We discovered a previously unreported population of the Antarctic vascular plant Colobanthus quitensis (Kunth) Bartl, containing 267 individuals on Gamage Point, Arthur Harbor, Anvers Island, Antarctic Peninsula (64°46'S, 64°04'W). Mean diameters of individual cushions ranged from 3.0 to 42.1 mm. Using a previously reported growth rate for this species of 3 mm yr-1 we estimate the population became established in early 1982 and has a mean age of 5 yr. This population was younger than two populations on Bonaparte Point (approximately 200 m distant) that had individuals we estimated to be >30 yr old and mean ages of 12 and 15 yr. We suspect that the Carnage Point population spread from one of the Bonaparte Point populations. Cushion recruitment per mature cushion in the Gamage Point population was positively correlated with mean summer (December-February) air temperatures, suggesting that temperature is an important factor limiting the establishment of C. quitensis in the maritime Antarctic. The presence of apparently suitable but uncolonized sites in the proximity of established populations of vascular plants, combined with increasing mean summer air temperatures on the Antarctic Peninsula, suggest that expansion of existing populations and the establishment of new populations on the Antarctic Peninsula is likely to continue.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)