A new report, prepared by T. Vercoe & B. Clarke, Australian Tree Seed Centre (CSIRO) with financial support from FAO, summarizes and reviews the results of international provenance trials of Eucalyptus urophylla which were coordinated by Australian Tree Seed Centre, the Centre Technique Forestier Tropical (former CTFT, now CIRAD-Fôret), France and FAO.
Eucalyptus urophylla is an important fast-growing timber species of the seasonally dry tropics. The species has demonstrated large provenance differences in growth on different sites. The report examines a range of provenance and species trials now about 10 years old in countries across 3 continents. It provides a database summary of their performance on the Multipurpose Tree Database (MPTDAT) system.
Data have been collected from the international provenance trials on 16 sites and from an additional 8 species and provenance trials on 14 sites. The published literature and anecdotal evidence identify the lower elevation provenances (mainly from Flores and Timor) as consistently good performers at lower elevation planting sites. A preliminary analysis of this data indicated, however, that although the highest elevation sources consistently produced the slowest growers, this trend did not hold above 1500m (altitude of origin). A taxonomic study resulted in the imminent publication of two new species, E. wetarensis MS and E. orophylla MS representing material from Wetar Island and some of the higher elevation populations on Timor respectively. A recent isozyme study supported the differentiation of E. wetarensis MS but not that of E. orophylla. In general, the performance data showed no real pattern to suggest a single superior provenance (or island of origin), the exceptions being the high elevation Timor sources (see above) which were consistently poor performers. Wetar seedlots were poorly represented in the database and no conclusive support for this split is possible.
Of the factors examined, soil texture and the mean minimum temperature of the coldest month had the broadest influence on growth. E. urophylla seemed to grow better in sandier soils and at a higher mean minimum temperature.
Flores and Timor Islands showed some of the best and worst performing provenances; some of this can be attributed to altitudinal differences as the very high altitude provenances consistently perform poorly. Other islands which produced good performers were Alor (5 trials) and Pantar (2 trials).
For more information please contact:
Jim Ball
Forest Resources Development Service
Forest Resources Division
FAO
Via Terme delle Caracalla
00100 Rome
Italy
Forest Genetic Resources No. 22. FAO, Rome (1994)
