Annual rings inBeilschmiedia tawa(Lauraceae)

Abstract

Evidence is presented that the growth rings in the wood of fast growing tawa are annual. Diameter growth rates oftawa are variable but usually 1–4 mm yr^-1 in trees > 20 cm diameter at 1.4 m height. Tawa probably has maximum longevity in the range 300–400 years. It shows unexplained biennial fluctuations in diameter increment, a feature shared with several New Zealand tree species.