title: Cell-level anatomical characteristics explain high mesophyll conductance and photosynthetic capacity in sclerophyllous Mediterranean oaks.
abstract: Leaf mass per area (LMA) has been suggested to negatively affect the mesophyll conductance to CO2(gm), which is the most limiting factor for area-based photosynthesis (AN) in many Mediterranean sclerophyll species. However, despite their high LMA, these species have similar ANto plants from other biomes. Variations in other leaf anatomical traits, such as mesophyll and chloroplast surface area exposed to intercellular air space (Sm/S and Sc/S), may offset the restrictions imposed by high LMA in gmand ANin these species. Seven sclerophyllous Mediterranean oaks from Europe/North Africa and North America with contrasting LMA were compared in terms of morphological, anatomical and photosynthetic traits. Mediterranean oaks showed specific differences in ANthat go beyond the common morphological leaf traits reported for these species (reduced leaf area and thick leaves). These variations resulted mainly from the differences in gm, the most limiting factor for carbon assimilation in these species. Species with higher ANshowed increased Sc/S, which implies increased gmwithout changes in stomatal conductance. The occurrence of this anatomical adaptation at the cell level allowed evergreen oaks to reach ANvalues comparable to congeneric deciduous species despite their higher LMA.
authors.affiliation: Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, 50059, Zaragoza, Spain.|Instituto Agroalimentario de Aragón -IA2- (CITA-Universidad de Zaragoza), 50013, Zaragoza, Spain.
authors.forename: José Javier
authors.initials: JJ
authors.lastname: Peguero-Pina
authors.affiliation: Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, 50059, Zaragoza, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Sisó
authors.affiliation: Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Flexas
authors.affiliation: Research Group on Plant Biology under Mediterranean Conditions, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Jeroni
authors.initials: J
authors.lastname: Galmés
authors.affiliation: Department of Physical, Chemical and Natural Systems, University Pablo Olavide, Carretera de Utrera km 1, 41013, Sevilla, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: García-Nogales
authors.affiliation: Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu, 51014, Estonia.
authors.forename: Ülo
authors.initials: Ü
authors.lastname: Niinemets
authors.affiliation: Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, 50059, Zaragoza, Spain.|Instituto Agroalimentario de Aragón -IA2- (CITA-Universidad de Zaragoza), 50013, Zaragoza, Spain.
authors.forename: Domingo
authors.initials: D
authors.lastname: Sancho-Knapik
authors.affiliation: Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, 50009, Zaragoza, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Saz
authors.affiliation: Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Gobierno de Aragón, Avda. Montañana 930, 50059, Zaragoza, Spain.|Instituto Agroalimentario de Aragón -IA2- (CITA-Universidad de Zaragoza), 50013, Zaragoza, Spain.
authors.forename: Eustaquio
authors.initials: E
authors.lastname: Gil-Pelegrín
mesh_terms: D002980:Climate; D005843:Geography; D019083:Mediterranean Region; D058503:Mesophyll Cells / Q000166:cytology* / Q000502:physiology; D010788:Photosynthesis; D054046:Plant Stomata / Q000502:physiology; D029963:Quercus / Q000166:cytology* / Q000502:physiology*; D013045:Species Specificity
keywords: 
  Quercus
  ; Mediterranean-type climate; anatomical adaptations; leaf mass per area (LMA); mesophyll conductance (gm); photosynthesis; sclerophylly