title: Physiological differences explain the co-existence of different regeneration strategies in Mediterranean ecosystems.
abstract: • Fire and drought are selective driving forces in Mediterranean plants, and thus their ability to resprout or recruit after these disturbances is of paramount importance. The contrast in regeneration niche between resprouters and seeders, and each group's different root characteristics, suggest that they are subjected to different degrees of environmental stress and, consequently, to different evolutionary forces. • We compared leaf traits, xylem traits related to hydraulic efficiency and vulnerability to cavitation, and the physiological response to an imposed drought between seedlings of resprouters and seedlings of seeders. We used 12 species co-existing in Mediterranean basin ecosystems. • Major differences were found in the xylem architecture and leaf traits, and in the response to drought conditions. Seeders were more efficient at transporting water to leaves but formed, in turn, a safer xylem network. They also presented higher photosynthesis and transpiration rates, and earlier stomatal closure with drought, but good leaf dehydration tolerance. • Seeders and resprouters can be considered two syndromes whose different functional characteristics are related to water availability and drought responses. These characteristics, together with their differences in rooting habits, account for their distinct regeneration niches and, thus, their co-existence.
authors.affiliation: Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Joint Research Unit University of Alicante-CEAM, PO Box 99, 03080, Alicante, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Vilagrosa
authors.affiliation: Departamento de Ecología, Universidad de Alicante, PO Box 99, 03080, Alicante, Spain.
authors.forename: Encarnación I
authors.initials: EI
authors.lastname: Hernández
authors.affiliation: Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Joint Research Unit University of Alicante-CEAM, PO Box 99, 03080, Alicante, Spain.
authors.forename: Vanessa C
authors.initials: VC
authors.lastname: Luis
authors.affiliation: INRA, UMR 547 PIAF, F-63100, Clermont-Ferrand, France.|Clermont Université, Université Blaise Pascal, UMR 547 PIAF, BP 10448, F-63000, Clermont-Ferrand, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Cochard
authors.affiliation: CIDE-CSIC, Ctra. Nàquera Km. 4.5 (IVIA), 46113, Montcada, Valencia, Spain.
authors.forename: Juli G
authors.initials: JG
authors.lastname: Pausas
mesh_terms: D055864:Droughts; D017753:Ecosystem; D019083:Mediterranean Region; D010788:Photosynthesis; D018521:Plant Physiological Phenomena; D054046:Plant Stomata / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology; D012038:Regeneration / Q000502:physiology*; D013045:Species Specificity; D014867:Water; D052584:Xylem / Q000502:physiology
chemical_list: D014867:Water
keywords: Mediterranean ecosystems; cavitation; drought resistance; fire; plant functional traits; regeneration syndrome; resprouting; xylem hydraulic characteristics