AOBPreview originally published online on September 26, 2008
Annals of Botany 2008 102(6):923-933; doi:10.1093/aob/mcn182
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Is Shade Beneficial for Mediterranean Shrubs Experiencing Periods of Extreme Drought and Late-winter Frosts?
1 Laboratorio Internacional de Cambio Global (LINC-Global), Instituto de Recursos Naturales, CCMA, CSIC, Serrano 115, E-28006 Madrid, Spain
2 Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnológicas, Universidad Rey Juan Carlos, c/ Tulipán s/n, 28933 Móstoles, Spain
3 Department of Biology, The University of York, PO Box 373, York YO10 5YW, UK
4 Department of Plant Physiology, University of Tartu, Riia 23, 51011 Tartu, Estonia and Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, E-18008 Granada, Spain
* For correspondence. E-mail valladares{at}ccma.csic.es
Received: 21 February 2008 Returned for revision: 16 May 2008 Accepted: 5 August 2008 Published electronically: 26 September 2008
Background and Aims: Plants are naturally exposed to multiple, frequently interactive stress factors, most of which are becoming more severe due to global change. Established plants have been reported to facilitate the establishment of juvenile plants, but net effects of plant–plant interactions are difficult to assess due to complex interactions among environmental factors. An investigation was carried out in order to determine how two dominant evergreen shrubs (Quercus ilex and Arctostaphylos uva-ursi) co-occurring in continental, Mediterranean habitats respond to multiple abiotic stresses and whether the shaded understorey conditions ameliorate the negative effects of drought and winter frosts on the physiology of leaves.
Methods: Microclimate and ecophysiology of sun and shade plants were studied at a continental plateau in central Spain during 2004–2005, with 2005 being one of the driest and hottest years on record; several late-winter frosts also occurred in 2005.
Key Results: Daytime air temperature and vapour pressure deficit were lower in the shade than in the sun, but soil moisture was also lower in the shade during the spring and summer of 2005, and night-time temperatures were higher in the shade. Water potential, photochemical efficiency, light-saturated photosynthesis, stomatal conductance and leaf 13C composition differed between sun and shade individuals throughout the seasons, but differences were species specific. Shade was beneficial for leaf-level physiology in Q. ilex during winter, detrimental during spring for both species, and of little consequence in summer.
Conclusions: The results suggest that beneficial effects of shade can be eclipsed by reduced soil moisture during dry years, which are expected to be more frequent in the most likely climate change scenarios for the Mediterranean region.
Key words: Frost, climate change, shade, drought, plant–plant interactions, Quercus ilex, Arctostaphylos uva-ursi, soil moisture, facilitation
CiteULike 
Connotea 
Del.icio.us What's this?
Related articles in Ann Bot:
- ContentSnapshots
Ann Bot 2008 102: NP.[Extract] [Full Text]
This article has been cited by other articles:
|
|
 |
|
  U. Niinemets, A. Diaz-Espejo, J. Flexas, J. Galmes, and C. R. Warren Role of mesophyll diffusion conductance in constraining potential photosynthetic productivity in the field J. Exp. Bot., May 1, 2009; 60(8): 2249 - 2270. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. D. Adams, M. Guardiola-Claramonte, G. A. Barron-Gafford, J. C. Villegas, D. D. Breshears, C. B. Zou, P. A. Troch, and T. E. Huxman Temperature sensitivity of drought-induced tree mortality portends increased regional die-off under global-change-type drought PNAS, April 28, 2009; 106(17): 7063 - 7066. [Abstract] [Full Text] [PDF]
|
|