title: Ozone-induced stomatal sluggishness changes carbon and water balance of temperate deciduous forests.
abstract: Tropospheric ozone concentrations have increased by 60-100% in the Northern Hemisphere since the 19(th) century. The phytotoxic nature of ozone can impair forest productivity. In addition, ozone affects stomatal functions, by both favoring stomatal closure and impairing stomatal control. Ozone-induced stomatal sluggishness, i.e., a delay in stomatal responses to fluctuating stimuli, has the potential to change the carbon and water balance of forests. This effect has to be included in models for ozone risk assessment. Here we examine the effects of ozone-induced stomatal sluggishness on carbon assimilation and transpiration of temperate deciduous forests in the Northern Hemisphere in 2006-2009 by combining a detailed multi-layer land surface model and a global atmospheric chemistry model. An analysis of results by ozone FACE (Free-Air Controlled Exposure) experiments suggested that ozone-induced stomatal sluggishness can be incorporated into modelling based on a simple parameter (gmin, minimum stomatal conductance) which is used in the coupled photosynthesis-stomatal model. Our simulation showed that ozone can decrease water use efficiency, i.e., the ratio of net CO2 assimilation to transpiration, of temperate deciduous forests up to 20% when ozone-induced stomatal sluggishness is considered, and up to only 5% when the stomatal sluggishness is neglected.
authors.affiliation: 1] Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo 060-8689, Japan [2] Institute of Sustainable Plant Protection, National Research Council of Italy, Via Madonna del Piano, I-50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Hoshika
authors.affiliation: 1] Research Group for Environmental Science, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki, 319-1195 Japan [2] Atmospheric Environmental Research, Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany.
authors.forename: Genki
authors.initials: G
authors.lastname: Katata
authors.affiliation: Atmospheric Environment and Applied Meteorology Research Department, Meteorological Research Institute, Tsukuba, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Deushi
authors.affiliation: Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu 183-8509, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo 060-8689, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Koike
authors.affiliation: Institute of Sustainable Plant Protection, National Research Council of Italy, Via Madonna del Piano, I-50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Paoletti
mesh_terms: D000393:Air Pollutants; D002245:Carbon Dioxide / Q000378:metabolism*; D003198:Computer Simulation; D008954:Models, Biological; D010126:Ozone; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology*; D018526:Plant Transpiration / Q000187:drug effects / Q000502:physiology*; D065947:Rainforest; D014197:Trees / Q000187:drug effects / Q000502:physiology*; D014867:Water / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology
chemical_list: D000393:Air Pollutants; D014867:Water; D002245:Carbon Dioxide; D010126:Ozone