Fig. 2
From: Macro- and microscopic leaf injury triggered by ozone stress in beech foliage (Fagus sylvatica L.)
Visible injury triggered by O3 within foliage of adult beech trees. a Gradients of leaf injury in the canopy, increasing in severity in the better illuminated branches. b Gradients of O3 injury at branch level, increasing in severity basipetally. c–h Singular or combined O3 injury at leaf level: bronzing (b; c, e, f), photobleaching (phb; e), stippling (st; g) and yellowish dots (nd; h). d Asymptomatic