Provenance variation and within-provenance genetic parameters in Eucalyptus urophylla across 125 test sites in Brazil, Colombia, Mexico, South Africa and Venezuela

Provenance and within-provenance genetic variation for stem volume growth in Eucalyptus urophylla was examined in a large trial series of 125 provenance/progeny tests in five countries. In general, heritability (within-provenance) for age-3 volume was around 0.15 for Brazil, Colombia, Mexico, and South Africa and was slightly lower in Venezuela, where tree volume was lower. Provenances from all seven islands in Indonesia where the species occurs were included in the trials. Substantial provenance variation was observed in all countries, with the best provenances showing from 25 to 30 % more volume than the mean. The average of between-country genetic correlation estimates for growth traits was 0.72, both among and within provenances. Provenance and family performance between Mexico and Venezuela were very similar, with estimated provenance and within-provenance genetic correlations of 1.00 and 0.90, respectively. There was some tendency for lower-elevation provenances to show better volume growth, but there were also very large differences observed between provenances located very close to one another. The results underscore the value of extensive provenance collections throughout the range of a species in order to ensure that the very best provenances are being captured.