CO2 environment, microclimate and photosynthetic characteristics of the moss Hylocomium splendens in a subarctic habitat

Sonesson, M.; Gehrke, Carola; Tjus, Martin

doi:10.1007/bf00317258

Cited by 59 publications

(48 citation statements)

References 12 publications

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“…It has a wide ecological amplitude (Tamm, 1953;Callaghan et a!., 1978;Sonesson et a!., 1992;1994) and extends from the temperate zone to the High Arctic of the N. Hemisphere (Schofield, 1985).…”

Section: The Plantmentioning

confidence: 99%

Genetic variation in the clonal bryophyte Hylocomium splendens at hierarchical geographical scales in Scandinavia

1997

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The widespread bryophyte Hylocomium splendens was sampled in a hierarchical fashion from populations representing four Scandinavian vegetation zones. Allozyme electrophoresis revealed variation at 11 out of 13 screened loci, allowing accurate identification of genotypes. From a total sample of 298 shoots 79 genotypes could be detected, giving the proportion of distinguishable genotypes (PD) of 0.265. The total allelic diversity (HT) based on polymorphic loci was 0.274. The relative differentiation among populations was low (GST= 0.073), indicating a high level of gene flow. Differences in population structuring occurred between a subarcticalpine site vs. three lowland sites. The subarctic-alpine population had one widespread clone, which appeared to be propagated by dispersal of vegetative fragments. That population also comprised many rare genotypes, often occurring together within 10 x 10 cm patches. The lowland populations had genotypes that were locally common and often dominant within the patches. When identical genotypes were observed in multiple patches within these populations, it was usually statistically highly probable that they had arisen by independent sexual recombinations.

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Section: The Plantmentioning

confidence: 99%

Genetic variation in the clonal bryophyte Hylocomium splendens at hierarchical geographical scales in Scandinavia

1997

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“…In laboratory studies, the moss Hylocomium splendens that naturally experiences high CO 2 levels in the birch woodlands of the Swedish sub-Arctic, was shown to have photosynthetic rates that were limited by light, temperature and water for most of the growing season (92). Enhanced CO 2 for 5 months decreased photosynthetic efficiency, light compensation point and maximum net photosynthesis and, surprisingly, growth (94).…”

Section: Responses Of Plants To Increased Atmospheric Comentioning

confidence: 99%

“…There are very few manipulation experiments of atmospheric CO 2 concentrations in the field in the Arctic (87-89), but there are more laboratory experiments on Arctic vascular plants (90) and mosses and lichens (91)(92)(93)(94).…”

Section: Responses Of Plants To Increased Atmospheric Comentioning

confidence: 99%

Responses to Projected Changes in Climate and UV-B at the Species Level

Callaghan¹,

Björn²,

Chernov³

et al. 2004

Ambio

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Environmental manipulation experiments showed that species respond individualistically to each environmental-change variable. The greatest responses of plants were generally to nutrient, particularly nitrogen, addition. Summer warming experiments showed that woody plant responses were dominant and that mosses and lichens became less abundant. Responses to warming were controlled by moisture availability and snow cover. Many invertebrates increased population growth in response to summer warming, as long as desiccation was not induced. CO 2 and UV-B enrichment experiments showed that plant and animal responses were small. However, some microorganisms and species of fungi were sensitive to increased UV-B and some intensive mutagenic actions could, perhaps, lead to unexpected epidemic outbreaks. Tundra soil heating, CO 2 enrichment and amendment with mineral nutrients generally accelerated microbial activity. Algae are likely to dominate cyanobacteria in milder climates. Expected increases in winter freeze-thaw cycles leading to ice-crust formation are likely to severely reduce winter survival rate and disrupt the population dynamics of many terrestrial animals. A deeper snow cover is likely to restrict access to winter pastures by reindeer/caribou and their ability to flee from predators while any earlier onset of the snow-free period is likely to stimulate increased plant growth. Initial species responses to climate change might occur at the sub-species level: an Arctic plant or animal species with high genetic/racial diversity has proved an ability to adapt to different environmental conditions in the past and is likely to do so also in the future. Indigenous knowledge, air photographs, satellite images and monitoring show that changes in the distributions of some species are already occurring: Arctic vegetation is becoming more shrubby and more productive, there have been recent changes in the ranges of caribou, and "new" species of insects and birds previously associated with areas south of the treeline have been recorded. In contrast, almost all Arctic breeding bird species are declining and models predict further quite dramatic reductions of the populations of tundra birds due to warming. Species-climate response surface models predict potential future ranges of current Arctic species that are often markedly reduced and displaced northwards in response to warming. In contrast, invertebrates and microorganisms are very likely to quickly expand their ranges northwards into the Arctic.

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“…by respiration of weakly photosynthetic or non-photosynthetic stems of vascular plants in the case of stem epiphytes, or respiration by roots and other soil biota for ground-dwelling bryophytes. However, in the high-latitude bryophytes examined by Sonesson et al (1992) and Tarnawaski et al (1992), the vascular plant source is less likely especially for mainland Antarctica (Tarnawaski et al 1992) with only two species of vascular plant (Fogg 1998). Here the simplest assumption is that the CO 2 from the substrate comes from bryophyte photosynthate produced from atmospheric CO 2 at some earlier Yeoh et al (1981) time, although earlier photosynthesis by terrestrial algae and cyanobacteria, or allochthonous inputs (e.g.…”

Section: Rubisco: Molecular Phylogenetic and Functional Studies In Rementioning

confidence: 99%

Land plant biochemistry

Raven

2000

Phil. Trans. R. Soc. Lond. B

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Biochemical studies have complemented ultrastructural and, subsequently, molecular genetic evidence consistent with the Charophyceae being the closest extant algal relatives of the embryophytes. Among the genes used in such molecular phylogenetic studies is that (rbcL) for the large subunit of ribulose bisphosphate carboxylase-oxygenase (RUBISCO). The RUBISCO of the embryophytes is derived, via the Chlorophyta, from that of the cyanobacteria. This clade of the molecular phylogeny of RUBISCO shows a range of kinetic characteristics, especially of CO 2 a¤nities and of CO 2 /O 2 selectivities. The range of these kinetic values within the bryophytes is no greater than in the rest of the embryophytes; this has implications for the evolution of the embryophytes in the high atmospheric CO 2 environment of the late Lower Palaeozoic. The di¡erences in biochemistry between charophycean algae and embryophytes can to some extent be related functionally to the structure and physiology of embryophytes. Examples of components of embryophytes, which are qualitatively or quantitatively di¡erent from those of charophytes, are the water repellent/water resistant extracellular lipids, the rigid phenolic polymers functional in waterconducting elements and mechanical support in air, and in UV-B absorption, £avonoid phenolics involved in UV-B absorption and in interactions with other organisms, and the greater emphasis on low M r organic acids, retained in the plant as free acids or salts, or secreted to the rhizosphere. The roles of these components are discussed in relation to the environmental conditions at the time of evolution of the terrestrial embryophytes. A signi¢cant point about embryophytes is the predominance of nitrogen-free extracellular structural material (a trait shared by most algae) and UV-B screening components, by contrast with analogous components in many other organisms. An important question, which has thus far been incompletely addressed, is the extent to which the absence from bryophytes of the biochemical pathways which produce components found only in tracheophytes is the result of evolutionary loss of these functions.

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CO2 environment, microclimate and photosynthetic characteristics of the moss Hylocomium splendens in a subarctic habitat

Cited by 59 publications

References 12 publications

Genetic variation in the clonal bryophyte Hylocomium splendens at hierarchical geographical scales in Scandinavia

Genetic variation in the clonal bryophyte Hylocomium splendens at hierarchical geographical scales in Scandinavia

Responses to Projected Changes in Climate and UV-B at the Species Level

Land plant biochemistry

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