Are the oxygen isotopic compositions of Fitzroya cupressoides and Nothofagus pumilio cellulose promising proxies for climate reconstructions in northern Patagonia?

作者：Lavergne Alienor; Daux Valerie; Villalba Ricardo; Pierre Monique; Stievenard Michel; Vimeux Francoise; Srur Ana Marina

来源：Journal of Geophysical Research-Biogeosciences, 2016, 121(3): 767-776.

DOI：10.1002/2015JG003260

• north Patagonia
• cellulose
• O-18
• Fitzroya cupressoides
• Nothofagus pumilio
• climate change

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.

• 出版日期2016-3
• 单位中国地震局