Data from: A seascape genetic analysis reveals strong biogeographical structuring driven by contrasting processes in the polyploid saltmarsh species Puccinellia maritima and Triglochin maritima.

Little is known about the processes shaping population structure in
saltmarshes. It is expected that the sea should act as a powerful agent of
dispersal. Yet, in contrast, import of external propagules into a
saltmarsh is thought to be small. To determine the level of connectivity
between saltmarsh ecosystems at a macro-geographical scale, we
characterised and compared the population structure of two polyploid
saltmarsh species, Puccinellia maritima and Triglochin maritima based on a
seascape genetics approach. A discriminant analysis of principal
components highlighted a genetic structure for both species arranged
according to a regional pattern. Subsequent analysis based on isolation by
distance and isolation by resistance frameworks indicated a strong role of
coastal sediment transport processes in delimiting regional structure in
P. maritima while additional overland propagule dispersal was indicated
for T. maritima. The identification and comparison of regional genetic
structure and likely determining factors presented here allows us to
understand the biogeographical units along the UK coast, between which
barriers to connectivity occur not only at the species level but at the
ecosystem scale. This information is valuable in plant conservation and
community ecology and in the management and restoration of saltmarsh
ecosystems.

目前，关于盐沼（saltmarshes）种群结构形成过程的认知仍十分有限。海洋本应作为强大的扩散媒介发挥作用，但与之相反的是，外界繁殖体（propagules）向盐沼的输入量却被认为较小。为明确宏观地理尺度（macro-geographical scale）下盐沼生态系统间的连通性（connectivity）水平，我们采用景观遗传学方法（seascape genetics approach），对两种多倍体（polyploid）盐沼物种——海滨碱茅（Puccinellia maritima）和海韭菜（Triglochin maritima）的种群结构进行了表征与比较。主成分判别分析（discriminant analysis of principal components）结果显示，两种物种的遗传结构（genetic structure）均呈现出区域分布模式。基于距离隔离（isolation by distance）和阻力隔离（isolation by resistance）框架的后续分析表明，海岸沉积物运输过程（coastal sediment transport processes）对海滨碱茅区域结构的界定具有重要作用，而海韭菜则存在额外的陆地繁殖体扩散现象。本文对区域遗传结构及其潜在决定因素的识别与比较，使我们能够理解英国海岸沿线的生物地理单元（biogeographical units）——这些单元之间的连通性障碍不仅存在于物种层面，也存在于生态系统层面。这些信息对于植物保护（plant conservation）、群落生态学（community ecology）研究以及盐沼生态系统的管理与恢复（management and restoration）具有重要价值。