Growth Rings, Age and Taxonomy of Dacrydium (Podocarpaceae) in Fiji

Abstract

The anatomy of growth rings in Dacrydium (Podocarpaceae) from Fiji is described. Fungal staining may mask the heartwood growth rings and generally prevents observation of rings on either roughly cut logs or sanded sections with the naked eye. Earlywood is formed during the wet season and coincides with a peak of leaf and shoot growth. Radiocarbon dating of three trees indicates that growth rings have an approximately annual frequency. The average trunk diameter growth rate is estimated as 2.6 mm year^-1. Life expectancy of established trees is estimated as 49 year. It is suggested that the endemic species D. nausoriense de Laub. may be an ecotype of D. nidulum de Laub. adapted to the drier climate of north-west Viti Levu.