Seasonal Trends in Nitrogen Status of Antarctic Lichens

• Published in: Annals of Botany
• Main Author: Hovenden, MJ
• Format: Article in Journal/Newspaper
• Language: English
• Published: Academic Press Ltd 2000
• Subjects: Biological Sciences; Plant Biology; Plant Physiology; Antarctic; Wilkes Land; Windmill Islands; Clark Peninsula; Antarc*; Antarctica
• Online Access: https://doi.org/10.1006/anbo.2000.1248; http://ecite.utas.edu.au/20493

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.