COMPATIBLE STEM TAPER AND STEM VOLUME FUNCTIONS FOR OAK (QUERCUS-ROBUR L AND Q-PETRAEA (MATT) LIEBL) IN DENMARK

In this paper we develop compatible stem taper and stem volume functio ns for oak (Quercus robur L and Q petraea (Matt) Liebl) in Denmark. In the compatible system of stem taper and volume functions the solid of revolution of the stem taper equation equals the volume according to the total stem volume function. The stem volume is explicitly expresse d in the stem taper function. Thus, it is possible to adjust estimates of the stem taper curve to a specific stand volume level (and thereby accounting for the effect of silvicultural practice on stem taper). T he accuracy of predictions from the stem volume function for oak is co mparable to similar functions for three broadleaved species and six co nifers. Comparable stem taper functions for other broadleaved species are not available, but compared lo conifers the stem taper function fo r oak performs relatively well considering the substantial number of f orked oak trees.