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Teleconnection between tree growth in the Amazonian floodplains and the El Niño–Southern Oscillation effect
Author(s) -
Schöngart Jochen,
Junk Wolfgang J.,
Piedade Maria Teresa F.,
Ayres José Marcio,
Hüttermann Aloys,
Worbes Martin
Publication year - 2004
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1529-8817.2003.00754.x
Subject(s) - amazonian , amazon rainforest , chronology , dendrochronology , teleconnection , climatology , multivariate enso index , floodplain , drainage basin , el niño southern oscillation , precipitation , la niña , geography , watershed , environmental science , pluvial , physical geography , amazon basin , period (music) , hydrology (agriculture) , geology , ecology , oceanography , archaeology , physics , cartography , geotechnical engineering , machine learning , meteorology , computer science , acoustics , biology
There is a limited knowledge about the El Niño–Southern Oscillation (ENSO) effects on the Amazon basin, the world's largest tropical rain forest and a major factor in the global carbon cycle. Seasonal precipitation in the Andean watershed annually causes a several month‐long inundation of the floodplains along the Amazon River that induces the formation of annual rings in trees of the flooded forests. Radial growth of trees is mainly restricted to the nonflooded period and thus the ring width corresponds to its duration. This allows the construction of a tree‐ring chronology of the long‐living hardwood species Piranhea trifoliata Baill. (Euphorbiaceae). El Niño causes anomalously low precipitation in the catchment that results in a significantly lower water discharge of the Amazon River and consequently in an extension of the vegetation period. In those years tree rings are significantly wider. Thus the tree‐ring record can be considered as a robust indicator reflecting the mean climate conditions of the whole Western Amazon basin. We present a more than 200‐year long chronology, which is the first ENSO‐sensitive dendroclimatic proxy of the Amazon basin and permits the dating of preinstrumental El Niño events. Time series analyses of our data indicate that during the last two centuries the severity of El Niño increased significantly.