Global convergence in the vulnerability of forests to drought

• Autores: Choat, Brendan; Jansen, Steven; Brodribb, Tim J.; Cochard, Hervé; Delzon, Sylvain; Bhaskar, Radika; Bucci, Sandra Janet; Field, Taylor S.; Gleason, Sean M.; Hacke, Uwe G.; Jacobsen, Anna L.; Lens, Frederic; Maherali, Hafiz; Martínez Vilalta, Jordi; Mayr, Stefan; Mencuccini, Maurizio; Mitchell, Patrick J.; Nardini, Andrea; Pittermann, Jarmila; Pratt, R. Brandon; Sperry, John S.; Westoby, Mark; Wright, Ian J.; Zanne, Amy E.
• Año de publicación: 2012
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Mortality; Cavitation; Embolisms; Forest
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Shifts in rainfall patterns and increasing temperatures associated with climate change are likely to cause widespread forest decline in regions where droughts are predicted to increase in duration and severity. One primary cause of productivity loss and plant mortality during drought is hydraulic failure. Drought stress creates trapped gas emboli in the water transport system, which reduces the ability of plants to supply water to leaves for photosynthetic gas exchange and can ultimately result in desiccation and mortality. At present we lack a clear picture of how thresholds to hydraulic failure vary across a broad range of species and environments, despite many individual experiments. Here we draw together published and unpublished data on the vulnerability of the transport system to drought-induced embolism for a large number of woody species, with a view to examining the likely consequences of climate change for forest biomes. We show that 70% of 226 forest species from 81 sites worldwide operate with narrow (<1a megapascal) hydraulic safety margins against injurious levels of drought stress and therefore potentially face long-term reductions in productivity and survival if temperature and aridity increase as predicted for many regions across the globe. Safety margins are largely independent of mean annual precipitation, showing that there is global convergence in the vulnerability of forests to drought, with all forest biomes equally vulnerable to hydraulic failure regardless of their current rainfall environment. These findings provide insight into why drought-induced forest decline is occurring not only in arid regions but also in wet forests not normally considered at drought risk.
Fil: Choat, Brendan. University of Western Sydney; Australia
Fil: Jansen, Steven. Universitat Ulm; Alemania
Fil: Brodribb, Tim J.. University of Tasmania; Australia
Fil: Cochard, Hervé. Institut National de la Recherche Agronomique; Francia. Clermont Université; Francia. Universite Blaise Pascal; Francia
Fil: Delzon, Sylvain. Institut National de la Recherche Agronomique; Francia. Universite de Bordeaux; Francia
Fil: Bhaskar, Radika. University Brown; Estados Unidos
Fil: Bucci, Sandra Janet. Universidad Nacional de la Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Field, Taylor S.. James Cook University; Australia
Fil: Gleason, Sean M.. Macquarie University; Australia
Fil: Hacke, Uwe G.. University of Alberta; Canadá
Fil: Jacobsen, Anna L.. California State University; Estados Unidos
Fil: Lens, Frederic. Naturalis Biodiversity Centre; Países Bajos
Fil: Maherali, Hafiz. University of Guelph; Canadá
Fil: Martínez Vilalta, Jordi. Consejo Superior de Investigaciones Científicas. Centre de Recerca Ecológica I Aplicacions Forestals; España. Universitat Autònoma de Barcelona; España
Fil: Mayr, Stefan. University Innsbruck; Austria
Fil: Mencuccini, Maurizio. Institució Catalana de Recerca i Estudis Avancats; España. Consejo Superior de Investigaciones Científicas. Centre de Recerca Ecológica I Aplicacions Forestals; España. Universitat Autònoma de Barcelona; España. University of Edinburgh; Reino Unido
Fil: Mitchell, Patrick J.. CSIRO; Australia
Fil: Nardini, Andrea. Università di Trieste; Italia
Fil: Pittermann, Jarmila. University of California; Estados Unidos
Fil: Pratt, R. Brandon. California State University; Estados Unidos
Fil: Sperry, John S.. University of Utah; Estados Unidos
Fil: Westoby, Mark. Macquarie University; Australia
Fil: Wright, Ian J.. Macquarie University; Australia
Fil: Zanne, Amy E.. Missouri Botanical Garden; Estados Unidos. The George Washington University; Estados Unidos