Provenance Variation in Stem Volume and Wood Density ofPinus caribaeaGrowing at Two Elevations in South Africa

Abstract

SYNOPSIS Provenance trials of Pinus caribaea Morelet of the international series coordinated by the Oxford Forestry Institute, University of Oxford, were established at the Mariti State forest (1000 m) in 1974 and the KwaMbonambi State forest (65 m) in 1973. The trials were assessed in 1980 for volume under bark (VUB) and wood density (DEN) and these two traits plus the derived indices of within sample density variation (VAR) and dry matter index (DMI) were analysed. Statistically, there were highly significant differences (p<0,001) between provenances for the four traits at both locations with the exception of DEN at the Mariti State forest (p<0,025). The 10 provenances common to both locations produced 67% more VUB at the KwaMbonambi State forest and had a DEN that was 11% higher. Simple correlation coefficients were calculated for the assessed traits for the 10 provenances common to both locations. Provenance means between locations were significantly (p<0,01) correlated for the traits VAR, VUB and DMI but not for DEN. The P. caribaea var. hondurensis Barrett and Golfari provenance Guanaja was above average for DEN, VUB and DMI and was among the lowest for VAR at both locations while provenances of P. caribaea var. caribaea Barrett and Golfari were almost always below the trial mean for VUB and DMI at both locations.