Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests
Résumé
textlessptextgreaterThe 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 textless 2000 mm yrtextlesssuptextgreater−1textless/suptextgreater (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 textless 2000 mm yrtextlesssuptextgreater−1textless/suptextgreater.textless/ptextgreater
Auteurs, date et publication :
Auteurs Fabien H. Wagner , Bruno Hérault , Damien Bonal , Clément Stahl , Liana O. Anderson , Timothy R. Baker , Gabriel Sebastian Becker , Hans Beeckman , Danilo Boanerges Souza , Paulo Cesar Botosso , David M. J. S. Bowman , Achim Bräuning , Benjamin Brede , Foster Irving Brown , Jesus Julio Camarero , Plínio Barbosa Camargo , Fernanda C. G. Cardoso , Fabrício Alvim Carvalho , Wendeson Castro , Rubens Koloski Chagas
Publication : Biogeosciences
Date : 2016
Volume : 13
Issue : 8
Pages : 2537–2562