Irene Bisang

Swedish Museum of Natural History · Department of Botany

Extinction risk is not randomly distributed among species but depends on species traits, their relationship to climate and land use, and corresponding threats by global change. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, this is still largely lacking for bryophytes. Here, we used r...

The Bryophyte Specialist Group (BSG) is part of the network of more than 10,500 volunteer experts in 175 countries that constitute the International Union for Conservation of Nature’s (IUCN) Species Survival Commission (SSC). These experts, organised in over 160 groups, work jointly for nature conservation, and to prevent the loss and support the r...

Background and Aims We examined the relationship between reproductive allocation and vegetative growth in three monoicous sexual systems of bryophytes. The sexual systems show a gradient of increasing distance between the sexes from gonioautoicous to cladautoicous to rhizautoicous. Here we investigated two hypotheses: (1) reproductive allocation di...

Background and aims: We examined the relationship between reproductive allocation and vegetative growth in three monoicous sexual systems of bryophytes. The sexual systems show a gradient of increasing distance between the sexes from gonioautoicous to cladautoicous to rhizautoicous. Here we investigated two hypotheses: (1) reproductive allocation...

Background and aims Plants have evolved an unrivalled diversity of reproductive strategies, including variation in the degree of sexual versus clonal reproduction. This variation has important effects on the dynamics and genetic structure of populations. We examined the association between large-scale variation in reproductive patterns and intraspe...

Bryophytes are a diverse group of organisms with unique properties, yet they are severely underrepresented in plant trait databases. Building on the recently published European Red List of bryophytes and previous trait compilations, we present the Bryophytes of Europe Traits (BET) dataset, including biological traits such as those related to life h...

We investigated whether the European near-endemic moss Drepanocladus lycopodioides has declined in its core distribution area in the southern Baltic Sea region and explored potential explanations for this. First, we re-visited sites with documented records from 1854 to 1957 in the Stockholm archipelago and nearby mainland in southern Sweden. Second...

Introduction Half a century since the creation of the International Association of Bryologists, we carried out a review to identify outstanding challenges and future perspectives in bryology. Specifically, we have identified 50 fundamental questions that are critical in advancing the discipline. Methods We have adapted a deep-rooted methodology of...

In der 17. Folge der ‚Beiträge zur bryofloristischen Erforschung der Schweiz‘ werden neue Fundorte von seltenen, gefährdeten oder anderweitig bemerkenswerten Moosen vorgestellt. Dabei handelt es sich um folgende Arten: Ephemerum recurvifolium, Leptophascum leptophyllum, Lewinskya killiasii subsp. killiasii, Microbryum starckeanum, Polytrichum nanum...

Meylania 69 (2022): 5-14 In der 17. Folge der ‚Beiträge zur bryofloristischen Erforschung der Schweiz' werden neue Fundorte von seltenen, gefährdeten oder anderweitig bemerkenswerten Moosen vorgestellt. Dabei handelt es sich um folgende Arten: Ephemerum recurvifolium, Leptophascum leptophyllum, Lewinskya killiasii subsp. killiasii, Microbryum star...

Ähnlich wie die Wildkräuter in Äckern sind auch die typischen, hochspezialisieren Ackermoose stark gefährdet und im Rückgang begriffen. Biodiversitätsförderflächen könnten dazu beitragen, ihren Rückgang zu stoppen. Entscheidend für den Erhalt der Ackermoose im Schweizer Kulturland ist jedoch, dass genügend und sorgfältig ausgewählte Getreidestoppel...

Introduction Codonoblepharon forsteri (Dicks.) Goffinet is a rare epiphytic moss characteristically associated with water-filled holes in trees. We reviewed its range and population and assessed effects of climate change. Methods An inventory of sites from where Codonoblepharon forsteri has been recorded was compiled. Extent of occurrence (EOO) an...

To understand colonization processes, it is critical to fully assess the role of dispersal in shaping biogeographical patterns at the gene, individual, population, and community levels. We test two alternative hypotheses (H I and H II) for the colonization of disturbed sites by clonal plants, by analyzing intraspecific genetic variation in one and...

Agricultural intensification represents one of the major drivers for the dramatic loss of biodiversity worldwide. To halt the decline of farmland biodiversity, Switzerland adopted agri-environment schemes (AES) in 1998. Here, we monitored the occurrence, abundance and habitats of two species of arable bryophyte specialists, the Field hornwort (Anth...

Background and Aims Horizontal Gene Transfer (HGT) is an important evolutionary mechanism because it transfers genetic material that may code for traits or functions, between species or genomes. It is frequent in mitochondrial and nuclear genomes but has not been demonstrated between plastid genomes of different green land plant species. Methods W...

Land-use changes including agricultural intensification are major drivers of biodiversity loss. As other countries, Switzerland introduced agri-environment schemes (AES) to counteract declining agro-biodiversity. Among numerous bryophytes of the agricultural landscape, arable bryophytes have adapted to recurrent tillage. They are short-lived above-...

The hornwort Anthoceros agrestis is emerging as a model system for the study of symbiotic interactions and carbon fixation processes. It is an annual species with a remarkably small and compact genome. Single accessions of the plant have been shown to be related to the cosmopolitan perennial hornwort Anthoceros punctatus. We provide the first detai...

Sex ratio variation is common among organisms with separate sexes. In bryophytes, sex chromosome segregation at meiosis suggests a balanced progeny sex ratio. However, most bryophyte populations exhibit female-biased phenotypic sex ratios based on the presence of reproductive structures on gametophytes. Many bryophyte populations do not form sexual...

This Red List is a summary of the conservation status of the European species of mosses, liverworts and hornworts, collectively known as bryophytes, evaluated according to IUCN’s Guidelines for Application of IUCN Red List Criteria at Regional Level. It provides the first comprehensive, region-wide assessment of bryophytes and it identifies those s...

The European Red List is a review of the status of European species according to IUCN regional Red Listing guidelines. It identifies those species that are threatened with extinction at the regional level – in order that appropriate conservation action can be taken to improve their status. This publication is a summary of the conservation status of...

IUCN Red List criteria widely recognised to objectively assess extinction risk of species across taxonomic groups. Application of IUCN criteria requires the use of critical terms that are difficult to apply to clonal organisms such as bryophytes. We pragmatically define 'mature individuals', 'generation length' and 'severe fragmentation' building u...

We present patterns of intra-specific variation in genotypic and phenotypic sex ratios in related to geographic scales and environmental factors in several long-lived bryophytes species with different levels of sexual reproduction. We conclude, that bryophyte sex response is complex, and depends on the species’ life history traits, such as the freq...

Hedenäs, L. & Bisang, I. 2019. Are the remains of the Central European population of Drepanocladus turgescens genetically distinct from Scandinavian populations? – Herzogia 32: 209–218.The wetland moss Drepanocladus turgescens occurs in interglacial refugia in both mountains and lowlands of Europe. It is relatively frequent in Scandinavia, but due...

In the Baltic area, the long-lived dioicous wetland moss Drepanocladus turgescens (T.Jensen) Broth. produces sporophytes rarely and at irregular intervals. Based on surveys of sporophyte occurrences at 13 sites in two regions in northern Gotland (Sweden) during three to five years, we ask: (1) Is sporophyte formation associated with precipitation a...

The IUCN Red List is recognised as a robust system for assessing the risk of extinction to organisms, but there are difficulties in applying the criteria to bryophytes and other clonal and colonial organisms. Three critical terms are addressed-generation length, mature individual and severe fragmentation-and definitions given in order to facilitate...

Background: A Red List of threatened bryophytes is lacking for Africa. The International Union for Conservation of Nature (IUCN) Species Survival Commission (SSC) Bryophyte Specialist Group has recently launched the ‘Top 10 Initiative’ to identify the 10 species on each continent that are at highest risk of extinction. Objectives: The main aim of t...

Biased adult sex ratios (SR), usually inferred from counts of sexually mature plants, are commonly observed in unisexual bryophyte species. For sex-expressing bryophytes, there is evidence of spatial variation of reproductive traits, including SRs, related to environmental conditions. However, how sexes in rarely fertile or non-fertile species are...

Available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>

Available at www.bryoecol.mtu.edu

Available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>

Available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>

Sex ratio variation is commonly observed in natural populations of many organisms with separate sexes and genetic sex determination, including bryophytes. Most bryophyte populations exhibit female-skewed expressed adult sex ratios, generally inferred from counts of sexually mature plants. For the rarely sexually reproducing perennial dioicous moss...

Sex identification before sexual maturity is notoriously difficult in plants with separate sexes, but is crucial to address many life history related issues. To study the performance of the two sexes in the rarely sexually reproducing dioecious moss Drepanocladus turgescens a molecular sex marker is needed. The female-targeting marker previously de...

SYNTHESYS3 consortium recognises the importance of the Societal Challenges identified by the Horizon2020 programme and relevance of natural history collections for solving problems outside the traditional and conventional fields. We have reviewed 26 Use Cases backed up by documentary evidence demonstrating how the collections, expertise and service...

Ecological Focus Areas (EFAs) are an important tool of the Swiss agri-environmental schemes to support biodiversity in landscapes dominated by agriculture. EFAs are usually designed to promote bird and vascular plant richness or ecological functions such as pollination. A parallel study revealed a beneficial effect of EFAs also on above-ground bryo...

Agricultural biodiversity has decreased substantially during the last few decades in Europe and globally. Agri-environmental schemes devised to promote sustainable farming have been a major policy instrument for the past decades to stop this negative trend. In Switzerland, these include Ecological Focus Area Areas (EFA), i.e. habitats subject to sp...

Dwarf males in mosses are restricted to certain lineages and have been proposed to be associated with epiphytism and subtropical environments. Here we explore which morphological and environmental characteristics are associated with male dwarfism in a set of 528 pleurocarpous mosses that represent the different lineages, habitats, and climatic cond...

Background and aims: Roughly half of the species of bryophytes have separate sexes (dioecious) and half are hermaphroditic (monoecious). This variation has major consequences for the ecology and evolution of the different species. In some sexually reproducing dioecious bryophytes, sex ratio has been shown to vary with environmental conditions. Thi...

Sex ratio variation is a common but unexplained phenomenon of many species with chromosomal sex determination, including many bryophytes. Expressed sex ratio variation could be related to environmental conditions in a few mosses investigated to date. However, many bryophyte populations are non-fertile during their entire life cycle and intraspecifi...

Infraspecific genetic diversity is generally underestimated in biodiversity assessments. We use haplotype patterns based on the nuclear gpd and plastid rpl16 to examine whether genetic diversity is related to geography, gender, habitat and/or frequency of sexual reproduction in Drepanocladus lycopodioides. This moss is restricted to western Eurasia...

Patterns of sex expression and sex ratios are key features of the life histories of organisms. Bryophytes are the only haploid-dominant land plants. In contrast with seed plants, more than half of bryophyte species are dioecious, with rare sexual expression and sporophyte formation and a commonly female-biased sex ratio. We asked whether variation...

The evolution of island syndromes has long served as a model to understand the mechanisms accounting for phenotypic differentiation. Combining literature data with actual observations, we determine whether typical syndromes such as the loss of dispersal power and the bias towards self‐compatibility ( B aker's law) apply to vagile organisms, using b...

The moss Drepanocladus trifarius (F. Weber & D. Mohr) Broth. ex Paris was used as a model species for a first evaluation of whether male and female haplotype patterns based on a combination of the nuclear molecular markers ITS and gpd, and the chloroplast rpl16 are congruent or not. In 23 female and 23 male shoots from specimens sampled in Northern...

Premise of research. Maintenance of dioecious and monoecious sexual systems at nearly equal frequencies, infrequent sexual expression, and distinctly female-skewed sex ratios among the dioecious species are reproductive characteristics of bryophytes, which are otherwise unusual among embryophytes. Most sex ratio assessments to date have relied on g...

The habitat of the pleurocarpous moss Drepanocladus trifarius is commonly described as mineral-rich wet fens. We sampled individual D. trifarius shoots at 214 pre-defined randomly distributed spots in an area of ca 15 km2 in a sloping fen in central–western Sweden. We assessed the habitat variation of the sampling spots in this area by means of a m...

Background: We recently demonstrated that dwarf male plants are much more common among mosses than hitherto thought. Dwarf plants, producing functional male sexual organs occur in 10–20% of the moss species worldwide. Aims: We investigated how an inadvertent omission of dwarf males affects estimates of male sex expression rates and sex ratios. Meth...

Dwarf males occur in several animal groups but are unique to mosses among the green land plants. Mosses, with more than 50% unisexual species and common fertilisation distances in the range of a few decimetres, have evolved various means to cope with potential problems to successfully achieve fertilisation and to ensure sporophyte production and se...

Dioecious plants, including many bryophytes, rarely exhibit discernible sexual dimorphism before sexual maturity. Because many species and populations of dioecious bryophytes do not express their sex, it remains mostly unresolved whether expressing individuals reflect the ratios of genetically male and female plants. The present study assesses the...

Traditionally managed arable fields host a specialised flora adapted to regular disturbance through tillage. Agricultural intensification during the 20th century resulted in a pronounced biodiversity decline in European agroecosystems. Anthoceros agrestis and Phaeoceros carolinianus, both largely confined to cultivated land in Central Europe and th...

We investigated biomass allocation patterns in sporophyte-bearing and non-sporophytic plants of the perennial moss Dicranum polysetum Sw. from southern Sweden by comparing dry masses of various reproductive and vegetative plant modules. Assessing parental vegetative biomass is critical in bryophytes due to continuous decay of basal shoot portions....

Evidence is accumulating that significant amounts of substances can move internally in ectohydric bryophytes, which lack specialized structures for internal water movement. This potential for resource translocation is likely to affect the productivity in individual shoot sections. We tested whether annual growth intervals in the pleurocarpous moss...

We present a method that permits the retrospective assessment of frequency changes in species, based on the evaluation of specimens in biological collections. The method assumes that the increase and decrease in the frequency of a species is reflected in the number of collected specimens. A comparison of the specimen numbers from different time per...

We studied infraspecific morphological variation within European Dicranum majus Sm. A principal components analysis based on six leaf characters scored in 82 specimens revealed two distinct plant types. Plants with bistratose submarginal upper leaf lamina cells, numerous spine-like dorsal lamina projections, a costa that is dorsally rough far down...

A fundamental assumption in life-history theory is that reproduction is costly. Higher reproductive investment for fruits than for flowers may result in larger costs of reproduction in females than in males, which is often used to explain male-skewed sex ratios in unisexual seed plants. In contrast, bryophytes have predominantly female-biased sex r...

Based on a literature survey and our own investigations of selected species, we present a compilation of expressed sex ratios in 103 taxa of dioicous bryophytes, including 56 mosses and 47 liverworts. We grouped the approaches used to determine sex into two categories: (1) sex assessment per herbarium specimen or per patch in the field; (2) sex ass...

Habitat preferences and habitat differentiation were studied among species of Acroporium (Sematophyllaceae) and related taxa between 140–2,000 m a.s.l. in Peninsular Malaysia (02.92°–04.87°N, 100.80°–101.83°E). Canonical Correspondence Analysis was used to reveal how species data were related to 16 environmental factors that represent geographical,...

We tested whether mate availability in the pleurocarpous dioicous mosses Rhytidiadelphus triquetrus and Abietinella abietina affects fertilization success by transplanting individual male shoots into non-sporophytic female colonies. Fertilization success in both species was limited by the availability of mates and distance-dependent, and the number...

HEDENÄS, L. & BISANG, I. 2004. Key to European Dicranum species. - Herzogia 17: 179-197. A key to the twenty-nine European Dicranum species is presented. The features that are important for their identifi- cation are discussed. For each species, diagnostic character states and information about habitat and geographical distribution are provided. Mo...

Population development and structure of the regionally annual hornworts Anthoceros agrestis and Phaeoceros carolinianus were studied in cultivated fields in the lowland of NW Switzerland. Ontogenetic stages of gametophytes and sporophytes were repeatedly surveyed at short time intervals in plots excluded from routine management during one growing s...

The geographical distributions, in the form of mosaic maps, altitudinal ranges, frequencies, habitat requirements, and threat status of the four pleurocarpous wetland mosses Hamatocaulis vernicosus, Pseudocalliergon lycopodioides, P. trifarium, and P. turgescens in Switzerland are presented. The total and European ranges of the taxa are outlined. H...

A method to evaluate whether changes in individual species' collecting frequencies over time deviate from what could be expected based on changes in the general collecting activity in an area is described. The method, which was presented in detail by Hedenäs et al. (2002), can be used to separate apparent frequency changes from real changes. The fa...

We investigated biomass allocation patterns in sporophyte-bearing and non-sporophytic plants of the perennial moss Dicranum polysetum Sw. from southern Sweden by comparing dry masses of various reproductive and vegetative plant modules. Assessing parental vegetative biomass is critical in bryophytes due to continuous decay of basal shoot portions....

A new, resource-efficient, herbarium-based method for estimating temporal frequency changes in species, especially of non-vascular plants and fungi, is presented. It is based on a reference data set for the temporal distribution of general collecting activity for the organism group and geographical area of interest. The reference data set includes...

The geographical distributions, in the form of mosaic maps, altitudinal ranges, frequencies, and habitats of 29 Sphagnum taxa known to occur in Switzerland are described. The detailed distribution patterns vary among individual taxa depending on their habitat requirements. Sphagnum fimbriatum is confined to lowlands in the north and north-west of t...

We investigated the cost of sporophyte production in the moss Dicranum polysetum both by examining patterns of growth and reproduction in unmanipulated shoots and by experimentally manipulating sexual reproduction. The estimated proportion of total carbon investment allocated to sexual reproduction in sporophyte-producing shoots over the study peri...

How we select species for conservation is based on the rationale for saving them from man-induced extinction. Motives related to aesthetic properties, ethical values, basic research needs, economical values, rarity and threat, and ecological values all provide arbitrary or insufficient criteria for selecting which species to preserve when resources...

The present paper is the first of a series on the distribution of Swiss bryophytes. Mosaic maps, based on a system of physiographic units, of one hornwort, three liverworts and seven mosses are presented. The distribution maps of all taxa are accompanied by summarized information on some evident characters of the plant, on the total, the European a...

Annual populations of Anthoceros agrestis and Phaeoceros carolinianus were surveyed over seven years in 28 arable fields in north-western Switzerland. Gametophytic occurrences of the two hornwort taxa are compared to management type recorded at each census (three categories based on the crop type: cereal, maize/root-crops, other) and to temperature...

The composition and structure of bryophyte and fern diaspore banks were studied in three agricultural fields situated at two different localities in the vicinity of Bern, Switzerland. Soil cores were taken in profiles at depths between 1.5 and 50 cm at three positions in each field. Fifteen bryophyte species and a considerable number of fern gameto...