Characterization of eighteen novel microsatellite markers and multiplex PCR protocol for Fagus sylvatica

Eighteen novel microsatellite markers for European Beech, Fagus sylvatica, were developed using next-generation sequencing technique. Subsequently, four multiplex PCRs were established for the fast and cost-effective use of the primers. In 60 individuals, we found 3-12 alleles per locus, an expected and observed heterozygosity of 0.445-0.821 and 0.250-0.867, respectively. Fixation index was significant in three loci. Yet, if these measures were jointly estimated with the probability of null alleles, these loci and an additional two indicated low occurrence of null alleles while the overall fixation index was non-significant. The loci were not in linkage disequilibrium. Overall, these markers will be useful for population genetic research to support management decisions for the preservation of this species in changing environmental condition

Seed weight increases with altitude in the Swiss Alps between related species but not among populations of individual species

Seed weight is a crucial plant life history trait, determining establishment success and dispersal ability. Especially in stressful environments, larger seeds may be selected at the expense of seed number, because larger seeds have a better chance of giving rise to an established offspring. We tested the hypotheses that between related species-pairs and among populations of single species a similar trend for increasing seed weight with increasing altitude should be present. Firstly, we measured seed weights from 29 species-pairs, with one species occurring in lowland areas and a congeneric species from high altitudes. Seeds of the alpine species were 28±8% larger than seeds from lowland species (P<0.01). Compared to the related lowland species, 55% of the alpine species had heavier seeds, 3% (one species) had lighter, and 41% had seeds of approximately equal weight. Secondly, we compared seed weights among populations of four species from different habitats and with different life histories. Seeds from between 11 and 34 populations per species were sampled along altitudinal gradients of 800-1,500m (ca. 800m in Scabiosa lucida, ca. 1,000m in Saxifraga oppositifolia, ca. 1,000m in Epilobium fleischeri, and ca. 1,500m in Carex flacca). In all the four species, we found no indication for heavier seeds at higher altitudes. Our results indicate a selection pressure for species with heavier seeds at higher altitude, but the trend does not seem to operate across all cases. Phylogenetic constraints may limit the correlation among altitude and seed weight, operating particularly against selection for larger seed size, the closer populations and species are related to each othe

Genetic diversity, phenotypic variation and local adaptation in the alpine landscape: case studies with alpine plant species

Plant survival in alpine landscapes is constantly challenged by the harsh and often unpredictable environmental conditions. Steep environmental gradients and patchy distribution of habitats lead to small size and spatial isolation of populations and restrict gene flow. Agricultural land use has further increased the diversity of habitats below and above the treeline. We studied the consequences of the highly structured alpine landscape for evolutionary processes in four study plants: Epilobium fleischeri, Geum reptans, Campanula thyrsoides and Poa alpina. The main questions were: (1) How is genetic diversity distributed within and among populations and is it affected by altitude, population size or land use? (2) Do reproductive traits such as allocation to sexual or vegetative reproduction vary with altitude or land use? Furthermore, we studied if seed weight increases with altitude. Within-population genetic diversity of the four species was high and mostly not related to altitude and population size. Nevertheless, genetic differentiation among populations was pronounced and strongly increasing with distance. In Poa alpina genetic diversity was affected by land use. Results suggest considerable genetic drift among populations of alpine plants. Reproductive allocation was affected by altitude and land use in Poa alpina and by succession in Geum reptans. Seed weight was usually higher in alpine species than in related lowland species. We conclude that the evolutionary potential to respond to global change is mostly intact in alpine plants, even at high altitude. Phenotypic variability is shaped by adaptive as well as by random evolutionary processes; moreover plastic responses to growth conditions seem to be crucial for survival of plants in the alpine landscap

Genetic variation and plant performance in fragmented populations of globeflowers ( Trollius europaeus ) within agricultural landscapes

The management of remnant populations in highly fragmented landscapes requires a thorough understanding of the processes shaping population persistence. We investigated relationships between population characteristics (i.e. size, density and pollinator abundance), offspring performance, genetic diversity and differentiation in Trollius europaeus, a plant with a nursery pollination system. In 19 populations of different sizes and located in north-east Switzerland, an area which has undergone widespread land use changes over the last decades, we assessed neutral genetic diversity (N total=383) using AFLPs and plant performance in a greenhouse experiment (N total=584) using competition and control treatments. Overall genetic differentiation was low (F ST=0.033) with a marginal significant isolation by distance effect (P=0.06) indicating (historical) genetic connectivity among the populations. Mean expected heterozygosity was H E of 0.309 (0.0257-0.393) while inbreeding coefficients (F IS) were significant in only three populations. Genetic diversity was not related to population size, plant density or pollinator abundance. Plant performance was reduced under competition (P<0.001) but the severity of competition was independent of genetic diversity and population size. In summary, remnant populations of T. europaeus retain genetic diversity and seem capable of persisting under the present conditions within an agricultural matrix. T. europaeus is a perennial herb, thus it may require several generations for the negative effects of fragmentation and isolation to manifest. Our findings indicate that small populations are as important as large populations for the conservation and management of genetic resource

The Personality Trait of Environmental Sensitivity Predicts Children's Positive Response to School-Based Antibullying Intervention

Background: Meta-analyses on the effectiveness of anti-bullying interventions show that average effects tend to be significant but small. Informed by the Vantage Sensitivity framework (Pluess and Belsky, 2013) the current study aims at testing whether individual differences in Environmental Sensitivity predict treatment response to an anti-bullying intervention. Method: Large randomized controlled trial with 2,042 pupils (grade 4 and 6) randomly assigned to a treatment or control condition. Results: Significant Intervention effects on victimization and internalizing symptoms (but not bullying or externalizing symptoms) were moderated by both Environmental Sensitivity and gender, with boys scoring high on sensitivity benefitting significantly more than less sensitive boys from the effects of the intervention regarding reduced victimization and internalizing symptoms. Conclusions: Findings are consistent with the notion of Vantage Sensitivity, suggesting that some individuals are disproportionately likely to respond to treatment while others are more resistant as a function of individual differences in environmental sensitivity

Seed weight increases with altitude in the Swiss Alps between related species but not among populations of individual species

Seed weight is a crucial plant life history trait, determining establishment success and dispersal ability. Especially in stressful environments, larger seeds may be selected at the expense of seed number, because larger seeds have a better chance of giving rise to an established offspring. We tested the hypotheses that between related species-pairs and among populations of single species a similar trend for increasing seed weight with increasing altitude should be present. Firstly, we measured seed weights from 29 species-pairs, with one species occurring in lowland areas and a congeneric species from high altitudes. Seeds of the alpine species were 28+/-8% larger than seeds from lowland species (P > 0.01). Compared to the related lowland species, 55% of the alpine species had heavier seeds, 3% (one species) had lighter, and 41% had seeds of approximately equal weight. Secondly, we compared seed weights among populations of four species from different habitats and with different life histories. Seeds from between 11 and 34 populations per species were sampled along altitudinal gradients of 800-1,500 m (ca. 800 m in Scabiosa lucida, ca. 1,000 m in Saxifraga oppositifolia, ca. 1,000 m in Epilobium fleischeri, and ca. 1,500 m in Carex flacca). In all the four species, we found no indication for heavier seeds at higher altitudes. Our results indicate a selection pressure for species with heavier seeds at higher altitude, but the trend does not seem to operate across all cases. Phylogenetic constraints may limit the correlation among altitude and seed weight, operating particularly against selection for larger seed size, the closer populations and species are related to each other

Effects of maternal sensitivity on low birth weight children's academic achievement : a test of differential susceptibility versus diathesis stress

Background: Differential Susceptibility Theory (DST) postulates that some children are more affected – for better and for worse – by developmental experiences, including parenting, than others. Low birth weight (LBW, 1,500–2,499 g) may not only be a predictor for neurodevelopmental impairment but also a marker for prenatally programmed susceptibility. The aim was to test if effects of sensitive parenting on LBW and very LBW (VLBW, <1,500 g) versus normal birth weight (NBW, ≥2,500 g) children's academic achievement are best explained by a differential susceptibility versus diathesis-stress model of person-X-environment interaction. Methods: Nine hundred and twenty-two children ranging from 600 g to 5,140 g birth weight were studied as part of a prospective, geographically defined, longitudinal investigation of neonatal at-risk children in South Germany (Bavarian Longitudinal Study). Sensitive parenting during a structured mother–child interaction task was observed and rated at age 6 years. Academic achievement was assessed with standardized mathematic, reading, and spelling/writing tests at age 8 years. Results: Maternal sensitivity positively predicted the academic achievement of both LBW (n = 283) and VLBW (n = 202) children. Confirmatory-comparative and model-fitting analysis (testing LBW vs. NBW and VLBW vs. NBW) indicated that LBW and VLBW children were more susceptible than NBW to the adverse effects of low-sensitive, but not beneficial effects of high-sensitive parenting. Conclusions: Findings proved more consistent with the diathesis stress than differential-susceptibility model of person-X-environment interaction: LBW and VLBW children's exposure to positive parenting predicted catch-up to their NBW peers, whereas exposure to negative parenting predicted much poorer functioning

Meta-analysis reveals microevolution in grassland plant species under contrasting management

Grassland species might be under differential selection pressure due to management regimes by man or unmanaged grazers. To investigate microevolutionary changes in plants, I used a meta-analysis and a comparative approach. This analysis incorporates 28 studies on 19 species in 3 paired management regimes with a total of 152 reported trait values resulting in 40 pooled Hedge's d effect sizes on genetic, vegetative and reproductive traits as well as 83 Hedge's ds of 14 specific traits. Of the pooled and specific traits, 60 and 72% indicated divergent selection pressures within a management regime. The pooled Hedge's ds did not differ among the management regimes. Within mown versus grazed sites, trait groups were affected differently with increased reproductive traits in plants originating from grazed sites. In the other management regimes, the trait groups were affected similarly, except of some specific traits. Longevity, palatability, clonality and biome origin did not explain differences in pooled effect sizes, but tended to explain differences in some specific traits. Overall, general selection patterns were rare probably due to a high heterogeneity of among and within species responses, which might level each other out. Moreover, the number of data points per group of interest is often low and thus, for a final conclusion more studies are needed. Nonetheless, the divergent plant reactions indicate that selection pressures within paired management regimes might be large enough to induce microevolutionary changes in grasslands. Subsequently, the increased variation within species under different management techniques might buffer species persistence in the long ter

Extensive contemporary pollen-mediated gene flow in two herb species, Ranunculus bulbosus and Trifolium montanum, along an altitudinal gradient in a meadow landscape

Background and Aims Genetic connectivity between plant populations allows for exchange and dispersal of adaptive genes, which can facilitate plant population persistence particularly in rapidly changing environments. Methods Patterns of historic gene flow, flowering phenology and contemporary pollen flow were investigated in two common herbs, Ranunculus bulbosus and Trifolium montanum, along an altitudinal gradient of 1200-1800 m a.s.l. over a distance of 1 km among five alpine meadows in Switzerland. Key Results Historic gene flow was extensive, as revealed by Fst values of 0·01 and 0·007 in R. bulbosus and T. montanum, respectively, by similar levels of allelic richness among meadows and by the grouping of all individuals into one genetic cluster. Our data suggest contemporary pollen flow is not limited across altitudes in either species but is more pronounced in T. montanum, as indicated by the differential decay of among-sibships correlated paternity with increasing spatial distance. Flowering phenology among meadows was not a barrier to pollen flow in T. montanum, as the large overlap between meadow pairs was consistent with the extensive pollen flow. The smaller flowering overlap among R. bulbosus meadows might explain the slightly more limited pollen flow detected. Conclusions High levels of pollen flow among altitudes in both R. bulbosus and T. montanum should facilitate exchange of genes which may enhance adaptive responses to rapid climate chang

Drought response and changing mean sensitivity of European beech close to the dry distribution limit

European beech (Fagus sylvatica L.) covers a large area mainly in the colline and montane ranges in Europe, and a drier and warmer climate, as expected for the coming decades, is likely to alter its distribution. So far, an altitudinal shift has been projected using a variety of modelling approaches. However, we lack knowledge about the climatic and edaphic factors that control the growth and competitive behaviour of beech at its dry distribution limit. We applied and further developed dendroecological methods to study the drought response and sensitivity pattern of beech at sites with different moisture regimes. We compared three pairs of sites from different geographical regions near the dry distribution limit of beech in Switzerland, consisting of a dry and mesic site each. Radial growth differed between mesic and dry sites, in that average ring-width at mesic sites was around double the width at dry sites. For the whole study period (1930-2006), the sites with the lowest available soil water capacity (AWC) were found to respond most sensitively to drought. However, in recent years, sites with higher AWC have shown increasing drought sensitivity, i.e. they have responded even more strongly to drought than the dry sites. This change in sensitivity corresponds to a seasonal shift in drought response at mesic sites, with a change in the months showing significant drought response in all three studied regions compared with the past. Even though dry sites generally displayed a larger number of negative pointer years than mesic sites, it appears that the frequency of pointer years has increased at mesic sites, i.e. they have become more sensitive particularly in the last quarter of the twentieth century. Yet, the frequency of pointer years at the dry sites has remained fairly constant. These results indicate that beech trees near their dry distribution limit are adapted to extreme conditions already, while changes in the growth patterns of beech under mesic conditions have to be expecte