Flow cytometry provides a reliable and fast method for estimating genome size and ploidy levels in plants. Until recently, most studies employed fresh tissues that usually provide high-quality results. However, the need for fresh tissues limits the use of the method with samples from remote areas or when an extremely high number of samples needs to be processed in a short time. Although there is growing evidence that fixed silica-dried material can be used for ploidy estimation in some taxa, no flora-wide study has been available so far. Here, we provide methodological aspects of an unprecedented study exploring ploidy variation of non-apomictic angiosperms in the Eastern Alps. We have analysed ~45,000 silica-dried samples of 1,134 species using flow cytometry with DAPI as stain. Surprisingly, we were able to obtain ploidy level information from as much as 1,103 (97%) of species. The unsuccessful species included succulent plants of the family Crassulaceae (genera Jovibarba, Rhodiola, Sedum, Sempervivum), the achlorophyllous parasitic or mycoheterotrophic genera Orobanche and Hypopitys, and a handful of others. About 80% of samples were successfully analysed using a single ‘universal’ protocol and leaf tissue, while in the remaining species the use of alternative tissues (such as petioles or flowers) and/or protocol modifications were needed (targeting composition of buffers, duration of incubation or staining time or use of alternative buffers). A total of 384 species (35%) included polyploid cytotypes. Among them, 151 (14%) included diploid and polyploid cytotypes, 25 species (2%) being ploidy variable with multiple polyploid cytotypes, and 208 (19%) being polyploids with just one cytotype. The remaining 719 (65%) species were diploid only. As a community resource, we provide relative genome sizes and ploidy assignments of 1,328 cytotypes retrieved from 1,103 species along with methodological details (e.g. buffers, standards, analysed plant organs, histogram quality, and other remarks). We believe that this dataset will facilitate future research in particular species as well as in flora-wide investigations of ploidy level variation of the central-European flora in general. We are confident that novel cytotypes of many species will be discovered in other geographic areas, and we would be delighted if the present dataset could serve the botanical community for comparison.
The aim of this study was to determine the current distribution of Dittrichia graveolens along motorways in Slovakia, including adjacent sections in the Czech Republic, Austria, and Hungary, to assess to what extent the density of the species depends on the age of operation of the studied motorways, and to predict the potential distribution of the species in Slovakia for the period 2021–2040. In total, 1,440 occurrence points of the species were recorded along 419.9 km of surveyed motorways (out of 826.5 km of surveyed roads). Of the 1,157 occurrence points, the highest proportion (1,065 points) was recorded in the western part of the country, with occurrence decreasing towards the east. The generalized additive mixed model showed that the occurrence density of D. graveolens was highest on older motorway sections, specifically those constructed in the late 1970s and late 1990s, while the most recently built sections (post 2012) exhibited significantly lower invasion densities. The MaxEnt model for D. graveolens under the SSP370 scenario demonstrated robust predictive performance (AUC = 0.85, TSS = 0.61). Focusing on the primary study region, the model revealed that over 24,000 km2 in Slovakia are climatically suitable for future invasion. However, given the species’ strict concentration along immediate road edges, the actual potential area of occupancy represents 32.9 km2 (0.07% of the total national area) localized within road verges. While current occurrences are heavily concentrated in the western lowlands, our predictions indicate a significant potential for continuous eastward expansion into the central and eastern regions along the road network. The primary climatic constraint is the minimum temperature of the coldest month (Bio06), which limits the species at higher altitudes. Our findings confirm that the D. graveolens invasion in Slovakia is driven by a combination of road operational age and climatic suitability. These road verges serve as critical corridors, facilitating the species’ predicted eastward expansion into new regions.
Dry grasslands on rock outcrops in deep river valleys of the Bohemian Massif are typically small and difficult to access, forming isolated open patches surrounded by forests. Although probably partly maintained by historical low-intensity land use, these habitats have often been regarded as near-natural due to their extreme environmental conditions and long-term continuity. However, it remains unclear how strongly these habitats have responded to rapidly changing environmental conditions over recent decades. In 2020–2024, we repeated vegetation sampling conducted in the 1990s (42 semipermanent plots) to analyse long-term vegetation changes in dry grasslands in the Dyje/Thaya river valley. We revealed a decline in rare and xerophilous species, the expansion of ruderal and nutrient-demanding species, and the increased cover of dwarf shrubs and tree seedlings. These changes differed between areas located within the Podyjí/Thayatal National Park and those in less protected parts of the valley, reflecting differences in the surroundings, namely the proportion of woody vegetation, degree of anthropogenic disturbance, game management, and conservation interventions. This suggests that the state of grassland vegetation is strongly linked to the surrounding landscape conditions and the effects of conservation management. Our research provides evidence that even these environmentally extreme habitats are undergoing significant long-term vegetation changes. Shifts toward ruderalized vegetation were more pronounced at sites outside of national parks, whereas sites in national parks exhibited slower and less extensive vegetation change, likely reflecting both the establishment of strict protection and historically lower anthropogenic pressure.
Ranunculus sect. Batrachium is one of the most taxonomically challenging groups of aquatic plants. The main factors contributing to this complexity include morphological reduction, phenotypic plasticity, polyploidy and hybridization. In this study, Batrachium diversity in the Pannonian Basin was investigated for the first time using molecular methods combined with morphological evaluation, genome size measurements and chromosome counting. Across 51 sampled populations, we identified seven traditionally recognized species known from other parts of central Europe, along with several hybrids, some of which have a complex origin involving backcrossing and introgression. Remarkably, we identified four previously unrecognized non-hybrid cytotypes, two of them belonging to the Ranunculus peltatus complex and two to the Ranunculus trichophyllus complex. DNA sequences indicate that these novel cytotypes are closely related to specific Mediterranean lineages of the European Batrachium species, either as their direct descendants or through unsampled or unknown ancestors closely related to them. The Pannonian Basin hosts a more diverse array of Batrachium lineages than previously described, including elements highly similar to Mediterranean lineages that are unique within central Europe, suggesting long-distance dispersal or relict persistence.
The fifteenth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 87 taxa in the genera Asperugo, Bassia, Brunnera, Bupleurum, CoeloVentenata. These maps were produced by taxonomic experts based on examined herbarium specimens, literature and field records. The paper encompasses both native and alien taxa, representing diverse ecological groups, from terrestrial herbs inhabiting dry grasslands, ruderal sites and forests to submerged aquatic species and alien woody plants. It also continues the mapping of orchids, one of the most rapidly declining plant groups, with valuable implications for nature conservation. Almost half of the species covered are listed on the national Red List, including the critically threatened Bassia prostrata, Groenlandia densa, Potamogeton coloratus and P. praelongus, each now restricted to single sites, as well as Bupleurum affine, B. tenuissimum, Goodyera repens and Ventenata dubia, surviving only in few, isolated populations. Four species, namely Bassia laniflora, Herminium monorchis, Potamogeton compressus and P. friesii, are now nationally extinct. Among the alien taxa included, only Bassia scoparia has become invasive, while the others are mostly casual introductions or escapes. Four of the previously introduced neophytes, Bupleurum croceum, Rapistrum rugosum, Sclerolaena tricuspis and Sedobassia sedoides, are no longer recorded in the country. Particular attention is given to Cotoneaster, whose diversity has only recently been fully recognized and taxonomically evaluated, resulting in 22 distinguished escaped species. Spatial distributions and often also temporal dynamics of individual taxa are displayed in grid maps and documented by records included in the Pladias database and available in the Supplementary materials. Each map is accompanied by a commentary providing an analysis of distribution patterns, habitat descriptions, taxonomic notes and biological characteristics.
The Ranunculus trichophyllus group has a complex evolutionary history and remains taxonomically unresolved. In central Europe outside the Alps, two tetraploid cytotypes distinguished as R. trichophyllus A and B have been recognized in previous studies. Another ecologically specialized taxon, R. confervoides (R. trichophyllus subsp. eradicatus), is reported to have a disjunct distribution in northern Europe, the Alps and Pyrenees, and mountains and northern regions of Asia and North America. However, the classification of the populations outside northern Europe as R. confervoides has recently been questioned. We studied the R. trichophyllus group in 35 lakes in the Alps and five in northern Europe, involving genome size determination, sequencing the nuclear ITS region and two non-coding plastid DNA regions, and recording 10 morphological characters. The populations referred to as R. confervoides in the Alps did not substantially differ from the northern European ones morphologically, had identical genome size and shared the plastid haplotypes and ITS genotypes with them. Consequently, we consider the northern and the Alpine populations to belong to the same species R. confervoides. Interestingly, we also identified plants that combine morphological characters of R. confervoides and R. trichophyllus A, even though the latter was not found in the Alps during our study. Their status remains unclear; they may represent hybrids, but partly they can be a manifestation of morphological plasticity of these taxa. Nine plastid haplotypes were observed in R. confervoides and the “intermediate” populations, which contrasts with only two haplotypes identified in each of the two R. trichophyllus cytotypes outside the Alps.
This paper presents the first comprehensive overview of the currently known Rubus taxa of the Bohemian Forest (= Böhmerwald, Bayerischer Wald, Šumava), a mountain range located in central Europe that extends across Austria, Czechia and Germany. The study is based on a detailed field survey conducted between 2019 and 2023 and subsequent evaluation of published and database records. A total of 60 species and one hybrid of brambles are accepted for the study area. The treatment of each taxon comprises a reference to a morphological description and illustration, a description of the overall distribution, a characterization of the distribution in the study area, including a classification into regional phytochorotypes, an elevation maximum occurrence, a grid distribution map, and a list of herbarium specimens and accepted records. A total of 30 species are documented for the first time from the study area. Furthermore, the following five species are described as new to science: R. bicoloristylus, R. cammensis, R. depressinervius, R. parvidentatus and R. suavis. The morphology, drawings, photographs of holotypes and species in situ, taxonomy, ecology and overall distribution including distribution maps of these species are provided. The lectotypes of eight taxa previously described from the Bohemian Forest are designated: R. heterophyllus Utsch including its two forms, R. hirsutus J. Presl et C. Presl, R. kuenicus Utsch including its three varieties and R. plicatus f. brevispinus Tocl. A critical evaluation of the literature, databases and herbaria revealed that records of 152 taxa previously reported from the Bohemian Forest are not acceptable based on current taxonomic and chorological knowledge. The majority of these erroneous records are attributed to misidentifications, which are explained by a lack of knowledge about the variability and plasticity of individual species and the application of inappropriate taxonomic approaches. The list of unaccepted taxa, accompanied by their original localities, is provided, along with a commentary on the reasons for their rejection. From the perspective of regional biodiversity, brambles represent an essential plant group that is largely a result of regional speciation processes. This is demonstrated by the prevalence of taxa with a central European distribution pattern (44 out of 56 recorded native species). Of these, 25 are endemic to the study area and adjacent areas.
Understanding the spatial patterns and drivers of species richness is crucial for biodiversity conservation. Using data from Pladias, a comprehensive botanical database of the Czech Republic, we mapped the richness of various plant species groups across grid cells in the country and examined the effects of current environmental conditions, current landscape structure, and historical landscape development. We also applied five methods to account for uneven sampling intensity and found that only rarefaction provided estimates of species richness independent of sampling intensity. Using spatial error models and a variation partitioning approach, we showed that plant richness at the country scale is predominantly driven by current environmental conditions. For overall species richness, as well as for native and threatened species richness, the most important factors were the proportion of carbonate bedrock and the level of climate moisture, while the heat sum in the growing season was crucial for naturalized alien species richness. Historical landscape development, especially the long-term continuity of forests and grasslands, significantly influenced the richness of all, native, and particularly threatened species. Human population density was positively related to all species groups, emerging as the most important variable for the richness of naturalized alien species. However, our study shows that uneven sampling intensity in the Pladias database may distort the effect of certain environmental factors, such as the heat sum in the growing season. These findings emphasize the importance of carefully considering the uneven intensity of sampling before analysing species richness and highlight the role of current environmental variables, current landscape structure, and historical landscape development in shaping plant species richness at the regional scale.
The growing global horticultural trade has a key role in the introduction of alien plant species into new areas, partly because it also entails the unintentional dispersal of many contaminant species over large distances. However, apart from sporadic reports of such contaminant species, this phenomenon is largely understudied. In order to study this, a systematic field survey of garden centres in Hungary was carried out to assess their role in unintentionally introducing invasive alien species. Twelve garden centres were surveyed in spring, summer and autumn and all individuals of alien species recorded. In addition to the pots and containers of plants for sale, all indoor and outdoor areas, such as flowerbeds, bare and covered surfaces, cracks in the pavement, lawns and other vegetated areas were surveyed. A total of 93,788 individuals of 67 alien species were recorded, seven of which were recorded for the first time in this country. Despite their small area, the studied garden centres hosted a large percentage of the local alien flora, indicating that they strongly accumulate alien species. There were large populations of many alien species, suggesting that garden centres can act as invasion hubs. Trait differences between the alien species in the garden centres and the regional alien flora indicate that the species most successful at colonizing garden centres are both good dispersers and possess an effective resource-acquisitive strategy. Thus, populations of alien plants in garden centres may be the source of local invasions. Moreover, individuals and seeds in the containers of ornamental plants are likely to be transported to distant areas by customers. Despite the limited spatial extent of this survey, the findings indicate that the horticultural trade may act not only as a source of plant introductions, but can also potentially influence the subsequent stages of the invasion process. Thus, there is a need for further studies on the role of species contaminating horticultural stock in alien plant invasions.
Inland sand grasslands are highly threatened habitats in central Europe and the Pannonian biogeographical region. They harbour several specialized and threatened species adapted to the dry, nutrient-poor conditions of sandy soils. The area of these grasslands decreased dramatically in the 19th and 20th centuries. Many remaining patches have been included in protected areas, and their conversion to other land-use types has been limited in recent decades. However, changes in these plant communities may have occurred due to environmental changes and altered management practices. To assess temporal changes in plant diversity and species composition in sand grasslands in the Vienna Basin (Czech Republic, Slovakia and Austria), we resurveyed 86 vegetation plots in 2023–2024 that were first sampled between 1952 and 2010. We compared changes in species composition using principal coordinate analysis and distance-based redundancy analysis. We tested changes in species richness of vascular plants using a linear mixed-effect model, proportions of specialized, ruderal, threatened, alien and woody species using generalized estimating equation models, and ecological indicator values using permutation tests. We compared these changes among three main vegetation types of sand grasslands (pioneer, acidophilous and basiphilous). The results indicate that the main types of sand grasslands in the Vienna Basin have persisted over recent decades and have not been replaced by other vegetation types. However, specialized species of sand and dry grasslands, as well as species adapted to grazing, have declined. In contrast, species with higher nutrient and moisture requirements have increased. This indicates an effect of eutrophication and natural succession following the abandonment of previous management. The decline in sand specialists was most pronounced in the pioneer sand vegetation, where species with higher Ellenberg-type indicator values for temperature also decreased, indicating a transition to more closed sand grasslands. These results indicate that appropriate conservation management and future monitoring are needed to maintain the habitat quality of inland sand vegetation.
The growing global horticultural trade has a key role in the introduction of alien plant species into new areas, partly because it also entails the unintentional dispersal of many contaminant species over large distances. However, apart from sporadic reports of such contaminant species, this phenomenon is largely understudied. In order to study this, a systematic field survey of garden centres in Hungary was carried out to assess their role in unintentionally introducing invasive alien species. Twelve garden centres were surveyed in spring, summer and autumn and all individuals of alien species recorded. In addition to the pots and containers of plants for sale, all indoor and outdoor areas, such as flowerbeds, bare and covered surfaces, cracks in the pavement, lawns and other vegetated areas were surveyed. A total of 93,788 individuals of 67 alien species were recorded, seven of which were recorded for the first time in this country. Despite their small area, the studied garden centres hosted a large percentage of the local alien flora, indicating that they strongly accumulate alien species. There were large populations of many alien species, suggesting that garden centres can act as invasion hubs. Trait differences between the alien species in the garden centres and the regional alien flora indicate that the species most successful at colonizing garden centres are both good dispersers and possess an effective resource-acquisitive strategy. Thus, populations of alien plants in garden centres may be the source of local invasions. Moreover, individuals and seeds in the containers of ornamental plants are likely to be transported to distant areas by customers. Despite the limited spatial extent of this survey, the findings indicate that the horticultural trade may act not only as a source of plant introductions, but can also potentially influence the subsequent stages of the invasion process. Thus, there is a need for further studies on the role of species contaminating horticultural stock in alien plant invasions.
Hybridization and polyploidization are significant evolutionary mechanisms. Allopolyploidy, the formation of polyploids through hybridization between distinct species followed by whole-genome duplication, is common mainly in plants, where it facilitates rapid speciation and ecological diversification. Hybridization between diploid species often results in F1 hybrids with reduced fertility due to irregular meiosis. However, subsequent genome duplication can restore fertility by providing homologous chromosome pairs. Understanding the initial hybridization between diploids is therefore crucial for elucidating the early stages of allopolyploid formation. Ranunculus sect. Batrachium is known for the frequent occurrence of hybrids and polyploids, many of which are allopolyploid. Surprisingly, no unequivocal natural hybrid between diploid species has been discovered until recently in spite of the large body of evidence on interspecific hybridization in this group. This study provides evidence for hybridization at the diploid level, based on an integrated morphological, cytological and molecular approach. A new interspecific hybrid R. circinatus x R. rionii was detected in two flooded sand pits in the Czech Republic and described as R. xlimnophilus. Maternal inheritance patterns indicated independent, reciprocal origin of the hybrids at each locality. The ecological and historical context of the hybrid's emergence is discussed, including colonization of a newly formed habitat that allowed coexistence of the two parental species, their hybridization and the subsequent vegetative persistence of the hybrid despite its sterility. Similar conditions may have prevailed during the early postglacial period, facilitating the formation of allopolyploids, which today constitute the majority of species diversity in this group. A review and categorization of the biotypes that constitute the complex diversity in Ranunculus sect. Batrachium is also provided.
Inland sand grasslands are highly threatened habitats in central Europe and the Pannonian biogeographical region. They harbour several specialized and threatened species adapted to the dry, nutrient-poor conditions of sandy soils. The area of these grasslands decreased dramatically in the 19th and 20th centuries. Many remaining patches have been included in protected areas, and their conversion to other land-use types has been limited in recent decades. However, changes in these plant communities may have occurred due to environmental changes and altered management practices. To assess temporal changes in plant diversity and species composition in sand grasslands in the Vienna Basin (Czech Republic, Slovakia and Austria), we resurveyed 86 vegetation plots in 2023-2024 that were first sampled between 1952 and 2010. We compared changes in species composition using principal coordinate analysis and distance-based redundancy analysis. We tested changes in species richness of vascular plants using a linear mixed-effect model, proportions of specialized, ruderal, threatened, alien and woody species using generalized estimating equation models, and ecological indicator values using permutation tests. We compared these changes among three main vegetation types of sand grasslands (pioneer, acidophilous and basiphilous). The results indicate that the main types of sand grasslands in the Vienna Basin have persisted over recent decades and have not been replaced by other vegetation types. However, specialized species of sand and dry grasslands, as well as species adapted to grazing, have declined. In contrast, species with higher nutrient and moisture requirements have increased. This indicates an effect of eutrophication and natural succession following the abandonment of previous management. The decline in sand specialists was most pronounced in the pioneer sand vegetation, where species with higher Ellenberg-type indicator values for temperature also decreased, indicating a transition to more closed sand grasslands. These results indicate that appropriate conservation management and future monitoring are needed to maintain the habitat quality of inland sand vegetation.
Due to the widespread importance of clonality in plants, investigating the mechanisms by which clonality-related traits are associated with community organization is crucial for a functional understanding of vegetation. In this study, the patterns in clonality and other life-history traits in a series of species-rich semi-dry grasslands (alliance Bromion erecti, order Brometalia erecti, class Festuco-Brometea) in the central-European region of Slovenia, all assigned to the same EUNIS (Middle European Bromus erectus semi-dry grasslands, code R1A32) and Natura 2000 habitat type [Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia), code 6210 (important orchid sites)] were studied. The aims of this research were (i) to assess the diversity of clonal growth organs (CGOs) and other clonal traits in semi-dry grasslands and (ii) determine differences in distribution of clonal growth organs and other clonal traits in three plant communities (associations). Data from 224 vegetation plots (phytosociological relev & eacute;s) with 247 species and nine plant traits of grassland species were used. This revealed that more than half of the plant species were clonal. Most common clonal growth organs (CGOs) were perennial splitting main root (produced by non-clonal plants), epigeogenous rhizomes and hypogeogenous rhizomes. For each plot, the community weighted mean (CWM) of all plant traits was calculated to determine differences between the three grassland types. Soil moisture and productivity seem to be the key factors associated with differences in clonal growth in the associations studied. Clonal tussock plants with rhizomes, and species with a rich bud bank and a high number of clonal offspring were abundant in grasslands with deep soils and mesic conditions (Onobrychido-Brometum association). Grasslands on stony soils over fissured limestone or dolomite and with more xeric conditions were characterized by rosette clonal plants with hypogeogenous rhizomes (Bromo-Danthonietum calycinae) and/or non-clonal plants with splitting main root (Scabioso hladnikianae-Caricetum humilis). The diversity and characteristics of clonality-related traits indicate that clonal growth is an essential feature of these species-rich grasslands. Importantly, the results of this study indicate that in order to support the characteristic species and functional composition of all types of grassland, management plans for semi-dry grassland habitats in the area studied need to be carried out at a finer scale (e.g. at the level of associations) than the level of EUNIS and Natura 2000 habitat types.
Understanding the spatial patterns and drivers of species richness is crucial for biodiversity conservation. Using data from Pladias, a comprehensive botanical database of the Czech Republic, we mapped the richness of various plant species groups across grid cells in the country and examined the effects of current environmental conditions, current landscape structure, and historical landscape development. We also applied five methods to account for uneven sampling intensity and found that only rarefaction provided estimates of species richness independent of sampling intensity. Using spatial error models and a variation partitioning approach, we showed that plant richness at the country scale is predominantly driven by current environmental conditions. For overall species richness, as well as for native and threatened species richness, the most important factors were the proportion of carbonate bedrock and the level of climate moisture, while the heat sum in the growing season was crucial for naturalized alien species richness. Historical landscape development, especially the long-term continuity of forests and grasslands, significantly influenced the richness of all, native, and particularly threatened species. Human population density was positively related to all species groups, emerging as the most important variable for the richness of naturalized alien species. However, our study shows that uneven sampling intensity in the Pladias database may distort the effect of certain environmental factors, such as the heat sum in the growing season. These findings emphasize the importance of carefully considering the uneven intensity of sampling before analysing species richness and highlight the role of current environmental variables, current landscape structure, and historical landscape development in shaping plant species richness at the regional scale.
The liverwort genus Aneura (Aneuraceae) has been the focus of many studies aimed at revealing the hidden cryptic diversity within the A. pinguis complex. In the last few years, the knowledge of its genetic heterogeneity and geographical distributions of the alleged species has notably increased. Genetic markers can be used to identify distinct taxa, resulting in a greater understanding of the diversification processes in this genus. This study investigated taxa of the genus Aneura present in Slovenia and shed light on the diversity of liverworts in the south-central part of Europe. The particular aim of this work was to use molecular methods to identify cryptic taxa and compile an up-to-date reference list of Slovenian bryophyte species with notes on their ecology. Using a standardized methodology outlined in several related studies, three plastid genetic regions (matK, trnH-psbA, trnL-trnF) and the complete nuclear ITS sequence dataset were analysed for 55 Aneura samples from different geographic regions in the country. Phylogenetic position of the specimens studied was investigated using distance and maximum likelihood methods. The genus Aneura is genetically separated into roughly 20 clades corresponding to proposed cryptic species, nine of which were confirmed for Slovenia. These were the clades A, B, C, E, G, M (previously regarded as A. maxima in Europe) and A. pinguis s. str. Additionally, two new lineages for Europe were discovered and discussed. Some accessions grouped closely with a North American taxon A. sharpii and a Southeast-Asian clade, which was first discovered in Thailand, but does not have a formal name. Several previously recorded European distinct phyletic lineages were detected in clades A, B, C and E. The monophyletic status of taxon B is unclear, as sequences from A. pellioides and accessions from Thailand were grouped within the confines of clade B. Furthermore, 20 morphological traits were selected for detailed study. Results from a morphological analysis indicate that the species differ somewhat in thallus width, thallus thickness, number of cells in the central part of the thallus, length of dorsal epidermal cells, the presence of a translucent margin and some other traits in the case of specific taxa. There were, however, many overlapping features among the clades examined. Ecological preferences in terms of suitable habitat characteristics are provided, narrowing the knowledge gap between the perceived ecological niches that these taxa occupy. The present paper outlines the taxonomic diversity and distribution of the genus Aneura in Slovenia and provides suggestions for further work.
Twenty-two years after publishing the first edition of the checklist of alien vascular plants introduced to Austria after 1492 (i.e. neophytes), we present a completely revised second edition. For the update presented here, we collected, compiled and standardized data on all known neophytes in Austria with data collection ending September 2022. In addition, we provide information on the regional distribution in the federal states, invasion status, habitat affiliation, the first records, the regions of origin, pathways of introduction and spread, and impacts. The second edition of the Austrian neophyte checklist contains 1,615 taxa-1,388 species, 7 aggregates, 138 hybrids, 70 subspecies, and 12 lower infraspecific taxa distributed across 135 families. Of these taxa, 548 were newly added in the second edition, which constitutes an increase of 45% of recorded neophyte plant taxa compared to the first edition. A total of 99 taxa included in the first edition of the checklist of neophytes were removed in the edition presented here due to erroneous or doubtful records, or due to being considered native or archaeophytic. The majority of neophytes (1,180) have only casual occurrences in Austria, while 207 taxa are locally established and 226 taxa have become widely established. The habitats showing the highest numbers of neophytes were ruderal (1,420 taxa) and segetal habitats (204 taxa). The most important donor regions for neophytes in Austria are temperate Asia (761 species), followed by Europe (607), North America (389), and Africa (311). While 118 neophytes were known by 1850 in Austria, this number increased to 265 in 1900, 514 in 1950, 1,084 in 2000, and currently 1,615 taxa. Reports of newly introduced taxa show a particularly pronounced increase since the mid-20th century, as 1,056 (65%) were first found after 1950, and 496(31%) were first recorded after 2000. The most important introduction pathways into Austria are known for 1,016 taxa, with escape (912) and stowaway (118 taxa) being by far the most common pathways. In total, 73 taxa were assessed to have negative impacts in Austria. Specifically, 48 have negative impacts on biodiversity, 26 on agriculture, nine on silviculture, six on human health, three on water management and one taxon negatively impacts animal health. To conclude, the revised inventory of neophytes in Austria documents the extraordinary dynamics of neophyte accumulation and spread in a botanically well-explored country and provides a wealth of data for research and environmental management.
The Ranunculus trichophyllus group has a complex evolutionary history and remains taxonomically unresolved. In central Europe outside the Alps, two tetraploid cytotypes distinguished as R. trichophyllus A and B have been recognized in previous studies. Another ecologically specialized taxon, R. confervoides (R. trichophyllus subsp. eradicatus), is reported to have a disjunct distribution in northern Europe, the Alps and Pyrenees, and mountains and northern regions of Asia and North America. However, the classification of the populations outside northern Europe as R. confervoides has recently been questioned. We studied the R. trichophyllus group in 35 lakes in the Alps and five in northern Europe, involving genome size determination, sequencing the nuclear ITS region and two non-coding plastid DNA regions, and recording 10 morphological characters. The populations referred to as R. confervoides in the Alps did not substantially differ from the northern European ones morphologically, had identical genome size and shared the plastid haplotypes and ITS genotypes with them. Consequently, we consider the northern and the Alpine populations to belong to the same species R. confervoides. Interestingly, we also identified plants that combine morphological characters of R. confervoides and R. trichophyllus A, even though the latter was not found in the Alps during our study. Their status remains unclear; they may represent hybrids, but partly they can be a manifestation of morphological plasticity of these taxa. Nine plastid haplotypes were observed in R. confervoides and the "intermediate" populations, which contrasts with only two haplotypes identified in each of the two R. trichophyllus cytotypes outside the Alps. This surprising haplotype diversity may result from faster fixation of mutations in the Alpine populations due to prevailing isolation and clonality. Alternatively and not exclusively, this diversity may indicate higher age of the Alpine R. confervoides. Three hybrids unknown so far were recorded in lakes at the foothills of the Alps: triploid R. circinatus x R. confervoides, pentaploid hybrids of R. confervoides with an unknown species, and hybrids between R. trichophyllus B and the same unknown species. In addition, one putative allohexaploid population of R. confervoides and R. trichophyllus parentage was found. Given ecological distinctness and prevailing cleistogamy in R. confervoides, its involvement in multiple hybridizations is rather surprising. However, this species can produce open flowers when growing on exposed shores of lakes. We hypothesize that in such conditions hybridization can happen and the hybrids may survive by vegetative growth for a very long time.
This paper presents the first comprehensive overview of the currently known Rubus taxa of the Bohemian Forest (= B & ouml;hmerwald, Bayerischer Wald, & Scaron;umava), a mountain range located in central Europe that extends across Austria, Czechia and Germany. The study is based on a detailed field survey conducted between 2019 and 2023 and subsequent evaluation of published and database records. A total of 60 species and one hybrid of brambles are accepted for the study area. The treatment of each taxon comprises a reference to a morphological description and illustration, a description of the overall distribution, a characterization of the distribution in the study area, including a classification into regional phytochorotypes, an elevation maximum occurrence, a grid distribution map, and a list of herbarium specimens and accepted records. A total of 30 species are documented for the first time from the study area. Furthermore, the following five species are described as new to science: R. bicoloristylus, R. cammensis, R. depressinervius, R. parvidentatus and R. suavis. The morphology, drawings, photographs of holotypes and species in situ, taxonomy, ecology and overall distribution including distribution maps of these species are provided. The lectotypes of eight taxa previously described from the Bohemian Forest are designated: R. heterophyllus Utsch including its two forms, R. hirsutus J. Presl et C. Presl, R. kuenicus Utsch including its three varieties and R. plicatus f. brevispinus Tocl. A critical evaluation of the literature, databases and herbaria revealed that records of 152 taxa previously reported from the Bohemian Forest are not acceptable based on current taxonomic and chorological knowledge. The majority of these erroneous records are attributed to misidentifications, which are explained by a lack of knowledge about the variability and plasticity of individual species and the application of inappropriate taxonomic approaches. The list of unaccepted taxa, accompanied by their original localities, is provided, along with a commentary on the reasons for their rejection. From the perspective of regional biodiversity, brambles represent an essential plant group that is largely a result of regional speciation processes. This is demonstrated by the prevalence of taxa with a central European distribution pattern (44 out of 56 recorded native species). Of these, 25 are endemic to the study area and adjacent areas. Seven other species exhibit a suboceanic distribution pattern, while five taxa show wider Eurasian distribution ranges. Five of the recorded brambles are aliens that have escaped from cultivation. In general, the highest observed abundance of individual species and species richness is found in the lower elevations, with the greatest diversity concentrated in the north-western part of the mountain range. Several bramble species reach their maximum elevation within the area studied. Given that the principal habitat of brambles is the edges of forest roads, it can be surmised that their distribution is positively influenced by human activity (forestry).
Recent data and syntheses in central Europe have led to the development of synthetic variables for describing the successional orderings of species. In particular, the "successional optimum" (SO), developed for describing the vegetation in the Czech Republic, reflects the number of years it takes for a species to reach peak abundance after a disturbance. The aim is to combine data on a species' functional traits and Ellenberg-type indicator values, in order to identify the main plant strategies and environmental factors that predict SO. In this study, linear models with regularization techniques and robust inference methods were used to determine the traits that explain species' SO, and then an analysis of the explained variance was used to assess the relative explanatory power of each trait. In parallel, the effects of Ellenberg-type indicator values, before and after detrending the SO by traits, were determined. This revealed that five traits had the greatest and most consistent effects: therophytic life form, seed mass, flowering duration, bud bank size and leaf dry matter content. The most important Ellenberg-type indicator values predicting SO were moisture and reaction, as light and nutrient concentrations were associated with these traits. The effects of traits were generally consistent and universal in the different environmental conditions, as the interaction of traits and environment did not change inferences or result in better models. This resulted in a robustly defined strategy that relates species to their successional ordering, highlighting the importance of life forms, competitive abilities, and reproductive strategies in succession.
