Plant height and hydraulic vulnerability to drought and cold

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Olson, Mark, E., Soriano, Diana, Rosell, Julieta, Anfodillo, Tommaso, Donoghue, Michael, Edwards, Erika, León-Gómez, Calixto, Dawson, Todd, Camarero Martínez, J. Julio, Castorena, Matiss, Echeverría, Alberto, Espinosa, Carlos, Fajardo, Alex, Gazol, Antonio, Isnard, Sandrine, Lima, Rivete, Marcati, Carmen, Méndez-Alonzo, Rodrigo
• Other Authors: Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Department of Land, Environment, Agriculture and Forestry (TeSAF), Università degli Studi di Padova = University of Padua (Unipd), Center Investigation Ecosistemas Patagonia, Universidad Austral de Chile, Instituto Pirenaico de Ecologìa = Pyrenean Institute of Ecology Zaragoza (IPE - CSIC), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ), University of California Institute for Mexico and the United States CN-15-1428, Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica of the Universidad Nacional Autonoma de Mexico IT200515, Consejo Nacional de Ciencia y Tecnologia (Mexico) 32404, 237061, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (Brazil) 2014/14778-6, 2015/14954-1, Fondo Nacional de Desarrollo Cientifico y Tecnologico (Chile) 1160329, Programa de Becas Posdoctorales, Direccion General de Asuntos del Personal Academico-Universidad Nacional Autonoma de Mexico; Ministerio de Economia, Industria y Competitividad Grant FPDI 2013-16600
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Adaptation; Allometry; Climatic change; Embolism vulnerability; Forest dieback; [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics; Phylogenetics and taxonomy; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Tundra
• Online Access: https://hal.umontpellier.fr/hal-02183759; https://doi.org/10.1073/pnas.1721728115

International audience As trees worldwide experience mortality or dieback with increasing drought and low tundras grow taller with warming, understanding the link between plant height and climate is increasingly important. We show that taller plants have predictably wider water-conducting conduits, and that wider conduits within species are more vulnerable to conduction-blocking embolisms. These two observations suggest that tall plants in formerly moist areas die because their wide conduits are excessively vulnerable under novel drought conditions. Also, the cold that limits conduit diameter, and therefore height, in tundra plants is relaxed under warming, permitting wider conduits and taller plants. That plant height appears linked to climate via plant hydraulics helps explain why vegetation height differs across biomes and is altering with climate change.Understanding how plants survive drought and cold is increasingly important as plants worldwide experience dieback with drought in moist places and grow taller with warming in cold ones. Crucial in plant climate adaptation are the diameters of water-transporting conduits. Sampling 537 species across climate zones dominated by angiosperms, we find that plant size is unambiguously the main driver of conduit diameter variation. And because taller plants have wider conduits, and wider conduits within species are more vulnerable to conduction-blocking embolisms, taller conspecifics should be more vulnerable than shorter ones, a prediction we confirm with a plantation experiment. As a result, maximum plant size should be short under drought and cold, which cause embolism, or increase if these pressures relax. That conduit diameter and embolism vulnerability are inseparably related to plant size helps explain why factors that interact with conduit diameter, such as drought or warming, are altering plant heights worldwide.