The biology and ecology of the liverwort <i>Cephaloziella varians</i> in Antarctica

Newsham, Kevin K.

doi:10.1017/s0954102009990630

Cited by 37 publications

(20 citation statements)

References 37 publications

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“…varians are restricted to drier sites and S. antarctici dominates the wettest areas (Wasley et al 2006b;Selkirk & Seppelt 1987), in the Ross Sea region C. purpureus has been reported as dominant in the wettest areas whilst Bryum species were more common in slightly drier areas (Seppelt et al 2010) and in the maritime Antarctic, C. varians was found in moist to wet environments (Newsham 2010) whilst S. antarctici is found in "dry" sites on Signy Island (Smith 1972). Comparisons of seasonal water availability (or δ 13 C measurements) in bryophytes from these other sites would be useful to standardise and explain these contrasting results.…”

Section: Discussionmentioning

confidence: 99%

Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts

et al. 2012

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M. (2012). Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts. Biodiversity,, 257-264. Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts AbstractExtreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves, will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic region, this study surveyed finescale bryophyte patterns and turf water and nutrient contents along community gradients in the Windmill Islands, East Antarctica. The survey found that the Antarctic endemic, Schistidium antarctici, dominated the wettest habitats, Bryum pseudotriquetrum distribution spanned the gradient, whilst Ceratodon purpureus and Cephaloziella varians were restricted to the driest habitats. These patterns, along with knowledge of these species relative physiology, suggest the endemic Schistidium antarctici will be negatively impacted under a drying trend. This study provides a model for quantitative finescale analysis of bryophyte distributions in cryptogamic communities and forms an important reference site for monitoring impacts of climate change in Antarctica. AbstractExtreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic region, this study surveyed finescale bryophyte patterns and turf water and nutrient contents along community gradients in the Windmill Islands, East Antarctica. The survey found that the Antarctic endemic, Schistidium antarctici, dominated the wettest habitats, Bryum pseudotriquetrum distribution spanned the gradient, whilst Ceratodon purpureus and Cephaloziella varians were restricted to driest habitats. These patterns, along ...

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Section: Discussionmentioning

confidence: 99%

Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts

et al. 2012

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“…Moss cushions conform to black body solar radiation (Newsham, 2010) and therefore have been found to reach temperatures above 40 °C during the summer months if situated in sun-exposed but wind-sheltered sites (Lewis Smith, 1988). The button, turf and hypolith habits of Antarctic bryophyte communities (see Fig.…”

Section: A Temperature Relationsmentioning

confidence: 99%

“…Schistidium antarctici 5 -10 Lab NP Kappen et al 1989 Cephaloziella varians ≥20 Lab O 2 evolution Newsham 2010 While the bulk of East Antarctica has experienced little significant change in temperature over the last 50 years ( Fig. 1; Turner and Overland, 2009), recent studies suggest that West Antarctica has warmed by over 0.1 °C per decade (Steig et al, 2009b;Ding et al, 2011).…”

Section: Field Laboratory Npmentioning

confidence: 99%

Dominating the Antarctic Environment: Bryophytes in a Time of Change

Bramley-Alves

King

Robinson

et al. 2013

Advances in Photosynthesis and Respiration

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Polar ecosystems, and particularly Antarctica, are one of the few environs in which bryophytes dominate the flora. Their success in these regions is due to bryophytes' ability to withstand an array of harsh conditions through their poikilohydric lifestyle. However, the unique conditions that allow bryophytes to proliferate over other forms of vegetation also create considerable limitations to growth and photosynthetic activity. High latitude areas are already experiencing some of the most pronounced and rapid climatic change, especially in the Arctic, the Sub-Antarctic Islands and Maritime Antarctica, and these are predicted to continue over the next century. This climatic change is already impacting the flora of the polar regions both via direct and/or indirect impacts on plant species. Water availability and temperature are undoubtedly the most influential factors that determine bryophyte productivity in the Antarctic, but the ozone hole is also having an impact either directly via increased ultraviolet-B radiation and/or indirectly through the increasing wind speeds associated with ozone depletion. In a time of shifting climate the dominance of bryophytes in these regions may be threatened.

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“…In addition, Schistidium antarctici was the most UV‐sensitive species among the three, which was related with its lowest UV‐screening potential. Despite the relationship of UVACs compartmentation with UV tolerance in bryophytes, only a few additional studies have analytically differentiated SUVACs and IUVACs (Fabón, Martínez‐Abaigar, Tomás, & Núñez‐Olivera, ; Fabón, Monforte, Tomás‐Las‐Heras, Martínez‐Abaigar, & Núñez‐Olivera, ; Hespanhol, Fabón, Monforte, Martínez‐Abaigar, & Núñez‐Olivera, ; Lappalainen, ; Newsham, ; Snell et al., ; Waterman et al., ). Although none of them tested the relationship between UVACs compartmentation and UV tolerance, these studies demonstrated that IUVACs were more abundant than SUVACs in all the mosses considered (except B. pseudotriquetrum , which had almost equal concentrations of SUVACs and IUVACs: Clarke & Robinson, ), but the only liverwort studied showed the opposite pattern (Fabón et al., ).…”

Section: Introductionmentioning

confidence: 99%

Cell compartmentation of ultraviolet‐absorbing compounds: An underexplored tool related to bryophyte ecology, phylogeny and evolution

2018

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Excessive exposure to ultraviolet (UV) radiation can be harmful to photosynthetic organisms, that most frequently respond with the accumulation of protective UV‐absorbing compounds (UVACs). UVACs location in different cell compartments can influence their preferential protective role as antioxidants and/or UV screens. However, the phylogenetic, ecological and evolutionary implications of UVACs compartmentation has been little studied, particularly in bryophytes. We analysed UVACs in the methanol‐soluble and ‐insoluble fractions (SUVACs and IUVACs respectively) in extracts of 87 bryophytes belonging to their three evolutionary lineages: 22 liverworts, 64 mosses and one hornwort. Assuming that the cell wall‐bound IUVACs are more effective UV screens than the mainly vacuolar SUVACs, thus conferring a higher UV tolerance, we evaluated whether UVACs levels and compartmentation were related to: (1) the bryophyte phylogeny down to the Order level; and (2) the bryophyte ecological attributes, including sun exposure and Ellenberg indicator values (numerical system classifying species' habitat along gradients of environmental factors). A similar phylogenetic and ecological analysis was conducted on the sclerophylly index (the ratio between the dry mass and the surface area of the bryophyte shoot). Mosses showed lower SUVACs but higher IUVACs and total UVACs, together with higher IUVAC/SUVAC ratios, than liverworts. Thus, mosses would better tolerate UV radiation than liverworts, which matches well with their general ecological preferences. As bryophytes were the earliest diverging land plants, we could infer that the different UVACs compartmentation between mosses and liverworts could have influenced their ecological segregation upon plant land colonization. UVACs compartmentation also differed between the two major moss lineages (acrocarpous and pleurocarpous), while the anatomically peculiar Sphagnales were the best characterized Order. There were not solid relationships between UVACs and the ecological attributes considered. Hence, UVACs might be mainly constitutive in bryophytes, depending more on the species phylogeny than on the habitat occupied in nature. Liverworts were less sclerophyllous than mosses, and, as in tracheophytes, water restrictions and high sun exposures increased sclerophylly. In conclusion, UVACs compartmentation represents an ecophysiological trait useful to understand the bryophyte ecophylogeny, because different compartmentation modalities seem to imply different UV adaptations and tolerance. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13048/suppinfo is available for this article.

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The biology and ecology of the liverwort Cephaloziella varians in Antarctica

Cited by 37 publications

References 37 publications

Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts

Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts

Dominating the Antarctic Environment: Bryophytes in a Time of Change

Cell compartmentation of ultraviolet‐absorbing compounds: An underexplored tool related to bryophyte ecology, phylogeny and evolution

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