Irene Bisang

Irene Bisang
Swedish Museum of Natural History · Department of Botany

PhD

About

101
Publications
17,096
Reads
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1,245
Citations
Introduction
My current research focuses on reproductive traits in unisexual bryophytes at various scales, their evolution and variation along enviromental parameters, and on impacts of land use change on bryophyte diversity; such as agricultural management on the arable flora or invasive species. I have also a long-term engagement in bryophyte conservation, and I am currently co-chairing the IUCN Bryophyte Specialist Group
Additional affiliations
May 2019 - present
Swedish Museum of Natural History
Position
  • Senior Researcher
Description
  • Organism- and collection-based research in bryology and conservation. collection management. Co-chair of IUCN SSC Bryophyte Specialist Group
April 2012 - April 2019
Swedish Museum of Natural History
Position
  • Research Associate
April 2009 - March 2012
Swedish Museum of Natural History
Position
  • Grant Liaison Officer
Education
August 1986 - July 1990
Universität Bern
Field of study
  • PhD studies. In parallel to part-time assignments as Lecturer / Research fellow at University of Zürich

Publications

Publications (101)
Article
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
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...
Chapter
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-...
Article
Full-text available
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...
Article
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...
Book
Full-text available
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...
Book
Full-text available
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...
Poster
Full-text available
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...
Presentation
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Poster
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...
Chapter
Available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>
Chapter
Available at www.bryoecol.mtu.edu
Chapter
Available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>
Chapter
Available at <http://digitalcommons.mtu.edu/bryophyte-ecology/>
Article
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...
Article
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...
Technical Report
Full-text available
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...
Poster
Full-text available
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...
Poster
Full-text available
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...
Article
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...
Article
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...
Presentation
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...
Article
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...
Article
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...
Article
* 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 (Baker's law) apply to vagile organisms, using b...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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....
Article
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
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...
Article
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,...
Article
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...
Article
Full-text available
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...
Article
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...
Article
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...
Article
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...
Article
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....
Article
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...
Article
Full-text available
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...
Article
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...
Article
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...