Premium
Growth responses of yellow‐poplar( Liriodendron tulipifera L.) exposed to 5 years of O 3 aloneor combined with elevated CO 2
Author(s) -
Rebbeck J.,
Scherzer A. J.
Publication year - 2002
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.2002.00933.x
Subject(s) - ozone , magnoliaceae , carbon dioxide , horticulture , shoot , charcoal , zoology , fumigation , chemistry , botany , growing season , biology , organic chemistry
Field‐grown yellow‐poplar ( Liriodendron tulipifera L.) werefumigated from May to October in 1992–96 within open‐topchambers to determine the impact of ozone (O 3 ) aloneor combined with elevated carbon dioxide (CO 2 ) on saplinggrowth. Treatments were replicated three times and included: charcoal‐filteredair (CF); 1 × ambient ozone (1 × O 3 );1·5 × ambient ozone (1·5 × O 3 );1·5 × ambient ozone plus 350 p.p.m.carbon dioxide (1·5 × O 3 + CO 2 )(target of 700 p.p.m. CO 2 ); and open‐air chamberlessplot (OA). After five seasons, the total cumulative O 3 exposure (SUM 00 = sumof hourly O 3 concentrations during the study) rangedfrom 145 (CF) to 861 (1·5 × O 3 ) p.p.m. × h (partsper million hour). Ozone had no statistically significant effecton yellow‐poplar growth or biomass, even though total root biomasswas reduced by 13% in the 1·5 × O 3 ‐exposedsaplings relative to CF controls. Although exposure to 1·5 × O 3 + CO 2 hada stimulatory effect on yearly basal area growth increment aftertwo seasons, significant increases in shoot and root biomass (∼ 60% increaserelative to all others) were not detected until the fifth season.After five seasons, the yearly basal area growth increment of saplingsexposed to 1·5 × O 3 + CO 2 ‐air increasedby 41% relative to all others. Based on this multi‐yearstudy, it appears that chronic O 3 effects on yellow‐poplargrowth are limited and slow to manifest, and are consistent withprevious studies that show yellow‐poplar growth is not highly responsiveto O 3 exposure. In addition, these results show thatenriched CO 2 may ameliorate the negative effects of elevatedO 3 on yellow‐poplar shoot growth and root biomass underfield conditions.