A slenderness coefficient of 50 has been proposed as a failure criterion for non-decayed solitary urban trees. This hypothesis is based on guidelines from forestry. We subjected forest tress covering a range of slenderness to destructive pulling tests. Our results show that the effect of slenderness on maximum bending moments is negligible. Therefore, the assessment of urban trees should not be based on a slenderness coefficient of 50.
Jillich S, Köhler J, Rust C, Rust S, Detter A (2013) Brechen schlanke Fichten leichter? In: Dujesiefken D (ed.) Jahrbuch der Baumpflege. pp 267–273.