Multiscale landscape genetics of American marten at their southern range periphery

Abstract

American marten (Martes americana) are a conservation priority in many forested regions of North America. Populations are fragmented at the southern edge of their distribution due to suboptimal habitat conditions. Facilitating gene flow may improve population resilience through genetic and demographic rescue. We used a multiscale approach to estimate the relationship between genetic connectivity and landscape characteristics among individuals at three scales in the northeastern United States: regional, subregional, and local. We integrated multiple modeling techniques and identified top models based on consensus. Top models were used to parameterize resistance surfaces at each scale, and circuit theory was used to identify potential movement corridors. Regional gene flow was affected by forest cover, elevation, developed land cover, and slope. At subregional and local scales, the effects were site specific and included subsets of temperature, elevation, developed land cover, and slope. Developed land cover significantly affected gene flow at each scale. At finer scales, lack of variance in forest cover may have limited the ability to detect a relationship with gene flow. The effect of slope on gene flow was positive or negative, depending on the site examined. Occupancy probability was a relatively poor predictor, and we caution its use as a proxy for landscape resistance. Our results underscore the importance of replication and multiscale approaches in landscape genetics. Climate warming and landscape conversion may reduce the genetic connectivity of marten populations in the northeastern United States, and represent the primary challenges to marten conservation at the southern periphery of their range.

Combined field and clinical methods clarify mortality causes and survival patterns of Pacific martens

“…It may be possible, however, to indirectly mitigate predation risk for martens, other subordinate carnivores, or prey species by decreasing the foraging efficacy of predators (Vanlandeghem et al 2021). At broad (Cushman et al 2011, Zielinski 2014, Aylward et al 2020) and fine scales (Tweedy et al 2019), martens are generally associated with structurally heterogeneous forest cover and often avoid areas with reduced cover (Moriarty et al 2016), rarely enter openings during snow‐free periods (Moriarty et al 2015, Martin et al 2021), and exhibit increased movement rates and energetic expenditures in simplified forest stands (Moriarty et al 2016, Martin et al 2020). Presumably, martens avoid open or structurally homogeneous areas to reduce risk of predation or competition, yet no studies have empirically investigated the influence of forest structure on marten predation risk or encounters with competitors.…”

Landscape characteristics determine the gene exchange pattern of Opisthopappus species in the Taihang Mountains

“…In recent years, more researches have been conducted on land use, human experience and ecosystem services (Hersperger et al, 2021;Lester et al, 2021;Song et al, 2017). Nevertheless, with the constant climate changes and increasing human activities, the landscape configuration of different regions is continuously changing (Aylward et al, 2020;Wang et al, 2021c). This change could affect the ecological and evolutionary processes of organisms, and even ecosystems.…”

Multiscale patterns of isolation by ecology and fine-scale population structure in Texas bobcats

“…Because the landscape variables impacting gene flow are not consistent across spatial scales (e.g., Anderson et al, 2010;Galpern, Manseau & Wilson, 2012;Hapeman et al, 2017), single-scale studies may overlook or underestimate important patterns of gene flow. As a result, recent studies have emphasized the importance of multiscale examinations of spatial genetic structure (Aylward, Murdoch & Kilpatrick, 2020;Burgess & Garrick, 2020;Kierepka et al, 2020). However, multiscale designs are less straightforward for populations of widespread, vagile, or generalist species due to their broad distribution, high abundance, and population connectivity (Reding et al, 2012;Kierepka & Latch, 2016b).…”