TY - JOUR
T1 - Effects of drought on xylem anatomy and water-use efficiency of two co-occurring pine species
AU - Martin-Benito, Dario
AU - Anchukaitis, Kevin J.
AU - Evans, Michael N.
AU - del Río, Miren
AU - Beeckman, Hans
AU - Cañellas, Isabel
N1 - Funding Information:
Acknowledgments: We would like to thank Guilermo Gea-Izquierdo (INIA, Spain) for his comments on an earlier version of this article. We acknowledge support to the Fulbright−MICIIN postdoctoral fellowship and Marie-Curie IEF grant (EU-grant 329935) awarded to DMB. DMB and KJA were further supported by NSF grant AGS-1338734. The Instituto Nacional de Investigaciones Agrarias y Alimentarias (INIA) provided funds to maintain the permanent research plot network (Project OT03-002). We also thank the Spanish Meteorological Agency (AEMET) for providing meteorological data. Anonymous reviewers are thanked for critically reading the manuscript and providing feedback that helped improve our manuscript. This is LDEO contribution #8144.
Publisher Copyright:
© 2017 by the authors.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Exploring how drought influences growth, performance, and survival in different species is crucial to understanding the impacts of climate change on forest ecosystems. Here, we investigate the responses of two co-occurring pines (Pinus nigra and Pinus sylvestris) to interannual drought in east-central Spain by dendrochronological and wood anatomical features integrated with isotopic ratios of carbon (δ13C) and oxygen (δ18O) in tree rings. Our results showed that drought induces both species to allocate less carbon to build tracheid cell-walls but increases tracheid lumen diameters, particularly in the transition wood between early and latewood, potentially maximizing hydraulic conductivity but reducing resistance to embolism at a critical phase during the growing season. The thicker cell-wall-to-lumen ratio in P. nigra could imply that its xylem may be more resistant to bending stress and drought-induced cavitation than P. sylvestris. In contrast, the higher intrinsic water-use efficiency (iWUE) in P. sylvestris suggests that it relies more on a water-saving strategy. Our results suggest that narrower cell-walls and reduced growth under drought are not necessarily linked to increased iWUE. At our site P. nigra showed a higher growth plasticity, grew faster and was more competitive than P. sylvestris. In the long term, these sustained differences in iWUE and anatomical characters could affect forest species performance and composition, particularly under increased drought stress.
AB - Exploring how drought influences growth, performance, and survival in different species is crucial to understanding the impacts of climate change on forest ecosystems. Here, we investigate the responses of two co-occurring pines (Pinus nigra and Pinus sylvestris) to interannual drought in east-central Spain by dendrochronological and wood anatomical features integrated with isotopic ratios of carbon (δ13C) and oxygen (δ18O) in tree rings. Our results showed that drought induces both species to allocate less carbon to build tracheid cell-walls but increases tracheid lumen diameters, particularly in the transition wood between early and latewood, potentially maximizing hydraulic conductivity but reducing resistance to embolism at a critical phase during the growing season. The thicker cell-wall-to-lumen ratio in P. nigra could imply that its xylem may be more resistant to bending stress and drought-induced cavitation than P. sylvestris. In contrast, the higher intrinsic water-use efficiency (iWUE) in P. sylvestris suggests that it relies more on a water-saving strategy. Our results suggest that narrower cell-walls and reduced growth under drought are not necessarily linked to increased iWUE. At our site P. nigra showed a higher growth plasticity, grew faster and was more competitive than P. sylvestris. In the long term, these sustained differences in iWUE and anatomical characters could affect forest species performance and composition, particularly under increased drought stress.
KW - Drought
KW - Pinus
KW - Tracheid
KW - Tree ring
KW - Water-use efficiency
KW - Wood anatomy
KW - Xylem bending stress
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U2 - 10.3390/f8090332
DO - 10.3390/f8090332
M3 - Article
AN - SCOPUS:85029748457
SN - 1999-4907
VL - 8
JO - Forests
JF - Forests
IS - 9
M1 - 332
ER -