ENSO signal in a new long tree-line chronology from Austrocedrus chilensis at Huinganco, Neuquen, Argentina.

MARIANO S. MORALES; JOSE A. BONINSEGNA

Mendoza, Argentina

Conferencia; International Conference on Dendrochronology for the Third Millennium; 2000

Laboratorio de dendrocronología

We visited several tree-line sites of Austrocedrus chilensis  at Huinganco, Neuquen Province, Argentina (36°30’S). These Austrocedrus chilensis sites represent the northern limit of the dispersion of the specie in Argentina and have a close resemblance with populations of Austrocedrus at El Asiento, Rio Clarillo and Rio Cipreses in Chile. The samples were collected at three sub-sites: Raja-palo, Quebrada Molina and Rahue Co. We collected 107 trees, usually two cores by tree, using increment borer to sample living trees and chainsaw to collect old stumps. The material was cross-dated and yield a 1423 years long chronology, representing the longest Austrocedrus chronology produced in Argentina. Event analysis using as date events the strong and very strong ENSO occurrence according to Quinn (1992) and Ortlieb (1993) and the residual chronology shows a clear signal to ENSO. The signal is stronger during the period from the XVIII century to present.