Gas exchange by the mesic-origin, arid land plantation species Robinia pseudoacacia under annual summer reduction in plant hydraulic conductance.
Tree Physiol
; 38(8): 1166-1179, 2018 08 01.
Article
em En
| MEDLINE
| ID: mdl-29608763
ABSTRACT
The mesic-origin plantation species Robinia pseudoacacia L. has been successfully grown in many arid land plantations around the world but often exhibits dieback and reduced growth due to drought. Therefore, to explore the behavior of this species under changing environmental conditions, we examined the relationship between ecophysiological traits, gas exchange and plant hydraulics over a 3-year period in trees that experienced reduced plant hydraulic conductance (Gp) in summer. We found that the transpiration rate, stomatal conductance (Gs) and minimum leaf water potential (Ψlmin) decreased in early summer in response to a decrease in Gp, and that Gp did not recover until the expansion of new leaves in spring. However, we did not observe any changes in the leaf area index or other ecophysiological traits at the leaf level in response to this reduction in Gp. Furthermore, model simulations based on measured data revealed that the canopy-scale photosynthetic rate (Ac) was 15-25% higher than the simulated Ac when it was assumed that Ψlmin remained constant after spring but almost the same as the simulated Ac when it was assumed that Gp remained high even after spring. These findings indicate that R. pseudoacacia was frequently exposed to a reduced Gp at the study site but offset its effects on Ac by plastically lowering Ψlmin to avoid experiencing any further reduction in Gp or Gs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carbono
/
Água
/
Robinia
/
Secas
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Asia
Idioma:
En
Revista:
Tree Physiol
Assunto da revista:
BOTANICA
/
FISIOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos