Genetic diversity is often considered a major determinant of long term population persistence and its potential to adapt to variable environmental conditions. The ability of populations to maintain their genetic diversity across generations seems to be a major prerequisite for their sustainability, which is particularly important for keystone forest tree species. However, little is known about genetic consequences of demographic alterations occurring during natural processes of ecological succession involving changes in the species composition. Using microsatellites, we investigated genetic diversity of adult and offspring generations in beech (Fagus sylvatica L.) and oak (Quercus robur L.) populations coexisting in a naturally established old-growth forest stand, showing some symptoms of ongoing ecological succession from oak-to beech-dominated forest. In general, adult generations of both species exhibited high levels of genetic diversity (0.657 for beech; 0.821 for oak), which, however, depended on the sets of selected genetic markers. Nevertheless, several symptoms such as differences in genetic diversity indices between generations, significant levels of inbreeding (up to 0.029) and low estimates of effective population size (48-80) confirmed the declining status of the oak population. On the other hand, the uniform distribution of genetic diversity indices across generations, low levels of inbreeding (0.004), low genetic differentiation among adults and offspring and, most importantly, large estimates of effective population size (119-716), all supported beech as a successive and successful tree species in the studied forest stand.
Monitoring patterns of mating and pollen dispersal in forest tree populations subjected to nature conservation is essential to understanding the dynamics of their reproductive processes and might be helpful in making management decisions aimed at conserving genetic diversity and integrity over the long term. However, little is known about effective pollen dispersal in natural populations of conifers, particularly in subdominant species such as larch. We investigated patterns of pollen dispersal in the Polish larch population ofŚwiętokrzyski National Park. The studied population was located on Chełmowa Mountain in a forest complex 160 ha in size, which is relatively isolated from other forest stands. We assessed if local pollen dispersal inferred from pollen dispersal kernels could provide indications of the level of background pollination from sources located outside of the forest complex. The analysis focused on two plots, each encompassing 126 adult trees, and seed samples (n = 600) collected from 20 trees. Using 11 nuclear microsatellites and spatially explicit mating models, we identified details of mating patterns. The rate of self-fertilization was low (0.0268). Background pollination was moderate (0.4058), and the mean pollen dispersal was found to be 167 m and 111 m, based on exponential-power and Weibull dispersal kernels, respectively. Specific simulations performed based on the estimated pollen dispersal kernels provided background pollination levels comparable to those observed for real data, suggesting that the pollen contributing to background pollination likely originated from the studied forest complex and not from other surrounding populations. These results confirm the high potential for maintaining the genetic integrity of the larch population and support efforts aimed at promoting regeneration of the stands, either natural or through the artificial planting of seedlings derived from trees growing in the core larch population of the protected area.
The study was conducted on five species of Veronica L. subsection Agrestes occurring in Central Europe: Veronica agrestis L., V. polita Fr., V. opaca Fr., V. persica Poir. and V. filiformis Sm. These species are very similar morphologically and are often misidentified. Last thorough studies of morphology and micromorphology of their seeds were conducted in 1960s. Based on 48 herbarium specimens, we examined SEM images of 422 seeds. We found that 22 of the 30 studied morphological traits differentiated five species at statistical level and V. agrestis and V. persica differed with the greatest number of features from other species. Our measurements of seed size were not fully congruent with previous studies, suggesting dependence of these features on external conditions. Seeds were usually cochlidiospermous and ovoid with a reticulate-verrucate seed coat, but these features were, at the same time, quite variable. The results of discriminant function confirmed that some characters of the seed size, shape and coat sculpture could be taxonomically useful in distinguishing species of Veronica subsect. Agrestes. In addition, we believe that similarity of the examined seeds may confirm unity of this group and the need of identifying a subsection.
The aim of the study was to identify the situational factors of a game which (a) might affect the victory or defeat in the game; (b) were common for matches played in a tournament for the hearing or deaf, including matches won or lost. The analysis included 37 matches of national deaf teams (5th World Deaf Basketball Championships, Poland) and 92 matches of national hearing teams (18th Basketball World Cup, China). During both tournaments, the matches played were divided into won and lost. We also presented analyses concerning 31 game situational variables related to the performance of national basketball teams at both events. All situational variables were subject to statistical analysis, including calculation of their means and standard deviations, and determination of minimum and maximum. Discriminant analysis was performed, too. The analyses showed no statistically significant differences in almost all game aspects between matches won by deaf and hearing basketball players. Statistically significant differences in situational variables were observed between matches won during the 5th World Deaf Basketball Championships and matches lost during the 18th Basketball World Cup. The discriminant analysis allowed to determine the situational variables that affected the winning or losing of a game: missed shots for 2 or 3 points, free throws, defensive and offensive rebounds, as well as assists, steals, and turnovers. A classification matrix indicated 21 results of direct match competitions achieved by deaf teams (winning and losing), which allowed to qualify these teams as hearing ones in terms of the values of game situational variables. Literature analysis revealed lack of scientific reports on deaf sport.
Pedunculate and sessile oaks (Quercus robur L.; Q. petraea [Matt] Liebl.) often coexist in mixed forest stands. However, species-specific investigations and forest management actions in such populations require reliable methods of identification of the species status of individuals. We investigated genetic diversity and species differentiation of adult and naturally established seedling cohorts in a mixed forest stand composed of Q. robur and Q. petraea, located in the Jamy Nature Reserve in north-central Poland. Using nineteen nuclear microsatellite loci and a model-based clustering approach as a tool for species delineation, we efficiently identified 105 and 60 adults, as well as 191 and 456 seedlings of pedunculate and sessile oaks, respectively. While the adult trees of both species were randomly distributed throughout the sample plot, the seedlings demonstrated significant spatial clustering, which was particularly evident for Q. petraea. The two oak species exhibited similar levels of genetic diversity in adult and offspring cohorts. Inbreeding was found to be low and significant only at the stage of seedlings. The estimates of effective population size were higher for Q. robur than Q. petraea, despite the overall greater reproductive success of the later one. There was a significant level of differentiation between the studied oak species, as measured by F st coefficient (0.084 -adults; 0.099 -seedlings). The results on genetic diversity and species differentiation obtained in the studied indigenous near-natural stand of Q. robur and Q. petraea could be considered as a reference for other population genetic studies of oaks.
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