Abstract

Seed burial experiments were conducted for 15 alpine species derived from 15 genera and 12 plant families from a subantarctic location on Cerro Riñón, Tierra del Fuego, 54°S, Chile. Batches of seed buried at 5 cm depth at 550 m elevation in February 1996 were exhumed after 335, 363, and 755 days, and their status and viability determined. Thirteen species (87%), one marginally (Acaena magellanica, Anemone multifida, Azorella lycopodioides, Bolax gummifera, Calceolaria biflora, Caltha appendiculata, Draba magellanica, Empetrum rubrum, Gentianella magellanica, Gunnera magellanica, Luzula alopecurus, Oremomyrrhis hookeri (marginal), Pernettya pumila), were judged as having potential to form a persistent soil seed bank, while two (Senecio magellanicus, Berberis buxifolia) only showed evidence of a transient seed bank. Seed viability in residual intact seeds was high and showed little tendency to diminish over the two-year experimental period, indicating optimal conditions for seed survival in the alpine soil. Fits of the number of remaining viable seeds at each exhumation date to the negative exponential model gave maximum seed longevity estimates of 1623 days in Draba magellanica, 2779 days in Empetrum rubrum, 3026 days in Gunnera magellanica, 777 days in Oreomyrrhis hookeri, and 5983 days in Pernettya pumila. Estimated seed longevities for some species at the subantarctic alpine site are among the highest reported for alpine species to date.