TY - JOUR T1 - The False Positive in Bioindicators of Air Pollution JF - Arboriculture & Urban Forestry (AUF) JO - JOA SP - 249 LP - 251 DO - 10.48044/jauf.1992.048 VL - 18 IS - 5 AU - W. David Hacker AU - Howard S. Neufeld Y1 - 1992/09/01 UR - http://auf.isa-arbor.com/content/18/5/249.abstract N2 - Yellow-poplar (Lirodendron tulipifera) seedlings were fumigated with a gradient of ozone to determine what effect ozone has on the species. The fumigated seedlings displayed physical symptoms of ozone injury but a large number of the individuals from the charcoal-filtered treatment showed physical symptoms of ozone when indeed no ozone was present. This is an indication that what appears to be ozone damage on yellow-poplar may not be caused by ozone. ER -