South America 180 Year Tree Ring Stable Isotope Data Ballantyne, A.; Baker, P.A.; Chambers, J.Q.; Villalba, R.; Argollo, J. Ballantyne, A. Baker, P.A. Chambers, J.Q. Villalba, R. Argollo, J. Monsoon PAGES 2k Network PAGES LOTRED SA2k Tropics drought CEOD Cedrela odorata L. earth science/paleoclimate/tree ring (delta 18O,alpha cellulose,null,per mil SMOW,null,tree ring,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/tree ring (delta 13C,alpha cellulose,null,per mil PDB,null,tree ring,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/tree ring (age,null,null,year Common Era,null,tree ring,null,null,N,null) earth science/paleoclimate/tree-ring earth science/paleoclimate/tree-ring (Puerto Maldonado>LATITUDE -12.6>LONGITUDE -69.2) (Volcan Granada>LATITUDE -22>LONGITUDE -66) We present results on the relationship between tree ring proxies and regional precipitation for several sites in tropical South America. The responsiveness of oxygen isotopes (d18O) and seasonal growth as precipitation proxies was first validated by high- resolution sampling of a Tachigali myrmecophila from Manaus, Brazil (3.1ºS, 60.0ºW). Monthly growth of Tachigali spp. was significantly correlated with monthly precipitation. Intra-annual measurements of cellulose d18O in Tachigali spp. were also significantly correlated with monthly precipitation at a lag of approximately one month. The annual ring-widths of two tropical tree taxa, Cedrela odorata growing in the Amazon (12.6ºS, 69.2ºW) and Polylepis tarapacana growing in the Altiplano (22.0ºS, 66.0ºW), were validated using bomb-derived radiocarbon 14C. Estimated dates were within two to three years of bomb inferred 14C dates, indicating that these species exhibit annual rings but uncertainties in our chronologies remain. A multi-proxy record spanning 180 years from Cedrela spp. showed a significant negative relationship between cellulose d18O and January precipitation. A 150-year record obtained from Polylepis spp. also showed a significant negative relationship between d18O and March precipitation, whereas annual ring width showed a significant positive correlation with December precipitation. These proxies were combined in a multivariate framework to reconstruct past precipitation, revealing a significant increase in monsoon precipitation at the Amazon site since 1890 and a significant decrease in monsoon precipitation at the Altiplano since 1880. Proxy time series also showed spatial and temporal coherence with precipitation variability due to El Niño forcing, suggesting that oxygen isotopes and ring widths in tropical trees may be important diagnostics for identifying regional differences in the response of the tropical hydrologic cycle to anthropogenic warming. STUDY NOTES: Tree ring isotope data from two South American locations and species, Cedrela odorata from the upper Amazon Basin and Polylepis tarapacana from the Altiplano. The isotope data correlate with seasonal precipitation and provide a monsoon strength signal for the Amazon and Altiplano for the past 180 years. IITRDB006 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Ballantyne, A. Investigator : Baker, P.A. Investigator : Chambers, J.Q. Investigator : Villalba, R. Investigator : Argollo, J. 2010-12-16 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/9910 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/southamerica/ballantyne2011tr-iso.xls https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/southamerica/ballantyne2011tr-iso.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/southamerica/ballantyne2011tr-iso.xls https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/southamerica/ballantyne2011tr-iso.txt English https://www.ncdc.noaa.gov/paleo/study/9910 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/southamerica/ballantyne2011tr-iso.xls https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/southamerica/ballantyne2011tr-iso.txt Ballantyne, A.P., P.A. Baker, J.Q. Chambers, R. Villalba, and J. Argollo. 2011. Regional differences in South American monsoon precipitation inferred from the growth and isotopic composition of tropical trees. Earth Interactions. doi: 10.1175/2010EI277.1 START YEAR: 1820 AD * END YEAR: 2004 AD -69.2 -22 -66 -12.6