ABSTRACT
Astronium graveolens Jacq. is a tree species of large occurrence in the Atlantic and the semideciduous forests. As ozone (O3) concentrations in São Paulo State are phytotoxic, it was decided to determine some physiological and biochemical responses of this species to O3 due to its importance in reclamation programs. Saplings were kept in two closed chambers: filtered air (FA) and filtered air enriched with O3 (AF + O3, 100 ppb, 4 h day-1, 7 days, n = 9). Leaf injury was assessed daily and at the end of the fumigation, carbon assimilation (A), stomatal conductance (gs), evapotranspiration (E), internal CO2 concentration (Ci), maximum carbon assimilation (Amax), lipid peroxidation (LP), and relative permeability of electrolytes (RPE) were established. O3 induced the appearance of leaf injuries and reduced A, gs, E, and Amax and did not change Ci, LP, and RPE. The species is moderately sensitive to O3. Long-term experiments should be conducted to verify if gas exchange reduction may adversely affect growth and hence affecting its use in reforestation programs.
Air pollution; tropical tree species; tropospheric ozone
