Littlefield Caitlin E, McRae Brad H, Michalak Julia L, Lawler Joshua J, Carroll Carlos
School of Environmental and Forest Sciences, University of Washington, Box 352100, Seattle, WA, 98195, U.S.A.
The Nature Conservancy, North America Region, 117 E Mountain Ave, Suite 201, Fort Collins, CO, 80524, U.S.A.
Conserv Biol. 2017 Dec;31(6):1397-1408. doi: 10.1111/cobi.12938. Epub 2017 Jul 10.
Increasing connectivity is an important strategy for facilitating species range shifts and maintaining biodiversity in the face of climate change. To date, however, few researchers have included future climate projections in efforts to prioritize areas for increasing connectivity. We identified key areas likely to facilitate climate-induced species' movement across western North America. Using historical climate data sets and future climate projections, we mapped potential species' movement routes that link current climate conditions to analogous climate conditions in the future (i.e., future climate analogs) with a novel moving-window analysis based on electrical circuit theory. In addition to tracing shifting climates, the approach accounted for landscape permeability and empirically derived species' dispersal capabilities. We compared connectivity maps generated with our climate-change-informed approach with maps of connectivity based solely on the degree of human modification of the landscape. Including future climate projections in connectivity models substantially shifted and constrained priority areas for movement to a smaller proportion of the landscape than when climate projections were not considered. Potential movement, measured as current flow, decreased in all ecoregions when climate projections were included, particularly when dispersal was limited, which made climate analogs inaccessible. Many areas emerged as important for connectivity only when climate change was modeled in 2 time steps rather than in a single time step. Our results illustrate that movement routes needed to track changing climatic conditions may differ from those that connect present-day landscapes. Incorporating future climate projections into connectivity modeling is an important step toward facilitating successful species movement and population persistence in a changing climate.
在气候变化的背景下，增强连通性是促进物种分布范围转移和维护生物多样性的重要策略。然而，迄今为止，很少有研究人员在确定增强连通性的优先区域时纳入未来气候预测。我们确定了可能促进北美西部气候引发的物种迁移的关键区域。利用历史气候数据集和未来气候预测，我们通过基于电路理论的新型移动窗口分析，绘制了将当前气候条件与未来类似气候条件（即未来气候相似区）相连的潜在物种迁移路线。除了追踪气候变化，该方法还考虑了景观渗透性和根据经验得出的物种扩散能力。我们将通过我们的气候变化知情方法生成的连通性地图与仅基于景观受人类改造程度的连通性地图进行了比较。与不考虑气候预测时相比，在连通性模型中纳入未来气候预测会使迁移的优先区域大幅转移并受到限制，占景观的比例更小。当纳入气候预测时，以电流衡量的潜在迁移在所有生态区都有所下降，尤其是在扩散受限导致无法到达气候相似区时。只有当以两个时间步长而非单个时间步长对气候变化进行建模时，许多区域才成为连通性的重要区域。我们的结果表明，追踪气候变化所需的迁移路线可能与连接当今景观的路线不同。将未来气候预测纳入连通性建模是朝着促进物种在变化气候中成功迁移和种群持续生存迈出的重要一步。
