Research Institute for Nature and Forest (INBO), Gaverstraat 4, B-9500, Geraardsbergen, Belgium.
Natuurpunt Studie, Coxiestraat 11, B-2800, Mechelen, Belgium.
BMC Ecol Evol. 2021 Dec 27;21(1):224. doi: 10.1186/s12862-021-01953-z.
To set up successful conservation measures, detailed knowledge on the dispersal and colonization capacities of the focal species and connectivity between populations is of high relevance. We developed species-specific nuclear microsatellite molecular markers for the grayling (Hipparchia semele), a butterfly endemic to Europe and of growing conservation concern in North-West Europe, and report on its population genetics, in a fragmented, anthropogenic landscape in Belgium. Our study included samples from 23 different locations nested in two regions and additional historical samples from two locations. We assessed contemporary, long-distance dispersal based on genetic assignment tests and investigated the effect of habitat loss and fragmentation on the population genetic structure and genetic variation using data of nine microsatellite loci.
Detected dispersal events covered remarkably long distances, which were up to ten times larger than previously reported colonisation distances, with the longest movement recorded in this study even exceeding 100 km. However, observed frequencies of long-distance dispersal were low. Our results point to the consequences of the strong population decline of the last decades, with evidence of inbreeding for several of the recently sampled populations and low estimates of effective population sizes (Ne) (ranging from 20 to 54 individuals).
Our study shows low frequencies of long-distance dispersal, which is unable to prevent inbreeding in most of the local populations. We discuss the significance for species conservation including future translocation events and discuss appropriate conservation strategies to maintain viable grayling (meta) populations in highly fragmented, anthropogenic landscapes.
为了制定成功的保护措施，详细了解目标物种的扩散和定居能力以及种群之间的连通性至关重要。我们为欧洲特有物种灰蝶（Hipparchia semele）开发了特定物种的核微卫星分子标记，并报告了其在比利时碎片化、人为景观中的种群遗传学。我们的研究包括来自两个地区的 23 个不同地点的样本以及来自两个地点的额外历史样本。我们基于遗传分配测试评估了当代的长距离扩散，并使用九个微卫星位点的数据研究了生境丧失和破碎化对种群遗传结构和遗传变异的影响。
检测到的扩散事件覆盖了非常长的距离，最长的移动距离甚至超过了 100 公里，是之前报道的定居距离的十倍多。然而，长距离扩散的观察频率较低。我们的结果表明了过去几十年种群数量急剧下降的后果，最近采样的几个种群存在近交的证据，有效种群大小（Ne）的估计值较低（范围从 20 到 54 个个体）。
我们的研究表明，长距离扩散的频率较低，这无法阻止大多数当地种群的近交。我们讨论了包括未来转移事件在内的物种保护的意义，并讨论了在高度碎片化、人为景观中维持可行灰蝶（元）种群的适当保护策略。
