Premium
Intraspecific variation in the use of water sources by the circum‐Mediterranean conifer Pinus halepensis
Author(s) -
Voltas Jordi,
Lucabaugh Devon,
Chambel Maria Regina,
Ferrio Juan Pedro
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13569
Subject(s) - aleppo pine , intraspecific competition , arid , mediterranean climate , soil water , biology , interspecific competition , pinus <genus> , afforestation , ecology , environmental science , botany
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 .