1. Herbaceous angiosperms are not more vulnerable to drought-induced embolism than angiosperm trees
- Author
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Frederic Lens, Catherine Picon-Cochard, Constant Signarbieux, Chloé E. L. Delmas, Hervé Cochard, Alexandre Buttler, Larissa Chacon Dória, Steven Jansen, Thibaud Chauvin, Marcelino del Arco, Sylvain Delzon, Naturalis Biodiversity Center, Universiteit Leiden [Leiden], UR 0874 Unité de recherche sur l'Ecosystème Prairial, Institut National de la Recherche Agronomique (INRA)-Unité de recherche sur l'Ecosystème Prairial (UREP)-Ecologie des Forêts, Prairies et milieux Aquatiques (EFPA), Institut National de la Recherche Agronomique (INRA), Santé et agroécologie du vignoble (UMR SAVE), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB)-Institut des Sciences de la Vigne et du Vin (ISVV)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Laboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier (PIAF), Institut National de la Recherche Agronomique (INRA)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP), Universität Ulm - Ulm University [Ulm, Allemagne], Unité de recherche Amélioration, Génétique et Physiologie Forestières (AGPF), Universidad de La Laguna, Biodiversité, Gènes & Communautés (BioGeCo), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB), COST Action FP1106 STReESS, Naturalis Biodiversity Center [Leiden], Unité de recherche sur l'Ecosystème Prairial (UREP), Universidad de La Laguna [Tenerife - SP] (ULL), and Picon-Cochard, Catherine
- Subjects
0106 biological sciences ,Physiology ,Biodiversité et Ecologie ,Growing season ,Plant Science ,Biology ,Poaceae ,complex mixtures ,010603 evolutionary biology ,01 natural sciences ,Trees ,Biodiversity and Ecology ,Magnoliopsida ,Species Specificity ,Osmotic Pressure ,Xylem ,Root pressure ,Botany ,Genetics ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Aridity index ,Transpiration ,sécheresse ,Water transport ,Vegetal Biology ,Plant Stems ,fungi ,prairie ,Water ,food and beverages ,Biological Transport ,Plant Transpiration ,15. Life on land ,Herbaceous plant ,Droughts ,Research Report - Focus Issue ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Biologie végétale ,010606 plant biology & botany - Abstract
The water transport pipeline in herbs is assumed to be more vulnerable to drought than in trees due to the formation of frequent embolisms (gas bubbles), which could be removed by the occurrence of root pressure, especially in grasses. Here, we studied hydraulic failure in herbaceous angiosperms by measuring the pressure inducing 50% loss of hydraulic conductance (P50) in stems of 26 species, mainly European grasses (Poaceae). Our measurements show a large range in P50 from 20.5 to 27.5 MPa, which overlaps with 94% of the woody angiosperm species in a worldwide, published data set and which strongly correlates with an aridity index. Moreover, the P50 values obtained were substantially more negative than the midday water potentials for five grass species monitored throughout the entire growing season, suggesting that embolism formation and repair are not routine and mainly occur under water deficits. These results show that both herbs and trees share the ability to withstand very negative water potentials without considerable embolism formation in their xylem conduits during drought stress. In addition, structure-function trade-offs in grass stems reveal that more resistant species are more lignified, which was confirmed for herbaceous and closely related woody species of the daisy group (Asteraceae). Our findings could imply that herbs with more lignified stems will become more abundant in future grasslands under more frequent and severe droughts, potentially resulting in lower forage digestibility.
- Published
- 2016