Tree taper

'''Tree taper''' is the degree to which a tree's stem or bole decreases in diameter as a function of height above ground. Within Forestry and for the purposes of timber production, trees with a high degree of taper are said to have poor form, while those with low taper have good form. The opposite is the case for open-grown amenity trees. The form of a tree is sometimes quantified by the Girard form class, which is the ratio, expressed as a percentage, of the butt-log scaling diameter to diameter at breast height.<ref>Mesavage, C., and J.W. Girard. 1946. Tables for estimating board foot volume of timber. Department of Agriculture, Forest Service, Washington, DC. 94 pp.</ref>

Taper is often represented by mathematical functions fitted to empirical data, called taper equations. One such function, attributed to Ormerod,<ref>Ormerod, D.W., 1973. A simple bole model. ''Forestry Chronicle''. 49:136-138.</ref> is

right|Tree taper equation

<math>d(h)^2 = {D^2} \left({H-h \over H-h_b}\right)^{1.6} </math>

where:

<math>d(h)</math> = stem diameter at height h,

<math>D</math> = tree diameter at breast height,

<math>H</math> = tree total height,

<math>h</math> height of interest (h ≤ H), and

<math>h_b</math> = breast height.

Once developed, taper equations can be used to predict the diameter at a given height, or the height for a given diameter.

== Footnotes == <references/>

Category:Forest modelling