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- Rosato, Vilma G., et al.
(författare)
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Caloplaca austrocitrina (Teloschistaceae) new for South America, based on molecular and morphological studies
- 2010
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 1938-4378. ; 113:1, s. 124-128
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Tidskriftsartikel (refereegranskat)abstract
- Specimens of Caloplaca belonging to the group of C. citrina (Hoffm.) Th. Fr. were collected in different localities in the provinces of Buenos Aires (Argentina) and studied using morphology and nrITS data. They were identified as C. austrocitrina Vondrak, Riha, Arup & Sochting, a species newly described from the Black Sea area, but also found in other European countries. These findings are the first mention of this species for South America and broaden its distribution range considerably. The results also show that the specimens from Argentina are genetically very similar to the European ones and that the variation in this gene within the species seems to be very low.
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- Sonesson, Mats, et al.
(författare)
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Seasonal variation in concentrations of carbohydrates and lipids in two epiphytic lichens with contrasting, snow-depth related distribution on subarctic birch trees
- 2011
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 1938-4378 .- 0007-2745. ; 114:3, s. 443-452
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Tidskriftsartikel (refereegranskat)abstract
- The lichens Parmelia olivacea and Parmeliopsis ambigua are common epiphytes in subarctic forests in Europe. They differ in abundance and vertical distribution particularly on birch trees, and these differences relate to the level and duration of the winter snow cover. Parmeliopsis ambigua is covered much of the cold season on the lower trunk whereas P. olivacea occurs well above the snow surface. Periods over 6 months under snow have no apparent effect on P. ambigua thalli while much shorter snow cover has been demonstrated to kill P. olivacea. It was hypothesized that the contrasting distributions are due to differences in growth rates and in size and quality of non-structural carbon stores in their tissues affecting their endurance to extended periods of dark respiration. To test these hypotheses, growth measurements were performed on both species and their thalli were sampled for chemical analyses. The results show that the mean annual margin extension growth of P. olivacea thalli was significantly higher than that of P. ambigua, i.e. 1.1 mm and 0.5 mm, respectively. The average non-structural carbohydrate concentration in the two species did not differ, but the annual concentration of storage lipids (triacylglycerol) in P. ambigua was four times higher than that in P. olivacea, despite a shorter growing season and lower rate of photosynthesis. The proportion of polyunsaturated fatty acids in structural (polar) lipids was high in both species, i.e. 77% in P. olivacea and 64% in P. ambigua, which appears to enable both species to withstand low ambient thallus temperatures. The higher concentration of storage lipids in P. ambigua allows survival in environments where P. olivacea would respire to death, e.g. under a prolonged snow cover. Parmeliopsis ambigua avoids competition by establishing toward the base of the tree trunk, where P. olivacea would not survive.
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3. |
- Wyatt, Robert, et al.
(författare)
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Differences in genetic diversity and reproductive performance of a moss, a leafy liverwort, and a thalloid liverwort from forests of contrasting ages
- 2023
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 1938-4378. ; 126:1, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- Two competing predictions regarding highly dispersible clonal plants, such as bryophytes, expect levels of genetic diversity to either increase or decrease over time following a disturbance that opens habitat for colonization. Following up on previous research that found higher levels of genetic variation in bryophytes from relatively undisturbed forest sites, we examined unisexual, haploid species of a moss (Plagiomnium ciliare), a leafy liverwort (Porella platyphylloidea), and a thalloid liverwort (Conocephalum conicum sensu lato) from the Mountains, Piedmont, and Coastal Plain of the southeastern United States. In terms of time since last disturbance, sites were ranked Mountains > Piedmont > Coastal Plain. Measures of genetic variation, including percentage of loci polymorphic, mean number of alleles per locus, mean expected heterozygosity, and number of multilocus genotypes, all fit the prediction that genetic diversity should increase over time. We also examined several components of reproductive success expected to influence levels of genetic variation, including colony size, colony mixing, sex expression, phenotypic sex ratio, and sporophyte production (percentage of females producing sporophytes). Most, but not all, of our predictions for populations of varying time since last disturbance were fulfilled, although other ecological differences related to soil, climate, and vegetation are also likely to influence reproductive success.
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4. |
- Caruso, Alexandro, et al.
(författare)
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Influence of substrate age and quality on species diversity of lichens and bryophytes on stumps
- 2009
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 0007-2745. ; 112, s. 520-531
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Tidskriftsartikel (refereegranskat)abstract
- Stumps from the last felling constitute a large proportion of dead wood in young managed forests. Yet, the knowledge of the diversity of stump-inhabiting organisms is poor. We studied the importance of substrate age and quality to lichen and bryophyte diversity on the cut surface of stumps in south-central Sweden. In total, we found 53 lichens and 35 bryophytes on 449 Norway spruce stumps in a forest stand chronosequence of four age classes: 4-5, 8-9, 12-13 and 16-18 years old stands. The influence of substrate age and substrate quality on species diversity differed between lichens and bryophytes. Lichen species richness was higher for age classes 2-4 compared to age class 1, whereas bryophyte richness was higher in age classes 3-4 than in 1. Further, lichen richness increased with increasing stump height and the presence of surface structural components (chairs and levels), which together with decay also influenced lichen species composition. Conversely, increasing stump height and the presence of levels decreased bryophyte richness, which in turn increased with increasing decay, surface area and number of surrounding trees and shrubs. Only decay explained differences in bryophyte species composition. Stumps in this region seem more important to overall lichen diversity, because there were on average more lichen species per stump and we only found common bryophytes but several uncommon lichens. The different responses of lichens and bryophytes to age and substrate variables indicates, however, the importance of including several organism groups in species diversity studies of dead wood.
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7. |
- Frisch, Andreas, et al.
(författare)
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Herpothallon rubroechinatum (Arthoniaceae), a new species from tropical and subtropical America
- 2010
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 0007-2745. ; 113, s. 144-148
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Tidskriftsartikel (refereegranskat)abstract
- Herpothallon rubroechinatum is described from the U.S.A. (Florida), Costa Rica and Peru. The new species is characterised by scattered red anthraquinone crystals being attached to hyphae projecting from the thallus, the globose to cylindrical pseudoisidia, a closely adnate thallus, and psoromic acid as the main lichen compound; pycnidia are common at the tips of the pseudoisidia. The medulla of the new species shows a patchily distributed amyloid reaction. Contrary to previous reports, the amyloidity of the medulla was observed in all Herpothallon species re-investigated during this study. H. rubroechinatum is compared to the two other red pigmented species that contain psoromic acid, H. australasicum that lacks pigment crystals on the pseudoisidia, and H. globosum that has a loosely attached thallus and a well developed red hypothallus.
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8. |
- Fritz, Örjan, et al.
(författare)
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Interacting effects of tree characteristics on the occurrence of rare epiphytes in a Swedish beech forest area
- 2009
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 0007-2745. ; 112, s. 488-505
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Tidskriftsartikel (refereegranskat)abstract
- Many epiphytes in Swedish beech forests are associated with old and damaged trees. In this study we examined the impact of bark, soil and stemflow pH, water-holding capacity and bark structures on this association. We also analyzed whether the influence of these factors differed between species of conservation concern (red-listed and indicator species of woodland key habitats) and species not of conservation concern. One hundred and one age-determined living beech trees (range 58-277 yrs) in 13 beech-dominated stands were surveyed in a forest landscape in southern Sweden. We recorded 119 species in total (76 lichens, 43 bryophytes) of which 21 were red-listed and 17 indicator species (26 lichens, 12 bryophytes). NMS ordination showed that the species composition of lichens changed primarily with tree age and along the gradient of smooth bark versus moss cover. Bark pH and tree vitality were the most important gradients for bryophyte composition. The combination of old damaged beech trees and high bark pH resulted in the highest mean number of species of conservation concern for both lichens and bryophytes. The link between these factors is partly explained by a positive effect of tree age on the stemflow pH. Species number of bryophytes not of conservation concern increased with bark pH, whereas the corresponding group of lichens was favored primarily by increased light availability. Neither the water-holding capacity of bark nor soil pH affected patterns of species number. The results from this study show that old beech trees infected by fungi, with a higher bark pH, are the most valuable trees for epiphytes of conservation concern.
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9. |
- Giralt, Mireia, et al.
(författare)
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A new chemotype of Buellia triseptata (Physciaceae)
- 2010
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Ingår i: The Bryologist. - : ABLS. - 0007-2745 .- 1938-4378. ; 113:1, s. 72-76
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Tidskriftsartikel (refereegranskat)abstract
- Two collections of a chemically distinctive corticolous Buellia species were discovered in the herbarium of Sampaio at the University of Porto (po). A detailed morphological and chemical study of the specimens, as well as of additional material for comparison purposes, showed that they agree with Buellia triseptata, only differing by containing xanthones. They are here provisionally regarded as representing a new chemotype of B. triseptata. Further, the generic assignment of B. triseptata is discussed.
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