Significant Spatial Structure Research Articles

Genome-Wide SNP Data Revealed Notable Spatial Genetic Structure in the Deep-Sea Precious Coral Corallium japonicum

Estimating the spatial extent of gamete and larval dispersal of deep-sea coral species, is challenging yet important for their conservation. Spatial autocorrelation analysis is useful for estimating the spatial range of dispersal of corals; however, it has not been performed for deep-sea coral species using genome-wide single nucleotide polymorphisms (SNPs). In this study, we examined the spatial genetic structure of a deep-sea coral species—the Japanese red coral, Corallium japonicum, sampled off the coast of Kochi, which lies to the southwest of the Shikoku Island in Japan; the Kochi region suffers from over-harvesting because of its high commercial value. We also examined the power of detecting significant spatial genetic structure by changing the number of loci and the proportion of missing data using both de novo analysis and mapping analysis. Similar results were obtained for both de novo and mapping analysis, although a higher number of loci were obtained by the mapping method. In addition, “many SNPs with a lot of missing data” was generally more useful than “a small number of SNPs with a small amount of missing data” to detect significant fine-scale spatial genetic structure. Our data suggested that more than 700 neutral SNPs were needed to detect significant fine-scale spatial genetic structure. The maximum first distance class that can detect significant spatial genetic structure within Kochi for the C. japonicum population was less than 11 km, suggesting that the over-harvesting of C. japonicum within a diameter of approximately 11 km in the Kochi area should be avoided, because this can cause the local extinction of this species.

High gene flow through pollen partially compensates spatial limited gene flow by seeds for a Neotropical tree in forest conservation and restoration areas

Gene flow may occur both through pollen movement and seed dispersal, although their relative contribution to overall species gene flow is not understood for most tropical trees, which compromises management recommendations. We investigated the implications of seed dispersal limitation, pollen dispersal capacity, and mating system to the spatial genetic structure of populations of the Neotropical legume tree, Centrolobium tomentosum, in Brazil’s Atlantic Forest. We estimated seed dispersal distribution by counting individuals around adult trees; pollen dispersal distribution and outcrossing rates from adult and offspring genotypes, using seven microsatellite loci. Spatial genetic structure was inferred through the correlation among kinship coefficients and geographical distances between pairs of individuals, using nuclear and chloroplast microsatellite markers. We observed restricted seed dispersal, with most seeds (78%) falling up to 10 m from the adult tree trunk. The best-fitted pollen dispersal distribution was the exponential power distribution, with a heavy tail and average pollen dispersal distance of 3191 m. The mating system was preferably allogamous, with an average of eight pollen donors. There was significant spatial genetic structure in all populations, with stronger structure obtained from chloroplast DNA, which suggests that the restricted gene flow by seed dispersal may be compensated by high outcrossing rates and long-distance pollen flow promoted by the large bees that pollinate the species. Our results emphasize the importance of pollination services in fragmented tropical landscapes, where most tree species are pollinated by animals and a large number of species experience seed dispersal limitation.

Spatiotemporal variation in mating system and genetic diversity of Araucaria angustifolia: Implications for conservation and seed collection

Understanding spatiotemporal variations in genetic diversity and mating system can allow policymakers to better support actions towards conservation and management of plant populations. However, multiyear studies are still scarce for many long-lived tree species. Therefore, we herein analyze how genetic diversity, genetic structure and mating system of Araucaria angustifolia vary within and among populations, generations (adults and seed cohorts) and years. We evaluated two A. angustifolia populations occurring in forest-grassland landscapes, one of them for three years. Differences in Ho and He were observed among generations and populations, with significant fixation indexes for all adult and seed cohorts evaluated. Pairwise FST values showed that genetic divergences were greater between populations, followed by those among years, and, finally, less relevant values among generations. No significant spatial genetic structure was found in either population. Paternity correlation, number of pollen donors, coancestry and proportion of half and full-sibs may vary over the years in A. angustifolia. In practical terms, the present study demonstrates how recommendations for seed collection may change according to the evaluated year, such as the number of seed trees, which ranged from 42 to 48. Furthermore, multiyear analyses allow a more comprehensive understanding of the genetic aspects for a long-lived tree species. Finally, we present and discuss these aspects and their variations in space, time and between reproductive events, including recommendations for seed collection.

New insights on the population genetic structure of the great scallop (Pecten maximus) in the English Channel, coupling microsatellite data and demogenetic simulations

Abstract The great scallop (Pecten maximus) is a commercially important bivalve in Europe, particularly in the English Channel, where fisheries are managed at regional and local scales through the regulation of fishing effort. In the long term, knowledge about larval dispersal and gene flow between populations is essential to ensure proper stock management. Yet, previous population genetic studies have reported contradictory results. In this study, scallop samples collected across the main fishing grounds along the French and English coasts of the English Channel (20 samples with temporal replicates for three sites, n = 1059 individuals), and the population genetic structure was analysed using 13 microsatellite loci. Coupling empirical genetic data with demogenetic modelling based on a biophysical model simulating larval exchanges among scallop beds revealed a subtle genetic differentiation between south‐west English populations and the rest of the English Channel, which was consistent with larval dispersal simulations. The present study provides a step forward in the understanding of great scallop population biology in the English Channel, underlining the fact that even in a context of potentially high gene flow and recent divergence times since the end of the last glacial maximum, weak but significant spatial genetic structure can be identified at a regional scale.

Gaussian processes, median statistics, Milky Way rotation curves

We use the Iocco et al. (2015) compilation of 2,780 circular velocity measurements to analyze the Milky Way rotation curve. We find that the error bars for individual measurements are non-gaussian, and hence instead derive median statistics binned central circular velocity values and error bars from these data. We use these median statistics central values and error bars to fit the data to simple, few parameter, rotation curve functions. These simple functions are unable to adequately capture the significant small scale spatial structure in these data and so provide poor fits. We introduce and use the Gaussian Processes (GP) method to capture this small scale structure and use it to derive Milky Way rotation curves from the binned median statistics circular velocity data. The GP method rotation curves have significant small-scale spatial structure superimposed on a broad rise to galactocentric radius $R\approx7$ kpc and a decline at larger $R$. We use the GP method median statistics rotation curve to measure the Oort $A$ and $B$ constants and other characteristic rotation curve quantities. We study correlations in the residual circular velocities (relative to the GP method rotation curve). Along with other evidence for azimuthal asymmetry of the Milky Way circular rotation velocity field, we find that larger residual circular velocities seem to favor parts of spiral arms.

Inbreeding depression from selfing and mating among relatives of Hymenaea courbaril L

Inbreeding in trees can result in inbreeding depression (ID), which may affect adaptation and growth of individuals that originate from self-fertilization and mating among relatives. To investigate how inbreeding can affect seed, and seedling growth, we used microsatellite loci to determine the mating system of a Hymenaea courbaril population and assess traits of seeds and seedlings for the expression of ID. Ninety-nine adult trees were mapped and genotyped and seeds collected from eight trees in a forest fragment in Sao Paulo State, Brazil. Seed length and weight were measured and germinated seedlings that had been grown under nursery conditions were genotyped and measured for height and root collar diameter (RCD) at two-month intervals (7–17 months of age). Individual fixation index was estimated for each seedling, from which they were classified as originating from mating among unrelated parents (tu), related parents (tr), or selfing (s). This classification was confirmed using paternity analysis. Phenotypic means and ID of the measured traits were calculated for each determined s, tr, and s+tr group. Mating was not random due to the occurrence of self-fertilization (1.3%), mating among relatives (5%), and correlated mating (15.6%). Biparental inbreeding was attributed to significant spatial genetic structure up to 250 m. The mean fixation index within familieswas significantly higher in seedlings (0.184) than in adults (-0.035), indicating ID from seedling to adult stages. The ID varied among seed and seedling traits throughout the study and between mating groups. Self-fertilization resulted in greater ID for seed length (8.5%) and weight (21.3%) than for tr (<7%). The ID for height and RCD of selfed individuals tended to decrease over the course of the study. The values for ID for seedling height and RCD of the s group were greater (15.8–25.6% for both traits) than for the tr group (3.1–8.2%), with a total (s+tr) similar between height (7.6–9.4%) and RCD (8.1–10.5%). We recommend that seed collection is conducted across a large number of forest fragments in the region where the restoration is to be implemented, preferably in forests that are connected or as close as possible to other remnants, to mitigate the effects of ID in future generations. Seeds must be collected from a minimum of 47H. courbaril trees, respecting a minimum distance of 250 m between each tree to avoid collection of seeds from related individuals.

Genetics of the Andean bear (Tremarctos ornatus; Ursidae, Carnivora) in Ecuador: when the Andean Cordilleras are not an Obstacle

One of the top carnivores in the Andean mountains is the Andean bear (Tremarctos ornatus, Ursidae), the only bear in South America. This is a flagship and key umbrella species in Ecuador because its conservation has a positive impact on the conservation of many other species in the Andes. But to preserve, first one must know the genetic characteristics of a species, among other things. For this, we analyzed six mitochondrial genes and seven nuclear DNA microsatellites of 108 Andean bear specimens sampled throughout Ecuador. We adopted three strategies for analyzing the data: by Province, by Region (north vs south), and by Cordillera. Four main results were obtained. First, the mitochondrial genetic diversity levels were elevated, but there were no differences in genetic diversity by Province or by Cordillera. By Regions, southern Ecuador had higher genetic diversity levels than to northern Ecuador. The genetic diversity for the microsatellites was only medium for the Andean bear at this country. Second, there was clear and significant evidence of female population expansions, for the overall sample, by Province, Region, and Cordillera. This population expansion was determined to have occurred in the time interval of 30,000–20,000 years ago (YA), during the last phase of the Pleistocene. We detected a population decrease to have occurred more recently, within the last 5000 years. It continued until about 300–200 YA when a population increase was again detected. Third, there were, practically, no phylogeographic pattern nor genetic differentiation among Andean bear populations in Ecuador by Province or by Cordillera for either mitochondrial or microsatellite markers. There was a little more genetic differentiation between northern and southern areas. Fourth, there was no trace of significant spatial genetic structure for the Andean bear in Ecuador in agreement with the genetic differentiation analyses. This shows that the Andean Cordilleras in this country did not present an obstacle to the dispersion of this species. Therefore, all of the Andean bear specimens in Ecuador should be treated as a unique Management Unit (MU) for conservation purposes, differently to that determined for other countries as Colombia.

Staying close: short local dispersal distances on a managed forest of two Patagonian Nothofagus species

Abstract Understanding the impact of management on the dispersal potential of forest tree species is pivotal in the context of global change, given the implications of gene flow on species evolution. We aimed to determine the effect of logging on gene flow distances in two Nothofagus species from temperate Patagonian forests having high ecological relevance and wood quality. Therefore, a total of 778 individuals (mature trees and saplings) of Nothofagus alpina and N. obliqua, from a single plot managed 20 years ago (2.85 hectares), were mapped and genotyped at polymorphic nuclear microsatellite loci. Historical estimates of gene dispersal distance (based on fine-scale spatial genetic structure) and contemporary estimates of seed and pollen dispersal (based on spatially explicit mating models) were obtained. The results indicated restricted gene flow (gene distance ≤ 45 m, both pollen and seed), no selfing and significant seed and pollen immigration from trees located outside the studied plot but in the close surrounding area. The size of trees (diameter at breast height and height) was significantly associated with female and/or male fertility. The significant fine-scale spatial genetic structure was consistent with the restricted seed and pollen dispersal. Moreover, both estimates of gene dispersal (historical and contemporary) gave congruent results. This suggests that the recent history of logging within the study area has not significantly influenced on patterns of gene flow, which can be explained by the silviculture applied to the stand. The residual tree density maintained species composition, and the homogeneous spatial distribution of trees allowed the maintenance of gene dispersal. The short dispersal distance estimated for these two species has several implications both for understanding the evolution of the species and for defining management, conservation and restoration actions. Future replication of this study in other Nothofagus Patagonian forests would be helpful to validate our conclusions.

Generation and modulation of terahertz gradient force in the interactions of two-color laser pulses with magnetized plasmas

Terahertz (THz) waves, as far-infrared light, offer new opportunities for the optical trapping and manipulation of single cells, in contrast to the other light sources. We present an efficient scheme to flexibly control multiple THz field distribution patterns generated by the laser–plasma interaction in a magnetized plasma. An analytical THz radiation field and two-dimensional particle-in-cell simulation are constructed to verify the feasibility of the scheme. Modulation of the THz gradient force and the energy flux by an asymmetrical THz field is investigated for the purpose of trapping and manipulating particles and cells. In particular, the stabilities of flexibly controlled THz radiation are investigated carefully in the form of the strong and short laser and super-strong magnetic field induced significant spatial structure instabilities and frequency instabilities of terahertz radiation.

Genetic diversity of Nile tilapia (Oreochromis niloticus) throughout West Africa

Nile tilapia (Oreochromis niloticus) is a globally significant aquaculture species rapidly gaining status as a farmed commodity. In West Africa, wild Nile tilapia genetic resources are abundant yet knowledge of fine-scale population structure and patterns of natural genetic variation are limited. Coinciding with this is a burgeoning growth in tilapia aquaculture in Ghana and other countries within the region underpinned by locally available genetic resources. Using 192 single nucleotide polymorphism (SNP) markers this study conducted a genetic survey of Nile tilapia throughout West Africa, sampling 23 wild populations across eight countries (Benin, Burkina Faso, Côte d’Ivoire, Ghana, Togo, Mali, Gambia and Senegal), representing the major catchments of the Volta, Niger, Senegal and Gambia River basins. A pattern of isolation-by-distance and significant spatial genetic structure was identified throughout West Africa (Global FST = 0.144), which largely corresponds to major river basins and, to a lesser extent, sub-basins. Two populations from the Gambia River (Kudang and Walekounda), one from the western Niger River (Lake Sélingué) and one from the upper Red Volta River (Kongoussi) showed markedly lower levels of diversity and high genetic differentiation compared to all other populations, suggesting genetically isolated populations occurring across the region. Genetic structure within the Volta Basin did not always follow the pattern expected for sub-river basins. This study identifies clear genetic structuring and differentiation amongst West African Nile tilapia populations, which concur with broad patterns found in previous studies. In addition, we provide new evidence for fine-scale genetic structuring within the Volta Basin and previously unidentified genetic differences of populations in Gambia. The 192 SNP marker suite used in this study is a useful tool for differentiating tilapia populations and we recommend incorporating this marker suite into future population screening of O. niloticus. Our results form the basis of a solid platform for future research on wild tilapia genetic resources in West Africa, and the identification of potentially valuable germplasm for use in ongoing breeding programs for aquaculture.

Wind pollination over 70 years reduces the negative genetic effects of severe forest fragmentation in the tropical oak Quercus bambusifolia.

Whether wind pollination in trees can offset the negative genetic consequences of anthropogenic forest fragmentation is not clearly established. To answer this question, we examined the demographic genetics of Quercus bambusifolia over a 70-year recovery period in highly fragmented forests in Hong Kong. We sampled 1138 individuals from 37 locations, and genetically analysed the chronosequence through the classification of tree diameters from the same populations using 13 microsatellite markers. Our study reveals that severe fragmentation caused a significant genetic bottleneck with very few remaining but genetically diverse individuals. We observed an enhanced genetic diversity during demographic recovery. We found full-sibs within populations and half-sibs across the study range. This reflects a limited seed dispersal and extensive pollen flow. Despite reduced genetic structure both among and within populations, overall a strong persisting genetic differentiation (F'ST = 0.240, P < 0.01) and significant small-scale spatial genetic structure (F(1) = 0.13, Sp = 0.024, P < 0.01) were observed. Existing bottlenecks and low effective population sizes within the temporal chronosequence suggest that the long-term effect of severe fragmentation cannot be entirely eliminated by wind pollination with demographic recovery in the absence of effective seed dispersal. Our results lead to recommendations for forest management.

Fine-scale diversity patterns in belowground microbial communities are consistent across kingdoms.

The belowground environment is heterogeneous and complex at fine spatial scales. Physical structures, biotic components and abiotic conditions create a patchwork mosaic of potential niches for microbes. Questions remain about mechanisms and patterns of community assembly belowground, including: Do fungal and bacterial communities assemble differently? How do microbes reach the roots of host plants? Within a 4 m2 plot in alpine vegetation, high throughput sequencing of the 16S (bacteria) and ITS1 (fungal) ribosomal RNA genes was used to characterise microbial community composition in roots and adjacent soil of a viviparous host plant (Bistorta vivipara). At fine spatial scales, beta-diversity patterns in belowground bacterial and fungal communities were consistent, although compositional change was greater in bacteria than fungi. Spatial structure and distance-decay relationships were also similar for bacteria and fungi, with significant spatial structure detected at <50 cm among root- but not soil-associated microbes. Recruitment of root microbes from the soil community appeared limited at this sampling and sequencing depth. Possible explanations for this include recruitment from low-abundance populations of soil microbes, active recruitment from neighbouring plants and/or vertical transmission of symbionts to new clones, suggesting varied methods of microbial community assembly for viviparous plants. Our results suggest that even at relatively small spatial scales, deterministic processes play a significant role in belowground microbial community structure and assembly.

Density-dependent fitness, not dispersal movements, drives temporal variation in spatial genetic structure in dark-eyed juncos (Junco hyemalis).

Some studies have found that dispersal rates and distances increase with density, indicating that density-dependent dispersal likely affects spatial genetic structure. In an 11-year mark-recapture study on a passerine, the dark-eyed junco, we tested whether density affected dispersal distance and/or fine-scale spatial genetic structure. Contrary to expectations, we found no effect of predispersal density on dispersal distance or the proportion of locally produced juveniles returning to the population from which they hatched. However, even though density did not affect dispersal distance or natal return rates, we found that density still did affect spatial genetic structure. We found significant positive spatial genetic structure at low densities of (postdispersal) adults but not at high densities. In years with high postdispersal (adult) densities that also had high predispersal (juvenile) densities in the previous year, we found negative spatial genetic structure, indicating high levels of dispersal. We found that density also affected fitness of recruits, and fitness of immigrants, potentially linking these population parameters with the spatial genetic structure detected. Immigrants and recruits rarely nested in low postdispersal density years. In contrast, in years with high postdispersal density, recruits were common and immigrants had equal success to local birds, so novel genotypes diluted the gene pool and effectively eliminated positive spatial genetic structure. In relation to fine-scale spatial genetic structure, fitness of immigrants and new recruits is poorly understood compared to dispersal movements, but we conclude that it can have implications for the spatial distribution of genotypes in populations.

The effect of population density on gene flow between adult trees and the seedling bank in Abies alba Mill.

Populations of smaller effective sizes or subjected to strong environmental filtering have a higher risk of stochastic changes in their genetic properties. This study tested the hypothesis that reducing the density of parent trees combined with environmental filtering during the stage of regeneration establishment affects gene flow between the parent and offspring populations of Abies alba Mill. The genetic variation and spatial genetic structure of parent trees and seedlings were compared in the Western Carpathians (southern Poland) in 27 stands with varying adult tree and regeneration densities. The analysis comprised 1592 individuals and was based on five nuclear microsatellite markers. The proportion of stands with significant spatial genetic structure in the adult tree and seedling cohorts increased as the density of adult trees decreased. The genetic differentiation between adult trees and seedlings expressed by the fixation index FST was between 0.005 and 0.021 and increased as the density of adult trees decreased but was not correlated with the seedling abundance. At the within-stand level, the analysis revealed shifts in the average number of alleles per locus (between − 15% and + 28%), the observed heterozygosity (between − 25% and + 20%) and expected heterozygosity (between − 8% and + 11%) between the populations of adult trees and seedlings. It was concluded that in mixed stands with densities of A. alba trees about 50 adult individuals per ha, there may be some risk of reduced effective population size and disturbed vertical gene flow, but significant shifts in the level of genetic variation are less likely.

High‐Resolution Local Measurements of F Region Ion Temperatures and Joule Heating Rates Using SuperDARN and Ground‐Based Optics

AbstractFrictional heating, frequently termed Joule heating, results from the difference in ion and neutral flows in the Earth's upper atmosphere and is a major energy sink for the coupled magnetosphere‐ionosphere‐thermosphere system. During disturbed geomagnetic conditions, energy input from the Earth's magnetosphere can strongly enhance ion velocities and densities, which will generally increase the rate of Joule heating. Previous theoretical and experimental studies have shown that small‐scale variations in Joule heating can be quite significant in the overall energy budget. In this study, we employ high‐resolution fitting of ion velocities obtained by Super Dual Auroral Radar Network (SuperDARN) coherent scatter, along with spatially resolved neutral wind data from the Poker Flat Scanning Doppler Imager, to examine the spatial and temporal structure of F region ion temperature enhancements, as well as changes in Joule heating rates due to the neutral wind. These results are compared to those obtained using Poker Flat Incoherent Scatter Radar in order to assess the validity of this analysis, with the objective of developing a method that can be applied to any current or future neutral measurements worldwide, thanks to the global coverage of SuperDARN. We examine the agreement between the ion temperatures predicted using the Scanning Doppler Imager‐SuperDARN method and the temperatures measured directly by Poker Flat Incoherent Scatter Radar and discuss possible reasons for any discrepancies. We observe significant spatial structure in both the ion temperature and Joule heating rates during periods of magnetic activity.

The Chironomidae of the Western Carpathian helocrenes: Metacommunity structuring and its drivers in unique habitats

Springs are unique and vulnerable habitats, which have always been rather out of focus of the scientist interest. Nevertheless, they frequently host very diverse and species-rich assemblages with high proportion of species more or less adapted to their unique environment and can act as biodiversity hotspots in some areas. The Western Carpathian springs are helocrene springs and represent wide variety of different habitat types, from mineral rich sparsely-vegetated or bryophytes-rich covered helocrenes to acidic peaty sites. Such diversification allows the creation of highly diverse assemblages, in which Chironomidae usually dominate in both species richness and abundance. The aim of this study was to provide a comprehensive overview of chironomid assemblages inhabiting the unique environment of spring fens and factors driving the metacommunity structuring and populations of individual taxa. We examined chironomid assemblages of 62 small, treeless helocrenes sites, which are highly isolated from each other by the terrestrial environment constituting dispersal barriers such as the east-west oriented mountain ridges and valleys. The sampling was performed to cover mesohabitat heterogeneity of study sites. Two main mesohabitats were sampled, the plot with flowing water and coarser substratum near water source (the lotic mesohabitat), and water-logged soil with standing water (the lentic mesohabitat). Study sites hosted nearly 100 chironomid taxa, both mesohabitats were inhabited by chironomid assemblages similar in number of species and abundances and the local environment was proved to be the main driver of compositional changes in chironomid assemblages as expected. Moreover, the significant spatial structure of assemblages was found at the lentic mesohabitat, while biotic interactions described by the abundance of Gammarus fossarum and taxa richness and abundances of predators did not significantly contribute to compositional changes in assemblages at any mesohabitat. Nevertheless, taxa-specific responses revealed populations of many taxa significantly affected by biotic interactions, especially at the more stable lotic mesohabitat, which is in concordance with suggested greater importance of biotic interactions at stable environment. Our results emphasized the importance of multilevel approach in community ecology for proper distinction between different mechanisms of metacommunity structuring. Biotic interaction such as competition can result into the same community patterns as environmental filtering, thus the involvement of detailed analyses of species requirements and interactions is necessary.

Weak population structure in the ant Formica fusca.

Dispersal is a fundamental trait of a species’ biology. High dispersal results in weakly structured or even panmictic populations over large areas, whereas weak dispersal enables population differentiation and strong spatial structuring. We report on the genetic population structure in the polygyne ant Formica fusca and the relative contribution of the dispersing males and females to this. We sampled 12 localities across a ∼35 km2 study area in Finland and generated mitochondrial DNA (mtDNA) haplotype data and microsatellite data. First, we assessed queen dispersal by estimating population differentiation from mtDNA haplotype data. Second, we analysed nuclear DNA microsatellite data to determine overall population genetic substructure in the study area with principal components analysis, Bayesian clustering, hierarchical F statistics and testing for evidence of isolation-by-distance. Third, we directly compared genetic differentiation estimates from maternally inherited mtDNA and bi-parentally inherited DNA microsatellites to test for sex-bias in dispersal. Our results showed no significant spatial structure or isolation by distance in neither mtDNA nor DNA microsatellite data, suggesting high dispersal of both sexes across the study area. However, mitochondrial differentiation was weaker (Fst-mt = 0.0047) than nuclear differentiation (Fst-nuc = 0.027), which translates into a sixfold larger female migration rate compared to that of males. We conclude that the weak population substructure reflects high dispersal in both sexes, and it is consistent with F. fusca as a pioneer species exploiting unstable habitats in successional boreal forests.

Environmental factors associated with the spatial distribution of invasive plant pathogens in the Iberian Peninsula: The case of Phytophthora cinnamomi Rands

Although spatial variability in the distribution of soil organisms is often regarded as random, recent attempts have found significant spatial structure at several scales. Understanding the drivers of this variability at large scale could help to evaluate the ecological and socio-economic impacts of soil organisms in the ecosystems. In the present study we aim to (i) understand the relative role of environmental factors and human influence on the distribution of one of the World’s most destructive and invasive plant pathogens, Phytophthora cinnamomi Rands, and (ii) to estimate its potential geographic distribution in the Iberian Peninsula as a proxy of its potential impact. For this purpose, we used a total of 277 records of P. cinnamomi (presence: n = 157; absences: n = 120) in the Iberian Peninsula and three sets of explanatory variables reflecting abiotic conditions (climate and soil), biotic conditions (main susceptible host tress distribution and vegetation cover based on NDVI) and human influence. The current distribution of P. cinnamomi in the Iberian Peninsula seems to be influenced principally by fine texture soil and climate, following the land use and lastly the presence of its main host forest species. Its potential distribution across the Iberian Peninsula suggests potential for further expansion along the northeast and southeast of Spain and central Portugal. Given the significant impact of this pathogen on forest ecosystems, the modelling of its distribution in the Iberian Peninsula offers an important decision tool for the monitoring and restoration of declining Mediterranean oak forests.

Small spotted bodies with multiple specific mitochondrial DNAs: existence of diverse and differentiated tigrina lineages or species (Leopardus spp: Felidae, Mammalia) throughout Latin America

We analysed two sets of mitochondrial (mt) DNA data from tigrinas (traditionally, Leopardus tigrinus) we sampled in Costa Rica, Venezuela, Colombia, Ecuador, Peru, Bolivia, northwestern and northeastern Argentina and southern Brazil. Additionally, the analysis included some GenBank sequences from southern, central and northeastern Brazil. The first mt set (mt ATP8+mt 16S rRNA with 41 tigrina) revealed the existence of seven different tigrina-like haplogroups. They could represent, at least, 4–6 different tigrina species following the Phylogenetic Species Concept (PSC). In the second mt set (mitogenomics with 18 tigrinas), we detected six different tigrina-like haplogroups. They could represent 4–5 different tigrina species – including a possible full new species, which has gone previously unnoticed to the world of science both morphologic and molecularly. Coat patterns of several of these different tigrinas support the molecular differences. We also detected intense hybridization in many Andean tigrina with margays (Leopardus wiedii) and ocelots (Leopardus pardalis) as well as hybridization of one Bolivian tigrina with Leopardus geoffroyi. Similar hybridization was found for many of the southern Brazilian tigrina (Leopardus guttulus). All of the temporal split estimates for these tigrina haplogroups, together with those of the Leopardus species recognized to date, began in the late Pliocene but mostly occurred during the Pleistocene. In agreement with the existence of multiple species within the traditional L. tigrinus species, we detected strong and significant spatial structure in the two mt data sets. There were clear circular clines. A major part of the analyses detected more genetic resemblance between the Central American + trans Andean Colombian and Ecuadorian tigrina (L. oncilla) with the most geographically distant tigrina from central and southern Brazil (L. guttulus; pure individuals not hybridized with L. geoffroyi). In comparison, the Andean tigrina taxa had intermediate geographical origins but were highly genetically differentiated both from the Central American + trans Andean Colombian-Ecuadorian tigrina and from the central and southern Brazilian tigrina.

Dispersal influences genetic and acoustic spatial structure for both males and females in a tropical songbird.

Animals exhibit diverse dispersal strategies, including sex‐biased dispersal, a phenomenon common in vertebrates. Dispersal influences the genetic structure of populations as well as geographic variation in phenotypic traits. Patterns of spatial genetic structure and geographic variation may vary between the sexes whenever males and females exhibit different dispersal behaviors. Here, we examine dispersal, spatial genetic structure, and spatial acoustic structure in Rufous‐and‐white Wrens, a year‐round resident tropical bird. Both sexes sing in this species, allowing us to compare acoustic variation between males and females and examine the relationship between dispersal and song sharing for both sexes. Using a long‐term dataset collected over an 11‐year period, we used banding data and molecular genetic analyses to quantify natal and breeding dispersal distance in Rufous‐and‐white Wrens. We quantified song sharing and examined whether sharing varied with dispersal distance, for both males and females. Observational data and molecular genetic analyses indicate that dispersal is female‐biased. Females dispersed farther from natal territories than males, and more often between breeding territories than males. Furthermore, females showed no significant spatial genetic structure, consistent with expectations, whereas males showed significant spatial genetic structure. Overall, natal dispersal appears to have more influence than breeding dispersal on spatial genetic structure and spatial acoustic structure, given that the majority of breeding dispersal events resulted in individuals moving only short distances. Song sharing between pairs of same‐sex animals decreases with the distance between their territories for both males and females, although males exhibited significantly greater song sharing than females. Lastly, we measured the relationship between natal dispersal distance and song sharing. We found that sons shared fewer songs with their fathers the farther they dispersed from their natal territories, but that song sharing between daughters and mothers was not significantly correlated with natal dispersal distance. Our results reveal cultural differences between the sexes, suggesting a relationship between culture and sex‐biased dispersal.