Table 3.

Rates of O3 uptake by 4 seed-source progenies of red maple from an atmosphere containing 0.2 ppm 03.*

Seed SourceO3 uptake
mg O3/hr/dm2mg O3/hr/g
State College, PA0.315a0.634a
Opelika, AL0.217b0.490b
Alfred, ME0.266bc0.557ab
Ely, MN0.231c0.545b
  • *Mean separation in columns by Duncan’s multiple range test, 5% level. Values represent the means of 20, 26, 22 and 20 seedlings, respectively. (From: Townsend,A.M. 1974. Sorption of ozone by nine shade tree species. J. Amer. Soc. Hort. Sci. 99: 206-208).