title: Ozone stomatal flux and O3 concentration-based metrics for Astronium graveolens Jacq., a Brazilian native forest tree species.
abstract: The current levels of surface ozone (O3) are high enough to negatively affect trees in large regions of São Paulo State, southeastern Brazil, where standards for the protection of vegetation against the adverse effects of O3 do not exist. We evaluated three O3 metrics - phytotoxic ozone dose (POD), accumulated ozone exposure over the threshold of 40 ppb h (AOT40), and the sum of all hourly average concentrations (SUM00) - for the Brazilian native tropical tree species Astronium graveolens Jacq. We used the DO3SE (Deposition of Ozone for Stomatal Exchange) model and calculated PODY for different thresholds (from 0 to 6 mmol O3 m(-2) PLA s(-1)), evaluating the model's performance through the relationship between measured and modelled conductance. The response parameters were: visible foliar injury, considered as incidence (% injured plants), severity (% injured leaves in relation to the number of leaves on injured plants), and leaf abscission. The model performance was suitable and significant (R(2) = 0.58; p < 0.001). POD0 was better correlated to incidence and leaf abscission, and SUM00 was better correlated to severity. The highest values of O3 concentration-based metrics (AOT40 and SUM00) did not coincide with those of POD0. Further investigation may improve the model and contribute to the proposition of a national standard for the protection of native species.
authors.affiliation: Instituto de Botânica, Caixa Postal 3005, São Paulo, SP, 01061-970, Brazil.
authors.forename: Jéssica C
authors.initials: JC
authors.lastname: Cassimiro
authors.affiliation: Universidade Estadual de Campinas, Instituto de Biologia, R. Monteiro Lobato, 255, Campinas, SP, 13 083 872, Brazil.
authors.forename: Bárbara B
authors.initials: BB
authors.lastname: Moura
authors.affiliation: Ecotoxicology of Air Pollution, CIEMAT, Avda. Complutense 2, 28040, Madrid, Spain.
authors.forename: Rocio
authors.initials: R
authors.lastname: Alonso
authors.affiliation: Universidade de São Paulo, Rua do Matão 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Sérgio T
authors.initials: ST
authors.lastname: Meirelles
authors.affiliation: Instituto de Botânica, Caixa Postal 3005, São Paulo, SP, 01061-970, Brazil. Electronic address: regmorae@uol.com.br.
authors.forename: Regina M
authors.initials: RM
authors.lastname: Moraes
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis*; D027926:Anacardiaceae / Q000187:drug effects* / Q000254:growth & development; D001938:Brazil; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D065928:Forests; D008954:Models, Biological; D010126:Ozone / Q000009:adverse effects / Q000032:analysis*; D010935:Plant Diseases / Q000139:chemically induced; D018515:Plant Leaves / Q000187:drug effects* / Q000254:growth & development; D054046:Plant Stomata; D014197:Trees / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: AOT40; Ozone flux; Phytotoxic ozone dose; SUM00; Stomatal conductance model