Classifying aerial stems of woody plants by developmental stages using relative growth rate.

•  Here we propose a new method for classifying aerial stems of woody plants by developmental stage, using the logarithmic reciprocal of relative growth rate (LRR) as an indicator of developmental stage. •  Stem analyses were conducted on naturally dead aerial stems of Lindera umbellata to clarify the changes in LRR over a lifetime. LRR, number of current-year shoots, and the recruitment and mortality rates of shoots of living stems were investigated. •  LRR was at a minimum value at age 1 yr and at a maximum just before each stem died. There was little difference between the ranges of stem LRR. The recruitment and mortality rates of shoots depended on LRR. •  LRR satisfied the necessary and sufficient condition for a variable as an indicator of stage better than either age or size. The LRR-structured model accurately demonstrates the real demographic processes in shoot populations over a lifetime of aerial stems. This result supports the utility of LRR as an indicator of stage. The method using LRR can be applied to analyses for other growth processes.