Laboratorio de Genética y Ecología, Departamento de Ecología de La Biodiversidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
Mol Ecol. 2024 Aug;33(16):e17469. doi: 10.1111/mec.17469. Epub 2024 Jul 17.
Functional connectivity, the extent to which a landscape facilitates or impedes the dispersal of individuals across the landscape, is a key factor for the survival of species. Anthropogenic activities, such as urbanization, agriculture and roads, negatively impact functional connectivity of most species, particularly low-vagility species like lizards. Here, we examine how a landscape modified by anthropogenic activities affects the functional connectivity, at both broad and fine scales, of a widely distributed generalist lizard Sceloporus grammicus in the eastern Trans-Mexican Volcanic Belt, Mexico. We estimated for the first time the species' genetic structure, gene flow and functional connectivity in agricultural and forest zones using genomic data, a comprehensive landscape characterization and novel methods including gravity models. Our results showed not only marked genetic differentiation across the study region but also that functional connectivity is maintained for tens of kilometres despite S. grammicus low vagility. Specifically, we found that substrate and air temperature facilitated connectivity over broad and fine scales, respectively, while agricultural cover, relative humidity and slope were important for connectivity and gene flow. Contrastingly, forest cover and roads favoured (broad-scale) and limited (fine-scale) connectivity, likely associated with movement facilitated by small forest patches and with thermoregulation. Altogether, these results support that S. grammicus alternates its thermoregulatory behaviour depending on the distance travelled and the habitat environmental conditions, and that it can disperse through relatively modified landscapes, mainly using agricultural zones. The information obtained is crucial to understanding the response of lizards to current anthropogenic pressures and their potential to adapt.
功能连接性，即景观促进或阻碍个体在景观中扩散的程度，是物种生存的关键因素。城市化、农业和道路等人为活动对大多数物种的功能连接性产生了负面影响，尤其是对蜥蜴等低迁移性物种。在这里，我们研究了受人为活动影响的景观如何影响广泛分布的一般性蜥蜴 Sceloporus grammicus 在墨西哥东跨墨西哥火山带的大尺度和小尺度上的功能连接性。我们首次使用基因组数据、全面的景观特征描述以及重力模型等新方法，估计了该物种在农业区和森林区的遗传结构、基因流动和功能连接性。我们的研究结果表明，该物种不仅在研究区域内存在明显的遗传分化，而且尽管 S. grammicus 的迁移能力较低，但功能连接性仍能维持数十公里。具体而言，我们发现基质和空气温度分别在大尺度和小尺度上促进了连通性，而农业覆盖、相对湿度和坡度对连通性和基因流动很重要。相比之下，森林覆盖和道路有利于（大尺度）和限制（小尺度）连通性，这可能与小森林斑块促进的迁移和热调节有关。总的来说，这些结果表明，S. grammicus 根据所经过的距离和栖息地环境条件改变其体温调节行为，并且它可以通过相对受干扰的景观进行扩散，主要利用农业区。所获得的信息对于了解蜥蜴对当前人为压力的反应及其适应能力至关重要。
