title: Response of vegetation to drought time-scales across global land biomes.
abstract: We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, tree-ring growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought, and we suggest that the persistence of the water deficit (i.e., the drought time-scale) could be playing a key role in determining the sensitivity of land biomes to drought. We found that arid biomes respond to drought at short time-scales; that is, there is a rapid vegetation reaction as soon as water deficits below normal conditions occur. This may be due to the fact that plant species of arid regions have mechanisms allowing them to rapidly adapt to changing water availability. Humid biomes also respond to drought at short time-scales, but in this case the physiological mechanisms likely differ from those operating in arid biomes, as plants usually have a poor adaptability to water shortage. On the contrary, semiarid and subhumid biomes respond to drought at long time-scales, probably because plants are able to withstand water deficits, but they lack the rapid response of arid biomes to drought. These results are consistent among three vegetation parameters analyzed and across different land biomes, showing that the response of vegetation to drought depends on characteristic drought time-scales for each biome. Understanding the dominant time-scales at which drought most influences vegetation might help assessing the resistance and resilience of vegetation and improving our knowledge of vegetation vulnerability to climate change.
authors.affiliation: Instituto Pirenaico de Ecología, Consejo Superior de Investigaciones Científicas, 50059 Zaragoza, Spain. svicen@ipe.csic.es
authors.forename: Sergio M
authors.initials: SM
authors.lastname: Vicente-Serrano
authors.forename: Célia
authors.initials: C
authors.lastname: Gouveia
authors.forename: Jesús Julio
authors.initials: JJ
authors.lastname: Camarero
authors.forename: Santiago
authors.initials: S
authors.lastname: Beguería
authors.forename: Ricardo
authors.initials: R
authors.lastname: Trigo
authors.forename: Juan I
authors.initials: JI
authors.lastname: López-Moreno
authors.forename: César
authors.initials: C
authors.lastname: Azorín-Molina
authors.forename: Edmond
authors.initials: E
authors.lastname: Pasho
authors.forename: Jorge
authors.initials: J
authors.lastname: Lorenzo-Lacruz
authors.forename: Jesús
authors.initials: J
authors.lastname: Revuelto
authors.forename: Enrique
authors.initials: E
authors.lastname: Morán-Tejeda
authors.forename: Arturo
authors.initials: A
authors.lastname: Sanchez-Lorenzo
mesh_terms: D058448:Biota; D055864:Droughts; D005843:Geography; D010788:Photosynthesis / Q000502:physiology; D018521:Plant Physiological Phenomena; D018547:Plant Stems / Q000254:growth & development; D018531:Spacecraft; D013997:Time Factors; D014197:Trees / Q000254:growth & development