Stem volume loss due to Diplodia infection in young Pinus radiata stand

Authors: D. Currie, E. Toes
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 1978, Issue N.Z.J.For. 23(1) 1978, pp 143-148, May 1978
Publisher: New Zealand Institute of Forestry

---

Abstract: In a 6-year-old stand of Pinus radiata in Tarawera Forest 14% of the trees were lightly, 22% moderately, and 64%) heavily infected by Diplodia pinea. Most of the heavily infected trees were also badly malformed. Only 6%o of the trees were acceptable for harvesting under the limitation of a minimum 3.7 m defect-free butt log as specified by Tasman Pulp and Paper Company's mill.
Mean height and diameter of the trees were inversely related to infection levels and thus the degree of malformation. Total volume of the stand was estimated to be 11 m3/ha, merchantable volume 10 m3/ha, and the potential merchantable volume (in the absence of infection) 27 m3/ha. A reduction of 63% in potential merchantable volume was thus estimated. These results represent an extremely severe case of tree malformation in a localised area.

---