Combining the least cost path method with population genetic data and species distribution models to identify landscape connectivity during the late Quaternary in Himalayan hemlock

Abstract

Himalayan hemlock (Tsuga dumosa) experienced a recolonization event during the Quaternary period; however, the specific dispersal routes are remain unknown. Recently, the least cost path (LCP) calculation coupled with population genetic data and species distribution models has been applied to reveal the landscape connectivity. In this study, we utilized the categorical LCP method, combining species distribution of three periods (the last interglacial, the last glacial maximum, and the current period) and locality with shared chloroplast, mitochondrial, and nuclear haplotypes, to identify the possible dispersal routes of T. dumosa in the late Quaternary. Then, both a coalescent estimate of migration rates among regional groups and establishment of genetic divergence pattern were conducted. After those analyses, we found that the species generally migrated along the southern slope of Himalaya across time periods and genomic makers, and higher degree of dispersal was in the present and mtDNA haplotype. Furthermore, the direction of range shifts and strong level of gene flow also imply the existence of Himalayan dispersal path, and low area of genetic divergence pattern suggests that there are not any obvious barriers against the dispersal pathway. Above all, we inferred that a dispersal route along the Himalaya Mountains could exist, which is an important supplement for the evolutionary history of T. dumosa. Finally, we believed that this integrative genetic and geospatial method would bring new implications for the evolutionary process and conservation priority of species in the Tibetan Plateau.

Quaternary climate change and habitat preference shaped the genetic differentiation and phylogeography of Rhodiola sect. Prainia in the southern Qinghai–Tibetan Plateau

“…The survival strategy of R. prainii in the interior part of the QTP during the LGM corresponded with the in situ survival hypothesis, while that of R. stapfii probably corresponded most closely with the tabula rasa hypothesis. Taken together with previous studies, the findings of this study suggest that southward valleys at the southern edge of the QTP are either not appropriate glacial refugia, or not sources of recolonization to the interior QTP (Cun & Wang, ; Opgenoorth et al, ; Ren et al, ; Yang et al, ; Yu et al, ).…”

“…Prainia , but it has been documented in the Juniperus tibetica complex (Opgenoorth et al, ), suggesting that preexisting populations in the interior QTP could block recolonization from the southern edge in some cases. This situation also exists in the southeastern QTP, where some cold‐adapted species recolonized the Himalayas from the Hengduan Mountains across biogeographic barriers, but other cold‐adapted species survived in situ (Cun & Wang, ; Li et al, , ; Liu et al, ; Opgenoorth et al, ; Yu et al, ).…”

Do plant populations on distinct inselbergs talk to each other? A case study of genetic connectivity of a bromeliad species in an Ocbil landscape

“…Dispersal is notoriously recognized in the literature as a key process in determining the spatial population structure of species (Nathan & Muller‐Landau, ). Therefore, knowledge of historical dispersal and the resulting gene population flow is crucial to understanding the population biology and evolution of species in their habitats (Howes et al., ; Lowe & Allendorf, ; Manel & Holderegger, ; Yu et al., ). The elucidation of biogeographic patterns through the conciliation of palaeoclimatic modeling methods with genetic analysis is a growing area of interest in landscape genetics (Chan, Brown, & Yoder, ; Collevatti et al., ; Lowe & Allendorf, ; Manel & Holderegger, ; Melo, Lima‐Ribeiro, Terribile, & Collevatti, ; Storfer, Murphy, Spear, Holderegger, & Waits, ; Vitorino, Lima‐Ribeiro, Terribile, & Collevatti, ), which is a field whose conceptual basis is founded in landscape ecology, population genetics, and spatial statistics (Manel & Holderegger, ; Manel, Schwartz, Luikart, & Taberlet, ; Sork & Waits, ; Storfer et al., ).…”

Dispersal corridors for plant species in the Poyang Lake Basin of southeast China identified by integration of phylogeographic and geospatial data

“…The assumptions behind CLCPs are as follows: (1) a high probability of occurrence in species distribution models (SDMs) has a low cost to dispersal through the landscape matrix; (2) populations with shared (and/or sister) haplotypes likely experienced dispersal between sample localities. Thus, if we obtained all the shared (and/or sister) haplotypes between populations and past species distribution, it would be feasible to calculate rather than infer historical dispersal corridors of plant species across the landscape during the Quaternary using ArcGIS tools (Chan et al., 2011; Yu et al., 2015). …”