Leaf age affects the responses of foliar injury and gas exchange to tropospheric ozone in Prunus serotina seedlings.
We investigated the effect of leaf age on the response of net photosynthesis (A), stomatal conductance (g(wv)), foliar injury, and leaf nitrogen concentration (N(L)) to tropospheric ozone (O(3)) on Prunus serotina seedlings grown in open-plots (AA) and open-top chambers, supplied with either carbon-filtered or non-filtered air. We found significant variation in A, g(wv), foliar injury, and N(L) (P < 0.05) among O(3) treatments. Seedlings in AA showed the highest A and g(wv) due to relatively low vapor pressure deficit (VPD). Older leaves showed significantly lower A, g(wv), N(L), and higher foliar injury (P < 0.001) than younger leaves. Leaf age affected the response of A, g(wv), and foliar injury to O(3). Both VPD and N(L) had a strong influence on leaf gas exchange. Foliar O(3)-induced injury appeared when cumulative O(3) uptake reached 8-12 mmol m(-2), depending on soil water availability. The mechanistic assessment of O(3)-induced injury is a valuable approach for a biologically relevant O(3) risk assessment for forest trees.
Zhang
Jianwei
J
Environmental Resources Research Institute, The Pennsylvania State University, University Park, PA 16802, USA. jianweizhang@fs.fed.us
Schaub
Marcus
M
Ferdinand
Jonathan A
JA
Skelly
John M
JM
Steiner
Kim C
KC
Savage
James E
JE
D000393:Air Pollutants / Q000378:metabolism / Q000633:toxicity*; D019069:Cell Respiration / Q000187:drug effects; D004784:Environmental Monitoring; D009584:Nitrogen / Q000378:metabolism; D010126:Ozone / Q000378:metabolism / Q000633:toxicity*; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects* / Q000378:metabolism; D054046:Plant Stomata / Q000187:drug effects / Q000378:metabolism; D027861:Prunus / Q000187:drug effects* / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism
D000393:Air Pollutants; D010126:Ozone; D009584:Nitrogen