Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, Ohio, USA.
Ohio Biodiversity Conservation Partnership, The Ohio State University, Columbus, Ohio, USA.
Ecol Appl. 2023 Mar;33(2):e2793. doi: 10.1002/eap.2793. Epub 2023 Jan 8.
Assessing the environmental factors that influence the ability of a threatened species to move through a landscape can be used to identify conservation actions that connect isolated populations. However, direct observations of species' movement are often limited, making the development of alternate approaches necessary. Here we use landscape genetic analyses to assess the impact of landscape features on the movement of individuals between local populations of a threatened snake, the eastern massasauga rattlesnake (Sistrurus catenatus). We linked connectivity data with habitat information from two landscapes of similar size: a large region of unfragmented habitat and a previously studied fragmented landscape consisting of isolated patches of habitat. We used this analysis to identify features of the landscape where modification or acquisition would enhance population connectivity in the fragmented region. We found evidence that current connectivity was impacted by both contemporary land-cover features, especially roads, and inherent landscape features such as elevation. Next, we derived estimates of expected movement ability using a recently developed pedigree-based approach and least-cost paths through the unfragmented landscape. We then used our pedigree and resistance map to estimate resistance polygons of the potential extent for S. catenatus movement in the fragmented landscape. These polygons identify possible sites for future corridors connecting currently isolated populations in this landscape by linking the impact of future habitat modification or land acquisition to dispersal ability in this species. Overall, our study shows how modeling landscape resistance across differently fragmented landscapes can identify habitat features that affect contemporary movement in threatened species in fragmented landscapes and how this information can be used to guide mitigation actions whose goal is to connect isolated populations.
评估影响受威胁物种在景观中移动能力的环境因素，可以用于确定连接隔离种群的保护措施。然而，对物种移动的直接观察往往受到限制，因此需要开发替代方法。在这里，我们使用景观遗传学分析来评估景观特征对受威胁蛇类——东部菱背响尾蛇（Sistrurus catenatus）个体在局部种群之间移动的影响。我们将连通性数据与来自两个大小相似的景观的栖息地信息联系起来：一个是未破碎化的大面积栖息地，另一个是以前研究过的由孤立栖息地斑块组成的破碎化景观。我们利用这种分析来确定在破碎化区域中进行修改或获取哪些景观特征可以增强种群连通性。我们发现，当前的连通性受到当代土地覆盖特征（尤其是道路）和固有景观特征（如海拔）的影响。接下来，我们使用最近开发的基于谱系的方法和无破碎化景观中的最小成本路径来估计预期的移动能力。然后，我们使用谱系和阻力图来估计在破碎化景观中 S. catenatus 潜在移动范围的阻力多边形。这些多边形通过将未来栖息地修改或土地获取的影响与该物种的扩散能力联系起来，确定了在这个景观中连接当前隔离种群的未来走廊的可能地点。总的来说，我们的研究表明，如何在不同破碎化的景观中建模景观阻力，可以确定影响破碎化景观中受威胁物种当前移动的栖息地特征，以及如何利用这些信息来指导旨在连接隔离种群的缓解措施。
