AGE-DEPENDENT TREE-RING GROWTH RESPONSES TO CLIMATE IN ARAUCARIA ARAUCANA FORESTS OF ARGENTINA

HADAD, M; ROIG, F

Valdivia

Simposio; Reconstructing Climate Variations in South America and the Antarctic Peninsula over the last 2000 years; 2010

PAGES

Dendrochronology generally operates under assumption that climate-growth relationships are age independent. However, several studies have demonstrated that tree physiology undergoes changes with age. The age-related climate-growth relationship migth potentially improve the veracity of past climate reconstructions. In this work we present three chronologies of tree-ring width of A. araucaria. Tree-ring width chronologies of A. araucana cores taken in northwest Patagonia, Argentina and agrouped into tree age classes (301 years). Were used to analyze age-dependent growth-climate response relationships. The tree-ring width chronologies have an extension of more than 700 years. Tree-ring stadistics showed change significantly in the between tree-ring width chronologies and between age classes. The mean ring-width values show that A. araucana has a biological-geometrical trend deceasing with age. The analyses of correlation of A. araucana answer positively to the rainfall, whereas to the temperature answers negatively. Preliminary analysis suggested that different climatic response relationships existed between age-classes radial growth. These results suggested the importance of incorporating trees of all ages into the chronology of A. araucana.