TY - JOUR

T1 - ENSO Drives interannual variation of forest woody growth across the tropics

AU - Rifai, Sami W.

AU - Girardin, Cecile A. J.

AU - Berenguer, Erika

AU - del Aguila-Pasquel, Jhon

AU - Dahlsjo, Cecilia A. L.

AU - Doughty, Christopher E.

AU - Jeffery, Kathryn J.

AU - Moore, Sam

AU - Oliveras, Imma

AU - Riutta, Terhi

AU - Rowland, Lucy M.

AU - Araujo Murakami, Alejandro

AU - Addo-Danso, Shalom D.

AU - Brando, Paulo

AU - Burton, Chad

AU - Ondo, Fidele Evouna

AU - Duah-Gyamfi, Akwasi

AU - Farfan Amezquita, Filio

AU - Freitag, Renata

AU - Hancco Pacha, Fernando

AU - Huasco, Walter Huaraca

AU - Ibrahim, Forzia

AU - Mbou, Armel T.

AU - Mihindou, Vianet Mihindou

AU - Peixoto, Karine S.

AU - Rocha, Wanderley

AU - Rossi, Liana C.

AU - Seixas, Marina

AU - Silva-Espejo, Javier E.

AU - Abernethy, Katharine A.

AU - Adu-Bredu, Stephen

AU - Barlow, Jos

AU - da Costa, Antonio C. L.

AU - Marimon, Beatriz S.

AU - Marimon-Junior, Ben H.

AU - Meir, Patrick

AU - Metcalfe, Daniel B.

AU - Phillips, Oliver L.

AU - White, Lee J. T.

AU - Malhi, Yadvinder

PY - 2018/11/19

Y1 - 2018/11/19

N2 - Meteorological extreme events such as El Niño events are expected to affect tropical forest net primary production (NPP) and woody growth, but there has been no large-scale empirical validation of this expectation. We collected a large high–temporal resolution dataset (for 1–13 years depending upon location) of more than 172 000 stem growth measurements using dendrometer bands from across 14 regions spanning Amazonia, Africa and Borneo in order to test how much month-to-month variation in stand-level woody growth of adult tree stems (NPPstem) can be explained by seasonal variation and interannual meteorological anomalies. A key finding is that woody growth responds differently to meteorological variation between tropical forests with a dry season (where monthly rainfall is less than 100 mm), and aseasonal wet forests lacking a consistent dry season. In seasonal tropical forests, a high degree of variation in woody growth can be predicted from seasonal variation in temperature, vapour pressure deficit, in addition to anomalies of soil water deficit and shortwave radiation. The variation of aseasonal wet forest woody growth is best predicted by the anomalies of vapour pressure deficit, water deficit and shortwave radiation. In total, we predict the total live woody production of the global tropical forest biome to be 2.16 Pg C yr−1, with an interannual range 1.96–2.26 Pg C yr−1 between 1996–2016, and with the sharpest declines during the strong El Niño events of 1997/8 and 2015/6. There is high geographical variation in hotspots of El Niño–associated impacts, with weak impacts in Africa, and strongly negative impacts in parts of Southeast Asia and extensive regions across central and eastern Amazonia. Overall, there is high correlation (r = −0.75) between the annual anomaly of tropical forest woody growth and the annual mean of the El Niño 3.4 index, driven mainly by strong correlations with anomalies of soil water deficit, vapour pressure deficit and shortwave radiation.This article is part of the discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.

AB - Meteorological extreme events such as El Niño events are expected to affect tropical forest net primary production (NPP) and woody growth, but there has been no large-scale empirical validation of this expectation. We collected a large high–temporal resolution dataset (for 1–13 years depending upon location) of more than 172 000 stem growth measurements using dendrometer bands from across 14 regions spanning Amazonia, Africa and Borneo in order to test how much month-to-month variation in stand-level woody growth of adult tree stems (NPPstem) can be explained by seasonal variation and interannual meteorological anomalies. A key finding is that woody growth responds differently to meteorological variation between tropical forests with a dry season (where monthly rainfall is less than 100 mm), and aseasonal wet forests lacking a consistent dry season. In seasonal tropical forests, a high degree of variation in woody growth can be predicted from seasonal variation in temperature, vapour pressure deficit, in addition to anomalies of soil water deficit and shortwave radiation. The variation of aseasonal wet forest woody growth is best predicted by the anomalies of vapour pressure deficit, water deficit and shortwave radiation. In total, we predict the total live woody production of the global tropical forest biome to be 2.16 Pg C yr−1, with an interannual range 1.96–2.26 Pg C yr−1 between 1996–2016, and with the sharpest declines during the strong El Niño events of 1997/8 and 2015/6. There is high geographical variation in hotspots of El Niño–associated impacts, with weak impacts in Africa, and strongly negative impacts in parts of Southeast Asia and extensive regions across central and eastern Amazonia. Overall, there is high correlation (r = −0.75) between the annual anomaly of tropical forest woody growth and the annual mean of the El Niño 3.4 index, driven mainly by strong correlations with anomalies of soil water deficit, vapour pressure deficit and shortwave radiation.This article is part of the discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.

KW - El Nino

KW - tropical forests

KW - woody net primary production

KW - drought

KW - meteorological anomalies

U2 - 10.1098/rstb.2017.0410

DO - 10.1098/rstb.2017.0410

M3 - Journal article

VL - 373

JO - Philosophical Transactions of the Royal Society B: Biological Sciences

JF - Philosophical Transactions of the Royal Society B: Biological Sciences

SN - 0962-8436

IS - 1760

M1 - 20170410

ER -