Division III.3 Evaluation period

Identification and quantification of visible ozone injury within Level II plot shall be carried out during: for conifers between October and February, and for broadleaves between July and beginning of September.

In general, identification of visible ozone injury on trees, shrubs and herbs within the LESS and for the ground vegetation within the IMP (optional) shall be carried out at least once during late summer (and in early summer if feasible) before natural leaf discoloration sets in and senescence and/or drought leads to leaf loss.