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Title:
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Intraspecific variation in the use of water sources by the circum-Mediterranean conifer Pinus halepensis
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Author:
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Voltas Velasco, Jordi; Lucabaugh, D.; Chambel, Maria Regina; Ferrio Díaz, Juan Pedro
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Notes:
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Summary The relevance of interspecific variation in the use of plant water sources has been recognized in drought-prone environments. By contrast, the characterization of intraspecific differences in water uptake patterns remains elusive, although preferential access to particular soil layers may be an important adaptive response for species along aridity gradients. Stable water isotopes were analysed in soil and xylem samples of 56 populations of the drought-avoidant conifer Pinus halepensis grown in a common garden test. We found that most populations reverted to deep soil layers as the main plant water source during seasonal summer droughts. More specifically, we detected a clear geographical differentiation among populations in water uptake patterns even under relatively mild drought conditions (early autumn), with populations originating from more arid regions taking up more water from deep soil layers. However, the preferential access to deep soil water was largely independent of aboveground growth. Our findings highlight the high plasticity and adaptive relevance of the differential access to soil water pools among Aleppo pine populations. The observed ecotypic patterns point to the adaptive relevance of resource investment in deep roots as a strategy towards securing a source of water in dry environments for P. halepensis
This work was funded by the Spanish project FENOPIN
(AGL2012-40151-C03-03). J.P.F. is supported by the Ram on y
Cajal programme (RYC-2008-02050). An earlier version of this
work was presented by D.L. to obtain an MSc degree in the Erasmus
Mundus Programme MEDfOR. The authors acknowledge
Mara Luc a and Pilar Sope~na for technical assistance and Javier
Rodr ıguez and Marif e D ıaz for providing isotope data from the
Red Espa~nola de Vigilancia de Is otopos en la Precipitaci on. |
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Subject(s):
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-Adaptation
-Drought
-Mediterranean climate
-Pinus halepensis (Aleppo pine) |
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Rights:
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(c) Voltas et al., 2015
(c) New Phytologist Trust, 2015
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Document type:
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Article
Article - Accepted version |
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Published by:
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Wiley
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