title: Growth overcompensation against O3 exposure in two Japanese oak species, Quercus mongolica var. crispula and Quercus serrata, grown under elevated CO2.
abstract: To assess the effects of elevated concentrations of carbon dioxide (CO2) and ozone (O3) on the growth of two mid-successional oak species native to East Asia, Quercus mongolica var. crispula and Quercus serrata, we measured gas exchange and biomass allocation in seedlings (initially 1-year-old) grown under combinations of elevated CO2 (550 μmol mol(-1)) and O3 (twice-ambient) for two growing seasons in an open-field experiment in which root growth was not limited. Both the oak species showed a significant growth enhancement under the combination of elevated CO2 and O3 (indicated by total dry mass; over twice of ambient-grown plants, p < .05), which probably resulted from a preferable biomass partitioning into leaves induced by O3 and a predominant enhancement of photosynthesis under elevated CO2. Such an over-compensative response in the two Japanese oak species resulted in greater plant growth under the combination of elevated CO2 and O3 than elevated CO2 alone.
authors.affiliation: Department of Plant Ecology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan. Electronic address: kitao@ffpri.affrc.go.jp.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Kitao
authors.affiliation: Department of Plant Ecology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan.
authors.forename: Masabumi
authors.initials: M
authors.lastname: Komatsu
authors.affiliation: Department of Plant Ecology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yazaki
authors.affiliation: Department of Plant Ecology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kitaoka
authors.affiliation: Department of Plant Ecology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tobita
mesh_terms: D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D010126:Ozone / Q000494:pharmacology*; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D029963:Quercus / Q000187:drug effects* / Q000254:growth & development; D012621:Seasons; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development
chemical_list: D002245:Carbon Dioxide; D010126:Ozone
keywords: Biomass partitioning; Elevated CO(2); Elevated O(3); Growth; Photosynthesis; Quercus mongolica var. crispula; Quercus serrata