title: Plasticity in leaf-level water relations of tropical rainforest trees in response to experimental drought.
abstract: The tropics are predicted to become warmer and drier, and understanding the sensitivity of tree species to drought is important for characterizing the risk to forests of climate change. This study makes use of a long-term drought experiment in the Amazon rainforest to evaluate the role of leaf-level water relations, leaf anatomy and their plasticity in response to drought in six tree genera. The variables (osmotic potential at full turgor, turgor loss point, capacitance, elastic modulus, relative water content and saturated water content) were compared between seasons and between plots (control and through-fall exclusion) enabling a comparison between short- and long-term plasticity in traits. Leaf anatomical traits were correlated with water relation parameters to determine whether water relations differed among tissues. The key findings were: osmotic adjustment occurred in response to the long-term drought treatment; species resistant to drought stress showed less osmotic adjustment than drought-sensitive species; and water relation traits were correlated with tissue properties, especially the thickness of the abaxial epidermis and the spongy mesophyll. These findings demonstrate that cell-level water relation traits can acclimate to long-term water stress, and highlight the limitations of extrapolating the results of short-term studies to temporal scales associated with climate change.
authors.affiliation: School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FE, UK.
authors.forename: Oliver
authors.initials: O
authors.lastname: Binks
authors.affiliation: School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FE, UK.|Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia.
authors.forename: Patrick
authors.initials: P
authors.lastname: Meir
authors.affiliation: School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FE, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Rowland
authors.affiliation: Centro de Geosciências, Universidade Federal do Pará, Belém, 66075-110, Brazil.
authors.forename: Antonio Carlos Lola
authors.initials: AC
authors.lastname: da Costa
authors.affiliation: EMBRAPA Amazônia Oriental, Belém, 66095-903, Brazil.
authors.forename: Steel Silva
authors.initials: SS
authors.lastname: Vasconcelos
authors.affiliation: Centro de Geosciências, Universidade Federal do Pará, Belém, 66075-110, Brazil.
authors.forename: Alex Antonio Ribeiro
authors.initials: AA
authors.lastname: de Oliveira
authors.affiliation: Museu Paraense Emílio Goeldi, Belém, 66077-830, Brazil.
authors.forename: Leandro
authors.initials: L
authors.lastname: Ferreira
authors.affiliation: Earth and Environmental Science, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
authors.forename: Bradley
authors.identifier: 0000-0002-4890-9999
authors.initials: B
authors.lastname: Christoffersen
authors.affiliation: Dipartimento di Scienze della Vita, Universitá di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Nardini
authors.affiliation: School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FE, UK.|ICREA at CREAF, 08193, Cerdanyola del Vallés, Spain.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Mencuccini
mesh_terms: D055864:Droughts; D016014:Linear Models; D008962:Models, Theoretical; D018515:Plant Leaves / Q000502:physiology*; D011312:Pressure; D011336:Probability; D065947:Rainforest; D012621:Seasons; D014867:Water / Q000502:physiology*
chemical_list: D014867:Water
keywords: Amazon rainforest; experimental drought; leaf anatomy; osmotic adjustment; plasticity; water relations