title: Variation in Ecophysiological Traits and Drought Tolerance of Beech (Fagus sylvatica L.) Seedlings from Different Populations.
abstract: Frequency and intensity of heat waves and drought events are expected to increase in Europe due to climate change. European beech (Fagus sylvatica L.) is one of the most important native tree species in Europe. Beech populations originating throughout its native range were selected for common-garden experiments with the aim to determine whether there are functional variations in drought stress responses among different populations. One-year old seedlings from four to seven beech populations were grown and drought-treated in a greenhouse, replicating the experiment at two contrasting sites, in Italy (Mediterranean mountains) and Germany (Central Europe). Experimental findings indicated that: (1) drought (water stress) mainly affected gas exchange describing a critical threshold of drought response between 30 and 26% SWA for photosynthetic rate and Ci/Ca, respectively; (2) the Ci to Ca ratio increased substantially with severe water stress suggesting a stable instantaneous water use efficiency and an efficient regulation capacity of water balance achieved by a tight stomatal control; (3) there was a different response to water stress among the considered beech populations, differently combining traits, although there was not a well-defined variability in drought tolerance. A combined analysis of functional and structural traits for detecting stress signals in beech seedlings is suggested to assess plant performance under limiting moisture conditions and, consequently, to estimate evolutionary potential of beech under a changing environmental scenario.
authors.affiliation: Istituto per la Protezione Sostenibile delle Piante, Consiglio Nazionale delle Ricerche Sesto Fiorentino, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cocozza
authors.affiliation: BIOGECO, INRA, Univ. Bordeaux Cestas, France.
authors.forename: Marina
authors.initials: M
authors.lastname: de Miguel
authors.affiliation: Institute of Forest Ecology, Slovak Academy of Science Zvolen, Slovak Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Pšidová
authors.affiliation: Institute of Forest Ecology, Slovak Academy of Science Zvolen, Slovak Republic.
authors.forename: L'ubica
authors.initials: L
authors.lastname: Ditmarová
authors.affiliation: Dipartimento Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise Campobasso, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Marino
authors.affiliation: Dipartimento Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise Campobasso, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Maiuro
authors.affiliation: Dipartimento Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise Campobasso, Italy.
authors.forename: Arturo
authors.initials: A
authors.lastname: Alvino
authors.affiliation: Johann Heinrich von Thünen Institute, Institute of Forest Ecosystems Eberswalde, Germany.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Czajkowski
authors.affiliation: Johann Heinrich von Thünen Institute, Institute of Forest Ecosystems Eberswalde, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bolte
authors.affiliation: Dipartimento di Bioscienze e Territorio, Università degli Studi del MolisePesche, Italy; The EFI Project Centre on Mountain Forests (MOUNTFOR), Edmund Mach FoundationSan Michele all'Adige, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Tognetti
keywords: European beech; chlorophyll a fluorescence; ecophysiology; gas exchange; water stress