Data from: Landscape does matter: disentangling founder effects from natural and human-aided post-introduction dispersal during an ongoing biological invasion

Environmental features impacting the spread of invasive species after
introduction can be assessed using population genetic structure as a
quantitative estimation of effective dispersal at the landscape scale.
However, in the case of an ongoing biological invasion, deciphering
whether genetic structure represents landscape connectivity or founder
effects is particularly challenging. We examined the modes of dispersal
(natural and human-aided) and the factors (landscape or founders history)
shaping genetic structure in range edge invasive populations of the Asian
tiger mosquito, Aedes albopictus, in the region of Grenoble (Southeast
France). Based on detailed occupancy-detection data and
environmental variables (climatic, topographic, land-cover), we modelled
A. albopictus potential suitable area and its expansion history since
first introduction. The relative role of dispersal modes was estimated
using biological dispersal capabilities and landscape genetics approaches
using genome-wide SNP dataset. We demonstrate that both natural
and human-aided dispersal have promoted the expansion of populations.
Populations in diffuse urban areas, representing highly suitable habitat
for A. albopictus, tend to disperse less, while roads facilitate
long-distance dispersal. Yet demographic bottlenecks during introduction
played a major role in shaping the genetic variability of these range edge
populations. The present study is one of the few investigating
the role of founder effects and ongoing expansion processes in shaping
spatial patterns of genetic variation in an invasive species at the
landscape scale. The combination of several dispersal modes and large
proportions of continuous suitable habitats for A. albopictus promoted
range filling of almost its entire potential distribution in the region of
Grenoble only few years after introduction.

可通过种群遗传结构（population genetic structure）作为景观尺度下有效扩散的定量评估指标，解析入侵物种引入后影响其扩散的环境特征。然而，针对正在进行的生物入侵，厘清遗传结构究竟反映景观连通性还是奠基者效应（founder effects），极具挑战。本研究以法国东南部格勒诺布尔地区的亚洲虎蚊（Aedes albopictus）分布边缘入侵种群为研究对象，解析了塑造其遗传结构的扩散模式（自然扩散与人为辅助扩散）及相关影响因素（景观特征与奠基者历史）。本研究基于详尽的占据-检测（occupancy-detection）数据与气候、地形、土地覆盖（land-cover）等环境变量，构建了白纹伊蚊（Aedes albopictus）的潜在适宜分布区及其自首次引入以来的扩张历史模型。本研究借助生物扩散能力分析与景观遗传学方法，并结合全基因组单核苷酸多态性（SNP）数据集，量化了不同扩散模式的相对贡献。研究结果显示，自然扩散与人为辅助扩散均推动了种群扩张：在对白纹伊蚊（Aedes albopictus）而言为高适宜生境的分散型城区中，种群扩散能力相对较弱；而道路则促进了长距离扩散。但引入过程中发生的种群瓶颈效应对该类分布边缘种群的遗传变异特征塑造起到了主导作用。本研究是少数在景观尺度下探究奠基者效应与持续扩张过程如何塑造入侵物种遗传变异空间格局的研究之一。多种扩散模式与大片连续适宜生境的共同作用，使得白纹伊蚊（Aedes albopictus）在引入后的短短数年内，便几乎填满了格勒诺布尔地区内的全部潜在分布范围。