Responses of native broadleaved woody species to elevated ozone in subtropical China.
To assess ozone sensitivity of subtropical broadleaved tree species and explore possible underlying mechanisms, six evergreen and two deciduous native species were exposed to either charcoal-filtered air or elevated O(3) (E-O(3), ∼150ppb) for one growing season. Initial visible symptoms in deciduous species appeared much earlier than those in evergreen species. The species which first showed visible symptoms also had the largest reductions in biomass. E-O(3) induced significant decreases in photosynthesis rate, chlorophyll content and antioxidant capacity but a significant increase in malondialdehyde content in two deciduous species and two evergreen species (Cinnamomum camphora and Cyclobalanopsis glauca). Except C. glauca, however, E-O(3) had no significant effects on stomatal conductance (g(s)), total phenols and ascorbate contents. Difference in O(3) sensitivity among all species was strongly attributed to specific leaf mass rather than g(s). It suggests that some subtropical tree species will be threatened by rising O(3) concentrations in the near future.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 2871 Mailbox, Shuangqing Road 18, Haidian District, Beijing 100085, China.
Weiwei
W
Zhang
Zhaozhong
Z
Feng
Xiaoke
X
Wang
Junfeng
J
Niu
D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D002681:China; D027423:Cinnamomum camphora / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D002980:Climate; D010126:Ozone / Q000032:analysis / Q000633:toxicity*; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology; D018515:Plant Leaves; D029963:Quercus / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D014197:Trees / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D014934:Wood
D000393:Air Pollutants; D010126:Ozone