Radial growth and biological rotation age of Prosopis caldenia Burkart in Central Argentina

Prosopis caldenia Burkart (caldén) is the most important woody species in the caldenales, the open xerophytic woodlands covering approximately 33 000 km2 in the semiarid central region of Argentina. Dendrochronological techniques were used to estimate mean radial growth and the biological rotation age of P. caldenia in San Luis, Central Argentina. Inter-annual variations in ring widths were measured on cross-sections from dominant and co-dominant trees at four sampling sites from across the natural distribution of P. caldenia in the province of San Luis. For a period of 65 years, the mean cumulative radial growth between these four stands varied from 174.9 to 246.09 mm, whereas the mean annual radial growth ranged from 2.7 to 4.0 mm yr−1. Biological rotation ages were estimated based on the temporal evolution of the annual basal area mean and current increments. At the four stands, the biological rotation age occurs at ages equal to or greater than 66 years. In comparison with the introduced species presently used for commercial reforestation in the region, P. caldenia shows similar rates of radial growth, is better-adapted to the extreme climatic variability of semiarid Central Argentina, and its wood largely exceeds in quality the wood of those species used for commercial reforestation.