A new analytical approach to landscape genetic modeling: least-cost transect analysis and linear mixed models

Landscape genetics aims to assess the effect of the landscape on intraspecific genetic structure. To quantify interdeme landscape structure, landscape genetics mostly uses landscape resistance surfaces and least-cost paths or straight-line transects. However, both approaches have drawbacks. Parameterization of resistance surfaces is a subjective process, and least-cost paths represent a single migration route. A transect-based approach might oversimplify migration patterns by assuming rectilinear migration. To overcome these limitations, we combined these two methods in a new landscape genetic approach: least-cost transect analysis (LCTA). Habitat-matrix resistance surfaces were used to create least-cost paths, which were subsequently buffered to form transects in which the abundance of several landscape elements was quantified. To maintain objectivity, this analysis was repeated so that each landscape element was in turn regarded as migration habitat. The relationship between landscape...景观遗传学（Landscape genetics）旨在评估景观对物种种内遗传结构的影响。为量化种群间的景观结构，景观遗传学主要采用景观阻力表面（landscape resistance surfaces）与最小成本路径（least-cost paths）或直线样带（straight-line transects）两类研究方法。然而这两种路径均存在局限：景观阻力表面的参数化过程带有主观性，而最小成本路径仅能表征单一迁移路径。基于样带的研究方法则假设生物呈直线式迁移，可能会过度简化真实的迁移模式。为克服上述局限，我们将两种方法相结合，提出了一种全新的景观遗传学研究手段：最小成本样带分析（least-cost transect analysis, LCTA）。该方法首先利用生境基质阻力表面（Habitat-matrix resistance surfaces）生成最小成本路径，随后对其进行缓冲以构建样带，并对样带内多种景观要素的丰度进行量化。为保证分析的客观性，我们重复执行该分析流程，将每一类景观要素依次视为迁移生境。景观与