历了分化的扩散相关的性状，增加了北方人口的流动性。比较一生的生殖策略，分散工会，成熟物候，和水果设计发现了相当大的差异。与南伊比利亚同种相比，中欧植物相当小，并经历了一个高度加速的世代更替，在南伊比利亚种群的种子传播几乎完全是由在整个成熟季节不断丰富的留鸟发生。相比之下，中欧的种子分散的移民的丰度变化很大，在成熟季节。几种鸟类都参与了这两个研究领域，但提供不同的重要性，种子传播。果实成熟模式是高度异步的整个成熟季节在南部伊比利亚，而中欧树木表现出复杂的成熟序列，导致在一个显着的相关性之间的水果丰富度和不断变化的分散可用性。中欧的水果较小，并表现出相当小的种子负荷比南伊比利亚的水果，因此可能是更有吸引力的小尺寸的主要传播者（西尔维娅莺）。化学分析表明，水，葡萄糖，果糖，蛋白质，灰分和酚类化合物的含量显着差异。F. Alnus认为，即使是来自食果动物的微弱的选择压力，也可能在大的时间尺度上引起扩散特征的进化调整。我们认为，我们今天所观察到的差异是在第四纪物种分布变化过程中演变而来的。
Many European tree species survived Pleistocene glaciations in Mediterranean refugia and rapidly recolonized temperate Europe afterwards. Inter- and postglacial migration processes are assumed to have catalized evolutionary optimizations of dispersal-related traits, but up to now empirical evidence is lacking in vertebrate-dispersed plants. We investigated if south Iberian glacial relict and central European "colonizer" populations of the bird-dispersed tree Frangula alnus have experienced differentiations of dispersal-related traits which increase the mobility of northern populations. A comparison of lifetime reproductive strategy, disperser guilds, ripening phenology, and fruit design revealed considerable differences. Compared to south Iberian conspecifics, central European plants were considerably smaller and experienced a highly accelerated generation turnover, In south Iberian populations seed dispersal was carried out almost completely by resident birds which occurred in constant abundances throughout the ripening season. In contrast, central European seeds were dispersed by migrants whose abundances changed considerably during the ripening season. Several bird species were involved in both study areas but rendered different importance for seed dispersal. The fruit ripening pattern was highly asynchronous throughout the ripening season in south Iberia, while central European trees showed a complex ripening sequence which resulted in a significant correlation between fruit abundance and changing disperser availability. Central European fruits were smaller and showed a considerably smaller seed load than south Iberian fruits, thus presumably being more attractive for their small-sized main dispersers (Sylvia warblers). Chemical analyses revealed significant differences in contents of water, glucose, fructose, proteins, ash, and phenolic compounds. The extensive differentiation of dispersal-related traits in F. alnus suggests that even weak selective pressures by frugivores may induce evolutionary adjustments of dispersal traits over large time scales. We suggest that the differences we observe today evolved during the species' distribution shifts in the Quaternary.