European Flora Research Articles

Trees growing in Eastern North America experience higher autumn solar irradiation than their European relatives, but is nitrogen limitation another factor explaining anthocyanin-red autumn leaves?: A comment on Peña-Novas and Marchetti 2021 (https://doi.org/10.1111/jeb.13903).

Trees growing at a particular latitude in Eastern North America (ENA) receive more autumn solar irradiation than do trees growing at the same latitude in Europe, a difference that could partly explain the higher percentage of anthocyanin-producing deciduous species in ENA compared with European floras. A proposed link between autumn light intensity and the production of anthocyanins is their function in photoprotection, which enables plants with red leaves to resorb nutrients for a longer time than can yellow or brown leaves. The innately 4-week-shorter foliage period of ENA trees compared with European ones may also play a role, as may stronger nitrogen limitation in poorer soils in ENA. We here test for a correlation between nitrogen access and fall anthocyanin in 126species (55genera, 22 families) from different temperate forests, using a Hierarchical Bayesian model and accounting for phylogenetic structure in the data. None of 81species with nitrogen-fixing symbionts produce autumn anthocyanin, whereas 42% of non-nitrogen-fixers do. Thus, when ample nitrogen is available from symbionts, the benefits of anthocyanin-derived photoprotection apparently do not outweigh the costs of anthocyanin production. If nitrogen limitation indeed plays a role in the dominance of red-autumn-colouring trees in ENA floras - while European floras predominantly produce yellow autumn leaves - there might also be continental differences in the frequency or abundance of nitrogen-fixing trees and shrubs, a new hypothesis that deserves testing.

Introduction and adaptation of an emerging pathogen to olive trees in Italy.

The invasive plant pathogen Xylella fastidiosa currently threatens European flora through the loss of economically and culturally important host plants. This emerging vector-borne bacterium, native to the Americas, causes several important diseases in a wide range of plants including crops, ornamentals, and trees. Previously absent from Europe, and considered a quarantine pathogen, X. fastidiosa was first detected in Apulia, Italy in 2013 associated with a devastating disease of olive trees (Olive Quick Decline Syndrome, OQDS). OQDS has led to significant economic, environmental, cultural, as well as political crises. Although the biology of X. fastidiosa diseases have been studied for over a century, there is still no information on the determinants of specificity between bacterial genotypes and host plant species, which is particularly relevant today as X. fastidiosa is expanding in the naive European landscape. We analysed the genomes of 79 X . fastidiosa samples from diseased olive trees across the affected area in Italy as well as genomes of the most genetically closely related strains from Central America. We provided insights into the ecological and evolutionary emergence of this pathogen in Italy. We first showed that the outbreak in Apulia is due to a single introduction from Central America that we estimated to have occurred in 2008 [95 % HPD: 1930–2016]. By using a combination of population genomic approaches and evolutionary genomics methods, we further identified a short list of genes that could play a major role in the adaptation of X. fastidiosa to this new environment. We finally provided experimental evidence for the adaptation of the strain to this new environment.

(2851) Proposal to reject the name Senecio nebrodensis (Asteraceae)

(2851) Proposal to reject the name <i>Senecio nebrodensis</i> (<i>Asteraceae</i>)

Species introductions through coconut fibre: Dactyloctenium aegyptium and Glinus oppositifolius, new records for the Balearic Islands, Spain

Based on plant material collected in the forest nursery of the Balearic Island Forestry Center (CEFOR) for autochthonous plant production and the University of the Balearic Islands experimental facilities, two new plant records are presented for the Mediterranean island of Mallorca. Dactyloctenium aegyptium, an invasive grass previously recorded in other areas of the Mediterranean basin, and Glinus oppositifolius, a new record for the European flora. In both cases the species are presumed to have arrived through contaminated batches of the coconut fibre substrate used in both facilities.

Combining current knowledge of Cypripedium calceolus with a new analysis of genetic variation in Italian populations to provide guidelines for conservation actions

AbstractThe split between conservation science and real‐world application is an ongoing issue despite several calls for unification. Researchers are empowered to partially bridge the research‐implementation gap by making their findings more accessible. Cypripedium calceolus is the most recognizable orchid of the European flora, and is currently facing habitat change and fragmentation, in addition to threats from collectors and illegal traders. Although several studies have focused on the ecological and genetic features of the species, a comprehensive account of how such aspects can be translated into concrete conservation recommendations is still missing. In this study, we describe microsatellite genetic variation in 188 individuals from different Italian populations of C. calceolus. Our results indicate the need for immediate conservation action for the most isolated populations in the Central Apennines and north‐western Italy. Although our genetic findings are specific to the Italian populations, our aim is to review ecological and population genetic aspects in C. calceolus and their implications for conservation against the existing threats. Therefore, our detailed guidelines for translocation, habitat management and post‐translocation monitoring can be used to inform conservation strategies in threatened populations of C. calceolus across its range.

Integrating palaeo- and archaeobotanical data for a synthesis of the Italian fossil record of Lycopus (Lamiaceae, Mentheae)

Lycopus is a widespread herbaceous plant, currently part of European flora. Fossil remains of fruits (nutlets or mericarps) attributed to this genus are frequently found in European archaeological and palaeontological sites, being easily preserved in sedimentary deposits. In a worldwide context, the oldest fossils are from the early Oligocene (ca. 30 Ma) of West Siberia, but they become more common in Miocene (23.0–5.3 Ma) records, ranging from West Siberia to Central Europe. In the literature, the Oligocene and Miocene remains (plus a few Pliocene ones) were assigned to fossil-species, whereas the abundant Pliocene and Pleistocene occurrences (5–0.01 Ma) in Europe were mainly assigned to the extant species L. europaeus. The present work is conceived as the result of an ad hoc research team whose task was to revise and summarize the Italian fossil record of Lycopus, assembling palaeobotanical and archaeobotanical data. We herein report ca. 6000 Lycopus nutlets from 61 sites located in nine regions of Northern and Central Italy. Based on the available information on extant species, we detected nine morphological types of nutlets that can be used for the characterisation of fossils. Our analysis suggests that from 4 to 2.6 Ma a single taxon (L. cf. pliocenicus) with L. americanus-type of nutlets occurred in Italy. The first occurrence of the latter morphological type is from the early Oligocene of West Siberia. The available fossils mildly suggest that extant L. americanus could be the descendant of ancient Eurasian plants characterised by the L. americanus-type of nutlets, through expansion of their range to North America. Conversely, the abundant Italian records of the last 0.2 Ma, including remains from archaeological sites, are only referable to the Eurasian species L. europaeus.

Climate and socio‐economic factors explain differences between observed and expected naturalization patterns of European plants around the world

AbstractAimThe number of naturalized (i.e. established) alien species has increased rapidly over recent centuries. Given the differences in environmental tolerances among species, little is known about what factors determine the extent to which the observed size of the naturalized range of a species and hence the extent to which the observed richness of naturalized species of a region approach their full potential. Here, we asked which region‐ and species‐specific characteristics explain differences between observed and expected naturalizations.LocationGlobal.Time periodPresent.Major taxa studiedVascular plants.MethodsWe determined the observed naturalized distribution outside Europe for 1,485 species endemic to Europe using the Global Naturalized Alien Flora (GloNAF) database and their expected distributions outside Europe using species distribution models. First, we investigated which of seven socio‐economic factors related to introduction pathways, anthropogenic pressures and inventory effort best explained the differences between observed and expected naturalized European floras. Second, we examined whether distributional features, economic use and functional traits explain the extent to which species have filled their expected ranges outside Europe.ResultsIn terms of suitable area, more than 95% of expected naturalizations of European plants were not yet observed. Species were naturalized in only 4.2% of their suitable regions outside of Europe (range filling) and in 0.4% of their unsuitable regions (range expansion). Anthropogenic habitat disturbance primarily explained the difference between observed and expected naturalized European floras, as did the number of treaties relevant to invasive species. Species of ornamental and economic value and with large specific leaf area performed better at filling and expanding beyond their expected range.Main conclusionsThe naturalization of alien plant species is explained by climate matching but also by the regional level of human development, the introduction pressure associated with the ornamental and economic values of the species and their adaptation to disturbed environments.

Assessing the Impact of the Habitats Directive: A Case Study of Europe’s Plants

Abstract The Habitats Directive will remain central to the EU’s continuing efforts to halt and ultimately reverse biodiversity loss under its 2030 Strategy for Biodiversity. Understanding the role this Directive plays in protecting European species is, therefore, critical if the EU is to deliver on its ambitious nature conservation agenda. This article presents a new study that furthers our understanding of EU law’s ability to deliver meaningful changes to a species’ conservation status by comparing the status of European plants that are protected under the Habitats Directive with those that are not, using the International Union for Conservation of Nature’s (IUCN) Red List. Its findings suggest that the Directive has had only a limited impact on European flora. The article concludes by proposing reforms that could address the shortcomings in the EU’s approach to conservation which are highlighted by the study.

(2810) Proposal to reject the name Thymus marschallianus (Lamiaceae)

(2810) Proposal to reject the name <scp><i>Thymus marschallianus</i></scp> (<i>Lamiaceae</i>)

New Eocene fossil fruits and leaves of Menispermaceae from the central Tibetan Plateau and their biogeographic implications

AbstractMenispermaceae are a pantropical and temperate family with an extensive fossil record during the Paleogene period, especially in North America and Europe, but with much less evidence from Asia. The latest fossil evidence indicates a succession of tropical to subtropical flora on the central Tibetan Plateau during the Paleogene. However, the biogeographic histories of these floras are still unresolved. Here, we report on endocarps and leaves of Menispermaceae from the Middle Eocene of Jianglang village, Bangor County, central Tibetan Plateau. The endocarps belong to two genera: Stephania, which is characterized by a horseshoe‐shaped endocarp and with one lateral crest ornamented by spiny to rectangular ribs, and a condyle area; and Cissampelos (s.l.), which has two characteristic lateral ridges and a conspicuous external condyle. Associated leaves belong to the genus Menispermites, and are characterized by actinodromous primary venation, brochidodromous secondary veins, entire margins, and the presence of marginal secondary veins. The biogeographic history of Menispermaceae is complex, but evidence from these new fossils indicates an early diversification of the group in Asia, probably in response to the warming climate during the Eocene. The Jianglang flora appears to be part of a boreotropical flora, connecting Asia with North American and European floras during the Middle Eocene. The modern distribution of menispermaceous taxa found in Jianglang, as well as other families represented in the Jianglang flora, show that a tropical to subtropical climate occurred during the Eocene in central Tibet.

The effects of drift and selection on latitudinal genetic variation in Scandinavian common toads (Bufo bufo) following postglacial recolonisation

Clinal variation is paramount for understanding the factors shaping genetic diversity in space and time. During the last glacial maximum, northern Europe was covered by glacial ice that rendered the region uninhabitable for most taxa. Different evolutionary processes during and after the recolonisation of this area from different glacial refugia have affected the genetic landscape of the present day European flora and fauna. In this study, we focus on the common toad (Bufo bufo) in Sweden and present evidence suggesting that these processes have resulted in two separate lineages of common toad, which colonised Sweden from two directions. Using ddRAD sequencing data for demographic modelling, structure analyses, and analysis of molecular variance (AMOVA), we provide evidence of a contact zone located between Uppland and Västerbotten in central Sweden. Genetic diversity was significantly higher in southern Sweden compared to the north, in accordance with a pattern of decreased genetic diversity with increasing distance from glacial refugia. Candidate genes under putative selection are identified through outlier detection and gene–environment association methods. We provide evidence of divergent selection related to stress response and developmental processes in these candidate genes. The colonisation of Sweden by two separate lineages may have implications for how future conservation efforts should be directed by identifying management units and putative local adaptations.

Influence of climate, soil, and land cover on plant species distribution in the European Alps

AbstractAlthough the importance of edaphic factors and habitat structure for plant growth and survival is known, both are often neglected in favor of climatic drivers when investigating the spatial patterns of plant species and diversity. Yet, especially in mountain ecosystems with complex topography, missing edaphic and habitat components may be detrimental for a sound understanding of biodiversity distribution. Here, we compare the relative importance of climate, soil and land cover variables when predicting the distributions of 2,616 vascular plant species in the European Alps, representing approximately two‐thirds of all European flora. Using presence‐only data, we built point‐process models (PPMs) to relate species observations to different combinations of covariates. We evaluated the PPMs through block cross‐validations and assessed the independent contributions of climate, soil, and land cover covariates to predict plant species distributions using an innovative predictive partitioning approach. We found climate to be the most influential driver of spatial patterns in plant species with a relative influence of ~58.5% across all species, with decreasing importance from low to high elevations. Soil (~20.1%) and land cover (~21.4%), overall, were less influential than climate, but increased in importance along the elevation gradient. Furthermore, land cover showed strong local effects in lowlands, while the contribution of soil stabilized at mid‐elevations. The decreasing influence of climate with elevation is explained by increasing endemism, and the fact that climate becomes more homogeneous as habitat diversity declines at higher altitudes. In contrast, soil predictors were found to follow the opposite trend. Additionally, at low elevations, human‐mediated land cover effects appear to reduce the importance of climate predictors. We conclude that soil and land cover are, like climate, principal drivers of plant species distribution in the European Alps. While disentangling their effects remains a challenge, future studies can benefit markedly by including soil and land cover effects when predicting species distributions.

New pollen genera and species from the Oligocene of northern Spain and a systematic, biostratigraphic and biogeographic re-evaluation of coeval taxa

The deposits of the As Pontes Basin in north-west Spain yield extraordinarily well-preserved microfloral assemblages that have unmatched diversity within the European Oligocene. The comprehensive examination of 300 miospore taxa has led to the discovery of two new fossil pollen genera, Eucommiopsispollenites gen. nov. and Pistaciapollenites gen. nov., as well as seven new species: Eucommiopsispollenites compactus sp. nov., Eucommiopsispollenites gracilis sp. nov., Nymphaeapollenites asponticus sp. nov., Nymphaeapollenites perforatus sp. nov., Pistaciapollenites heteroporatus sp. nov., Punctilongisulcites cryptornatus sp. nov. and Symplocoipollenites diktyotos sp. nov. Moreover, the botanical affinity and geographic distribution of 13 additional species of particular interest are discussed in detail, because these are either recorded for the first time anywhere within the Paleogene (Lythraceaepollenites bavaricus, Myrtaceidites myrtiformis, Punctilongisulcites punctiechinatus, Rhuspollenites ornatus and Vitispollenites tener), in the Iberian Peninsula (Aglaoreidia pristina, Diospyrospollenites ovalis, Pseudospinaepollis pseudospinosus, Reevesiapollis reticulatus and Tricolporopollenites vancampoae), or are studied for the first time using scanning electron microscopy (SEM) (Pentapollenites regulatius, Polycolpites helmstedtensis and Triporopollenites robustus). SEM analysis has enabled the conclusive botanical assignment of two species: Polycolpites helmstedtensis, with affinity to the extant tropical genus Eriandra, and Triporopollenites robustus, related to Myricaceae. In view of these affinities, new combinations are proposed accordingly: Polygalacidites helmstedtensis comb. nov. and Myricipites robustus comb. nov. The results of this study carry significant biostratigraphic and palaeobiogeographic implications at a regional and wider, continental scale. Firstly, the similarities of the As Pontes microflora with other Oligocene assemblages located various thousands of kilometres apart indicates the spread of a relatively homogenous broadleaved evergreen flora in Europe and allows for the recognition of Myricipites robustus and the genus Pentapollenites as key biostratigraphic index taxa across the continent. Secondly, the last occurrence datums of thermophilous taxa that became extinct in the Eocene in more northern latitudes indicates that the Iberian Peninsula functioned as a refuge area for thermic vegetation at least since the early Oligocene. http://zoobank.org/urn:lsid:zoobank.org:pub:16AFE374-A8B4-4CE9-B5B4-31807E2A6962

Репродуктивная стратегия Poa bulbosa L. в степных сообществах Нижнего Поволжья

Poa bulbosa L. is a native cereal of the European and Mediterranean flora and an invasive species in North America. The study of its reproductive strategy in different environmental and climatic conditions is important for the development of effective methods of containment and prevention of invasions. Plants of two coenopopulations were investigated embryologically. In addition, the morphology of reproductive organs was analyzed in 175 herbarium specimens collected in the flora of the Lower Volga region from 1919 to 2017. It was found that in the steppe phytocenoses of the Lower Volga region P. bulbosa reproduce mainly vegetatively by basal bulbs and pseudoviviparous bulblets. Rarely, seed mode reproduction in the form of facultative apomixis is realized. There was no dependence of the mode of reproduction (pseudovivipary / seed reproduction) on the date of growing season beginning and on the average temperature in the period from the beginning of the growing season to flowering. The effectiveness of pseudovivipary is low due to the aridity of the Lower Volga region climate. Bulblets germinate in inflorescences and then dry. This holds back the P. bulbosa wider distribution in the studied region.

An updated phylogenetic bioregionalization for the European fern flora

Biogeographic regions have been extensively used as reference units in macroecological studies and to prioritize biodiversity conservation efforts. However, classical bioregionalizations were delineated based on taxonomical similarity across space, and thus the importance of historical factors may have been underrated. This limitation may be particularly relevant for lineages with long and complex evolutionary histories, such as ferns. Here, we drew on an exhaustive distribution dataset including all fern species and subspecies of Europe (661 grid-cells of c. 110 × 110 km each), as well as a nearly complete molecular phylogeny to define fern phyloregions based on their phylogenetic relatedness. Also, we quantified the degree of specificity of individual phylogenetic clades to the phyloregions using a new index of geographical confinement based on phylogenetic diversity. Six distinct phyloregions were identified, with a primary divide between north-eastern and south-western Europe. Both phylogenetic beta diversity and clade specificity were overall low, supporting the idea that dispersal limitation is not a major driver of fern distribution. Yet, the phylogenetic specificity analysis revealed that ancient fern lineages show preference for northern latitudes, which explained the northeast to southwest split of the territory. More than 40 years after the only bioregionalization analysis for the European fern flora, our study provides a fresh regional delineation that takes into account the evolutionary history of the group. In addition to classical bioregionalization approaches, our phylogenetic specificity index allowed us to elucidate the identity of the clades that ultimately shaped the bioregions, which might otherwise had remained obscure.

Changes of 70 years in the non-native and native flora of a Hungarian county seat (Pécs, Central Europe)

The research of European urban flora is still based on the study of Western and Central European settlements, while relatively few data are available from the southern and eastern parts of Europe. This paper presents the first grid-based approach that surveyed the spontaneous and sub-spontaneous flora and its temporal changes of a Hungarian city located in this latter region of Europe. The changes during 70 years in the flora of a Hungarian county seat, Pécs were investigated. The contemporary city areas were used as two different study areas in the analyses. Changes in species richness, proportions of dispersal types, life form traits and alien statuses were examined during the mentioned period. With 1641 vascular plant species found at 232.88 km2 in the last 70 years, the flora of Pécs represents a diversity hotspot within Europe. In contrast with other European cities we found significant (19.37%) increase in the number of species over the last 70 years. As a result of temporal changes in the city flora, differnces were found only in the case of neophytes’ life forms regardless of the spatial approach. Similar to the other cities globally the number of woody species neophytes and short-lived alien plants increased.

Macroevolutionary patterns in European vegetation

AbstractQuestionHabitat‐specific species pools are shaped by ecological and evolutionary processes such as speciation, extinction, and migration. However, their role is poorly known because of the lack of robust data on species pools across a large number of plant community types and large areas. Here, we analyse a unique dataset of species pools of diagnostic species for all European vegetation types, asking: (a) what are the patterns of phylogenetic structure and phylogenetic beta‐diversity across European vegetation types and biomes; (b) what are the drivers of these patterns; and (c) is there a signal of niche conservatism at the level of biomes and broad categories of vegetation types?LocationEurope, Canary Islands, Madeira, Azores, Cyprus, Caucasus, Iceland and Greenland.MethodsWe built a dataset comprising 10,804 vascular plant species (almost 85% of the European flora) assigned to 106 vegetation types representing all European vegetated habitats, grouped into 11 biomes. This dataset represented habitat‐specific species pools. We analysed the phylogenetic structure of the species pools and related it to distribution range sizes of individual vegetation types, their successional status, levels of disturbance and environmental stress.ResultsIn European vegetation, phylogenetic overdispersion is associated with late‐successional habitats: several forest types, aquatic vegetation, and rock‐cliff vegetation serve as depositories of relict lineages. In contrast, phylogenetic clustering is typical of early successional and disturbed vegetation in anthropogenic, coastal and saline habitats, and in open‐canopy Mediterranean vegetation. The phylogenetic similarity of vegetation types is higher within than between broad categories of vegetation types and biomes.ConclusionsThe variable phylogenetic structure of European vegetation types is a heritage of evolutionary processes in the Tertiary and Quaternary. Habitat‐specific species pools of different vegetation types and biomes have been formed by different evolutionary processes as indicated by the observation that certain clades are significantly associated with certain vegetation types or biomes, hence indicating the phylogenetic niche conservatism.

A multivariate morphometric analysis of diagnostic traits in southern Italy and Sicily pubescent oaks

Species identification within the species complex of Q. pubescens is a well-known taxonomic challenge among European botanists. Some of the specific pubescent oak binomials currently accepted in various European floras and checklists were originally described in Sicily and southern Calabria. As a consequence, several species belonging to the pubescent oaks group (Q. pubescens, Q. amplifolia, Q. congesta, Q. dalechampii, Q. leptobalana and Q. virgiliana) are reported in the taxonomic and phytosociological literature. To verify whether it was possible to associate a diverse set of morphological characters with each of these different taxa, thirteen natural populations of pubescent oak from Sicily and southern Calabria were sampled. A total of 391 trees, 3,887 leaves and 1,047 fruits were collected. Overall, 28 morphological characters of oak leaves and fruits were statistically analysed using univariate and multivariate procedures. The results showed that neither the groups of morphological diversity identified by cluster analysis, nor those obtained by our expert identification through the use of analytical keys, matched with the current taxonomical frameworks as proposed by the most recent floras and checklists. Nearly all of the morphological characters considered displayed a more or less continuous trend of variation, both within and among populations. In the light of these findings it seems unlikely that more than one biological species of pubescent oak occurs in Sicily and southern Calabria.

Stenogrammitis myosuroides (Polypodiaceae): a new addition to the European flora from southwest Ireland

The occurrence of the fern Stenogrammitis myosuroides (Sw.) Labiak in Europe is reported for the first time. A small population was discovered on two boulders beside a stream in Atlantic oak woodland in the Killarney National Park, Co. Kerry, in southwest Ireland. The main identification features of this taxa and features that distinguish it from other similar taxa are laid out and discussed. S. myosuroides is elsewhere known to occur in the Neotropics, in Cuba, Jamaica and the Dominican Republic, and is thought to have colonised its Irish site through long-distance spore dispersal. Two Grammitid species of similar ecology have been discovered in the Azores in the past five decades and a number of bryophyte species share a similar disjunct distribution between Ireland and the Neotropics, all of which supports the theory that long-distance dispersal is the most plausible explanation for the occurrence of S. myosuroides in Ireland. It is not clear how long S. myosuroides has been present in Ireland, although morphological differences suggest that it may have been separated from the Neotropical populations for a long period. However, molecular analysis is required to elucidate this.

Morphological characteristics as a key attribute for a successful determination of selected Cotoneaster species

Article Details: Received: 2019-12-17 | Accepted: 2019-01-24 | Available online: 2020-03-31 https://doi.org/10.15414/afz.2020.23.01.15-23 In this paper, morphological features, such as the number of pyrenes in pome and the number of pomes in infructescence, were used for determination of closely related tetraploid Cotoneaster species. Samples were collected from various localities in the Western Carpathians. The collection of samples, designed for counting of pyrenes in pome, included 2353 pomes of >130 individuals. Number of pyrenes in pome ranged from 1 to 5. Statistical analysis revealed a significant difference in pyrenes per pome mean values between C. integerrimus (3.01), C. melanocarpus agg. (2.46; including C. matrensis) and C. tomentosus (3.93). The collection of samples, designed for counting of pomes in infructescence, included 1019 infructescences of 141 individuals. Number of pomes in infructescence ranged from 1 to 5. Statistical analysis also revealed a significant difference in pomes per infructescence mean values between C. integerrimus (1.14) and C. melanocarpus agg. (1.54; including C. matrensis), and between C. integerrimus and C. tomentosus (1.50). Keywords: pyrenes, pomes, infructescence, Cotoneaster, Western Carpathians