Climate-growth relationships and paleoclimate potential of Austrocedrus chilensis revisited by extending its tree-ring network in Argentina

Abstract

The climatic variations observed in recent decades in Patagonia have affected the dynamics of the Andean forests. In this study, new and existing Austrocedrus chilensis chronologies were subjected to analysis in 28 sites representative of the species’ longitudinal and latitudinal distribution in Argentina. This study covers the western and humid distribution of the species in Argentina, which have been little studied to date. The climate data set comprised precipitation and temperature data from 21 meteorological stations and three global temperature series. The results demonstrate the presence of a robust common climate signal among the regional (REGIONAL) and sub-regional (XERNOR and HUMSUR) chronologies. The growth of A. chilensis trees from regional and subregional chronologies is primarily constrained by elevated temperatures and reduced precipitation during the late spring and summer months of the current and late winter of the previous growing seasons. The relationships between A. chilensis growth and atmospheric circulation patterns (El Nino-Southern ˜ Oscillation, Antarctic Oscillation, and Pacific Decadal Oscillation) suggest that the species may be able to provide information on the past influence of climatic forcings throughout northern Patagonia. Our findings indicate that future warming islikely to have a negative impact on the growth of A. chilensis across a significant portion of its current distribution in Argentina.