The biology of the panga, Pterogymnus laniarius (Teleostei: Sparidae), on the Agulhas Bank, South Africa

Aspects of the biology of the panga, Pterogymnus laniarius, a commercially important endemic southern African, demersal sparid fish species, are described from material collected monthly between February 1994 and July 1995 on the Agulhas Bank, South Africa. Growth studies based on sectioned sagittal otoliths revealed that the panga is relatively slow growing with ages of 16 years being recorded. Growth was best described by the von Bertalanffy growth model as L_t = 379.4 (1-e^{–0.13(t+1.78)}). Estimates of total mortality, natural and fishing mortality were estimated at 0.36 year^–1 0.28 year^–1 and 0.08 year^–1, respectively. Detailed histological examination revealed that panga are late gonochorists, males and females maturing after a non-functional intersexual interval. Females mature at approximately 200 mm fork length or 4 years of age. Reproductive activity occurs throughout the year, peaking slightly in winter when small pelagic eggs are spawned. Gametogenesis was found to be similar to that of other sparid fishes and marine teleosts in general. The panga feeds predominantly on crustaceans with a distinct ontogenetic shift in feeding habits. Juvenile fish feed predominantly in the water column on mysids after which they move to the benthos with subadult fish feeding on ophiuroids and amphipods. Adult fish remain on or near the benthos, feeding predominantly on crabs with polychaetes, ophiuroids and fishes also present in the diet in smaller quantities. Several aspects of the panga's biology such as it's late gonochoristic reproductive style, protracted spawning season, maturation before recruitment and the ability to utilise large areas of the Agulhas Bank by feeding on soft substratum prey are thought to enable this species to sustain a higher fishing pressure than other sympatric sparid species. The panga's longevity, slow growth and high natural mortality rate mitigates against these factors and needs to be considered in the development of a management strategy.     

Microsatellite markers for the cardinal tetra Paracheirodon axelrodi,a commercially important fish from central Amazonia

The cardinal tetra Paracheirodon axelrodi is a very popular aquarium fish and the most important ornamental fishery resource for riverine communities inhabiting the Rio Negro floodplain in central Amazonia. Here we describe the isolation and characterization of 14 microsatellite DNA loci for cardinal tetras. Number of alleles and heterozygosity per locus in a sample of 30 fish ranged from 2 to 22 and from 0.49 to 0.92, respectively. These markers provide powerful tools for studies on conservation and management of cardinal tetra resources and for investigating evolutionary processes underlying population diversification in Amazonian flooded forest fishes.     

Development and characterization of microsatellite markers for the Amazonian blackwing hatchetfish,Carnegiella marthae (Teleostei,Gasteropelecidae)

The blackwing hatchetfish, Carnegiella marthae, is a small characin species distributed in forest streams of the Negro and upper Orinoco River basins in Amazonia. Freshwater hatchetfish are popular in the aquarium trade and represent an economic resource for the riverine people from middle Rio Negro, in Brazil. We isolated and characterized seven microsatellite DNA loci for the blackwing hatchetfish. Number of alleles and heterozygosity per locus in a sample of 30 fish ranged from three to 17 and from 0.19 to 0.87, respectively. These microsatellite loci provide powerful markers for studies on taxonomy, management and phylogeographic history of Amazonian hatchetfish.     

From research to implementation: Nature conservation in the Eastern Rhodopes mountains (Greece and Bulgaria), European Green Belt

Nature conservation should ideally build on the scientific recommendations that are concluded from applied conservation research, as well as on monitoring schemes that evaluate the effectiveness of recommendations. We considered as a case study a system of six protected areas located in the Eastern Rhodopes mountains in the southern part of the European Green Belt (EGB). To investigate nature conservation effectiveness, we reviewed 196 articles from scientific journals and books, eight doctoral and master theses, and 39 scientific reports regarding the Greek (one protected area, 428 km²) and the Bulgarian (five protected areas, 904 km²) part of the study area. We extracted 743 conservation recommendations, and through questionnaires completed by 10 local experts, we found that 74% of the recommendations were familiar for the experts. In the Greek (GR) and the Bulgarian part (BG) only 52% and 16%, respectively, of the recommendations were implemented, and only 15% (GR) and 3.1% (BG) were implemented and evaluated regarding their effectiveness. According to the experts, the main reasons for non-implementation and non-evaluation were absence or incompetence of the responsible authorities. Some recommendations obtained a remarkable low rate of implementation, such as those regarding agriculture and livestock rearing practices (GR: 29%, BG: 16%) or mammal conservation (GR: 0%, BG: 16%). Some other recommendations obtained rather high rates at least for Greece, such as tourism and environmental education (GR: 57%, BG: 42%) and bird conservation (GR: 57%, BG: 11%). We found that researchers and conservation managers at both sides of the Greek-Bulgarian border face similar implementation problems, related often to the lack of political will for nature conservation and establishment of competent authorities. The role of the EGB is crucial in enhancing the established cross-border collaborations between stakeholders involved in nature conservation.     

Genetic diversity in an endangered alpine plant, Eryngium alpinum L. (Apiaceae), inferred from amplified fragment length polymorphism markers

Eryngium alpinum L. is an endangered species found across the European Alps. In order to obtain base-line data for the conservation of this species, we investigated levels of genetic diversity within and among 14 populations from the French Alps. We used the amplified fragment length polymorphism (AFLP) technique with three primer pairs and scored a total of 62 unambiguous, polymorphic markers in 327 individuals. Because AFLP markers are dominant, within-population genetic structure (e.g. FIS) could not be assessed. Analyses based either on the assumption of random-mating or on complete selfing lead to very similar results. Diversity levels within populations were relatively high (mean Nei's expected heterozygosity = 0.198; mean Shannon index = 0.283), and a positive correlation was detected between both genetic diversity measurements and population size (Spearman rank correlation: P = 0. 005 and P = 0.002, respectively). Moreover, FST values and exact tests of differentiation revealed high differentiation among populations (mean pairwise FST = 0.40), which appeared to be independent of geographical distance (nonsignificant Mantel test). Founder events during postglacial colonizations and/or bottlenecks are proposed to explain this high but random genetic differentiation. By contrast, we detected a pattern of isolation by distance within populations and valleys. Predominant local gene flow by pollen or seed is probably responsible for this pattern. Concerning the management of E. alpinum, the high genetic differentiation leads us to recommend the conservation of a maximum number of populations. This study demonstrates that AFLP markers enable a quick and reliable assessment of intraspecific genetic variability in conservation genetics.     

Microsatellite markers for two species of dampwood termites in the genus Zootermopsis (Isoptera: Termopsidae)

Dampwood termites in the genus Zootermopsis inhabit forested areas in western North America. To better understand the colony composition and breeding structure of Zootermopsis, we identified polymorphic microsatellite loci to use in population analysis. Microsatellite loci were isolated from Zootermopsis nevadensis nevadensis (Hagen); however, all primers amplified homologous loci in Zootermopsis angusticollis (Hagen) and Zootermopsis nevadensis nuttingi (Hagen). Twelve loci were polymorphic in one or more of the above subspecies and species. The number of alleles per locus ranged from one to six, with some allelic differences among subspecies and species. We are currently utilizing the microsatellite markers to investigate the population genetics of Zootermopsis.     

Exploring patterns of population subdivision in the net-winged midge, Elporia barnardi (Diptera: Blephariceridae), in mountain streams of the south-western Cape, South Africa

1. The net-winged midges (Diptera: Blephariceridae) are a highly specialized group whose morphological characteristics and specific habitat requirements suggest a limited potential for dispersal. Levels of genetic variation were examined within streams, between streams in the same range and between mountain ranges in larval populations of Elporia barnardi in the south-western Cape of South Africa. The aim was to examine the hypothesis that population structure would reflect the poor potential for dispersal.
2. Significant deviations from Hardy–Weinberg equilibrium in 17 of the 57 individual comparisons indicate a non-random mating population. Given the swarming behaviour and life history traits, larvae sampled may reflect the product of limited matings.
3. Analysis of population substructuring revealed significant levels of differentiation among geographically proximate populations. Large differences between streams within Table Mountain, similar in magnitude to those between mountain ranges, suggest that movement of individuals out of the stream catchment is rare. Observed F _ST values are more similar to those of fully aquatic species than other lotic insects with winged adult stages.
4. Results suggest that mountain ridges provided effective physical barriers to the dispersal of E. barnardi , with the catchment representing the effective population unit.     

Isozyme analysis of Galaxias species (Teleostei: Galaxiidae) from the Taieri River, South Island, New Zealand: a species complex revealed

We examined genetic differentiation among 23 samples of non-migratory river galaxias from 17 streams in the Taieri River system, South Island, New Zealand. Four major genetic types were found, two of which occur in narrow sympatry in one location. These were compared with topotypical material representing Galaxias anomalus from the Clutha system (Otago) and G. vulgaris from the Waimakariri system (Canterbury) in order to establish identity. Morphological examination of these four major genetic types revealed consistent concomitant differences. The results suggest that there are at least three species of river galaxias in the Taieri system: G. anomalus, G. vulgaris and at least one previously undescribed species. We propose that the genetic structuring and subsequent speciation of this group has been promoted by the absence of the marine juvenile phase that is found in five other members of the genus native to New Zealand. This structuring may be exacerbated by population fragmentation over the last century owing to the negative influence of introduced trout. The phylogenetic diversity within the river system mirrors the diverse flora and invertebrate fauna of the region, and has conservation implications that parallel those resulting from our improved knowledge of the New Zealand herpetofauna through the application of genetic analysis.     

Between an ocean and a high place: coastal drainage isolation generates endemic cryptic species in the Cape kurper Sandelia capensis (Anabantiformes: Anabantidae), Cape Region,South Africa

This study investigated the range-wide phylogenetics and biogeography of the Cape kurper Sandelia capensis, a primary freshwater fish endemic to and widespread within the Cape Floristic Region (CFR) of South Africa. Maximum likelihood, Bayesian phylogenetic and haplotype network analyses, based on two mitochondrial and two nuclear genes, revealed the existence of three reciprocally monophyletic, deeply divergent and allopatric clades that probably represent cryptic species. The West Coast Clade is largely confined to the Langvlei, Verlorenvlei, Berg and Diep Rivers, the Klein River Clade is endemic to the Klein River and the South Coast Clade is found everywhere else in the range of S. capensis sensu lato. It was hypothesised that divergences within S. capensis sensu lato probably occurred because of isolation of coastal drainages by persistent drainage divides or vicariance of current tributaries by the drowning of their confluences by high sea levels. The current distribution of lineages could be due to historical range expansion and gene flow via river capture or some other mode of transdivide dispersal or dispersal during periods of low sea level via palaeoriver confluences of currently isolated coastal rivers. Comparison of BEAST2 estimated divergence times with the timing of climatic, geological and geomorphological events supported long-term coastal drainage isolation, punctuated by rare transdivide dispersal events and limited palaeoriver dispersal, as the best explanation of current phylogeographic and divergence patterns in S. capensis. Hydrological barriers that block upstream passage in palaeotributaries could hypothetically explain why S. capensis failed to disperse through certain palaeoriver confluences. There were several sites where biogeographic patterns have likely been confounded by human translocation of S. capensis. Alien fish predators and water extraction may threaten the three cryptic species more severely than previously realised, due to their smaller population sizes and inhabitation of only a portion of the range previously ascribed to S. capensis sensu lato. The preponderance of cryptic diversity and endemism in the CFR suggests that additional undescribed cryptic species of obligate freshwater fishes may be found in short coastal river systems around the world, especially in regions with a history of geological stability and a narrow continental shelf.     

Genetic and geographic differentiation in the Rio Negro tuco-tuco (Ctenomys rionegrensis): inferring the roles of migration and drift from multiple genetic markers

Among tuco-tucos, Ctenomys rionegrensis is especially amenable to the study of the forces driving population differentiation because of the restricted geographic range it occupies in Uruguay. Within this limited area, the Rio Negro tuco-tuco is limited to sandy soils. It nonetheless exhibits remarkable variation in pelage color, including melanic, agouti, and dark-backed individuals. Two hypotheses have been put forth to explain this pattern: (1) local differentiation and fixation of alternative pelage types by genetic drift under limited gene flow; or (2) fixation by natural selection that may take place even in the presence of gene flow. A previous allozyme study rejected the genetic drift hypothesis on the basis of high inferred levels of migration. New estimates of gene flow from microsatellites and mitochondrial cytochrome b sequences were obtained for C. rionegrensis populations to further test these hypotheses. Much lower levels of gene flow were estimated with these more sensitive markers. Microsatellite-based estimates of gene flow are close to zero and may come closest to estimating current levels of migration. A lack of equilibrium between migration and genetic drift is also strongly suggested by the absence of an isolation-by-distance pattern found in all three genetic datasets. The microsatellite genotype data show that the species is strongly structured geographically, with subpopulations constituting distinct genetic entities. If current levels of gene flow are very low, as indicated by the new data, the local fixation of alternative alleles, including those responsible for pelage color polymorphism, is possible by drift alone. A scenario is thus proposed in which the species expanded in the recent past from a more restricted geographic range and has subsequently differentiated in near isolation, with genetic drift possibly playing a primary role in overall genetic differentiation. The local fixation of pelage color types could also be due to drift, but selection on this trait cannot be ruled out without direct analysis.     

Significant population structure and asymmetric gene flow patterns amidst expanding populations of Clinus cottoides (Perciformes,Clinidae): application of molecular data to marine conservation planning in South Africa

Clinus cottoides is a fish endemic to the coast of South Africa, predominantly inhabiting rock pools. All South African clinids are viviparous, but probably breed throughout the year; as such, their dispersal may be limited, unlike species with pelagic larval stages. We analysed 343 fish from 14 localities on the west, south and east coasts using two mitochondrial genes and the second intron of the S7 ribosomal gene. Mitochondrial DNA analyses recovered significant genetic differentiation between fish populations from the east coast and other sampling locations, with a second break found between Gansbaai and Cape Agulhas on the south coast. Nuclear DNA recovered shallower, but significant, levels of population structure. Coalescent analyses suggested remarkably asymmetrical gene flow between sampling locations, suggesting that the cold Atlantic Benguela Current and Indian Ocean Agulhas counter‐current play important roles in facilitating dispersal. There was no gene flow between the east coast and the other sites, suggesting that these populations are effectively isolated. Divergence times between them were estimated to at least 68 000 years. Neutrality tests and mismatch distributions suggest recent population expansions, with the exception of peripheral western and eastern populations (possibly a consequence of environmental extremes at the edge of the species distribution). Analyses of the current South African marine protected areas network show that it is not connected and that De Hoop, one of South Africa's largest marine reserves, appears to be an important source population of recruits to both the south and southwest coasts.     

Development of polymorphic microsatellite markers for Dalbergia nigra (Papilionoideae), an endangered tree from the Brazilian Atlantic Forest

Dalbergia nigra is an endangered tree restricted to the Brazilian Atlantic Forest. Ten polymorphic microsatellite loci were isolated and characterized in 47 trees from two populations. The total number of alleles per locus ranged from three to 12 alleles. The levels of observed and expected heterozygosities ranged from 0.304 to 0.740 and from 0.278 to 0.872, respectively. Significant deviations from Hardy-Weinberg were detected for only three loci in each population. No pair of loci exhibited significant linkage disequilibrium. These microsatellites provide an efficient tool to investigate genetic structure in forest remnants with the purpose of conservation of this species.     

Phylogeographical analysis of an estuarine fish, Salanx ariakensis (Osmeridae: Salanginae) in the north-western Pacific

This study extended the geographic coverage of a previous study to explore population genetic structure and demographic history in the Ariake icefish Salanx ariakensis from three populations of continental coastlines and one island population in the north-western Pacific based on a partial sequence of the mitochondrial cytochrome b gene. The S. ariakensis showed high genetic diversity and strong genetic structure. Phylogenetic analysis showed a shallow gene tree with no clear phylogeographical structure. Contiguous range expansion and restricted gene flow were inferred to be main population events by nested-clade analysis. Significant genetic differentiations between populations could be attributable to negligible gene flow by coalescent analysis. High nucleotide diversity of each population was due to geographic mixing of heterogenous haplotypes during lowering sea levels of the Pleistocene. These findings indicate that cycles of geographic isolation and secondary contact happened in the Pleistocene glacial–interglacial cycles shaping genetic structure and population demography of S. ariakensis .     

High genetic diversity within the morphologically conservative dwarf loach, Kichulchoia brevifasciata (Teleostei: Cobitidae), an endangered freshwater fish from South Korea

The dwarf loach, Kichulchoia brevifasciata, is a primary freshwater fish endemic to South Korea (Republic of Korea). Due to its limited geographic range, special habitat requirements, and scarcity, this species has been considered one of the most endangered cobitid loaches in the world. Gene tree and species tree reconstruction derived from mitochondrial and nuclear sequence data supports the exclusivity of K. brevifasciata and the existence of two highly distinct genetic lineages (eastern and western lineages). Intraspecific genetic variation based on the corrected genetic distance ranged from 0.0013 to 0.0017 (cytochrome b) and 0–0.0012 (nuclear loci) within each lineage and 0.0349 (cytochrome b) and 0.0037–0.0104 (nuclear loci) between the lineages. Although morphologically homogeneous, eastern and western lineages were estimated to have diverged roughly 2.79 million years ago (4.25–1.42, 95 % HPD). Future conservation efforts for K. brevifasciata should consider these genetically distinct lineages as separate evolutionary entities and adopt conservation efforts accordingly.     

Microsatellite markers for the tambaqui (Colossoma macropomum, Serrasalmidae, Characiformes), an economically important keystone species of the Amazon River floodplain

Colossoma macropomum is a keystone species of the Amazon floodplain, and is an important but severely overexploited commercial species. To provide tools for addressing ecological and conservation questions, we developed 14 highly polymorphic microsatellite markers that had between four and 21 alleles per locus in the 25 tested individuals. With the exception of comparisons involving the locus Cm1F5 that also showed heterozygosity deficiency, no pairs of loci were at linkage disequilibrium. Many of the microsatellite loci were also variable in three other serrasalmid species which span the phylogenetic depth of the Serrasalmidae.     

Nested clade and phylogeographic analyses of the chub, Leuciscus cephalus (Teleostei, cyprinidae), in Greece: implications for Balkan Peninsula biogeography

Phylogenetic relationships among Greek populations of the chub, Leuciscus cephalus, were investigated using 600 bp of the cytochrome b gene. The aim of this study was to test the assumption that the main difference in ichthyological composition between both sides of the Balkan Peninsula is directly linked to differences in the dispersion mechanisms used by fish in order to extend their distribution range. Phylogenetic and nested clade analyses clearly showed that populations in Greece are significantly differentiated. Greek populations were found to descend from three lineages in three geographical provinces: Western, Central, and Eastern Greece. The chub reached Western Greece at the beginning of the Pleistocene and Eastern Greece during the mid-Pleistocene. Chub dispersion occurred mainly by river confluence due to sea level lowering and river capture in Western Greece and sea dispersal with low-salinity conditions within the Aegean Sea in Eastern Greece. However, in Central Greece, the original mtDNA lineage has presumably been lost owing to a genetic introgression following a second invasion from the Danube during the final stage of the last glaciation. This study provides new elements for a better understanding of the composition of the contemporary ichthyofauna in Greece and highlights possible evolutionary mechanisms responsible for the high endemism rate in the Western Greek biogeographic province.     

Morphological and genetic differentiation between populations of river crabs (Decapoda: Potamonautidae) from the Western Gape, South Africa, with a taxonomic re-examination of Gecarcinautes brincki

As part of a larger study on the systematics of river crabs of the family Potamonautidae in southern Africa, several populations of potamonautid crabs were collected from the Cape Peninsula and surrounds, Western Cape. Two species were represented: Gecarcinautes brincki and Potamonautes perlatus. The structure of the mandibular palp in the eight populations of G. brincki examined was variable, and in four populations, the structure of this palp was the same as that which can be found in species of Potamonautes. This paper re-examines the taxonomic status of G. brincki , quantifies the morphological and genetic differentiation between populations of G. brincki and P. perlatus from the Cape Peninsula, and determines the extent of morphological and genetic differentiation among geographically separated populations of G. brincki. Examination of type and other material confirmed that Gecarcinautes brincki conforms to the current diagnosis of the genus Potamonautes (family Potamonautidae) to which it is therefore transferred. Discriminant functions analysis and protein gel electrophoresis showed that P. perlatus and P. brincki are morphometrically and genetically distinct, with the three P. perlatus populations separating from the six P. brincki populations at a genetic identity value of I = 0.66 (D = 0.419). The results also showed that P. brincki is a highly structured entity, with die populations collected from the Cape Peninsula clearly separating both genetically (I = 0.75, corresponding to D = 0.296), and morphologically (presence or absence of a flange on the terminal segment of the mandibular palp) from those collected further east. The lack of gene flow between populations of this species is discussed in the light of current species concepts.     

Phylogeography of Eastern Polynesian sandalwood (Santalum insulare), an endangered tree species from the Pacific: a study based on chloroplast microsatellites

Aim Patterns of genetic variation within forest species are poorly documented in island ecosystems. The distribution of molecular variation for Santalum insulare, an endangered tree species endemic to the islands of eastern Polynesia, was analysed using chloroplast microsatellite markers. The aims were to quantify the genetic diversity; to assess the genetic structure; and to analyse the geographical distribution of the diversity within and between archipelagoes. The ultimate goal was to pre‐define evolutionary significant units (ESUs) for conservation and restoration programmes of this species, which constitutes a natural resource on small, isolated islands. Location Eleven populations, each representative of one island, covering most of the natural occurrence of S. insulare were sampled: five populations from the Marquesas Archipelago; three from the Society Archipelago; and three from the Cook–Austral Archipelago. These South Pacific islands are known for their high degree of plant endemism, and for their human occupation by Polynesian migrations. The extensive exploitation of sandalwood by Europeans nearly 200 years ago for its fragrant heartwood, used overseas in incense, carving and essential oil production for perfume, has dramatically reduced the population size of this species. Methods We used chloroplast microsatellites, which provide useful information in phylogeographical forest tree analyses. They are maternally inherited in most angiosperms and present high polymorphism. Among the 499 individuals sampled, 345 were genotyped successfully. Classical models of population genetics were used to assess diversity parameters and phylogenetic relationships between populations. Results Four microsatellite primers showed 16 alleles and their combinations provided 17 chlorotypes, of which four exhibited a frequency > 10% in the total population. The gene diversity index was high for the total population (H_e = 0.82) and varied among archipelagoes from H_e = 0.40 to 0.67. Genetic structure is characterized by high levels of differentiation between archipelagoes (36% of total variation) and between islands, but differentiation between islands varied according to archipelago. The relationship between genetic and geographical distance confirms the low gene flow between archipelagoes. The minimum spanning tree of chlorotypes exhibits three clusters corresponding to the geographical distribution in the three main archipelagoes. Main conclusions The high level of diversity within the species was explained by an ancient presence on and around the hotspot traces currently occupied by young islands. Diversity in the species has enabled survival in a range of habitats. Relationships between islands show that the Cook–Austral chlorotype cluster constitutes a link between the Marquesas and the Society Islands. This can be explained by the evolution of the island systems over millions of years, and extinction of intermediary populations on the Tuamotu Islands following subsidence there. Based on the unrooted neighbour‐joining tree and on the genetic structure, we propose four ESUs to guide the conservation and population restoration of Polynesian Sandalwood: the Society Archipelago; the Marquesas Archipelago; Raivavae Island; and Rapa Island.     

Patterns of local and regional genetic structuring in the meadow grasshopper,Chorthippus parallelus (Orthoptera: Acrididae), in Central Germany revealed using microsatellite markers

The meadow grasshopper, Chorthippus parallelus (Zetterstedt), is common and widespread in Central Europe, with a low dispersal range per generation. A population study in Central Germany (Frankenwald and Thüringer Schiefergebirge) showed strong interpopulation differences in abundance and individual fitness. We examined genetic variability using microsatellite markers within and between 22 populations in a short‐ to long‐distance sampling (19 populations, Frankenwald, Schiefergebirge, as well as a southern transect), and in the Erzgebirge region (three populations), with the latter aiming to check for effects as a result of historical forest cover. Of the 671 C. parallelus captured, none was macropterous (functionally winged). All populations showed a high level of expected and observed heterozygosity (mean 0.80–0.90 and 0.60–0.75, respectively), whereas there was evidence of inbreeding (F_IS values all positive). Allelic richness for all locus–population combinations was high (mean 9.3–11.2), whereas alleles per locus ranged from 15–62. At a local level, genic and genotypic differences were significant. Pairwise F_ST values were in the range 0.00–0.04, indicating little interpopulation genetic differentiation. Similarly, the calculated gene flow was very high, based on the respective F_ST (19.5) and using private alleles (7.7). A Neighbour‐joining tree using Nei's D_A and principal coordinate analysis separated two populations that were collected in the Erzgebirge region. Populations from this region may have escaped the effects of the historical forest cover. The visualization of the spatial arrangement of genotypes revealed one geographical barrier to gene flow in the short‐distance sampling. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 875–890.