| 1. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 2. |
- Tyler, Torbjörn, et al.
(författare)
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Nu startar projekt Skånes Mossor!
- 2007
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Ingår i: Myrinia. - 1102-4194. ; 17:1, s. 52-57
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 3. |
- Tyler, Torbjörn, et al.
(författare)
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Nu startar projekt Skånes Mossor!
- 2007
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Ingår i: Botaniska Notiser. - 0006-8195. ; 140:2, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- The Lund Botanical Society 2007-03-23 decided to launch a project with the following aims: 1) to map the frequency and distribution of all bryophytes in the province of Skåne, southernmost Sweden, thereby making way for future studies of changes in the flora, 2) to find and document as many sites as possible for nationally and regionally rare or endangered bryophytes and initiate conservation actions at these sites, 3) to increase our knowledge of the ecological demands of individual taxa, and 4) to enhance the level of knowledge concerning bryophytes among both amateur botanists and professional nature conservationists. The province has been divided into 534 5 x 5 km grid-squares. The central square kilometre within each grid-square will be surveyed and the result used for unbiased estimates of the frequency of each taxon. In addition, within each grid-square, a variable number of special areas which may be presumed to have a rich or unusual bryophyte flora have been preselected for the survey. Additional areas may be selected by the recorders themselves, but the ultimate goal is not to survey the grid-square as a whole. A special determination key and nomenclatural check-list to all 658 taxa hithereto known from the province, as well as various instructions and forms for the volonteer recorders, have been made available on the Internet and a central database with an Internet interface is under way. Various kinds of courses have been initiated with the aim of educating future recorders. The aim is to survey all grid-squares during a 20 year period and the project is now calling for support from bryologists world-wide.
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| 4. |
- Tyler, Torbjörn, et al.
(författare)
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Projekt Skånes Mossor 2008-2013 - en deltidsrapport
- 2014
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Ingår i: Nordic Journal of Botany. - 0107-055X. ; 147:2, s. 1-32
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Tidskriftsartikel (refereegranskat)abstract
- About 25% of the 531 5x5 km grid squares have been investigated during the six first years of the ongoing survey of the bryophyte flora of the province of Skåne, c. 50 persons have participated and 65,539 records and 21,135 vouchers have been collected. Of the 687 taxa that have ever been reported from the province, 591 have been recorded since 1995 and 34 have been found as new to the province since then. In this part-time report, the records and our present knowledge about each taxon ever found in the province are briefly summarized and it is concluded that our knowledge of the bryophyte flora of the province has increased multifold during these six years of intense surveying.
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| 5. |
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| 6. |
- Bengtsson, Bengt Olle, et al.
(författare)
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The effective size of bryophyte populations.
- 2009
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Ingår i: Journal of Theoretical Biology. - : Elsevier BV. - 1095-8541 .- 0022-5193. ; 258:Available online 8 January 2009, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- Bryophytes with their dominant haploid stage conform poorly to the life cycles generally treated in population genetical models. Here we make a detailed analysis of what effective sizes bryophyte model populations have as a function of their breeding system. It is found that the effective size is rarely much smaller than the scored number of haploid gametophytic individuals, even when the limited number of diploids (sporophytes) formed is taken into account. The most severe decrease in effective size occurs when unisexual gametophytic females produce only a small number of fertile diploid sporophytes in male biased populations; this effect is due to the restricted sampling of male gametophytic individuals that then occurs. It is shown that the harmonic mean of diploid sporophytes formed per haploid gametophytic individuals is the relevant measure in these calculations and not the standard (and generally larger) arithmetic mean.
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| 7. |
- Bengtsson, Fia, 1986-
(författare)
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Functional Traits in Sphagnum
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Peat mosses (Sphagnum) are ecosystem engineers that largely govern carbon sequestration in northern hemisphere peatlands. I investigated functional traits in Sphagnum species and addressed the questions: (I) Are growth, photosynthesis and decomposition and the trade-offs between these traits related to habitat or phylogeny?, (II) Which are the determinants of decomposition and are there trade-offs between metabolites that affect decomposition?, (III) How do macro-climate and local environment determine growth in Sphagnum across the Holarctic?, (IV) How does N2 fixation vary among different species and habitats?, (V) How do species from different microtopographic niches avoid or tolerate desiccation, and are leaf and structural traits adaptations to growth high above the water table?Photosynthetic rate and decomposition in laboratory conditions (innate growth and decay resistance) were related to growth and decomposition in their natural habitats. We found support for a trade-off between growth and decay resistance, but innate qualities translated differently to field responses in different species. There were no trade-offs between production of different decay-affecting metabolites. Their production is phylogenetically controlled, but their effects on decay are modified by nutrient availability in the habitat. Modelling growth of two species across the Holarctic realm showed that precipitation, temperature and vascular plant cover are the best predictors of performance, but responses were stronger for the wetter growing species. N2 fixation rates were positively related to moss decomposability, field decomposition and tissue phosphorus concentration. Hence, higher decomposition can lead to more nutrients available to N2-fixing microorganisms, while higher concentrations of decomposition-hampering metabolites may impede N2 fixation. A mesocosm experiment, testing effects of water level drawdown on water content and chlorophyll fluorescence, showed that either slow water loss or high maximum water holding capacity can lead to desiccation avoidance. Furthermore, leaf anatomical traits rather than structural traits affected the water economy.This thesis has advanced the emerging field of trait ecology in Sphagnum by comparing many species and revealing novel mechanisms and an ever more complex picture of Sphagnum ecology. In addition, the species-specific trait measurements of this work offers opportunities for improvements of peatland ecosystem models.
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| 8. |
- Bengtsson, Fia, et al.
(författare)
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Mechanisms behind species-specific water economy responses to water level drawdown in peat mosses
- 2020
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Ingår i: Annals of Botany. - : Oxford University Press (OUP). - 0305-7364 .- 1095-8290. ; 126:2, s. 219-230
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Tidskriftsartikel (refereegranskat)abstract
- Background and AimsThe ecosystem engineers Sphagnum (peat mosses) are responsible for sequestering a large proportion of carbon in northern peatlands. Species may respond differently to hydrological changes, and water level changes may lead to vegetation shifts in peatlands, causing them to revert from sinks to sources of carbon. We aimed to compare species-specific responses to water level drawdown within Sphagnum, and investigate which traits affect water economy in this genus.MethodsIn a mesocosm experiment, we investigated how water level drawdown affected water content (WC) in the photosynthetically active apex of the moss and maximum quantum yield of photosystem II (i.e. Fv/Fm) of 13 Sphagnum species. Structural traits were measured, and eight anatomical traits were quantified from scanning electron microscopy micrographs.Key ResultsMixed-effects models indicated that at high water level, large leaves were the most influential predictor of high WC, and at low water level WC was higher in species growing drier in the field, with larger hyaline cell pore sizes and total pore areas associated with higher WC. Higher stem and peat bulk density increased WC, while capitulum mass per area and numerical shoot density did not. We observed a clear positive relationship between Fv/Fm and WC in wet-growing species.ConclusionsWhile we found that most hummock species had a relatively high water loss resistance, we propose that some species are able to maintain a high WC at drawdown by storing large amounts of water at a high water level. Our result showing that leaf traits are important warrants further research using advanced morphometric methods. As climate change may lead to more frequent droughts and thereby water level drawdowns in peatlands, a mechanistic understanding of species-specific traits and responses is crucial for predicting future changes in these systems.
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| 9. |
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| 10. |
- Bisang, Irene, et al.
(författare)
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Can the meiotic sex ratio explain the sex ratio bias in adult populations in the dioicous moss Drepanocladus lycopodioides?
- 2017
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Ingår i: Journal of Bryology. - : Informa UK Limited. - 0373-6687 .- 1743-2820. ; 39:2, s. 115-120
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Tidskriftsartikel (refereegranskat)abstract
- 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 Drepanocladus lycopodioides, we showed that a female bias also exists in the genetic adult sex ratio, using a specifically designed molecular sex-associated marker. Here, we investigated whether the meiotic spore sex ratio contributes to the observed bias in genetic adult sex ratio in natural populations. Earlier attempts to study meiotic sex ratios have involved commonly cultivated ruderals that rapidly express sex in the laboratory. We established single-spore cultures from field-collected sporophytes from these populations and used the marker to assess the sex of individual sporelings. Spore germinability was (near) complete, and mortality among sporelings was virtually absent. The true meiotic sex ratio did not differ from equality, but strongly differed both from the observed genetic sex ratios in the natural adult populations, and from the European scale genetic sex ratio. We conclude that the biased population sex ratios in this species arise at life cycle stages after spore germination. Sexual dimorphism may selectively favour female proliferation during some phase of gametophyte development. Based on methodological progress, we successfully used a perennial study species with rare sexual reproduction, which significantly broadens the life history spectrum investigated in bryophyte sex ratio studies.
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| 11. |
- Boquete, María Teresa, et al.
(författare)
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Current and historical factors drive variation of reproductive traits in unisexual mosses in Europe : A case study
- 2023
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Ingår i: Journal of Systematics and Evolution. - : Wiley. - 1674-4918 .- 1759-6831. ; 61:1, s. 213-226
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Tidskriftsartikel (refereegranskat)abstract
- Unisexual bryophytes provide excellent models to study the mechanisms that regulate the frequency of sexual versus asexual reproduction in plants, and their ecological and evolutionary implications. Here, we determined sex expression, phenotypic sex ratio, and individual shoot traits in 242 populations of the cosmopolitan moss Pseudoscleropodium purum spanning its whole distributional range. We tested whether niche differentiation, sex-specific differences in shoot size, and biogeographical history explained the spatial variation of reproductive traits. We observed high levels of sex expression and predominantly female-biased populations, although both traits showed high intraspecific variation among populations. Sex expression and sex ratio were partly explained by current macroscale environmental variation, with male shoots being less frequent at the higher end of the environmental gradients defined by the current distribution of the species. Female bias in population sex ratio was significantly lower in areas recolonized after the last glacial maximum (recent populations) than in glacial refugia (long-term persistent populations). We demonstrated that reproductive trait variation in perennial unisexual mosses is partially driven by macroscale and historical environmental variation. Based on our results, we hypothesize that sexual dimorphism in environmental tolerance and vegetative growth contribute to sex ratio bias over time, constraining the chances of sexual reproduction, especially in long-term persistent populations. Further studies combining genetic analyses and population monitoring should improve our understanding of the implications of the intraspecific variation in the frequency of sexual versus asexual reproduction in bryophyte population fitness and eco-evolutionary dynamics.
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| 12. |
- Cheng, Jingmin, et al.
(författare)
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Interspecific competition affects spore germination and gametophore development of mosses
- 2023
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Ingår i: Open Research Europe. - 2732-5121. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Interactions between moss species in their earliest growth stages have received little attention. To what extent interspecific competition or priority effects influence spore germination, protonemal development and gametophore emergence is unknown. We evaluated such effects in pairwise interaction between six common bryophyte species: Atrichum undulatum, Bryum argenteum, Ceratodon purpureus, Funaria hygrometrica, Hypnum cupressiforme, Leptobryum pyriforme Methods: Interspecific interactions were assessed in vitro. Spores were sterilized and sown on agar plates in three treatments: 1) as single species cultures (controls), 2) as pairwise species cultures inoculated simultaneously, and 3) with a time lag of 20 days between species. Data on the time needed for spore germination, germination rate, the time needed for gametophore differentiation, number of gametophores per germinated spore and average diameter of colonies were collected. We also performed spore germination tests in single-species cultures at the start and end of the study, as well as tests for density-dependency at spore germination and gametophore formation. Results: We observed strong pairwise interactive effects when sowing spores of different species simultaneously or with a delay of 20 days. The results indicate that spore germination is often inhibited by interspecific competition. The first species has an advantage as compared to the later colonizing species, i.e., an apparent priority effect. Interspecific interactions were also evident during gametophore development and included both inhibition and facilitation. Conclusion: We found pronounced differences in the relative performance of species in interaction with other species during spore germination and gametophore formation. Allelopathic effects are the most probable explanation for these observations. Our results under sterile lab conditions are likely to reflect processes that occur in the wild, governing biotic filtering and bryophyte community assembly during primary and secondary colonization.
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| 13. |
- Cronberg, Nils
(författare)
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Absence of genetic variation in populations of the liverwort Plagiochila porelloides from northern Greece and southern Scandinavia
- 2000
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Ingår i: Lindbergia. - 0105-0761. ; 25:1, s. 20-24
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Populations of the leafy liverwort Plagiochila porelloides from lowland southern Scandinavia and mountain peaks on mainland Greece were screened for polymorphisms at 16 putative isozyme loci. The study areas were chosen to represent regions severely and mildly affected by the Pleistocene glaciations, respectively. As in an earlier study from Poland, total absence of variability was recorded. It is concluded that a population ancestral to the present-day populations may have passed through a severe bottleneck. The data are uninformative regarding the circumstances of this event.
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| 14. |
- Cronberg, Nils, et al.
(författare)
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Alger och blågröna bakterier
- 2008
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Ingår i: Botanik – systematik, evolution och mångfald. - 9789144043043 ; , s. 77-121
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 15. |
- Cronberg, Nils, et al.
(författare)
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Allelopathy in bryophytes - a review
- 2018
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Ingår i: Lindbergia. - : Dutch Bryological and Lichenological Society and Nordic Bryological Society. - 0105-0761. ; 41, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Allelopathy in bryophytes shapes ecosystems by influencing the species composition of both vascular plants and other bryophytes. Several allelopathically active chemicals in bryophytes have been discovered since the latter half of the 20th century and laboratory studies have showed their inhibiting impact on germination, growth and establishment of surrounding plants. However, other studies failed to demonstrate these effects. In the field, other properties of bryophytes might have stronger impacts, such as mechanical obstruction or alterations in temperature. In laboratory studies, water might not be an adequate extractant for active substances, since all of the chemicals claimed to be allelopathic are lipophilic with potentially longer retention times of the active substances in the soil when compared to water-soluble substances.
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| 16. |
- Cronberg, Nils
(författare)
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Animal-mediated fertilization in bryophytes – parallel or precursor to insect pollination in angiosperms?
- 2012
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Ingår i: Lindbergia. - 0105-0761. ; 35, s. 76-85
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Tidskriftsartikel (refereegranskat)abstract
- Bryophytes have until now been absent from all hypotheses regarding the origin of insect pollination of seed plants. The discovery that both springtails and mites are able to transfer sperm in mosses makes it possible to suggest a ’Bryophyte precursor hypothesis of plant pollination’ stating that animal-mediated fertilization in mosses and insect pollination in seed plants is historically linked by homologous or analogous evolution of structures responsible for attraction and reward aimed at a pool of fertilization vectors originally co-evolved with bryophytes and subsequently co-opted by seed plants. The earliest point in time when animal-mediated fertilization of bryophytes, involving springtails and mites, could have arisen is Late Silurian/Early Devonian, ca 280 Myr before the evolutionary radiation of angiosperms. Soil-dwelling microarthropods and wingless insects are assumed to have been the primary vectors transporting sperm in ancient mosses and possibly other groups of bryophytes. These animals may later have secondarily expanded to transfer pollen in gymnosperms and angiosperms, similar to the frequent pollinator shifts observed among angiosperm groups. Several ancestral traits pointed out by recent studies of early angiosperms are in favour of this hypothesis, such as small size of flowers, small and non-sticky pollen, adaptations for growth in moist and shaded habitats close to running water, and weedy growth forms with rapid life-cycles in disturbed habitats. It is also possible to envisage a link from sexual attractants excreted by oogonia in charophyte algae and archegonia in bryophytes to guide sperm, via sugar released to attract insects in pollination drop mechanisms in gymnosperms to more advanced structures specialized for insect attraction such as nectaries and nectar discs in angiosperms.
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| 17. |
- Cronberg, Nils, et al.
(författare)
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Biogeografi
- 2008
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Ingår i: Botanik – systematik, evolution och mångfald. - 9789144043043 ; , s. 387-407
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Cronberg, Nils, et al.
(författare)
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Clonal distribution, fertility and sex ratios of the moss Plagiomnium affine (Bland.) T.Kop. in forests of contrasting age
- 2003
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Ingår i: Journal of Bryology. - : Informa UK Limited. - 1743-2820 .- 0373-6687. ; 25, s. 155-162
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Tidskriftsartikel (refereegranskat)abstract
- Six populations of the clonal forest floor moss Plagiomnium affine from forests of different age were screened for genetic variation at 23 allozyme loci, of which nine were polymorphic. Samples consisting of two adjacent unconnected shoots were taken at regular intervals along one transect from each population. A total of 602 shoots was analysed. Almost 80% of the shoots were sterile (i.e. not expressing male or female gender). Sex remained unknown for only 10% of shoots after identification of genets based on electrophoretic data. We identified a mean number of 3.7 fertile clones per population. The mean length of clones along transects in each population ranged between 2 and 3 in. The size distribution within populations was bimodal, with a few dominant clones and a varying number of much smaller clones. The overall sex ratio was slightly female biased at the ramet level, but balanced at the genet level. Forest age was negatively correlated with percentage of sterile shoots and positively correlated with frequency of sporophytes. In both cases correlations were significant only if population 1, which was subject to extreme soil disturbance by badgers, was excluded. We conclude that the effective population size is larger, and the susceptibility to genetic drift is lower, in old forests.
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| 19. |
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| 20. |
- Cronberg, Nils, et al.
(författare)
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Clonal structure and genet-level sex ratios suggest different roles of vegetative and sexual reproduction in the clonal moss Hylocomium splendens
- 2006
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Ingår i: Ecography. - : Wiley. - 1600-0587 .- 0906-7590. ; 29:1, s. 95-103
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Tidskriftsartikel (refereegranskat)abstract
- The allozyme haplotype was determined for 157 ramets of the unisexual, perennial, clonal moss Hylocomium splendens within five 10×10 cm plots, which had been the subject of demographic studies over a 5-yr period. In addition, 25 shoots were analyzed from outside the plots and from four neighbouring patches. Only four haplotypes were encountered within the plots; one female type occurred in all plots and one male type in four plots, whereas two male haplotypes occurred in only one plot. Genets grew intermingled in all but one plot. The sex ratio within the five plots was female-biased at the ramet level (male:female=1:2.6), but male-biased at the genet level (3:1). Sporophytes were produced abundantly during the study period, but no signs of recruitment from spores were observed in the plots. Nine additional genets were encountered in neighbouring patches but from only one patch each. Four (44%) of these could potentially have been derived from spores generated within the plots. Our results suggest that each patch of H. splendens is colonized by a small number of genets, whereas different patches have different sets of genets, i.e. clonal diversity is determined by vegetative reproduction at within-patch scales and structured by sexual processes at among-patch scales.
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| 21. |
- Cronberg, Nils
(författare)
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Colonization dynamics of the clonal moss Hylocomium splendens on islands in a Baltic land uplift area: reproduction, genet distribution and genetic variation
- 2002
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Ingår i: Journal of Ecology. - : Wiley. - 1365-2745 .- 0022-0477. ; 90:6, s. 925-935
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Tidskriftsartikel (refereegranskat)abstract
- 1 Islands representing four stage classes, dated by their height above sea level, in a Baltic land uplift area were used to study genet level dynamics during colonization of the clonal moss Hylocomium splendens. Allozyme electrophoresis involving 10 polymorphic loci enabled accurate identification of 103 haplotypes from a sample of 694 shoots collected along transects across 10 islands. 2 The populations consisted initially of scattered colonies with single clones. The number of clones, and the tendency of colonies to be multiclonal,increased significantly with increasing age of islands, whilst their mean size decreased significantly. In the Skeppsvik Archipelago, H. splendens thus shows repeated recruitment. 3 The percentage male or female fertile shoots relative to sterile shoots was positively correlated with age of the islands. The sex ratios were skewed during early colonization. 4 Spore capsules were found only in the oldest succession stage-classes. This can be explained by a greater chance for fertile males and females to grow within the fertilization range, which is limited to a few centimetres. 5 Genetic variation was accumulating with increasing population age. Correlations were stronger for mean number of alleles per locus (A) than for gene diversity (H-S). 6 No isolation by distance was detected among populations, indicating efficient and essentially random gene flow, probably occurring via wind-dispersed spores.
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| 22. |
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| 23. |
- Cronberg, Nils
(författare)
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Genetic differentiation between populations of the moss Hylocomium splendens from low versus high elevation in the Scandinavian mountain range
- 2004
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Ingår i: Lindbergia. - 0105-0761. ; 29:1, s. 64-72
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Tidskriftsartikel (refereegranskat)abstract
- To test the genetic relationship between alpine and subalpine forms of Hylocomium splendens, pairwise sampling was undertaken of populations from four areas, representing the southern and northern ranges of the Scandes. From each population I sampled 75 shoots in a hierarchical fashion, and these were screened for variation at 12 allozyme loci. The pairwise genetic identity (I) among subalpine and alpine populations was, respectively, 0.970 and 0.972, versus 0.946 between the altitudinal groups. This suggests that populations from subalpine and alpine zones are genetically differentiated. The total gene diversity (HT) based on polymorphic loci was slightly higher for alpine populations (0.330) than for subalpine populations (0.244), whereas the relative differentiation among populations (GST) was lower for alpine populations (0.054) than for subalpine populations (0.080). The number of observed clones was high in all populations, ranging from 18 to 29. Mean number of recorded haplotypes within 10x10 cm patches was higher in alpine populations than in subalpine populations, which in part could be explained by the nearly double ramet density in the former. I conclude that two main genetic variants of Hylocomium splendens, with different climate associations, occur in Scandinavia.
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| 24. |
- Cronberg, Nils, et al.
(författare)
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Genetic diversity and phenotypic variation in marginal populations of the locally endangered species Hordeum secanlinum (Poaceae).
- 1997
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Ingår i: Plant Systematics and Evolution. - 1615-6110. ; 206:1-4 /March, s. 285-294
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Tidskriftsartikel (refereegranskat)abstract
- Electrophoresis was used to compare variation in hordein polypeptide patterns and isozymes in five marginal populations ofHordeum secalinum (four Swedish and one Danish population) and four populations along the Atlantic coast from Denmark to Spain. Hordein patterns were uniform within and among Swedish and Danish populations whereas the materials from France and Spain were divergent. The banding patterns for nine isozymes (AAT, IDH, MDH, PGD, GPI, ME, ACP, EST, and PRX) agreed with those reported for otherHordeum species. All putative loci were monomorphic with the exception of PRX, which showed three different phenotypes. The five marginal populations varied in seed set and cultivated plants differed in phenological traits.
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| 25. |
- Cronberg, Nils
(författare)
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Genetic diversity of the epiphytic bryophyte Leucodon sciuroides in formerly glaciated versus nonglaciated parts of Europe
- 2000
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Ingår i: Heredity. - 1365-2540. ; 84:6, s. 710-720
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Tidskriftsartikel (refereegranskat)abstract
- Twelve populations of the epiphytic bryophyte Leucodon sciuroides from three major regions representing formerly glaciated and nonglaciated regions of Europe were screened for polymorphisms at 15 putative isozyme loci. The populations clustered into three distinct groups consisting of: (i) a single population from Crete, representing a cryptic unknown taxon; (ii) four Scandinavian populations and two populations from northern Greece; and (iii) the remaining populations from mainland Greece and Crete. The Scandinavian populations were genetically depleted compared with most Greek populations, thus fitting the expectation of generally lower levels of variation in formerly glaciated areas. The transition zone between genetically diverse and depleted populations appears to be located through northern Greece, coinciding with the northern limit of the Mediterranean region. This indicates that genetic variation was lost in populations at the northern limit of glacial refugia. The two groups of populations fit a progenitor-derivative model. They also have contrasting reproductive strategies: the Mediterranean populations reproduce sexually, whereas the other populations propagate vegetatively. Epiphytic species, growing on substrates that are limited in space and time, appear to be especially vulnerable to loss of genetic variation. Lack of genetic variation and therefore low adaptability to increased levels of atmospheric pollution may explain why many epiphytic lichen and bryophytes, including L. sciuroides, are declining over much of Europe.
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