Provenance Variation in Stem Volume and Wood Density of Pinus oocarpa and P. patula ssp. tecunumanii Growing at Two Elevations in South Africa

SYNOPSIS

Provenance trials of Pinus oocarpa Schiede and P. patula Schiede and Deppe ssp. tecunumanii (Eguiluz and Perry) Styles of the international series coordinated by the Oxford Forestry Institute, University of Oxford, were established in South Africa at the Wilgeboom State forest (945 m) and the KwaMbonambi State forest (65 m) in 1973. The trials were assessed in 1980 for volume under bark and wood density and these two traits plus the derived indices of within sample density variation and dry matter index were analysed. Statistically, there were highly significant differences (p<0,001) between provenances for the four traits at both locations with the exception of density at the KwaMbonambi State forest (p<0,25). The five provenances common to both locations produced 92% more volume under bark and were 12% higher in density at the Wilgeboom State forest indicating that sites in the Eastern Transvaal are more suitable for P. oocarpa/P. patula ssp. tecunumanii plantations than sites in Zululand. In contrast to the P. oocarpa/P. patula ssp. tecunumanii provenances, the P. elliottii Engelm. seed source had a higher density at lower altitude and this is similar to the results normally encountered for P. caribaea Morelet.