Growth rate of Antarctic mosses derived from bomb radiocarbon.

• Main Authors: Fink, D, Hua, Q, Clarke, LJ, Robinson, SA
• Format: Other/Unknown Material
• Language: English
• Published: 2009
• Subjects: Antarctica; Mosses; Bombs; Growth; Isotope Dating; Mass Spectroscopy; Antarctic; East Antarctica; Vestfold Hills; Vestfold; Windmill Islands; Antarc*; Schistidium antarctici
• Online Access: http://apo.ansto.gov.au/dspace/handle/10238/2825

At the previous Radiocarbon Conference in Oxford, 2006, we reported our preliminary results on the use of bomb radiocarbon for the determination of growth rates of two moss species collected from east Antarctica in January 2005. Here, we present an update of this study for four different moss species (Bryoerythrophyllum recurvirostre, Bryum pseudotriquetrum, Schistidium antarctici, and Ceratodon purpureus) from the Vestfold Hills and Windmill Islands in east Antarctica. Samples were collected as a “core” from moss turfs. Approximately 10–20 of the longest shoots were separated from each core and cut into 3-mm sections for AMS 14C analysis. The samples were cleaned with dilute HCl acid, then combusted to CO2 and converted to graphite. AMS radiocarbon measurements have been carried out using the STAR facility at ANSTO. The 14C profile in most cores showed both the rising and falling limbs of bomb radiocarbon, implying that these mosses began growing over 50 years ago. Our results indicated that these Antarctic mosses have grown slowly with average rates ranging from 0.6 to 1.3 mm yr–1. This study is the first to determine the growth rates of Antarctic mosses over a time period spanning decades rather than individual or multiple field seasons. The results also give us an opportunity to investigate whether temporal variations in moss growth rates correlate with climatic change in Antarctica.