Studies on the Taxonomy and Distribution of Sphagnum V. A New Species of Sphagnum from Quebec

Spore capsules of four Sphagnum species were buried at different depths in peat on a bog. Spore viability was determined after 0, 1, 2 and 3 yr. Viability generally declined with time, but viable spores were still found at all depths after 3 yr. The light-coloured spores of S. balticum and S. tenellum retained their viability better than the darker spores of S. fuscum and S. lindbergii. Survival was highest under wet but aerobic conditions, but was also high under humid or periodically desiccated conditions. By contrast, most spores stored under wet, anaerobic conditions died within 2-3 yr. These results, and predictions from them, are not consistent with earlier results for spores of long-lived and dominant bryophytes, or for seeds of phanerogams of undisturbed wetlands and forests. There was no correlation between spore size and longevity across species, but the small spores from small capsules of S. balticum and S. tenellum generally showed higher viability than those from the medium-sized and large capsules of the same species. This suggests a positive intraspecific relationship between longevity and dispersal distance. There was an indication of conditional dormancy, controlled by weather, in Sphagnum spores. The experiments indicate that Sphagnum spores can form a long-term persistent spore bank under suitable conditions, with a half-life of between 1 and 20 yr (mean across species of 2n6 and 5n0 yr at two depths studied), and with potential values in individual spore capsules of several decades, or even of centuries. Sphagnum spores kept refrigerated showed 15-35% viable spores after 13 yr. The capacity to form a persistent spore bank that can be activated whenever favourable conditions occur might help explain the wide geographical distribution of many Sphagnum species in the boreal and temperate zones, where they have managed to colonize almost every suitable patch of acidic, nutrient-poor wetland.

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“…12 µm diameter), presumably of the parasitic fungus Bryophytomyces sphagni (Nawashin) (Maass & Harvey, 1973 ;Bell, 1989).…”

Section: Field Experimentsmentioning

confidence: 99%

Experimental evidence for a persistent spore bank in Sphagnum

Sundberg

Rydin

2000

New Phytologist

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“…The most likely explanation is that spring wetness enhances spermatozoid dispersal and fertilization (Maass and Harvey 1973;Grabovik 1986;Cronberg 1993). However, stepwise regressions were run on the data over precipitation (monthly totals of all 1-to 5-month periods in May-September) and sporophyte densities presented by Grabovik (1986) from Russia and it was found that precipitation in the preceding summer (here in May-June) was again the most important (positive) predictor for sporophyte production in two subpopulations of S. fuscum over 5 years (R 2 = 0.87 and 0.77, p = 0.021 and 0.05).…”

Section: Factors Affecting Sporophyte Densitymentioning

confidence: 99%

“…Sporophyte production in Sphagnum varies among regions: virtually all Sphagnum species have been found with sporophytes in Scandinavia (reviewed by Cronberg 1993), the southeastern United States (Andrus 1986), and Nova Scotia (Maass and Harvey 1973), while seven of 32 taxa are reported to lack sporophytes in the British Isles (Hill 1978). Monoecious species generally produce sporophytes frequently, while dioecious species often do so occasionally or rarely (Cronberg 1993).…”

Section: Introductionmentioning

confidence: 98%

“…Thus, it can be used to provide an indication of clone size and (or) local distribution of sexes. Maass and Harvey (1973) reported that the majority of Sphagnum species in Nova Scotia produced sporophytes in 4 out of 5 years. They suggested that the lack of sporophytes in one year was an effect of a long dry period in March-May that inhibited fertilization.…”

Section: Introductionmentioning

confidence: 98%

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Sporophyte production and spore dispersal phenology in Sphagnum: the importance of summer moisture and patch characteristics

Sundberg¹

2002

Can. J. Bot.

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Sporophyte production in Sphagnum was followed annually in 80 permanent 1-m 2 plots at the bog expanse of a pristine mire during 1993-1999 and in 60 plots in peat pits abandoned 50 years ago during 1996-1999 in east central Sweden. The nine most abundant Sphagnum species produced sporophytes, with mean annual production ranging from 0.64 to 20 sporophytes/dm 2 of cover among species. An estimated mean of 16 million Sphagnum spores/m 2 mire area was produced annually at both mires. At the pristine mire, sporophyte production was positively related to the amount of precipitation the previous summer, suggesting that gametangium formation is especially sensitive to summer droughts. At the wetter peat pits, the amount of precipitation during spring in the year of sporophyte formation appeared more important, probably by positively affecting male gamete dispersal and fertilization. Larger patches had a higher probability of producing sporophytes at least once, showing areas with both sexes present among dioecious species, and thus giving an indication of clone size. Only slight differences in sporophyte production were found between the two mires, apart from effects of hydrological conditions and patch size. This indicates numerous colonizations at the peat pits. Summer droughts affected sporophyte maturation negatively by drying out sporophytes prematurely. Spore release phenology differed among species by up to a month and lasted from the beginning of July until the end of August. The early timing of spore dispersal in the most drought-sensitive, lawn-inhabiting sphagna should reduce the risk of sporophytes drying out prematurely during summer droughts.Résumé : L'auteur a suivi annuellement la production des sporophytes de Sphagnum dans 80 parcelles permanentes de 1 m 2 , à la marge d'expansion d'une tourbière vierge, de 1993 à 1999, et dans 60 parcelles dans une tourbière excavée et abandonnées depuis 50 ans, de 1996 à 1999, du centre oriental de la Suède. Les neuf espèces les plus abondantes de Sphagnum produisent des sporophytes avec une production annuelle moyenne de 0,64 à 20 sporophytes/dm 2 de couverture, pour l'ensemble des espèces. On estime que la production annuelle de spores de Sphagnum atteint 16 million/m 2 dans chacune des deux tourbières. Dans la tourbière vierge, la production de sporophytes est positivement reliée à la quantité de précipitation au cours de l'été précédent, ce qui suggère que la formation des gamétanges est particulière-ment sensible aux sécheresses estivales. Dans les tourbières excavées plus humides, la quantité de précipitations au cours du printemps de l'année de formation des sporophytes semble plus importante, probablement en favorisant la dispersion des gamètes mâles et la fertilisation. Les superficies les plus grandes offrent une plus grande probabilité de produire des sporophytes au moins une fois, mettant en évidence les surfaces comportant les deux sexes parmi les espèces dioïques et donnant ainsi une indication de la dimension du clone. On observe que de petites différen...

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“…Three other section Sphagnum species are reported to be polyploids: S centrale, S. palustre, and S.papillosum (Bryan 1955;holmen 1955;Maass & harvey 1973;Fritsch 1991;Temschetal. 1998), and preliminary data for S. palustre shows that it has a pattern of microsatellite alleles similar to that of S. cristatum (E. F. Karlin & a. J. Shaw unpubl.…”

Section: Sphagnum Cristatummentioning

confidence: 99%

Systematics ofSphagnumsectionSphagnumin New Zealand: A microsatellite‐based analysis

Karlin

Boles

Shaw

2008

New Zealand Journal of Botany

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The systematics of Sphagnum section Sphagnum in New Zealand has been controversial. Two species are currently recognised in the New Zealand flora, S. cristatum and S. perichaetiale, but the presence of the widespread S. magellanicum has been debated. An analysis of 16 microsatellite loci shows that the gametophytes of Sphagnum perichaetiale appear to have one monoploid set of chromosomes (i.e., are haploid). Fixed heterozygosity at 10 loci indicates that S. cristatum is an alloploid. A red morphotype of S. cristatum, similar in macroappearance to S. magellanicum, is not genetically differentiated from the more common brown-green morphotypes of S. cristatum. Although analysis of the microsatellite data for S. cristatum showed most of the genetic variation to be within populations, significant variation did occur among populations within regions and also between regions.

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Studies on the Taxonomy and Distribution of Sphagnum V. A New Species of Sphagnum from Quebec

Cited by 7 publications

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Experimental evidence for a persistent spore bank in Sphagnum

Experimental evidence for a persistent spore bank in Sphagnum

Sporophyte production and spore dispersal phenology in Sphagnum: the importance of summer moisture and patch characteristics

Systematics ofSphagnumsectionSphagnumin New Zealand: A microsatellite‐based analysis

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