Nutrient and water addition effects on day- and night-time conductance and transpiration in a C3 desert annual.
Oecologia
; 148(2): 219-25, 2006 Jun.
Article
em En
| MEDLINE
| ID: mdl-16456684
ABSTRACT
Recent research has shown that many C3 plant species have significant stomatal opening and transpire water at night even in desert habitats. Day-time stomatal regulation is expected to maximize carbon gain and prevent runaway cavitation, but little is known about the effect of soil resource availability on night-time stomatal conductance (g) and transpiration (E). Water (low and high) and nutrients (low and high) were applied factorially during the growing season to naturally occurring seedlings of the annual Helianthus anomalus. Plant height and biomass were greatest in the treatment where both water and nutrients were added, confirming resource limitations in this habitat. Plants from all treatments showed significant night-time g (approximately 0.07 mol m(-2) s(-1)) and E (approximately 1.5 mol m(-2) s(-1)). In July, water and nutrient additions had few effects on day- or night-time gas exchange. In August, however, plants in the nutrient addition treatments had lower day-time photosynthesis, g and E, paralleled by lower night-time g and E. Lower predawn water potentials and higher integrated photosynthetic water-use efficiency suggests that the nutrient addition indirectly induced a mild water stress. Thus, soil resources can affect night-time g and E in a manner parallel to day-time, although additional factors may also be involved.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transpiração Vegetal
/
Clima Desértico
/
Helianthus
Idioma:
En
Revista:
Oecologia
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Estados Unidos