Definitions for "Age class"
Birds that are grouped together because they are about the same age. For example, most gulls are brown or brownish gray in the year that they hatch. For Urban Bird Studies, these brownish gulls are grouped into an age class called Juveniles.
One of the intervals into which the range of age of trees growing in a forest is divided for classification or use; also the trees falling into such an interval. Cf. Age gradation ( BCFT ).
An interval into which the age range of trees or forest stands is divided for classification or use (e.g., 0-10 years, 10-20 years, etc.).