Growth rings in rimu from south Westland terrace forest

Abstract

A study of growth rings in relatively fast-grown rimu trees from terrace forest in south Westland revealed a number with conspicuously dark latewood bands. These have been called marker rings. The regular occurrence of these marker rings in the same sequence in a number of trees indicates that growth rings are formed contemporaneously in all relatively fast growing trees. A good correlation between the occurrence of marker rings and cool autumn temperatures in the years in which they were formed is very strong evidence that the rings are formed annually. Discontinuous false rings were found in some fast-grown trees, but continuous false rings were not discovered. Discontinuous growth rings were found in strongly fluted trees, in leaning trees, and in very slow-growing trees. No evidence of missing rings was found, but it is possible that growth rings could be absent from slow-growing trees. © Taylor & Francis Group, LLC.