Henry Väre

Contrasting effects of biotic interactions on richness and distribution of vascular plants, bryophytes and lichens in an arctic–alpine landscape

Biotic interactions may strongly affect the distribution of individual species and the resulting patterns of species richness. However, the impacts can vary depending on the species or taxa examined, suggesting that the influences of interactions on species distributions and diversity are not always straightforward and can be taxon-contingent. The aim of this study was therefore to examine how the importance of biotic interactions varies within a community. We incorporated three biotic predictors (cover of the dominant vascular species) into two correlative species richness modelling frameworks to predict spatial variation in the number of vascular plants, bryophytes and lichens in arctic–alpine Fennoscandia, in N Europe. In addition, predictions based on single-species distribution models were used to determine the nature of the impact (negative vs. positive outcome) of the three dominant species on individual vascular plant, bryophyte and lichen species. Our results suggest that biotic variables can be as important as abiotic variables, but their relative contributions in explaining the richness of sub-dominant species vary among dominant species, species group and the modelling framework implemented. Similarly, the impacts of biotic interactions on individual species varied among the three species groups and dominant species, with the observed patterns partly reflecting species’ biogeographic range. Our study provides additional support for the importance of biotic interactions in modifying arctic–alpine biodiversity patterns and highlights that the impacts of interactions are not constant across taxa or biotic drivers. The influence of biotic interactions, including the taxon contingency and range-based impacts, should therefore be accounted for when developing biodiversity forecasts.

Into Africa: Molecular phylogenetics and historical biogeography of sub-Saharan African woodferns (Dryopteris)

PREMISE OF THE STUDY Our goal was to infer the phylogenetic relationships and historical biogeography of the genus Dryopteris with a focus on taxa in sub-Saharan Africa and neighboring islands. In general, little is known about the relationships between African fern species and their congeners in other geographic regions, and our aim was to determine whether the sub-Saharan African species of Dryopteris are monophyletic and evolved within Africa or arrived there via repeated dispersals into Africa from other regions. METHODS We obtained sequence data for five chloroplast markers from 214 species of Dryopteris and 18 outgroups. We performed phylogenetic and molecular dating analyses using a Bayesian relaxed clock method in BEAST with fossil and secondary calibration points and estimated ancestral ranges for the genus globally by comparing multiple models in BioGeoBEARS. KEY RESULTS We found that 22 of 27 accessions of sub-Saharan African Dryopteris belong to a large clade of 31 accessions that also includes taxa from Indian and Atlantic Ocean islands. Additional accessions of taxa from our regions of interest have Asian, Hawaiian, European, or North American species as their closest relatives. CONCLUSIONS The majority of sub-Saharan African Dryopteris species are descended from a shared common ancestor that dispersed to Africa from Asia approximately 10 Ma. There have been subsequent dispersal events from the African mainland to islands in the Atlantic and Indian Oceans, including Madagascar. Several additional species are estimated to have descended from ancestors that reached Africa via separate events over the last roughly 20 million years.

Development and characterization of chloroplast microsatellite markers in a fine-leaved fescue, Festuca rubra (Poaceae)

Premise of the study: Chloroplast microsatellite markers were developed for Festuca rubra to examine its population genetic characteristics, taxonomy, and coevolution with its endophyte Epichloë festucae. Methods and Results: Thirteen polymorphic markers were identified from the chloroplast genome of a F. ovina accession and intergenic chloroplast sequences of F. rubra accessions. They amplified a total of 65 alleles in a sample of 93 individuals of F. rubra originating from six different populations located in the Faroe Islands, Finland, Greenland, Norway, and Spain. Conclusions: The developed microsatellite primer pairs can be used by researchers in population genetic and taxonomic studies, and by plant breeders in breeding programs on grasses.

Typification and check-list of Ensete Horan. names (Musaceae) with nomenclatural notes

ABSTRACT All the names accepted in the genus Ensete Horan. are listed and typifications supplemented. All Ensete names have originally been described as belonging to the genus Musa L. Altogether, 37 names were found, the fossil Ensete oregonense excluded, 36 species and variety are considered. Currently, eight species are recognised, i.e. E. agharkarii, E. gilletii, E. glaucum, E. holstii, E. homblei, E. perrieri, E. superbum and E. ventricosum, and one variety, E. glaucum var. wilsonii comb. nov. Of the names, eight are illegitimate, and three dubious. A great confusion seems to be connected with E. ventricosum, which is indigenous in Africa. We consider that 14 names are synonymous with it. As herbarium specimens of type material are often of bad quality and sometimes completely undiscovered or perhaps lost completely, some typification is based on the drawings. In this article, nine Musa names, currently included in Ensete, are lectotypified.

Typification of Musa mannii, M. sanguinea and M. x kewensis (Musaceae)

SummaryIn 1949 a single plant of Musa mannii Baker, grown in Trinidad from seeds imported from Java, was incorrectly identified as Musa sanguinea Hook. f. As a consequence, the circumscription of M. mannii became confused. M. mannii is very rare or extinct in its indigenous area in Assam, India. However, it is grown in many botanic gardens worldwide. In contrast, M. sanguinea is a common sympatric species with M. aurantiaca in upper Assam and Arunachal Pradesh, India, but it is today unknown to most botanists. The aim of this study is to settle the true identity of M. mannii and M. sanguinea. The names are typified, as well as Musa × kewensis Baker (M. mannii × ornata).

Improving forecasts of arctic-alpine refugia persistence with landscape-scale variables

ABSTRACT Refugia, the sites preserving conditions reminiscent of suitable climates, are projected to be crucial for species in a changing climate, particularly at high latitudes. However, the knowledge of current locations of high-latitude refugia and particularly their ability to retain suitable conditions under future climatic changes is limited. Occurrences of refugia have previously been mainly assessed and modelled based solely on climatic features, with insufficient attention being paid to potentially important landscape-scale factors. Here, climate-only models and ‘full’ models incorporating topo-edaphic landscape-scale variables (radiation, soil moisture and calcareousness) were developed and compared for 111 arctic-alpine plant species in Northern Fennoscandia. This was done for both current and future climates to determine cells with resilient climatic suitability harbouring refugia. Our results show that topographic and edaphic landscape-scale predictors both significantly improve models of arctic-alpine species distributions and alter projections of refugia occurrence. The predictions of species–climate models ignore landscape-scale ecological processes and may thus provide inaccurate estimates of extinction risk and forecasts of refugia where species can persist under a changing climate.

Geographic Variation in Festuca rubra L. Ploidy Levels and Systemic Fungal Endophyte Frequencies

Polyploidy and symbiotic Epichloë fungal endophytes are common and heritable characteristics that can facilitate environmental range expansion in grasses. Here we examined geographic patterns of polyploidy and the frequency of fungal endophyte colonized plants in 29 Festuca rubra L. populations from eight geographic sites across latitudes from Spain to northernmost Finland and Greenland. Ploidy seemed to be positively and negatively correlated with latitude and productivity, respectively. However, the correlations were nonlinear; 84% of the plants were hexaploids (2n = 6x = 42), and the positive correlation between ploidy level and latitude is the result of only four populations skewing the data. In the southernmost end of the gradient 86% of the plants were tetraploids (2n = 4x = 28), whereas in the northernmost end of the gradient one population had only octoploid plants (2n = 8x = 56). Endophytes were detected in 22 out of the 29 populations. Endophyte frequencies varied among geographic sites, and populations and habitats within geographic sites irrespective of ploidy, latitude or productivity. The highest overall endophyte frequencies were found in the southernmost end of the gradient, Spain, where 69% of plants harbored endophytes. In northern Finland, endophytes were detected in 30% of grasses but endophyte frequencies varied among populations from 0% to 75%, being higher in meadows compared to riverbanks. The endophytes were detected in 36%, 30% and 27% of the plants in Faroe Islands, Iceland and Switzerland, respectively. Practically all examined plants collected from southern Finland and Greenland were endophyte-free, whereas in other geographic sites endophyte frequencies were highly variable among populations. Common to all populations with high endophyte frequencies is heavy vertebrate grazing. We propose that the detected endophyte frequencies and ploidy levels mirror past distribution history of F. rubra after the last glaciation period, and local adaptations to past or prevailing selection forces such as vertebrate grazing.

What We Do (and Don't) Know about Ferns: Dryopteris (Dryopteridaceae) as a Case Study

Abstract Ferns are the second largest group of vascular land plants after the angiosperms, but remain chronically underrepresented in studies of plant phylogeny, biogeography, physiology, and genomics. The genus Dryopteris, the woodferns, is a large group with a worldwide distribution, and recent research has made it one of the better understood fern genera and a potential model for understanding many aspects of fern biology and evolution. Here we review historical and current understanding of the genus, and outline promising avenues of future research in ferns for which Dryopteris is an ideal study system, particularly for research on polyploid complexes, biogeographic distributions, and physiological ecology.

(025–027) Proposals to amend Article 41 for incorporating different styles of bibliographic citations

1 Botanical Museum, Finnish Museum of Natural History, University of Helsinki, Unioninkatu 44, P.O. Box 7, 00014 Helsinki, Finland 2 Herbarium, Komarov Botanical Institute of Russian Academy of Sciences, Prof. Popov str. 2, 197376 St. Petersburg, Russia 3 Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, U.K. 4 Herbarium, Botanische Staatssammlung München, Menzinger Straße 67, 80638 München, Germany Author for correspondence: Alexander N. Sennikov, alexander.sennikov@helsinki.fi