A comparison of methods used in obtaining current annual increment.

Abstract

In the course of a limited investigation carried out on a Norway spruce stand near Lough Key in Co. Roscommon, current annual increment was evaluated by four different methods. Stems were entered in quarter-girth classes and a mean basal tree (7.24 ins. b.h.q.g.) calculated for the whole sample area, the plots being treated collectively. Two trees 16% from either end of the quarter girth distribution of all the plots were also picked, these turned out to be 5.75 ins. and 8.25 ins. b.h.q.g. The following methods were applied: stem analysis, which was used on five trees; Schneider' Formula applied to the 16% trees; Schneider's Formula applied to mean basal area trees; and leader growth tables. There was no significant difference in results...