title: Ozone uptake by adult urban trees based on sap flow measurement.
abstract: The O(3) uptake in 17 adult trees of six urban species was evaluated by the sap flow-based approach under free atmospheric conditions. The results showed very large species differences in ground area scaled whole-tree ozone uptake (F(o)₃), with estimates ranging from 0.61 ± 0.07 nmol m(-2) s(-1) in Robinia pseudoacacia to 4.80 ± 1.04 nmol m(-2) s(-1) in Magnolia liliiflora. However, average F(o)₃by deciduous foliages was not significantly higher than that by evergreen ones (3.13 vs 2.21 nmol m(-2) s(-1), p = 0.160). Species of high canopy conductance for O(3) (G(o)₃) took up more O(3) than those of low G(o)₃, but that their sensitivity to vapour pressure deficit (D) were also higher, and their F(o)₃decreased faster with increasing D, regardless of species. The responses of F(o)₃to D and total radiation led to the relative high flux of O(3) uptake, indicating high ozone risk for urban tree species.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Weiqi
authors.initials: W
authors.lastname: Zhou
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Wang
authors.forename: Fuyuan
authors.initials: F
authors.lastname: Gao
authors.forename: Hua
authors.initials: H
authors.lastname: Zheng
authors.forename: Lei
authors.initials: L
authors.lastname: Tong
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Ouyang
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D010126:Ozone / Q000032:analysis / Q000378:metabolism*; D014197:Trees / Q000737:chemistry / Q000378:metabolism*; D014506:Urban Renewal
chemical_list: D000393:Air Pollutants; D010126:Ozone