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Abstracts of volume 87, 2015

Čeplová N., Lososová Z., Zelený D., Chytrý M., Danihelka J., Fajmon K., Láníková D., Preislerová Z., Řehořek V. & Tichý L. (2015): Phylogenetic diversity of central-European urban plant communities: effects of alien species and habitat types. – Preslia 87: 1–16.
Urban habitats differ in their disturbance regimes, which act as an environmental filter determining plant community species composition. This is why plant communities in different urban habitats provide a suitable model for studying the effects of disturbance on phylogenetic diversity. We explore how phylogenetic diversity varies across urban plant communities and whether the introduction of alien species changes the phylogenetic diversity of resident communities of native species. In 32 cities in central Europe and Benelux countries we studied seven types of habitats subject to different disturbance regimes. Plots of 1 ha were sampled in each habitat by recording all spontaneously occurring species of vascular plants. A phylogenetic tree was constructed for all recorded species and phylogenetic diversity based on phylogenetic distances was calculated for each plot. A null model corresponding to random distribution of species on the phylogenetic tree was used to test whether phylogenetic diversity is non-random. Phylogenetic diversity was compared between the subsets of native and alien species, further divided into archaeophytes and neophytes. Phylogenetic diversity of plant communities in all the urban habitats studied was lower than in the null model. It varied with the disturbance regime in all the species subsets (native species, archaeophytes and neophytes). Introduction of alien species reduced phylogenetic diversity of the urban plant communities studied. Archaeophytes (widespread and common species that had enough time to spread to all suitable habitats) tended to decrease phylogenetic diversity more strongly than neophytes (often rare species which are still spreading and depend on dispersal vectors). Low phylogenetic diversity of disturbed plant communities in urban habitats probably results from strong environmental filtering, which selects species from a limited number of lineages that have traits that enable them to survive in disturbed habitats.
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Strgulc Krajšek S. & Dolenc Koce J. (2015): Sexual reproduction of knotweed (Fallopia sect. Reynoutria) in Slovenia. – Preslia 87: 17–30.
Fallopia japonica and Fallopia ×bohemica are two very invasive taxa belonging to the group Fallopia sect. Reynoutria, which cause serious problems in Europe and North America. Both of these taxa and the less invasive F. sachalinensis occur in Slovenia. Their main mode of reproduction is vegetative, although some Fallopia plants in Slovenia produce large numbers of seeds. Morphological analyses of selected natural populations reveal that F. japonica plants with only male sterile flowers typically produce many seeds. Fewer seeds were produced by F. ×bohemica and F. sachalinensis plants, although they produce viable pollen. Seed germination and survival of seedlings after three years were moderate outdoors in a botanical garden. The nuclear genome size of maternal plants and their corresponding seedlings was determined using DNA image cytometry in order to detect the ploidy level and potential donors of pollen. Based on the C-values all of the maternal plants were of one of three ploidy levels, which correspond to the octoploid F. japonica var. japonica, hexaploid F. ×bohemica and tetraploid F. sachalinensis. The variability in the genome size of the seedlings is high, and the most frequent pollen donor is F. ×bohemica.
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Laube J., Ziegler K., Sparks T. H., Estrella N. & Menzel A. (2015): Tolerance of alien plant species to extreme events is comparable to that of their native relatives. – Preslia 87: 31–53.
In addition to increases in temperature and CO2, other features of climate change, such as extreme events and short-term variations in climate are thought to be important. Some evidence indicates that invasive plant species might benefit from climate change via these features. However, apart from theory-based predictions, knowledge of the tolerance of invasive species to short-term climatic stress is very limited. We investigated whether three naturalized alien plant species in central Europe, Ambrosia artemisiifolia, Hieracium aurantiacum and Lysimachia punctata perform better under stressful conditions than comparable native species. A greenhouse experiment with a fixed stress sequence of frost, drought and water logging was set up. We applied this stress treatment to two life history stages (seedling and adult plants), plants grown in monoculture (mild intraspecific competition) and in a highly competitive setting with intra- and interspecific competition. Whilst small differences in plant responses were detected the alien species overall were not more tolerant to stress. The responses of alien and native congeners/confamilials to stress in all treatments (monoculture, competition, adult, seedling) were similar, which indicates that stress thresholds are phylogenetically conserved. All species were more vulnerable to stress at the seedling stage and when subject to competition. Our data indicates that results obtained from experiments using only monocultures and one development stage are not appropriate for drawing generalizations about lethal thresholds. Moreover, rather abrupt species-specific thresholds exist, which indicates that a prediction of species responses based on just two stress levels, as is the case in most studies, is not sufficient.
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Zeisek V., Kirschner J., Štěpánek J. & Amini Rad M. (2015): Microsatellite variation, sexual reproduction and taxonomic revision of Taraxacum sect. Dioszegia: relationships at a large spatial scale. – Preslia 87: 55–85.
The coexistence of agamospermy and sexuality characterizes most of the ~60 sections of the genus Taraxacum. Section Dioszegia, comprising T. serotinum and its allies, are an exception because only sexuals are reported for all the members of this group. On the basis of the analysis of microsatellite (SSRs) variation, distribution and morphology, we addressed problems related to their mode of reproduction, among-population relationships, taxonomy and within-population variation, using samples from populations in an area extending from southern France to the European part of southern Russia and Iran. We found strong isolation by distance and deep spatio-temporal structure among populations. As a rule, outcrossing was the dominant mode of reproduction, with one notable exception: T. serotinum subsp. tomentosum (≡ T. pyrrhopappum) was autogamous and not heterozygous. This subspecies is understood as a relic of a continental migration of T. serotinum in the late glacial/early post-glacial period, which became autogamous. Taraxacum haussknechtii is relatively highly heterozygous with a high degree of connectivity among populations, whereas populations of T. serotinum subsp. serotinum show high level of inter-population variability. A taxonomic revision of sect. Dioszegia recognizes T. serotinum subsp. serotinum (including an aberrant taxon, newly described as var. iranicum), T. serotinum subsp. tomentosum and T. haussknechtii. Full synonymy was compiled and lectotypes designated for six names. A list of the herbarium material studied is given for the latter three taxa, and a distribution map is provided for T. haussknechtii.
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Těšitel J., Fibich P., de Bello F., Chytrý M. & Lepš J. (2015): Habitats and ecological niches of root-hemiparasitic plants: an assessment based on a large database of vegetation plots. – Preslia 87: 87–108.
Root hemiparasites are a specialized group of green photosynthetic plants that obtain resources from the roots of other plants. Some root hemiparasites are considered to be important keystone species in temperate grasslands while others are listed as endangered. In this study, we used vegetation- plot data from the Czech National Phytosociological Database to construct habitat suitability models for root hemiparasites occurring in the Czech Republic. These models were based on a formalized vegetation classification, species co-occurrence patterns in vegetation units and actual presence of hemiparasitic species in the database. The resulting habitat models defined as sets of suitable plots for each species were further described by a climatic gradient, community Ellenberg indicator values and the leaf-height-seed (LHS) plant ecology strategy scheme values characterizing the associated vegetation. Using the properties of each vegetation unit, descriptors of the habitat suitability models and information from experimental studies, we interpreted the habitat suitability models as axes and shapes of ecological niches of individual root-hemiparasitic species. The individual hemiparasites differed in their favoured type of vegetation but almost all types of vegetation in the Czech Republic could host some of them. Semi-natural and natural grasslands with moderate availability of mineral macronutrients and water were identified as types of vegetation with a high incidence of hemiparasites and the highest number of species of hemiparasites. High incidence but low species richness of hemiparasites was recorded in forests and scrub. In contrast, most species of root hemiparasites did not occur in extreme habitats with a high level of stress or disturbance and at nutrient-rich and moist sites dominated by fast-growing species, i.e. at sites with intense above-ground competition. This reflects the ecophysiological fundamentals of the hemiparasitic strategy, which provides efficient yet low-cost access to below-ground abiotic resources. On the one hand, this advantage diminishes at sites where primary macronutrients and soil moisture are abundant but on the other hand, exploitation of this advantage, however, requires non-extreme environmental conditions. Apart from this common pattern, individual species of hemiparasites differ in their ecological requirements, which frequently underlie their possible use as ecosystem engineers in grassland restoration or their conservation status.
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Lepší M., Lepší P., Koutecký P., Bílá J. & Vít P. (2015): Taxonomic revision of Sorbus subgenus Aria occurring in the Czech Republic. – Preslia 87: 109–162.
Results of a taxonomic revision of Sorbus subg. Aria occurring in the Czech Republic are presented in a central-European context. Flow cytometry and multivariate morphological analyses were employed to assess the taxonomic diversity within the group. Diploid, triploid and tetraploid taxa were detected. Diploids are represented by a single species, Sorbus aria, which is morphologically very variable. This extensive variability is specific to this species and separates it, among other characters, from polyploid taxa. An epitype for S. aria is designated here. In the Czech Republic, S. aria has been recorded only in southern Moravia, and published records from Bohemia relate to other polyploid taxa of the subg. Aria. Native occurrences previously recorded for S. austriaca and S. carpatica in the Czech Republic are erroneous and relate to individuals of S. aria with lobed leaves. Three new triploid species are described: S. cucullifera M. Lepší et P. Lepší from the Podyjí and Thaytal National Parks between the towns of Znojmo and Vranov nad Dyjí, and S. moravica M. Lepší et P. Lepší and S. pontis-satani M. Lepší et P. Lepší from the Moravian Karst area near the city of Brno. Tetraploid taxa include S. danubialis and two newly distinguished taxa: S. thayensis M.Lepší et P. Lepší and S. collina M. Lepší, P. Lepší et N. Meyer. Sorbus thayensis is endemic to the Podyjí and Thayatal National Parks and in a similar manner as a triploid species varies very little morphologically, which indicates that these polyploid taxa reproduce apomictically. All these new species are assumed to have originated from interbreeding between S. danubialis and S. aria. Up until now, Sorbus collina has been referred to as S. aria in the Czech Republic, as S. pannonica in Germany and as S. graeca in Austria and Hungary. Records referring to S. graeca in southern Moravia (Czech Republic) do not belong to S. collina, but are untypical individuals of S. danubialis. In the Czech Republic, S. collina occurs in central and north-western Bohemia. Sorbus danubialis is confined to central and north-western Bohemia and southern Moravia, and is taxonomically uniform. Old records of the existence of diploid individuals of S. danubialis in Bohemia are incorrect. Detailed distribution maps for all stenoendemics, photographs of the type specimens and line drawings of all polyploid species known from the Czech Republic are presented.
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Olšavská K., Šingliarová B., Kochjarová J., Labdíková Z., Škodová I., Hegedüšová K. & Janišová M. (2015): Exploring patterns of variation within the central-European Tephroseris longifolia agg.: karyological and morphological study. – Preslia 87: 163–194.
Tephroseris longifolia agg. is an intricate complex of perennial outcrossing herbaceous plants. Recently, five subspecies with rather separate distributions and different geographic patterns were assigned to the aggregate: T. longifolia subsp. longifolia, subsp. pseudocrispa and subsp. gaudinii predominate in the Eastern Alps; the distribution of subsp. brachychaeta is confined to the northern and central Apennines and subsp. moravica is endemic in the Western Carpathians. Carpathian taxon T. l. subsp. moravica is known only from nine localities in Slovakia and the Czech Republic and is treated as an endangered taxon of European importance (according to Natura 2000 network). As the taxonomy of this aggregate is not comprehensively elaborated the aim of this study was to detect variability within the Tephroseris longifolia agg. using methods of plant systematics (multivariate morphometrics of 525 individuals/33 populations based on 49 characters, DAPI flow cytometry of 98 individuals/33 populations). The relative DNA content at the homoploid level (2n ~ 6x ~ 48) varied by 25.8% and significant taxa-specific differences were confirmed among plants of T. l. subsp. pseudocrispa, subsp. gaudinii, subsp. brachychaeta and a group consisting of T. l. subsp. moravica and subsp. longifolia. The morphometric study indicated six morphotypes roughly corresponding to the previously distinguished subspecies. The exceptions were populations traditionally assigned to T. l. subsp. longifolia, for which two distinct morphotypes with different geographic origins were identified: Alpine morphotype and Pannonian morphotype. In general, the differences in DNA content and morphology argue for a classification at the species level for plants of T. l. subsp. brachychaeta, while differences among other morphotypes fit a subspecific level. Surprisingly, Pannonian populations of T. l. subsp. longifolia are morphologically closer to populations of the Western-Carpathian endemic subsp. moravica than to Alpine populations of nominate subspecies. Based on this, the taxonomic position of Pannonian morphotype and subsequently the endemic status of T. l. subsp. moravica require further study. A key for identifying the taxa and morphotypes of Tephroseris longifolia agg. in central Europe is presented.
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Paule J., Kolář F. & Dobeš C. (2015): Arctic-alpine and serpentine differentiation in polyploid Potentilla crantzii. – Preslia 87: 195–215.
The link between polyploidy and the disjunct arctic-alpine European distribution of Potentilla crantzii was studied with particular reference to the role of serpentine habitats. Flow cytometry, AFLPs and cpDNA sequencing provided insights into ploidy level variation and the genetic structure of European populations. We recorded a ploidy differentiated arctic-alpine disjunction with tetraploids limited to the central- and southern-European mountain chains and hexaploids dominating in the Subarctic. Two lowland serpentine populations in the Czech Republic and Austria exhibited contrasting genetic patterns suggesting different evolutionary histories, with the tetraploid Czech population showing a conspicuously high genetic diversity. Finally, our genetic and cytological data did not support a distinct taxonomic status for the serpentine populations that were traditionally differentiated as P. crantzii subsp. serpentini.
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Chytrý M., Dražil T., Hájek M., Kalníková V., Preislerová Z., Šibík J., Ujházy K., Axmanová I., Bernátová D., Blanár D., Dančák M., Dřevojan P., Fajmon K., Galvánek D., Hájková P., Herben T., Hrivnák R., Janeček Š., Janišová M., Jiráská Š., Kliment J., Kochjarová J., Lepš J., Leskovjanská A., Merunková K., Mládek J., Slezák M., Šeffer J., Šefferová V., Škodová I., Uhlířová J., Ujházyová M. & Vymazalová M. (2015): The most species-rich plant communities in the Czech Republic and Slovakia (with new world records). – Preslia 87: 217–278.
We provide an inventory of the sites and vegetation types in the Czech Republic and Slovakia that contain the highest numbers of vascular plant species in small areas of up to 625 m2. The highest numbers of species were recorded in semi-natural grasslands, in which we report four new world records for fine-scale species richness: 17 species of vascular plants in 0.0044 m2 in a mountain meadow in the Krkonoše Mts, 52 and 63 species in 0.25 and 0.5 m2, respectively, in the Kopanecké lúky meadows in the Slovak Paradise (Slovenský raj), and 109 species in 16 m2 in the Porážky meadows in the White Carpathians (Bílé Karpaty). The previous world record of 43 species in 0.1 m2 was equalled in the Čertoryje meadows in the White Carpathians, however, the previous record referred to shoot presence while the new record considers only the species rooted in the plot. We interpreted and corrected the data from the Czech Republic that Wilson et al. (2012) used to compile a list of world records and provide an updated list. The updated list contains five world records from the Czech Republic and two from Slovakia. The most species-rich grasslands and forests in the Czech Republic and Slovakia are concentrated in regions with base-rich soils in the Western Carpathians, especially in the flysch zone in SE Moravia and the Czech-Slovak borderland, and in limestone and volcanic areas in central Slovakia. The richest types of non-forest vegetation include semi-dry base-rich meadows (Bromion erecti and Cirsio-Brachypodion pinnati), base-rich pastures and mesic meadows (Cynosurion cristati and Arrhenatherion elatioris), Nardus stricta grasslands (Violion caninae and Nardo strictae-Agrostion tenuis) and some wet meadows and natural subalpine grasslands. A special type of species-rich herbaceous to open woodland vegetation develops as successional stages on gravel accumulations in Carpathian rivers after severe flooding. The maximum counts of vascular plant species in non-forest vegetation in the Czech Republic and Slovakia are 7 species/0.0009 m2, 11/0.0011 m2, 12/0.004 m2, 17/0.0044 m2, 23/0.01 m2, 37/0.04 m2, 43/0.1 m2, 52/0.25 m2, 63/0.5 m2, 82/1 m2, 88/4 m2, 109/16 m2, 116/25 m2, 131/49m2 and 133/100m2. While the maximum counts for plots smaller than 0.5m2 are from various regions and probably mainly depend on appropriate management, the maximum counts for plots larger than 0.5m2 are for two areas only, the south-eastern part of the White Carpathians and Kopanecké lúky meadows, suggesting the importance of regionally specific landscape processes for high species richness at such scales. Czech and Slovak forest vegetation is much poorer than grasslands, reaching maxima of 100, 109 and 118 species in plots of 100, 400 and 500 m2, which are considerably smaller than global maxima for temperate forests. Most of the species-rich sites occur on base-rich soils, in habitats with intermediate values of environmental factors, are subject to low-intensity management or natural disturbance, occur in landscapes with large areas of natural and semi-natural vegetation and probably have a long historical continuity.
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Hájek M., Jiroušek M., Navrátilová J., Horodyská E., Peterka T., Plesková Z., Navrátil J., Hájková P. & Hájek T. (2015): Changes in the moss layer of Czech fens indicate early succession triggered by nutrient enrichment. – Preslia 87: 279–301.
Temperate fens are rapidly losing their specialized species. This applies even to seemingly untouched fens, in which the moss layer in particular is undergoing rapid succession. We analysed historical and recent vegetation-plot data from fens in the agricultural landscape on the Bohemian Massif (Czech Republic) to test the hypotheses that (i) more acidicolous and/or competitively stronger species that benefit from increased nutrient availability regionally increase in frequency and in percentage cover, and (ii) these competitively stronger bryophytes have become more tolerant of high pH because of the increased nutrient supply. We worked with two datasets: a precise dataset (the most similar pairs of samples from the same fens) and a large dataset (all of the historical and recent samples from the area studied).We found that calcicolous brown mosses specialized for growing in fens have recently been retreating to places with the highest pH, being replaced by more nutrient-demanding species such as Calliergonella cuspidata, Sphagnum palustre, S. teres and Straminergon stramineum in most of rich fens. Sphagnum fallax and S. flexuosum spread only in poor fens. At the level of individual species, the intensity of change in species abundance (cover-weighted frequency change) correlated significantly with the median potassium concentration in the biomass of species based on a large set of recent data. We conclude that nature conservancy authorities should monitor changes in the species composition of the moss layer as this may signal the initial phase of nutrient enrichment of seemingly intact fens in agricultural landscapes.
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Király G., Trávníček B. & Žíla V. (2015): Taxonomic revision of Rubus ser. Pallidi in Hungary and adjacent regions. – Preslia 87: 303–318.
The apomictic taxa of section Rubus, subsection Hiemales E. H. L. Krause, series Pallidi W. C. R. Watson occurring in Hungary and adjacent regions are herein revised based on comprehensive field studies and herbarium revisions. The standard batological literature did not previously confirm the occurrence of this series in the region. However, the revision revealed that a formerly overlooked taxon grows in Hungary, which is described herein as a new species under the name Rubus saladiensis. In addition, we placed another regional species, R. brunneri, which was formerly included in ser. Vestiti, in ser. Pallidi. We present diagnostic features, drawings and photographs of both species plus characteristics of their habitats, distribution maps and lists of the specimens revised. Rubus saladiensis occurs in Illyrian Aremonio-Fagion forest communities in the Zala Hills (SW Hungary). Rubus brunneri is typically found in the region with beech forests and scattered acidic Scots pine-oak stands in the border region of Austria, Hungary and Slovenia. The presence of other taxa from this series reported in the region was not confirmed by herbarium vouchers so these records are treated as misinterpretations. The ranges of both R. brunneri and R. saladiensis have distinct sub-Atlantic characteristics in the Pannonian Basin. The climate in their distribution area (hills along the Rába and Mura rivers in the south-western part of the basin) is humid, precipitation-rich and similar in many aspects to that in the western foothills of the Alps. We demonstrate that the occurrence of the ser. Pallidi in the Pannonian Basin is of geobotanical importance and the species presented here have a distribution in the region unlike that of other series in the subgenus Rubus.
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Molnár V. A., Sonkoly J., Lovas-Kiss Á., Fekete R., Takács A., Somlyay L. & Török P. (2015): Seed of the threatened annual legume, Astragalus contortuplicatus, can survive over 130 years of dry storage. – Preslia 87: 319–328.
Long-term seed viability is of crucial importance for short-lived species, since persistent seed banks can buffer the fluctuations in the establishment of plants from year to year. Temporarily flooded habitats are an unpredictable environment for plants, and for some species the only chance they have of surviving is the formation of persistent seed banks. Astragalus contortuplicatus is an annual species of periodically flooded habitats and is considered an endangered species in Hungary. Altogether 1993 seeds of this species were tested in a germination experiment: 1200 were freshly harvested and 793 were collected from herbarium specimens of various ages. Seed viability was tested using the germination method. The freshly harvested seeds were used for selecting the best out of seven frequently used dormancy-breaking methods for this species. The highest percentage of germination was recorded for the combined treatment of scarification and light. Thus, this method was used to test the viability of the seeds collected from herbarium specimens. The oldest seeds that germinated were 131 years old. Until now there are no records of seeds of herbaceous legumes germinating that are more than 100 years old. This record is the 9th oldest of all the literature records of viable seeds originating from biological collections. All the seeds that germinated developed into healthy, fertile plants, the seeds of which also readily germinated. Fitted linear regression showed a significant negative relationship between seed age and percentage germination. Based on this linear regression the calculated theoretical maximum viability is 309 years. Our results suggest that seeds of A. contortuplicatus stored in collections can be successfully used in this species’ reintroduction for conservation purpose, to areas in which the plants were collected.
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Vítová J., Vít P. & Suda J. (2015): Rare occurrence of reciprocal hybridization in a sympatric population of the Czech stenoendemic Dianthus arenarius subsp. bohemicus and widespread D. carthusianorum. – Preslia 87: 329–345.
Hybridization between rare and common plant congeners can pose a serious threat to the rare species through gene swamping, production of hybrid seed at the expense of conspecific seed and/or hybrid competition for abiotic or biotic resources. Assessing the frequency and dynamics of interspecific hybridization is therefore of paramount importance for conservation purposes. Here we investigate, using DNA flow cytometry, multivariate morphometrics and chloroplast DNA sequencing, the frequency and direction of interspecific hybridization between the critically endangered Czech endemic psammophyte Dianthus arenarius subsp. bohemicus and its sympatric congener D. carthusianorum (Caryophyllaceae) in a single population in central Bohemia. Flow cytometry allowed unambiguous identification of both parental species, based on differences in the amounts of nuclear DNA and revealed a few individuals (< 1.1% of the samples analysed) with intermediate genome sizes that corresponded to F1 hybrids. Clear discontinuities in estimated genome sizes and a low variation within recognized taxonomic groups make backcrossing to parental species or introgression unlikely. Interspecific hybrids were considerably less fertile, producing largely aborted pollen grains and no seed. Analysis of chloroplast haplotypes provided evidence for reciprocal hybridization (both species served as maternal and paternal parents). Length of the lowermost pair of cauline leaves, calyx length and petal length (incl. separate lengths of petal claw and petal limb) were taxonomically the most informative characters, allowing reliable identification of both parental species and their hybrids. The results indicate that interspecific hybridization has only a minor effect on the genetic integrity of the endemic D. arenarius subsp. bohemicus in its last remaining natural population. Nonetheless, we recommend periodic monitoring especially as the recent controlled large-scale disturbances (mechanical removal of the vegetation cover) in the locality may promote the establishment of interspecific crosses.
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Kelemen A., Lazzaro L., Besnyői V., Albert Á.-J., Konečná M., Dobay G., Memelink I., Adamec V., Götzenberger L., de Bello F., Le Bagousse-Pinguet Y. & Lepš J. (2015): Net outcome of competition and facilitation in a wet meadow changes with plant’s life stage and community productivity. – Preslia 87: 347–361.
Positive and negative plant-plant interactions generally co-occur in communities but their relative importance should depend on site productivity; the importance of facilitation is expected to increase and that of competition to decrease with the adversity of the environment. Moreover the effect of surrounding vegetation on an individual’s performance can vary depending on the individual’s life stage and on the variables used to characterize an individual’s performance. To test these theories, we established a transplant experiment in a wet meadow in order to assess the effects of surrounding vegetation on individual plants under varying environmental conditions and changes in these effects during an individual’s development within one growing season. We asked whether (i) the net effects of plant interactions differ with differences in productivity and disturbance, and (ii) the net effects of interactions differ according to life stage, species and the performance measure used. We utilized a long-term experiment with three treatments (application of fertilizer, mowing and removal of the dominant species) in a full factorial design, yielding eight combinations, with three replicate plots per combination. In each plot four individuals of three species (Lysimachia vulgaris, Prunella vulgaris and Plantago lanceolata) were transplanted, two into gaps and two into intact vegetation. Survival (alive/dead) of each individual was recorded twice during the season. The presence of flowers and above- and below-ground biomass were recorded at the end of the transplant experiment. The survival of transplants early in the season was higher when growing among vegetation, indicating that at an early stage in its life the net effect of the surrounding vegetation was positive. At later stages, competition became more important and had a negative effect on biomass production and plant reproduction. This negative effect was more pronounced in fertilized plots while the effect of mowing and removal of dominant species on plant interactions was generally negligible. Our results indicate, particularly under more productive conditions, the importance of changes in the net outcome of plant interactions during different life stages, highlighting the dynamic nature of positive and negative interactions within a community.
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Kolář F., Kaplan Z., Suda J. & Štech M. (2015): Populations of Knautia in ecologically distinct refugia on the Hercynian massif belong to two endemic species. – Preslia 87: 363–386.
Comprehensive taxonomic studies in which a combination of molecular, cytogenetic, morphological and ecological approaches are used have resulted in remarkable discoveries even in well-known floras. In particular, recognition of new local endemics has important implications for conservation and management of plant diversity. Due to Quaternary climatic oscillations, the vascular flora of the Czech Republic only includes a few endemic taxa, usually microspecies with an apomictic mode of reproduction. Here we re-evaluate the taxonomy of Knautia arvensis, an intricate eco-geographically differentiated diploid-polyploid complex, and identify two new sexual species endemic to central Europe, which were previously included in the polymorphic K. arvensis. While K. serpentinicola Smejkal ex Kolář, Z. Kaplan, J. Suda et Štech is a diploid and tetraploid species restricted to four isolated serpentine areas in the Czech Republic and Germany, diploid K. pseudolongifolia (Szabó) Żmuda is known from a single subalpine site in the Krkonoše Mts. Our investigation of 38 populations of K. arvensis s. str. and the two newly recognized species sampled across eastern central Europe revealed a distinct yet incomplete (i.e. confounded by phenotypic plasticity) morphological differences between the three species. These results together with available data on cytological (distinct nuclear genome size), genetic (independent evolutionary histories) and ecological (distinct ecological preferences) variation support an independent taxonomic status for the newly described species. Our study highlights the importance of ecologically stable habitats where plant competition is not severe (Holocene refugia) for preserving unique plant diversity. In addition, it demonstrates the value of multi-disciplinary taxonomic research even in botanically well-known areas.
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Táborská M., Přívětivý T., Vrška T. & Ódor P. (2015): Bryophytes associated with two tree species and different stages of decay in a natural fir-beech mixed forest in the Czech Republic. – Preslia 87: 387–401.
Species richness and composition of bryophyte communities on two species of trees at different stages of decay were studied on 57 logs of Abies alba and Fagus sylvatica in the natural montane beech-fir forest reserve Salajka (Czech Republic). There were 68 species of bryophytes. At the stand level, the species richness recorded on Fagus was higher than that on Abies. This is due to a higher diversity of epiphytic species on Fagus in the early stages of decay, when the conditions of logs are more heterogeneous and there are more microhabitats than on Abies. The log-level species richness was higher on Abies in later stages of decay because it is more favourable for epixylic species occurring on very acid and constantly moist substrates. Both at the stand- and log level, the highest species richness was recorded at intermediate stages of decay, which constitute a transitional phase in the decay succession in which species associated with all stages of decay overlap and therefore the overall number is relatively high. Species composition differed significantly on the two trees, with two clearly defined groups of indicator species. In contrast, the different stages of decay were not so sharply distinguished in terms of indicator species. We also found significant differences in pH both between the two trees and stages of decay, which may also affect compositional patterns on the logs studied. In conclusion, the species richness and composition of bryophytes on dead wood is associated with both stage of decay and species of tree and their various combinations, which further increase the total diversity. Therefore, successful bryophyte conservation should be focused on the preservation of mixed stands and the continuity of dead wood in the montane beech-fir zone of Europe.
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Procházková K., Němcová Y. & Neustupa J. (2015): A new species Jenufa aeroterrestrica (Chlorophyceae incertae sedis, Viridiplantae), described from Europe. – Preslia 87: 403–416.
The chlorophycean genus Jenufa includes chlorelloid green microalgae with an irregularly spherical cell outline and a parietal perforated chloroplast with numerous lobes. Two species of the genus are known from tropical microhabitats. However, sequences recently obtained from various temperate subaerial biofilms indicate that members of the Jenufa lineage do not only occur in the tropics. In this paper, we describe and characterize a new species of the genus Jenufa, J. aeroterrestrica, which was identified in five samples of corticolous microalgal biofilms collected in Europe. These strains shared the general morphological and ultrastructural features of the genus Jenufa, but differed in having a larger average cell size and higher numbers of autospores. Phylogenetic analyses showed that the strains clustered in a sister position to two previously described tropical species, together with previously published European 18S rDNA sequences. This pattern was also supported by the ITS2 rDNA sequences of the genus Jenufa. Our data and previously published sequences indicate that the newly described species J. aeroterrestrica frequently occurs in temperate and sub-Mediterranean European subaerial biofilms, such as those occurring on tree bark or surfaces of stone buildings.
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Kaplan Z., Danihelka J., Štěpánková J., Bureš P., Zázvorka J., Hroudová Z., Ducháček M., Grulich V., Řepka R., Dančák M., Prančl J., Šumberová K., Wild J. & Trávníček B. (2015): Distributions of vascular plants in the Czech Republic. Part 1. – Preslia 87: 417–500.
Despite a long history of botanical research on the Czech flora and the large amount of data on plant distribution that has been collected, there is still no comprehensive piece of work with distribution maps in this country and no distribution maps are available for more than a half of plant taxa. This paper is the first part of a series of publications prepared within the PLADIAS project, intended as the first step towards a complete atlas of the distribution of both native and alien vascular plants in the Czech Republic. It contains grid distribution maps of 75 taxa of the genera Achillea, Aegilops, Aira, Alopecurus, Avena, Bolboschoenus, Carex, Cladium, Elatine, Eleocharis, Eriophorum, Glyceria, Polypogon, Sclerochloa, Scheuchzeria, Sparganium, Tofieldia, Tragus and Viola. The maps are based on all available herbarium, literature and field records, which were stored at the CzechDistrib database, checked geographically and evaluated taxonomically, and shown in maps using the Central European mapping grid template derived from quadrants of 5 × 3 arc minutes (corresponding to approximately 5.5 × 5.9 km). Many of these maps resulted from detailed revisions carried out during the work on the Flora of the Czech Republic. Maps of taxonomically difficult groups are based solely or mainly on herbarium specimens revised by taxonomic experts. If useful, recent versus old records, native versus alien occurrences, or records based on revised herbarium specimens versus all other records are distinguished using different symbols. Records used for producing maps are listed in electronic appendices. The maps are accompanied by texts that include an outline of general distribution, information on habitats and specific details on the distribution in the country. Where appropriate, comments on taxonomy, biology or spatial and temporal dynamics in distribution are given.
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