Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Journal of Geophysical Research : Biogeosciences 767-776 north Patagonia cellulose O-18 Fitzroya cupressoides Nothofagus pumilio climate change ARGENTINE CHILI ANDES PATAGONIE 2016 fdi:010066809 ENG Journal of Geophysical Research : Biogeosciences 2169-8953 ISI:000374345000010 3 10.1002/2015jg003260 https://www.documentation.ird.fr/hor/fdi:010066809 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-10/010066809.pdf 121 Horizon (IRD) Tree ring O-18 chronologies from two native species (Fitzroya cupressoides and Nothofagus pumilio) in northern Patagonia were developed to assess their potential for paleoclimate reconstructions. The five annually resolved cellulose O-18 chronologies (two for F. cupressoides and three for N. pumilio) are located on the Andes along the steep west-to-east precipitation gradient. Over the common 60years long interval, the five site-O-18(cell) chronologies exhibit a strong common signal as indicated by the significant mean intercorrelation (r=0.61, p<0.05) and the high percentage (65%) of total variance explained by the first empirical orthogonal function. Although correlation analyses reveal that the two mean species-O-18(cell) chronologies are mainly modulated by December-May temperature, the N. pumilio chronology shows a greater sensitivity to record temperature variations (r=0.57, p<0.05). The O-18(cell) of N. pumilio contains a regional temperature signal representative of a large area in southern South America under the influence of the Southern Annular Mode. This study indicates that O-18(cell) in N. pumilio is a promising proxy to reconstruct past variations in temperature in South America south of 38 degrees S. 021 ; 082 ; 020 ; 076 UR050 Argentine