Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests
Authors: Wagner Fabien H. , Hérault Bruno , Bonal Damien , Stahl Clément , Anderson Liana O. , Baker Timothy R. , Becker Gabriel Sebastian , Beeckman Hans , Boanerges Souza Danilo , Botosso Paulo Cesar , Bowman David M. J. S. , Bräuning Achim , Brede Benjamin , Brown Foster Irving , Camarero Jesus Julio , Camargo Plínio Barbosa , Cardoso Fernanda C. G. , Carvalho Fabrício Alvim , Castro Wendeson , Chagas Rubens Koloski , Chave Jérome , Chidumayo Emmanuel N. , Clark Deborah A. , Costa Flavia Regina Capellotto , Couralet Camille , da Silva Mauricio Paulo Henrique , Dalitz Helmut , de Castro Vinicius Resende , de Freitas Milani Jaçanan Eloisa , de Oliveira Edilson Consuelo , de Souza Arruda Luciano , Devineau Jean-Louis , Drew David M. , Dünisch Oliver , Durigan Giselda , Elifuraha Elisha , Fedele Marcio , Ferreira Fedele Ligia , Figueiredo Filho Afonso , Finger César Augusto Guimarães , Franco Augusto César , Freitas Júnior João Lima , Galvão Franklin , Gebrekirstos Aster , Gliniars Robert , Graça Paulo Maurício Lima de Alencastro , Griffiths Anthony D. , Grogan James , Guan Kaiyu , Homeier Jürgen , Kanieski Maria Raquel , Kho Lip Khoon , Koenig Jennifer , Kohler Sintia Valerio , Krepkowski Julia , Lemos-Filho José Pires , Lieberman Diana , Lieberman Milton Eugene , Lisi Claudio Sergio , Longhi Santos Tomaz , López Ayala José Luis , Maeda Eduardo Eijji , Malhi Yadvinder , Maria Vivian R. B. , Marques Marcia C. M. , Marques Renato , Maza Chamba Hector , Mbwambo Lawrence , Melgaço Karina Liana Lisboa , Mendivelso Hooz Angela , Murphy Brett P. , O'Brien Joseph J. , Oberbauer Steven F. , Okada Naoki , Pélissier Raphaël , Prior Lynda D. , Roig Fidel Alejandro , Ross Michael , Rossatto Davi Rodrigo , Rossi Vivien , Rowland Lucy , Rutishauser Ervan , Santana Hellen , Schulze Mark , Selhorst Diogo , Silva Williamar Rodrigues , Silveira Marcos , Spannl Susanne , Swaine Michael D. , Toledo José Julio , Toledo Marcos Miranda , Toledo Marisol , Toma Takeshi , Tomazello Filho Mario , Valdez Hernández Juan Ignacio , Verbesselt Jan , Vieira Simone Aparecida , Vincent Grégoire , Volkmer de Castilho Carolina , Volland Franziska , Worbes Martin , Zanon Magda Lea Bolzan , Aragão Luiz E. O. C. 
Published: April 2016

Abstract. The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is  < 2000 mm yr−1 (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall  < 2000 mm yr−1.