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Effects of a rapid, unseasonal rewetting event on mineral location in Antarctic lichens

Citation

Hovenden, MJ, Effects of a rapid, unseasonal rewetting event on mineral location in Antarctic lichens, New Phytologist, 137, (2) pp. 241-246. ISSN 0028-646X (1997) [Refereed Article]

DOI: doi:10.1046/j.1469-8137.1997.00785.x

Abstract

During the middle of the 1992 austral winter in the northern Windmill Islands, continental Antarctica, a highly unusual climatic event occurred in which the air temperature exceeded 0 °C for some 60 h, at the end of which there was a significant rain shower before the ambient temperature returned to subzero conditions. This event caused most of the snow cover to melt and refreeze as clear ice. Lichens were thus rehydrated in the dark, in some places completely inundated, then frozen in ice. The effect that these conditions had on the distribution of K, Na, Mg and Ca within the thallus was estimated for two of the dominant macrolichen species, Umbilicaria decussata (Vill.) Zahlbr. and Usnea sphacelata R.Br, from three sites on a knoll on Clark Peninsula. One site acted as a natural control, owing to the very deep snow cover at the site, which protected lichens from the rewetting event. Despite persistent differences between species and the various sites, there was no overall effect of the climatic event on the membrane integrity of either lichen species. Only Usnea sphacelata from the most exposed site showed a significant leakage of K across the cell membrane, which indicated a loss of membrane integrity. Overall, both species were tolerant of the extreme conditions, although Umbilicaria decussata was the more tolerant.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Terrestrial Ecology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Hovenden, MJ (Associate Professor Mark Hovenden)
ID Code:10342
Year Published:1997
Web of Science® Times Cited:3
Deposited By:Plant Science
Deposited On:1997-08-01
Last Modified:2011-08-11
Downloads:0

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