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Close to the edge: effects of repeated severe drought on stem hydraulics and non-structural carbohydrates in European beech saplings.
Tomasella, Martina; Nardini, Andrea; Hesse, Benjamin D; Machlet, Anna; Matyssek, Rainer; Häberle, Karl-Heinz.
Afiliación
  • Tomasella M; Department of Life Sciences, Università degli Studi di Trieste, Via L. Giorgieri 10, Trieste, Italy.
  • Nardini A; Department of Ecology and Ecosystem Management-Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, Freising, Germany.
  • Hesse BD; Department of Life Sciences, Università degli Studi di Trieste, Via L. Giorgieri 10, Trieste, Italy.
  • Machlet A; Department of Ecology and Ecosystem Management-Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, Freising, Germany.
  • Matyssek R; Department of Ecology and Ecosystem Management-Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, Freising, Germany.
  • Häberle KH; Department of Ecology and Ecosystem Management-Chair for Ecophysiology of Plants, Technische Universität München, Hans-Carl-von-Carlowitz Platz 2, Freising, Germany.
Tree Physiol ; 39(5): 717-728, 2019 05 01.
Article en En | MEDLINE | ID: mdl-30668841
Severe drought events threaten tree water transport system, productivity and survival. Woody angiosperms generally die when embolism-induced loss of hydraulic conductance (PLC) surpasses 80-90% under intense water shortage. However, the recovery capability and possible long-term carry-over effects of repeated drought events could dictate the fate of species' population under climate change scenarios. Potted saplings of European beech (Fagus sylvatica L.) were subjected to two drought cycles in two consecutive growing seasons, aiming to induce minimum leaf water potentials (Ψmd) of about -4 MPa, corresponding to hydraulic thresholds for survival of this species. In the first cycle, a well-irrigated (C) and a drought-stressed group (S) were formed, and, in the following summer, each group was divided in a well-irrigated and a drought-stressed one (four groups in total). The impact of the multiple drought events was assessed by measuring wood anatomical traits, biomass production, water relations, stem hydraulics and non-structural carbohydrate (NSC) content. We also investigated possible connections between stem hydraulics and carbon dynamics during the second drought event and following re-irrigation. S plants had lower Ψmd and maximum specific hydraulic conductivity (Ks) than C plants in the following growing season. Additionally, aboveground biomass production and leaf number were lower compared to C trees, resulting in lower water consumption. However, PLC was similar between groups, probably due to the production of new functional xylem in spring. The second drought event induced 85% PLC and promoted conversion of starch-to soluble sugars. Nevertheless, 1 week after re-irrigation, no embolism repair was observed and soluble sugars were reconverted to starch. The previous drought cycle did not influence the hydraulic performance during the second drought, and after re-irrigation S plants had 40% higher wood NSC content. Our data suggest that beech cannot recover from high embolism levels but multiple droughts might enhance stem NSC availability.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Transpiración de Plantas / Fagus / Metabolismo de los Hidratos de Carbono / Sequías Idioma: En Revista: Tree Physiol Asunto de la revista: BOTANICA / FISIOLOGIA Año: 2019 Tipo del documento: Article País de afiliación: Italia Pais de publicación: Canadá

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Transpiración de Plantas / Fagus / Metabolismo de los Hidratos de Carbono / Sequías Idioma: En Revista: Tree Physiol Asunto de la revista: BOTANICA / FISIOLOGIA Año: 2019 Tipo del documento: Article País de afiliación: Italia Pais de publicación: Canadá