Population structure of Columbia spotted frogs (Rana luteiventris) is strongly affected by the landscape

Landscape features such as mountains, rivers, and ecological gradients may strongly affect patterns of dispersal and gene flow among populations and thereby shape population dynamics and evolutionary trajectories. The landscape may have a particularly strong effect on patterns of dispersal and gene flow in amphibians because amphibians are thought to have poor dispersal abilities. We examined genetic variation at six microsatellite loci in Columbia spotted frogs (Rana luteiventris) from 28 breeding ponds in western Montana and Idaho, USA, in order to investigate the effects of landscape structure on patterns of gene flow. We were particularly interested in addressing three questions: (i) do ridges act as barriers to gene flow? (ii) is gene flow restricted between low and high elevation ponds? (iii) does a pond equal a ‘randomly mating population’ (a deme)? We found that mountain ridges and elevational differences were associated with increased genetic differentiation among sites, suggesting that gene flow is restricted by ridges and elevation in this species. We also found that populations of Columbia spotted frogs generally include more than a single pond except for very isolated ponds. There was also evidence for surprisingly high levels of gene flow among low elevation sites separated by large distances. Moreover, genetic variation within populations was strongly negatively correlated with elevation, suggesting effective population sizes are much smaller at high elevation than at low elevation. Our results show that landscape features have a profound effect on patterns of genetic variation in Columbia spotted frogs.     

Habitat fragmentation causes bottlenecks and inbreeding in the European tree frog (Hyla arborea)

A genetic study of the European tree frog, Hyla arborea, in Denmark was undertaken to examine the population structure on mainland Jutland and the island of Lolland after a period of reduction in suitable habitat and population sizes. The two regions have experienced the same rate of habitat loss but fragmentation has been more severe on Lolland. Genetic variation based on 12 polymorphic DNA microsatellites was analysed in 494 tree frogs sampled from two ponds in Jutland and 10 ponds on Lolland. A significant overall deviation from Hardy-Weinberg expectations could be attributed to three ponds, all on Lolland. This was most probably caused by an inbreeding effect reducing fitness, which was supported by the observed significant negative correlation between larva survival and mean F(IS) value and mean individual inbreeding coefficient. A significant reduction in genetic variation (bottleneck) was detected in most of the ponds on Lolland. Population-structure analysis suggested the existence of at least 11 genetically different populations, corresponding to most of the sampled population units. The results indicated that the populations were unique genetic units and could be used to illustrate the migration pattern between newly established ponds arisen either by natural colonization of tree frogs or by artificial introduction. A high degree of pond fidelity in the tree frogs was suggested. A severe fragmentation process reducing population size and fitness within some of the populations probably caused the significant reduction in genetic variation of tree frog populations on Lolland.     

Microsatellite variation and fine-scale population structure in the wood frog (Rana sylvatica)

We investigated genetic population structure in wood frogs (Rana sylvatica) from a series of Prairie Pothole wetlands in the northern Great Plains. Amphibians are often thought to exist in demographic metapopulations, which require some movement between populations, yet genetic studies have revealed strong subdivision among populations, even at relatively fine scales (several km). Wood frogs are highly philopatric and studies of dispersal suggest that they may exhibit subdivision on a scale of approximately 1-2 km. We used microsatellites to examine population structure among 11 breeding assemblages separated by as little as 50 m up to approximately 5.5 km, plus one population separated from the others by 20 km. We found evidence for differentiation at the largest distances we examined and among a few neighbouring ponds, but most populations were strikingly similar in allele frequencies, suggesting high gene flow among all but the most distant populations. We hypothesize that the few significant differences among neighbouring populations at the finest scale may be a transient effect of extinction-recolonization founder events, driven by periodic drying of wetlands in this hydrologically dynamic landscape.     

Microsatellite variation and population structure of a recovering Tree frog (Hyla arborea L.) metapopulation

Numbers and sizes of populations of the European tree frog in The Netherlands have dramatically decreased in the second half of the last century due to extensive habitat destruction and fragmentation. We have studied the genetic structure of a slowly recovering meta-population. Strong genetic differentiation, estimated at eight microsatellite loci, was found between clusters of populations (F _st-values above 0.2). Within clusters, consisting of ponds within a radius of about 5 km, European tree frog populations were less differentiated (F _st<0.08) and exact tests showed that most of the ponds within clusters were not significantly differentiated. Although local population sizes have been increasing since 1989, and some new ponds have been colonised in the direct vicinity of ponds that have been populated continuously, little evidence for gene flow between clusters of ponds was found (only one exception). Furthermore, levels of genetic diversity were low compared to populations in comparable areas elsewhere in Europe. Therefore, a continuous conservation effort is needed to prevent any further loss of genetic diversity. The alleviation of important barriers to dispersal between the clusters should be given a high priority for the restoration of the meta-population as a whole.     

Fine-scale spatial genetic structure and dispersal among spotted salamander (Ambystoma maculatum) breeding populations

We examined fine-scale genetic variation among breeding aggregations of the spotted salamander (Ambystoma maculatum) to quantify dispersal, interpopulation connectivity and population genetic structure. Spotted salamanders rely on temporary ponds or wetlands for aggregate breeding. Adequate breeding sites are relatively isolated from one another and field studies suggest considerable adult site fidelity; therefore, we expected to find population structure and differentiation at small spatial scales. We used microsatellites to estimate population structure and dispersal among 29 breeding aggregations in Tompkins County, New York, USA, an area encompassing 1272 km(2). Bayesian and frequency-based analyses revealed fine-scale genetic structure with two genetically defined demes: the North deme included seven breeding ponds, and the South deme included 13 ponds. Nine ponds showed evidence of admixture between these two genetic pools. Bayesian assignment tests for detection of interpopulation dispersal indicate that immigration among ponds is common within demes, and that certain populations serve as sources of immigrants to neighbouring ponds. Likewise, spatial genetic correlation analyses showed that populations < or = 4.8 km distant from each other show significant genetic correlation that is not evident at higher scales. Within-population levels of relatedness are consistently larger than expected if mating were completely random across ponds, and in the case of a few ponds, within-population processes such as inbreeding or reproductive skew contribute significantly to differentiation from neighbouring ponds. Our data underscore the importance of these within-population processes as a source of genetic diversity across the landscape, despite considerable population connectivity. Our data further suggest that spotted salamander breeding groups behave as metapopulations, with population clusters as functional units, but sufficient migration among demes to allow for potential rescue and recolonization. Amphibian habitats are becoming increasingly fragmented and a clear understanding of dispersal and patterns of population connectivity for taxa with different ecologies and life histories is crucial for their conservation.     

Quantification and reduction of bias from sampling larvae to infer population and landscape genetic structure

A well-designed sampling scheme is critical for obtaining accurate results from population genetic studies. Larval samples contain only the genetic material of successful breeders, often of a single year, and may be biased towards particular families. To quantify the bias of using larval samples to infer population and landscape genetic structure and explore how this bias may be reduced using sibship analysis, we analysed eight microsatellite loci from 484 tissue samples of larvae and adults of Columbia spotted frogs (Rana luteiventris) and long-toed salamanders (Ambystoma macrodactylum) at nine breeding sites in north Idaho. Differences in allele frequencies between adult and larval samples were not detected after full-siblings were removed from the larval data set for Columbia spotted frogs; for long-toed salamanders, these differences remained at two out of four ponds. Data from Columbia spotted frog larvae indicated higher levels of differentiation among populations (median difference in F_ST = 0.020, P < 0.01), as predicted by population genetic theory, whereas data from larval samples of long-toed salamanders showed some evidence of lower levels of differentiation among populations (median difference in F_ST = 0.012, P = 0.06). For both species, removing all but one individual from each full-sibling family led to parameter estimates that were closer to those calculated from adult samples for both population and landscape genetic measures. Removal of full-siblings is likely to improve estimates of population genetic parameters; however, knowledge of the species’ breeding system is essential for understanding additional sources of bias when inferring population genetic structure from larval samples.     

Population Patterns of a Riparian Frog (Rana swinhoana) Before and After an Earthquake in Subtropical Taiwan

We compared the population dynamics of a riparian ranid frog, Rana swinhoana, before (1996–1999) and after (1999–2001) a strong earthquake. This earthquake caused little disturbance to the vegetation and landscape of the study site but the stream and ponds dried up within a week. Nearly all frogs marked (1002 of 1004) before the earthquake had disappeared after the earthquake. Smaller, unmarked frogs began to appear in stream habitats about 9 mo after the earthquake, and the frog population was much smaller than it was before the earthquake. Population dynamics and temporal and spatial distribution of frogs before and after the earthquake correlated closely with the hydrology of the stream and ponds. The movement patterns of frogs before and after the earthquake were similar, suggesting frog behavior did not change in response to drastic changes in hydrology, and frogs continued to exhibit strong site-fidelity. Following the earthquake, stream water volume was much lower, especially in the summer, which allowed the normally winter-breeding frogs to breed year-round. Results demonstrate that a population of R. swinhoana can disappear suddenly as the result of a natural disturbance. We propose that anuran species that exhibit strong site-fidelity are particularly susceptible to extirpation of local populations because frogs may lack the behavioral plasticity to respond to sudden water depletion.     

Divergent landscape effects on population connectivity in two co-occurring amphibian species

The physical and environmental attributes of landscapes often shape patterns of population connectivity by influencing dispersal and gene flow. Landscape effects on movement are typically evaluated for single species. However, inferences from multiple species are required for multi‐species management strategies increasingly being applied in conservation. In this study, I compared the spatial genetic patterns of two amphibian species across the northeastern United States and estimated the influence of specific landscape features on the observed genetic structure. The spotted salamander (Ambystoma maculatum) and wood frog (Rana sylvatica) share many ecological attributes related to habitat use, phenology and site fidelity. However, I hypothesized that important differences in their movement patterns and life history would create distinct genetic patterns for each species. Using 14 microsatellite loci, I tested for differences in the level of genetic differentiation between the two species across 22 breeding ponds. The effects of eight landscape features were also estimated by evaluating 32 landscape resistance models. Spotted salamanders exhibited significantly higher genetic differentiation than wood frogs. Different landscape features were also identified as potential drivers of the genetic patterns in each species, with little overlap in model support between species. Collectively, these results provide strong evidence that these two amphibian species interact with the landscape in measurably different ways. The distinct genetic patterns observed are consistent with key differences in movement ability and life history between A. maculatum and R. sylvatica. These results highlight the importance of considering more than one species when assessing the impacts of the landscape matrix on population connectivity, even for ecologically similar species within the same habitats.     

Spatial genetic structure of <Emphasis Type="Italic">Lissotriton helveticus L</Emphasis>. following the restoration of a forest ponds network

Preserving amphibian genetic diversity through ecological restoration and conservation actions is a major challenge since their populations are declining worldwide. We studied the genetic diversity and spatial genetic structure of the palmate newt (Lissotriton helveticus) 2 years after the restoration of a pond network in northwestern France with the aim of reconstructing fine-scale genetic structure and patterns of colonization. We sampled newts from 29 forest ponds including both restored and non-degraded reference ponds, and genotyped 391 individuals at 12 microsatellite loci. We used two Bayesian clustering methods to spatially delineate genetic clusters, and we also detected potential recent migrants within the network. All ponds showed low levels of observed heterozygosity (Ho?=?0.534) and a mean F _IS of 0.251, possibly indicating a Wahlund or bottleneck effect. Pairwise F _ST suggested limited evidence of genetic differentiation among ponds. Within the pond network, we identified 3 to 4 genetic clusters. Combined with the detection of migrants, the results suggest an increase in gene flow within the restored pond network and that a high number of migrants came from the reference ponds. Our findings indicate an unexpected high dispersal ability for this small-bodied species. Overall, the absence of population structure represents a positive beginning for the restoration project. It also emphasizes the importance of spatial design in restoring a pond network and that such genetic data and methods should be used to monitor amphibians in restored habitats.     

Population structure of Moroccan water frogs: genetic cohesion despite a fragmented distribution

This study analyses the allozymic variation of 20 presumptive loci in eight populations of Rana saharica from Morocco. Populations were collected from the very different climatic zones of this country: the Rif area, the Atlas mountains and the desert. Moroccan water-frog populations are genetically well differentiated from the geographically closed Algerian populations. Thus, to check if such a differentiation process is taking place within Moroccan water frogs, we attempted to analyse the genetic structure and patterns of gene flow of Moroccan populations, by means of estimates of Hardy-Weinberg equilibrium, F-statistics and indirect measures of gene flow. F_st(0.250) and F_is(0.254) values were similar, which means that both intra and interpopulation differentiation contribute equally to the amount of genetic divergence revealed. F_is values indicated some degree of structure within ponds, which is possibly related to the homing behaviour of some amphibians. On the other hand, F_st and genetic distances between populations were not very high. Despite the low levels of gene flow estimated, together with the homing behaviour revealed and the spatially discontinuous distribution, it was found that genetic differentiation among populations was not as high as expected. The likelihood of genetic homogeneity being the consequence of continuous population extinction and recolonization events is discussed.     

Analysis on Genetic Diversity of Dolichomitriopsis diversiformis(Lembophyllaceae) in Fanjing Mountain

Dolichomitriopsis diversiformis is the only Dolichomitriopsis species in China, and is the member of Lembophyllaceae. Ten random primer pairs were selected to amplified 153 individuals from 14 D. diversiformis populations from both northern and southern slops of Fanjing Mountains by using RAPD methods, and 196 sites were derived . Results suggested that (1) D. diversiformis from FanjingMount kept a high level genetic diversity, and the genetic diversity is relative low at the population level ; (2) genetic diversity have no relationship with altitude, but populations on southern slope have a little higher diversity than that on the northern slope; (3) 63.29% genetic diversity exist among populations, and only 36.71% within population. These results suggested that small habitat was the major impact factors of D. diversiformis genetic diversity, genetic drift and habit adaption should be the prominent reason of population differentiation .     

Latitudinal countergradient variation in the common frog (Rana temporaria) development rates--evidence for local adaptation

Adaptive genetic differentiation along a climatic gradient as a response to natural selection is not necessarily expressed at phenotypic level if environmental effects on population mean phenotypes oppose the genotypic effects. This form of cryptic evolution--called countergradient variation--has seldom been explicitly demonstrated for terrestrial vertebrates. We investigated the patterns of phenotypic and genotypic differentiation in developmental rates of common frogs (Rana temporaria) along a ca. 1600 km latitudinal gradient across Scandinavia. Developmental rates in the field were not latitudinally ordered, but displayed large variation even among different ponds within a given latitudinal area. In contrast, development rates assessed in the laboratory increased strongly and linearly with increasing latitude, suggesting a genetic capacity for faster development in the northern than the southern larvae. Experiments further revealed that environmental effects (temperature and food) could easily override the genetic effects on developmental rates, providing a possible mechanistic explanation as to why the genetic differentiation was not seen in the samples collected from the wild. Our results suggest that the higher developmental rates of the northern larvae are likely to be related to selection stemming from seasonal time constrains, rather than from selection dictated by low ambient temperatures per se. All in all, the results provide a demonstration of environmental effects concealing substantial latitudinally ordered genetic differentiation understandable in terms of adaptation to clinal variation in time constrains.     

Population genetic patterns suggest a behavioural change in wild common frogs (Rana temporaria) following disease outbreaks (Ranavirus)

We use 14 microsatellite loci to investigate the impact of a viral disease ( Ranavirus ) on the population genetic structure of wild common frogs ( Rana temporaria ). Populations with a history of Ranavirus mortalities (and 83% declines in the number of frogs) were compared with populations with no history of infection. Infected ponds showed significantly elevated F _IS (homozygote excess), significantly reduced relatedness, and no detectable effect on allelic richness. We hypothesize that the elevated F _IS and reduced relatedness are consequences of assortative mating, and that allelic richness is maintained by immigration from nearby populations. Simulations indicate that the elevated F _IS cannot be explained by population size reductions, but can indeed be explained by assortative mating (even if a mate choice locus is unlinked to the genetic markers). While the majority of studies consider demographic outcomes following disease outbreaks, our results indicate that emerging infectious diseases could also result in behavioural changes.     

Spatiotemporal allozyme variation in the damselfly, <Emphasis Type="BoldItalic">Lestes viridis</Emphasis> (Odonata: Zygoptera): gene flow among permanent and temporary ponds

Several insect species seem to persist not only in permanent but also in temporary ponds where they face particularly harsh conditions and frequent extinctions. Under such conditions, gene flow may prevent local adaptation to temporary ponds and may promote phenotypic plasticity, or maintain apparent population persistence. The few empirical studies on insects suggest the latter mechanism, but no studies so far quantified gene flow including both pond types. We investigated the effects of pond type and temporal variation on population genetic differentiation and gene flow in the damselfly Lestes viridis in northern Belgium. We report a survey of two allozyme loci (Gpi, Pgm) with polyacrylamide gel electrophoresis in 14 populations from permanent and temporary ponds, and compared these results with similar data from the same permanent populations one year before. The data suggested that neither pond-drying regime, nor temporal variation have a substantial effect on population genetic structuring and did not provide evidence for stable population differentiation in L. viridis in northern Belgium. Gene flow estimates were high within permanent and temporary ponds, and between pond types. Our data are consistent with a source-sink metapopulation system where temporary ponds act as sinks in dry years, and are quickly recolonized after local population extinction. This may create a pattern of apparent population persistence of this species in permanent and temporary ponds without clear local adaptation.     

Fine-scale population structure and dispersal in Biomphalaria glabrata, the intermediate snail host of Schistosoma mansoni, in Venezuela

Biomphalaria glabrata is the main intermediate host of Schistosoma mansoni in America and one of the most intensely studied species of freshwater snails, yet very little is known about its population biology. Here, we used seven highly polymorphic microsatellite loci to analyse genetic diversity in the Valencia lake basin, which represents the core of the endemic area for schistosomiasis in Venezuela. Populations were sampled at short spatial scale (a few kilometres), both inside the lake and in ponds or rivers near the lake. Our results indicate that B. glabrata essentially cross-fertilizes, with little variation in selfing rates among populations. Our markers detected considerable genetic variation, with an average heterozygosity of 0.60. More diversity per population was found within than outside the lake, suggesting an influence of connectivity among populations on the levels of genetic diversity. A marked population structure was detected and lake populations were less structured than other populations. Most individuals were assigned to their population of origin using an assignment test. No strong demographic signal (e.g. bottleneck) was detected, though lake populations are likely to experience bottlenecks more frequently than the other populations analysed. Differences in gene flow therefore seem to play an important role in population differentiation and in the restoring of genetic diversity in demographically unstable populations.     

Population biology of the invasive freshwater snail Physa acuta approached through genetic markers, ecological characterization and demography

Abstract The respective role of factors acting on population functioning can be inferred from a variety of approaches, including population genetics and demography. We here investigated the role of four of these factors (mating systems, population size, bottlenecks and migration) in the hermaphroditic freshwater snail Physa acuta. Twenty-four populations were sampled either around Montpellier (local scale), or at the scale of France (global scale). At local scale, eight populations were sampled twice, before and after summer drying out. The genetic structure of these populations was studied using microsatellite loci. Populations were classified according to openness (ponds vs. rivers) and water regime (permanent vs. temporary) allowing predictions on genetic patterns (e.g. diversity within populations and differentiation). At local scale, progeny-arrays analysis of the selfing rate was conducted, and size distributions of individuals were followed over two years. Results with regard to the four factors mentioned above were: (i) Estimates of population selfing rates derived from inbreeding coefficients were only slightly higher than those from progeny-arrays. (ii) More variation was detected in rivers than in ponds, but no influence of water regime was detected. One reason might be that permanent populations are not going less often through low densities than those from temporary habitats at the time scale studied. (iii) There was limited evidence for genetic bottlenecks which is compatible with the fact that even marked reduction in water availability was not necessarily associated with demographic bottlenecks. More generally, bottlenecks reducing genetic variation probably occur at population foundation. (iv) Lower genetic differentiation was detected among rivers than among ponds which might be related to limitations on gene flow. Demographic and temporal genetic data further indicates that flooding in rivers is unlikely to induce marked gene flow explaining the strong genetic differentiation at short geographical scale in such habitats. Finally, the demographic data suggest that some populations are transitory and subject to recurrent recolonization, a pattern that was also detected through genetic data.     

Canopy Closure and Emigration by Juvenile Gopher Frogs

ABSTRACT Although studies have addressed effects of abrupt transitions in habitat type (e.g., forest-clear-cut or forest-field edges) on amphibian movements, little is known about effects of more subtle habitat transitions on patterns of migration and habitat use in amphibians. We used radiotelemetry to study movement patterns of juvenile gopher frogs (Rana capito) emigrating from ponds that were surrounded by longleaf pine (Pinus palustris) forest that varied in structure as a result of fire suppression. Our primary purpose was to determine if frogs emigrate directionally from their natal ponds and select habitat at random during their first month following metamorphosis. We found that frogs emigrated in nonrandom directions from ponds that were surrounded by heterogeneous habitat and selected fire-maintained habitat that was associated with an open canopy, few hardwood trees, small amounts of leaf litter, and large amounts of wiregrass (Aristida beyrichiana). Fire-maintained habitat contained higher densities of burrows excavated by gopher tortoises (Gopherus polyphemus) and small mammals, which are the priamry refuge sites for both juvenile and adult gopher frogs. Frogs moved up to 691 m from their natal ponds, frequently crossed dirt roads, and even seemed to use these roads as migration corridors. To maintain suitable terrestrial habitat for gopher frogs, including habitat used by migrating individuals, it is important to apply frequent prescribed fire to uplands surrounding breeding ponds that lead all the way to the edges of breeding ponds, as well as through ponds during periodic droughts.     

Novel tetranucleotide microsatellite DNA markers for the wood frog,Rana sylvatica

Fifteen tetranucleotide microsatellite loci were identified and characterized for wood frogs (Rana sylvatica) collected from three vernal pools in the southeastern US. These markers revealed a high degree of genetic diversity (nine to 34 alleles per locus), heterozygosity (30.6–92.3%) and allelic heterogeneity (69% of comparisons were statistically significant). Considerable differentiation among populations was observed as genetic distances (chord) ranged between 0.40 and 0.55 and all F_ST values (0.02–0.05) were statistically significant. Genotypic assignment tests correctly classified 103 of 113 individuals to their respective collection. These markers should prove useful for investigating fine‐scale population structure and metapopulation dynamics.     

Surprisingly little population genetic structure in a fungus‐associated beetle despite its exploitation of multiple hosts

In heterogeneous environments, landscape features directly affect the structure of genetic variation among populations by functioning as barriers to gene flow. Resource‐associated population genetic structure, in which populations that use different resources (e.g., host plants) are genetically distinct, is a well‐studied example of how environmental heterogeneity structures populations. However, the pattern that emerges in a given landscape should depend on its particular combination of resources. If resources constitute barriers to gene flow, population differentiation should be lowest in homogeneous landscapes, and highest where resources exist in equal proportions. In this study, we tested whether host community diversity affects population genetic structure in a beetle (Bolitotherus cornutus) that exploits three sympatric host fungi. We collected B. cornutus from plots containing the three host fungi in different proportions and quantified population genetic structure in each plot using a panel of microsatellite loci. We found no relationship between host community diversity and population differentiation in this species; however, we also found no evidence of resource‐associated differentiation, suggesting that host fungi are not substantial barriers to gene flow. Moreover, we detected no genetic differentiation among B. cornutus populations separated by several kilometers, even though a previous study demonstrated moderate genetic structure on the scale of a few hundred meters. Although we found no effect of community diversity on population genetic structure in this study, the role of host communities in the structuring of genetic variation in heterogeneous landscapes should be further explored in a species that exhibits resource‐associated population genetic structure.     

Landscape genetic structure of <Emphasis Type="Italic">Betula maximowicziana</Emphasis> in the Chichibu mountain range,central Japan

We evaluated the genetic structure of 16 Betula maximowicziana populations in the Chichibu mountain range, central Japan, located within a 25-km radius; all but two populations were at altitudes of 1,100–1,400 m. The results indicate the effects of geographic topology on the landscape genetic structure of the populations and should facilitate the development of local-scale strategies to conserve and manage them. Analyses involving 11 nuclear simple sequence repeat loci showed that most populations had similar intrapopulation genetic diversity parameters. Population differentiation (F _ST = 0.021, G′_ST = 0.033) parameters for the populations examined were low but were relatively high compared to those obtained in a previous study covering populations in a much larger area with a radius of approximately 1,000 km (F _ST = 0.062, G′_ST = 0.102). Three populations (Iriyama, Kanayamasawa, and Nishizawa) were differentiated from the other populations by Monmonier’s and spatial analysis of molecular variance algorithms or by STRUCTURE analysis. Since a high mountain ridge (nearly 2,000 m) separates the Kanayamasawa and Nishizawa populations from the other 14 populations and the Kanayamasawa and Nishizawa populations are themselves separated by another mountain ridge, the genetic structure appears to be partly due to mountain ridges acting as genetic barriers and restricting gene flow. However, the Iriyama population is genetically different but not separated by any clear geographic barrier. These results show that the landscape genetic structure is complex in the mountain range and we need to pay attention, within landscape genetic studies and conservation programs, to geographic barriers and local population differentiation.