The mobilization and transport of newly fixed carbon are driven by plant water use in an experimental rainforest under drought.
J Exp Bot
; 75(8): 2545-2557, 2024 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-38271585
ABSTRACT
Non-structural carbohydrates (NSCs) are building blocks for biomass and fuel metabolic processes. However, it remains unclear how tropical forests mobilize, export, and transport NSCs to cope with extreme droughts. We combined drought manipulation and ecosystem 13CO2 pulse-labeling in an enclosed rainforest at Biosphere 2, assessed changes in NSCs, and traced newly assimilated carbohydrates in plant species with diverse hydraulic traits and canopy positions. We show that drought caused a depletion of leaf starch reserves and slowed export and transport of newly assimilated carbohydrates below ground. Drought effects were more pronounced in conservative canopy trees with limited supply of new photosynthates and relatively constant water status than in those with continual photosynthetic supply and deteriorated water status. We provide experimental evidence that local utilization, export, and transport of newly assimilated carbon are closely coupled with plant water use in canopy trees. We highlight that these processes are critical for understanding and predicting tree resistance and ecosystem fluxes in tropical forest under drought.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Carbono
/
Floresta Úmida
Idioma:
En
Revista:
J Exp Bot
Assunto da revista:
BOTANICA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Alemanha