TY  - JOUR
AU  - Ziegler, C.
AU  - Coste, S.
AU  - Stahl, C.
AU  - Delzon, S.
AU  - Levionnois, S.
AU  - Cazal, J.
AU  - Cochard, H.
AU  - Esquivel-Muelbert, A.
AU  - Goret, J.-Y.
AU  - Heuret, P.
AU  - Jaouen, G.
AU  - Santiago, L.S.
AU  - Bonal, D.
PY  - 2019//
TI  - Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought
T2  - Ann. Forest Sci.
JO  - Annals of Forest Science
SP  - 115
VL  - 76
IS  - 4
PB  - Springer
KW  - Amazon rainforest
KW  - Embolism resistance
KW  - Hydraulic safety margins
KW  - Turgor loss point
KW  - Water potential
N2  - Key message: Abundant Neotropical canopy-tree species are more resistant to drought-induced branch embolism than what is currently admitted. Large hydraulic safety margins protect them from hydraulic failure under actual drought conditions. Context: Xylem vulnerability to embolism, which is associated to survival under extreme drought conditions, is being increasingly studied in the tropics, but data on the risk of hydraulic failure for lowland Neotropical rainforest canopy-tree species, thought to be highly vulnerable, are lacking. Aims: The purpose of this study was to gain more knowledge on species drought-resistance characteristics in branches and leaves and the risk of hydraulic failure of abundant rainforest canopy-tree species during the dry season. Methods: We first assessed the range of branch xylem vulnerability to embolism using the flow-centrifuge technique on 1-m-long sun-exposed branches and evaluated hydraulic safety margins with leaf turgor loss point and midday water potential during normal- and severe-intensity dry seasons for a large set of Amazonian rainforest canopy-tree species. Results: Tree species exhibited a broad range of embolism resistance, with the pressure threshold inducing 50% loss of branch hydraulic conductivity varying from − 1.86 to − 7.63 MPa. Conversely, we found low variability in leaf turgor loss point and dry season midday leaf water potential, and mostly large, positive hydraulic safety margins. Conclusions: Rainforest canopy-tree species growing under elevated mean annual precipitation can have high resistance to embolism and are more resistant than what was previously thought. Thanks to early leaf turgor loss and high embolism resistance, most species have a low risk of hydraulic failure and are well able to withstand normal and even severe dry seasons. © 2019, The Author(s).
SN  - 12864560 (Issn)
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076431919&doi=10.1007%2fs13595-019-0905-0&partnerID=40&md5=4bc23ce5b68e360d3fa3e037575a02bc
UR  - http://dx.doi.org/10.1007/s13595-019-0905-0
N1  - exported from refbase (http://php.ecofog.gf/refbase/show.php?record=901), last updated on Thu, 26 Dec 2019 10:25:32 -0300
ID  - Ziegler_etal2019
ER  -