At a microscopic scale, the shape and fine cell relief of the petal epidermal cells of a flower play a key role in its interaction with pollinators. In particular, conical shaped petal epidermal cells have been shown to have an important function in providing grip on the surface of bee-pollinated flowers and can influence bee visitation rates. Previous studies have explored interspecific variation in this trait within genera and families, but naturally-occurring intraspecific variation has not yet been comprehensively studied. Here, we investigate petal epidermal cell morphology in 32 genotypes of the crop , which has a yield highly dependent on pollinators. We hypothesise that conical cells may have been lost in some genotypes as a consequence of selective sweeps or genetic drift during breeding programmes. We find that 13% of our lines have a distribution of conical petal epidermal cells that deviates from that normally seen in flowers. These abnormal phenotypes were specific to the ad/abaxial side of petals, suggesting that these changes are the result of altered gene expression patterns rather than loss of gene function.

is a representative of threatened ephemeral wetland plant communities in summer-dry shoreline habitats. We compared variation and plasticity in traits related to fitness and growth of plants germinating from the soil seed bank and established plants from river and secondary anthropogenic habitats. Plants from sites at rivers, fishponds and fish storage ponds were cultivated and selfed to get homogenous seed material for a germination and an environmental manipulation experiment involving three different water regimes. Differences in traits and their plasticities were evaluated by means of linear mixed models. followed a low-oxygen escape strategy when flooded. Seeds of plants derived from the soil seed bank germinated faster than seeds of plants derived from established plants suggesting that short-term selection of genotypes is mediated by the particular conditions on the site during germination. The experiment revealed significant differences between river and secondary habitats as well as between the soil seed bank and established plants. For example, plants from river habitats produced the highest number of culms with inflorescences. The difference was most evident under partial submergence. Plants from fish storage ponds rapidly reached the reproductive phase, but produced less culms with inflorescences. This seemingly allows them to cope with numerous and irregular disturbances and intensive substrate moisture changes. Our results suggest that populations have adapted to conditions at secondary habitats provided by fish farming during the last centuries.

Grazing is an important management action to conserve biodiversity in semi-natural grasslands but it is important to understand how grazing influences the life-history components and population dynamics of plant species. In this study, we analysed effects of grazing intensity and abandonment on population dynamics of the semi-natural grassland species which is an important nectar source for pollinating species and an indicator of biodiversity in agricultural landscapes. We recorded life-history stage, survival, establishment of seedlings and ramets, number of inflorescences and grazing marks on permanently marked individuals in eight populations in mid-Norway for three consecutive years. Matrix modelling was used to estimate population growth rates and elasticities, and life Table response experiments (LTREs) were used to assess the contribution of different life-history components to the observed variation in population growth rates between different management treatments. Generalized linear mixed effects models (GLMMs) were used to investigate the effect of management on vital rates and number of inflorescences as well as damage to individuals. Populations in abandoned grasslands had more inflorescences, a lower proportion of seedlings and a higher proportion of flowering ramets compared to populations in grasslands under high grazing intensity. There were no differences in population growth rates between different grazing intensities. Fecundity however, contributed more to the growth rate in grazed grasslands compared to abandoned grasslands where clonal regeneration contributed the most. Survival of non-flowering rosettes made the largest impact to overall growth rates. Our results indicate that a long life-span and clonal growth buffer the effect of environmental change in abandoned grasslands and that there is a trade-off between fertility and clonal regeneration in populations.

Canopy transpiration () of a 150-year old L. stand in an inner alpine dry valley, Tyrol, Austria was estimated throughout two growing seasons 2011 and 2012 by means of xylem sap flow measurements. Although there were prolonged periods of limited soil water availability did not show a clear trend with respect to soil water availability and averaged 0.4 ± 0.19 mm day under conditions of non-limiting soil water availability and 0.37 ± 0.17 mm day when soil water availability was limited. This is because canopy conductance declined significantly with increasing evaporative demand and thus significantly reduced tree water loss. The growing season total of was 74 mm and 88 mm in 2011 and 2012, respectively, which is significantly below the values estimated for other forest ecosystems in Central Europe, and thus reflecting a strong adaptation to soil drought during periods of high evaporative.

Plant phenological events are influenced by climate factors such as temperature and rainfall. To evaluate phenological responses to water availability in a Spring Heath-Pine wood (Erico-Pinetum typicum), the focus of this study was to determine intra-annual dynamics of apical and lateral growth of co-occurring early successional and and late successional exposed to drought. The effect of reduced plant water availability on growth phenology was investigated by conducting a rainfall exclusion experiment. Timing of key phenological dates (onset, maximum rate, end, duration) of growth processes were compared among species at the rain-sheltered and control plot during 2011 and 2012. Shoot and needle elongation were monitored on lateral branches in the canopy at . 16 m height and radial growth was recorded by automatic dendrometers at . 1.3 m height of > 120 yr old trees. Different sequences in aboveground growth phenology were detected among the three species under the same growing conditions. While onset of radial growth in April through early May was considerably preceded by onset of needle growth in (5 - 6 weeks) and shoot growth in (. 3 weeks), it occurred quite simultaneously with onset of shoot growth in . Low water availability had a minor impact on onset of aboveground growth, which is related to utilization of stored water, but caused premature cessation of aboveground growth. At the control plot mean growing season length was 130 days in , 95 days in and 73 days in supporting the hypothesis that early successional species are resource expenders, while late successional species are more efficient in utilizing resources and develop safer life strategies. High synchronicity found in culmination of radial growth in late spring (mid-May through early June) prior to occurrence of more favourable environmental conditions in summer might indicate sink competition for carbohydrates to belowground organs. This is supported by completion of apical growth in mid June in all species, except for needle growth of , which lasted until early August. Phenological observations of conifers exposed to drought revealed that tree water status early during the growing season determines total annual aboveground growth and besides temperature, species-specific endogenous and/or environmental factors (most likely photoperiod and/or different threshold temperatures) are involved in controlling apical and lateral growth resumption after winter dormancy.

In alpine species the classification of the various mechanisms underlying seed dormancy has been rather questionable and controversial. Thus, we investigated 28 alpine species to evaluate the prevailing types of dormancy. Embryo type and water impermeability of seed coats gave an indication of the potential seed dormancy class. To ascertain the actual dormancy class and level, we performed germination experiments comparing the behavior of seeds without storage, after cold-dry storage, after cold-wet storage, and scarification. We also tested the light requirement for germination in some species. Germination behavior was characterized using the final germination percentage and the mean germination time. Considering the effects of the pretreatments, a refined classification of the prevailing dormancy types was constructed based on the results of our pretreatments. Only two out of the 28 species that we evaluated had predominantly non-dormant seeds. Physiological dormancy was prevalent in 20 species, with deep physiological dormancy being the most abundant, followed by non-deep and intermediate physiological dormancy. Seeds of four species with underdeveloped embryos were assigned to the morphophysiologial dormancy class. An impermeable seed coat was identified in two species, with no additional physiological germination block. We defined these species as having physical dormancy. Light promoted the germination of seeds without storage in all but one species with physiological dormancy. In species with physical dormancy, light responses were of minor importance. We discuss our new classification in the context of former germination studies and draw implications for the timing of germination in the field.