Average diameter

Average diameter of stand
Forest Measurement and Modelling.

The average diameter at breast height (dbh) is occasionally used to describe a relatively homogeneous stand. The arithmetic- or quadratic- mean dbh is the usual statistic calculated:

These mean values may be used in conjunction with estimates of the number of trees / ha to determine competition within a stand. The mean values may also be compared with the median and mode dbh to determine if the diameter distribution is skewed.

The quadratic mean diameter has a stronger correlation to stand volume than does the arithmetic mean. The basal area of a tree with dbh equal to the quadratic mean diameter is equal to the mean basal area of the stand.

[s_diam.htm] Revision: 6/1999