The thallus nitrogen (N) concentration of two dominant macrolichens of continental Antarctica (Usnea sphacelata and Umbilicaria decussata) was estimated each month for I year on a low rounded knoll on Clark Peninsula, Windmill Islands, Wilkes Land, Antarctica. Thallus N was significantly higher in Umbilicaria decussata than in Usnea sphacelata and varied according to site. During the winter months, when the lichens were metabolically inactive, thalli gradually accumulated N. At the onset of warmer conditions, thallus N content fell dramatically in both species, with the timing of the decline being related to microclimatic conditions. The strongly seasonal pattern of metabolic activity in these species is reflected in their nitrogen relations. (C) 2000 Annals of Botany Company.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Plant Biology
Research Field:	Plant Physiology
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:	20493
Year Published:	2000
Web of Science® Times Cited:	4
Deposited By:	Plant Science
Deposited On:	2000-08-01
Last Modified:	2011-08-04
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