A comment on García et al. (2005, 2007) and related papers on mating patterns and gene dispersal in Prunus mahaleb

In two studies on mating patterns and spatial components of pollen and seed dispersal of Prunus mahaleb based on parentage analysis, García et al. (2005, 2007) depicted their 196 focal trees as a spatially isolated population where all reproductive trees had been genotyped. Additional distributional data for P. mahaleb trees in their study area, however, revealed that García and colleagues’ depiction of their study system bears little resemblance to reality. The trees these authors studied did not form a discrete, geographically isolated population. Around 300 ungenotyped reproductive trees occurred within the 1.5‐km distributional gap to the nearest population proclaimed by García and colleagues. Since exhaustive sampling of potential parental genotypes is essential in parentage analyses, the occurrence of a large number of ungenotyped trees in the immediate neighbourhood of focal trees can severely affect the main conclusions of García et al. (2005, 2007) as well as of several related publications on gene dispersal and mating patterns of P. mahaleb conducted on the same trees and relying on the same false premises of spatial isolation and exhaustive sampling.     

The importance of pre-mating barriers and the local demographic context for contemporary mating patterns in hybrid zones of Eucalyptus aggregata and Eucalyptus rubida

The frequency of hybridization in plants is context dependent and can be influenced by the local mating environment. We used progeny arrays and admixture and pollen dispersal analyses to assess the relative importance of pre‐mating reproductive barriers and the local demographic environment as explanations of variation in hybrid frequency in three mapped hybrid zones of Eucalyptus aggregata and E. rubida. A total of 731 open‐pollinated progeny from 36 E. aggregata maternal parents were genotyped using six microsatellite markers. Admixture analysis identified substantial variation in hybrid frequency among progeny arrays (0–76.9%). In one hybrid zone, hybrid frequency was related to pre‐mating barriers (degree of flowering synchrony) and demographic components of the local mating environment (decreasing population size, closer proximity to E. rubida and hybrid trees). At this site, average pollen dispersal distance was less and almost half (46%) of the hybrid progeny were sired by local E. rubida and hybrid trees. In contrast, at the other two sites, pre‐mating and demographic factors were not related to hybrid frequency. Compared to the first hybrid zone where most of the E. rubida (76%) and all hybrids flowered, in the remaining sites fewer E. rubida (22–41%) and hybrid trees (0–50%) flowered and their reproductive success was lower (sired 0–23% of hybrids). As a result, most hybrids were sired by external E. rubida/hybrids located at least 2–3 km away. These results indicate that although pre‐mating barriers and local demography can influence patterns of hybridization, their importance can depend upon the scale of pollen dispersal.     

Comparison of contemporary mating patterns in continuous and fragmented Eucalyptus globulus native forests

While habitat fragmentation is a central issue in forest conservation studies in the face of broad-scale anthropogenic changes to the environment, its effects on contemporary mating patterns remain controversial. This is partly because of the inherent variation in mating patterns which may exist within species and the fact that few studies have replication at the landscape level. To study the effect of forest fragmentation on contemporary mating patterns, including effective pollen dispersal, we compared four native populations of the Australian forest tree, Eucalyptus globulus . We used six microsatellite markers to genotype 1289 open-pollinated offspring from paired fragmented and continuous populations on the island of Tasmania and in Victoria on mainland Australia. The mating patterns in the two continuous populations were similar, despite large differences in population density. In contrast, the two fragmented populations were variable and idiosyncratic in their mating patterns, particularly in their pollen dispersal kernels. The continuous populations showed relatively high outcrossing rates (86–89%) and low correlated paternity (0.03–0.06) compared with the fragmented populations (65–79% and 0.12–0.20 respectively). A greater proportion of trees contributed to reproduction in the fragmented ( de/d ≥ 0.5) compared with the continuous populations ( de/d  =   0.03–0.04). Despite significant inbreeding in the offspring of the fragmented populations, there was little evidence of loss of genetic diversity. It is argued that enhanced medium- and long-distance dispersal in fragmented landscapes may act to partly buffer the remnant populations from the negative effects of inbreeding and drift.     

Pollen and seed dispersal inferred from seedling genotypes: the Bayesian revolution has passed here too

Understanding precisely how plants disperse their seeds and pollen in their neighbourhood is a central question for both ecologists and evolutionary biologists because seed and pollen dispersal governs both the rate of spread of an expanding population and gene flow within and among populations. The concept of a 'dispersal kernel' has become extremely popular in dispersal ecology as a tool that summarizes how dispersal distributes individuals and genes in space and at a given scale. In this issue of Molecular Ecology, the study by Moran & Clark (2011) (M&C in the following) shows how genotypic and spatial data of established seedlings can be analysed in a Bayesian framework to estimate jointly the pollen and seed dispersal kernels and finally derive a parentage analysis from a full-probability approach. This approach applied to red oak shows important dispersal of seeds (138 m on average) and pollen (178 m on average). For seeds, this estimate contrasts with previous results from inverse modelling on seed trap data (9.3 m). This research gathers several methodological advances made in recent years in two research communities and could become a cornerstone for dispersal ecology.     

Effects of male fecundity, interindividual distance and anisotropic pollen dispersal on mating success in a Scots pine (Pinus sylvestris) seed orchard

Quantifying the effect of pollen dispersal and flowering traits on mating success is essential for understanding evolutionary responses to changing environments and establishing strategies for forest tree breeding. This study examined, quantitatively, the effects of male fecundity, interindividual distance and anisotropic pollen dispersal on the mating success of Scots pine (Pinus sylvestris), utilizing a well-mapped Scots pine seed orchard. Paternity analysis of 1021 seeds sampled from 87 trees representing 28 clones showed that 53% of the seeds had at least one potential pollen parent within the orchard. Pronounced variation in paternal contribution was observed among clones. Variations in pollen production explained up to 78% of the variation in mating success, which was 11.2 times greater for clones producing the largest amount of pollen than for clones producing the least pollen. Mating success also varied with intertree distance and direction, which explained up to 28% of the variance. Fertilization between neighboring trees 2.3 m apart was 2.4 times more frequent than between trees 4.6 m apart, and up to 12.4 times higher for trees downwind of the presumed prevailing wind direction than for upwind trees. The effective number of pollen donors recorded in the seed orchard (12.2) was smaller than the theoretical expectation (19.7). Based on the empirical observations, a mating model that best describes the gene dispersal pattern in clonal seed orchards was constructed.     

Pollen and seed flow patterns of Carapa guianensis Aublet. (Meliaceae) in two types of Amazonian forest

Various factors affect spatial genetic structure in plant populations, including adult density and primary and secondary seed dispersal mechanisms. We evaluated pollen and seed dispersal distances and spatial genetic structure of Carapa guianensis Aublet. (Meliaceae) in occasionally inundated and terra firme forest environments that differed in tree densities and secondary seed dispersal agents. We used parentage analysis to obtain contemporary gene flow estimates and assessed the spatial genetic structure of adults and juveniles. Despite the higher density of adults (diameter at breast height ≥ 25 cm) and spatial aggregation in occasionally inundated forest, the average pollen dispersal distance was similar in both types of forest (195 ± 106 m in terra firme and 175 ± 87 m in occasionally inundated plots). Higher seed flow rates (36.7% of juveniles were from outside the plot) and distances (155 ± 84 m) were found in terra firme compared to the occasionally inundated plot (25.4% and 114 ± 69 m). There was a weak spatial genetic structure in juveniles and in terra firme adults. These results indicate that inundation may not have had a significant role in seed dispersal in the occasionally inundated plot, probably because of the higher levels of seedling mortality.     

Realized gene flow within mixed stands of Quercus robur L. and Q. petraea (Matt.) L. revealed at the stage of naturally established seedling

The estimates of contemporary gene flow assessed based on naturally established seedlings provide information much needed for understanding the abilities of forest tree populations to persist under global changes through migration and/or adaptation facilitated by gene exchange among populations. Here, we investigated pollen‐ and seed‐mediated gene flow in two mixed‐oak forest stands (consisting of Quercus robur L. and Q. petraea [Matt.] Liebl.). The gene flow parameters were estimated based on microsatellite multilocus genotypes of seedlings and adults and their spatial locations within the sample plots using models that attempt to reconstruct the genealogy of the seedling cohorts. Pollen and seed dispersal were modelled using the standard seedling neighbourhood model and a modification—the 2‐component seedling neighbourhood model, with the later allowing separation of the dispersal process into local and long‐distance components. The 2‐component model fitted the data substantially better than the standard model and provided estimates of mean seed and pollen dispersal distances accounting for long‐distance propagule dispersal. The mean distance of effective pollen dispersal was found to be 298 and 463 m, depending on the stand, while the mean distance of effective seed dispersal was only 8.8 and 15.6 m, which is consistent with wind pollination and primarily seed dispersal by gravity in Quercus. Some differences observed between the two stands could be attributed to the differences in the stand structure of the adult populations and the existing understory vegetation. Such a mixture of relatively limited seed dispersal with occasional long distance gene flow seems to be an efficient strategy for colonizing new habitats with subsequent local adaptation, while maintaining genetic diversity within populations.     

Evaluating the influence of different aspects of habitat fragmentation on mating patterns and pollen dispersal in the bird-pollinated Banksia sphaerocarpa var. caesia

Habitat fragmentation can significantly affect mating and pollen dispersal patterns in plant populations, although the differential effects of the various aspects of fragmentation are poorly understood. In this study, we used eight microsatellite loci to investigate the effect of fragmentation on the mating system and pollen dispersal within one large and eight small population remnants of Banksia sphaerocarpa var. caesia, a bird-pollinated shrub in the southern agricultural region of Western Australia. The large population had a much larger neighbourhood size and lower selfing rate, maternal pollen pool differentiation and within-plot mean pollen dispersal distance than the small populations. Outcrossing was consistently high and ranged from 85.7% ± 2.6 to 98.5% ± 0.9, and mating patterns suggested nearest-neighbour pollination. Pollen immigration into small populations ranged from 2.8% ± 1.8 to 16.5% ± 3.2. Using the small populations, we tested for correlations between various fragmentation variables and mating system and pollen dispersal parameters. We found significant negative linear relationships between population isolation and outcrossing rate; population shape and neighbourhood size; and conspecific density and mean pollen dispersal distance. There were significant positive linear relationships between population shape and pollen pool differentiation and between population size and number of different fathers per seed crop. Our results suggest that birds may use a series of fragmented populations as a vegetation corridor while foraging across the landscape and that population connectivity is a critical determinant of pollinator visitation. Our results also suggest that the effect of a linear population shape on the mating system and pollen dispersal is routinely underestimated.     

NM+: software implementing parentage-based models for estimating gene dispersal and mating patterns in plants

NM+ is computer software designed for making inferences on plant gene dispersal and mating patterns by modelling parentage probabilities of offspring based on the spatially explicit neighbourhood model. NM+ requires a sample of mapped and genotyped candidate parents and offspring; however, offspring may optionally be assigned to single maternal parents (forming so-called half-sib progeny arrays). Using maximum likelihood, NM+ estimates a number of parameters, including proportions of offspring due to self-fertilization, pollen immigration from outside of a defined study site, parameters of pollen (and/or seed) dispersal kernels (exponential-power, Weibull, geometric or 2Dt) and selection gradients relating covariates (phenotypic traits) with male (and/or female) reproductive success. NM+ allows for missing data both in parents and in offspring. It accounts for null alleles and their frequencies can optionally be considered as estimable parameters. Data files are formatted in a table-like structure so they can be easily prepared in a spreadsheet software. By default NM+ is for studying plant populations, however, it can be used for any organism as long as data requirements and model assumptions are met. NM+ runs under Windows, but it can be launched under Linux using WINE emulator. NM+ can be downloaded free of charge from http://www.genetyka.ukw.edu.pl/index_pliki/software.htm.     

Long distance pollen-mediated gene flow at a landscape level: the weed beet as a case study

Gene flow is a crucial parameter that can affect the organization of genetic diversity in plant species. It has important implications in terms of conservation of genetic resources and of gene exchanges between crop to wild relatives and within crop species complex. In the Beta vulgaris complex, hybridization between crop and wild beets in seed production areas is well documented and the role of the ensuing hybrids, weed beets, as bridges towards wild forms in sugar beet production areas have been shown. Indeed, in contrast to cultivated beets that are bi-annual, weed beets can bolt, flower and reproduce in the same crop season. Nonetheless, the extent of pollen gene dispersal through weedy lineages remains unknown. In this study, the focus is directed towards weed-to-weed gene flow, and we report the results of a pollen-dispersal analysis within an agricultural landscape composed of five sugar beet fields with different levels of infestation by weed beets. Our results, based on paternity analysis of 3240 progenies from 135 maternal plants using 10 microsatellite loci, clearly demonstrate that even if weedy plants are mostly pollinated by individuals from the same field, some mating events occur between weed beets situated several kilometres apart (up to 9.6 km), with rates of interfield-detected paternities ranging from 11.3% to 17.5%. Moreover, we show that pollen flow appears to be more restricted when individuals are aggregated as most mating events occurred only for short-distance classes. The best-fit dispersal curves were fat-tailed geometric functions for populations exhibiting low densities of weed beets and thin-tailed Weibull function for fields with weed beet high densities. Thus, weed beet populations characterized by low density with geographically isolated individuals may be difficult to detect but are likely to act as pollen traps for pollen emitted by close and remote fields. Hence, it appears evident that interfield pollen-mediated gene flow between weed beets is almost unavoidable and could contribute to the diffusion of (trans)genes in the agricultural landscape.     

Contemporary gene flow and mating system of Arabis alpina in a Central European alpine landscape

Background and Aims

Gene flow is important in counteracting the divergence of populations but also in spreading genes among populations. However, contemporary gene flow is not well understood across alpine landscapes. The aim of this study was to estimate contemporary gene flow through pollen and to examine the realized mating system in the alpine perennial plant, Arabis alpina (Brassicaceae).

Methods

An entire sub-alpine to alpine landscape of 2 km² was exhaustively sampled in the Swiss Alps. Eighteen nuclear microsatellite loci were used to genotype 595 individuals and 499 offspring from 49 maternal plants. Contemporary gene flow by pollen was estimated from paternity analysis, matching the genotypes of maternal plants and offspring to the pool of likely father plants. Realized mating patterns and genetic structure were also estimated.

Key Results

Paternity analysis revealed several long-distance gene flow events (≤1 km). However, most outcrossing pollen was dispersed close to the mother plants, and 84 % of all offspring were selfed. Individuals that were spatially close were more related than by chance and were also more likely to be connected by pollen dispersal.

Conclusions

In the alpine landscape studied, genetic structure occurred on small spatial scales as expected for alpine plants. However, gene flow also covered large distances. This makes it plausible for alpine plants to spread beneficial alleles at least via pollen across landscapes at a short time scale. Thus, gene flow potentially facilitates rapid adaptation in A. alpina likely to be required under ongoing climate change.     

林木种子园花粉污染与防治措施

林木种子园花粉污染是影响种子园种子遗传品质的重要因子,由于野生同种花粉进入种子园而增加遗传损失。本文综述了国内外林木种子园花粉污染研究的概况、污染水平、影响污染水平的因子和减少污染的措施。研究表明：DNA分子标记在分析种子园交配动态和种子园管理效果方面非常有效（例如,cpDNA、RAPD和SSR）;种子园污染水平比预期的更高;花粉产量好像对污染水平没有影响;空间和生殖隔离也没有产生预期的效果。目前,人工辅助授粉和疏伐是减少花粉污染的两种有效措施。为了改善种子园林木的亲本平衡,人工处理技术的使用,例如：赤霉素A4/7处理技术和无性繁殖技术在种子园很受欢迎。污染程度其他方面的研究工作仍在继续,本文提到的基因流的研究。并对我国种子园花粉污染研究和花粉管理提出建议：当分析种子园花粉污染时,涉及到花粉基因型自然的（花粉扩散）、生理（开花时间）和花粉生活力等因素都应该被考虑。     

Patterns and levels of gene flow in Rhododendron metternichii var. hondoense revealed by microsatellite analysis

Parentage analysis was conducted to elucidate the patterns and levels of gene flow in Rhododendron metternichii Sieb. et Zucc. var. hondoense Nakai in a 150 x 70 m quadrant in Hiroshima Prefecture, western Japan. The population of R. metternichii occurred as three subpopulations at the study site. Seventy seedlings were randomly collected from each of three 10 x 10 m plots (S1, S2, and S3) on the forest floor of each subpopulation (A1, A2, and A3). Almost all parents (93.8%) of the 70 seedlings were unambiguously identified by using 12 pairs of microsatellite markers. Within the quadrant, adult trees less than 5 m from the centre of the seedling bank (plots S1, S2, and S3) produced large numbers of seedlings. The effects of tree height and distance from the seedling bank on the relative fertilities of adult trees were highly variable among subpopulations because of the differences in population structure near the seedling bank: neither distance nor tree height had any significant effect in subpopulation A1; distance from the seedling bank had a significant effect in subpopulation A2; and tree height had a significant effect in subpopulation A3. Although gene flow within each subpopulation was highly restricted to less than 25 m and gene flow among the three subpopulations was extremely small (0-2%), long-distance gene flow from outside the quadrant reached 50%. This long-distance gene flow may be caused by a combination of topographical and vegetational heterogeneity, differences in flowering phenology, and genetic substructuring within subpopulations.     

Extensive long-distance pollen dispersal and highly outcrossed mating in historically small and disjunct populations of Acacia woodmaniorum (Fabaceae), a rare banded iron formation endemic

Background and Aims

Understanding patterns of pollen dispersal and variation in mating systems provides insights into the evolutionary potential of plant species and how historically rare species with small disjunct populations persist over long time frames. This study aims to quantify the role of pollen dispersal and the mating system in maintaining contemporary levels of connectivity and facilitating persistence of small populations of the historically rare Acacia woodmaniorum.

Methods

Progeny arrays of A. woodmaniorum were genotyped with nine polymorphic microsatellite markers. A low number of fathers contributed to seed within single pods; therefore, sampling to remove bias of correlated paternity was implemented for further analysis. Pollen immigration and mating system parameters were then assessed in eight populations of varying size and degree of isolation.

Key Results

Pollen immigration into small disjunct populations was extensive (mean minimum estimate 40 % and mean maximum estimate 57 % of progeny) and dispersal occurred over large distances (≤1870m). Pollen immigration resulted in large effective population sizes and was sufficient to ensure adaptive and inbreeding connectivity in small disjunct populations. High outcrossing (mean t_m = 0·975) and a lack of apparent inbreeding suggested that a self-incompatibility mechanism is operating. Population parameters, including size and degree of geographic disjunction, were not useful predictors of pollen dispersal or components of the mating system.

Conclusions

Extensive long-distance pollen dispersal and a highly outcrossed mating system are likely to play a key role in maintaining genetic diversity and limiting negative genetic effects of inbreeding and drift in small disjunct populations of A. woodmaniorum. It is proposed that maintenance of genetic connectivity through habitat and pollinator conservation will be a key factor in the persistence of this and other historically rare species with similar extensive long-distance pollen dispersal and highly outcrossed mating systems.     

Contemporary pollen and seed dispersal in a Prunus mahaleb population: patterns in distance and direction

Pollination and seed dispersal determine the spatial pattern of gene flow in plant populations and, for those species relying on pollinators and frugivores as dispersal vectors, animal activity plays a key role in determining this spatial pattern. For these plant species, reported dispersal patterns are dominated by short-distance movements with a significant amount of immigration. However, the contribution of seed and pollen to the overall contemporary gene immigration is still poorly documented for most plant populations. In this study we investigated pollination and seed dispersal at two spatial scales in a local population of Prunus mahaleb (L.), a species pollinated by insects and dispersed by frugivorous vertebrates. First, we dissected the relative contribution of pollen and seed dispersal to gene immigration from other parts of the metapopulation. We found high levels of gene immigration (18.50%), due to frequent long distance seed dispersal events. Second, we assessed the distance and directionality for pollen and seed dispersal events within the local population. Pollen and seed movement patterns were non-random, with skewed distance distributions: pollen tended moved up to 548 m along an axis approaching the N-S direction, and seeds were dispersed up to 990 m, frequently along the SW and SE axes. Animal-mediated dispersal contributed significantly towards gene immigration into the local population and had a markedly nonrandom pattern within the local population. Our data suggest that animals can impose distinct spatial signatures in contemporary gene flow, with the potential to induce significant genetic structure at a local level.     

Mating patterns and pollen dispersal in a heterodichogamous tree, Juglans mandshurica (Juglandaceae)

Mating patterns in heterodichogamous species are generally considered to be disassortative between flowering morphs, but this hypothesis has hitherto not been vigorously tested. Here, mating patterns and pollen dispersal were studied in Juglans mandshurica, a heterodichogamous wind-pollinated species that is widely distributed in northern and north-eastern China. Paternity analyses carried out on 11 microsatellite loci were used to estimate morph-specific rates of outcrossing and disassortative mating. Pollen dispersal and genetic structure were also investigated in the population under study. The mating pattern of J. mandshurica was highly outcrossing and disassortative. Pairwise values of intramorph relatedness were much higher than those of intermorph relatedness, and a low level of biparental inbreeding was detected. There was no significant difference in outcrossing and disassortative mating rates between the two morphs. The effective pollen dispersal distribution showed an excess of near-neighbor matings, and most offspring of individual trees were sired by one or two nearby trees. These results corroborate the previous suggestion that mating in heterodichogamous plant species is mainly disassortative between morphs, which not only prevents selfing but also effectively reduces intramorph inbreeding.     

Cryptic behaviours, inverse genetic landscapes, and spatial avoidance of inbreeding in the Pacific jumping mouse

Although the behaviour of individuals is known to impact the genetic make-up of a population, observed behavioural patterns do not always correspond to patterns of genetic structure. In particular, philopatric or dispersal-limited species often display lower-than-expected values of relatedness or inbreeding suggestive of the presence of cryptic migration, dispersal, or mating behaviours. I used a combination of microsatellite and mark-recapture data to test for the influence of such behaviours in a dispersal-limited species, the Pacific jumping mouse, within a semi-isolated population over three seasons. Despite short dispersal distances and a low rate of first generation migrants, heterozygosities were high and inbreeding values were low. Dispersal was male-biased; interestingly however, this pattern was only present when dispersal was considered to include movement away from paternal home range. Not unexpectedly, males were polygynous; notably, some females were also found to be polyandrous, selecting multiple neighbouring mates for their single annual litter. Patterns of genetic structure were consistent with these more inconspicuous behavioural patterns. Females were more closely related than males and isolation by distance was present only in females. Furthermore, detailed genetic landscapes revealed the existence of strong, significant negative correlations, with areas of low genetic distance among females overlapping spatially with areas of high genetic distance among males. These results support the hypothesis that the detected cryptic components of dispersal and mating behaviour are reducing the likelihood of inbreeding in this population through paternally driven spatial mixing of male genotypes and polyandry of females.     

Pollen flow in the wildservice tree, Sorbus torminalis (L.) Crantz. IV. Whole interindividual variance of male fecundity estimated jointly with the dispersal kernel

Interindividual variance of male reproductive success (MRS) contributes to genetic drift, which in turn interacts with selection and migration to determine the short-term response of populations to rapid changes in their environment. Individual relative MRS can be estimated through paternity analysis and can be further dissected into fecundity and spatial components. Existing methods to achieve this decomposition either rely on the strong assumption of a random distribution of pollen donors (TwoGener) or estimate only the part of the variance of male fecundity that is explained by few covariates. We developed here a method to estimate jointly the whole variance of male fecundity and the pollen dispersal curve from the genotypic information of sampled seeds and their putative fathers and geographical information of all individuals in the study area. We modelled the relative individual fecundities as a log-normally distributed random effect. We used a Bayesian approach, well suited to the hierarchical nature of the model, to estimate these fecundities. When applied to Sorbus torminalis , the estimated variance of male fecundity corresponded to an effective density of trees 13 times lower than the observed density ( d_obs / d_ep ~  13). This value is between the value ( ~ 2) estimated with a classical mating model including three covariates (neighbourhood density, diameter, flowering intensity) that affect fecundity and the value ( ~ 30) estimated with TwoGener. The estimated dispersal kernel was close to previous results. This approach allows fine monitoring of ongoing genetic drift in natural populations, and quantitative dissection of the processes contributing to drift, including human actions.     

Fat-tailed gene flow in the dioecious canopy tree species Fraxinus mandshurica var. japonica revealed by microsatellites

Pollen flow, seed dispersal and individual reproductive success can be simultaneously estimated from the genotypes of adults and offspring using stochastic models. Using four polymorphic microsatellite loci, gene flow of the wind-pollinated and wind-seed-dispersed dioecious tree species, Fraxinus mandshurica var. japonica, was quantified in a riparian forest, in northern Japan. In a 10.5-ha plot, 74 female adults, 76 male adults and 292 current-year seedlings were mapped and genotyped, together with 200 seeds. To estimate dispersal kernels of pollen and seeds, we applied normal, exponential power, Weibull, bivariate t-distribution kernels, and two-component models consisting of two normal distribution functions, one with a small and one with a large variance. A two-component pollen flow model with a small contribution (26.1%) from short-distance dispersal (sigma = 7.2 m), and the rest from long-distance flow (sigma = 209.9 m), was chosen for the best-fitting model. The average distance that integrated pollen flows inside and outside the study plot was estimated to be 196.8 m. Tree size and flowering intensity affected reproduction, and there appeared to be critical values that distinguished reproductively successful and unsuccessful adults. In contrast, the gene flow model that estimated both pollen and seed dispersal from established seedlings resulted in extensive seed dispersal, and the expected spatial genetic structures did not satisfactorily fit with the observations, even for the selected model. Our results advanced small-scale individual-based parentage analysis for quantifying fat-tailed gene flow in wind-mediated species, but also clarified its limitations and suggested future possibilities for gene flow studies.