Changes in growth, leaf abscission, and biomass associated with seasonal tropospheric ozone exposures of Populus tremuloides clones and seedlings. - Karnosky,D..F..; Gagnon,Z..E..; Dickson,R..E..; Coleman,M..D..; Lee,E..H..; Isebrands,J..G.. (Canadian Journal of Forest Research, 1996)