Geographic variation in tree growth and wood density of Guazuma crinita Mart. in the Peruvian amazon
Guazuma crinita Mart. is a fast-growing timber tree in the Peruvian Amazon. A trial of 11 Peruvian provenances was established in three planting zones. Tree growth at 6, 12, 18 and 30 months and wood density at 32 months were analyzed across and within zones. Zones accounted for more variation than provenances. Density varied significantly due to provenances in the analysis across zones, whereas growth exhibited strong provenance by zone interactions. The local provenance grew well and produced relatively dense wood in all zones. The relative magnitude of variation due to provenances depended on the planting zone. Density was greater in the lower than in the upper stem. Density increased with longitude from the more humid to the drier part of the sample region. In general, correlations indicated that larger trees had lower density and a larger difference in density between the lower and upper stem, but the strength of these relationships depended on the provenance and zone. Results suggest that fast-growing provenances can be selected at an early age without significantly reducing wood density. The local provenance is recommended for reforestation pending future research demonstrating the superiority of foreign provenances. Some practical implications for tree-improvement programs are discussed.