Although there was no relationship between PAH-concentrations in these meadow plants and species-specific leaf areas (data on SLA from Grime & Hunt 1975, Hunt & Cornelissen 1997) – the results of biomonitoring studies (Fig. 1) confirm the importance of surface-to-volume ratios. Bryophytes, which have no epidermis, grass and kale
are scavenging more PAH than plants with compact, smooth leaves. Böhme et al. (1999) found that Achillea millefolium had the highest potential for the accumulation of SOCs and explained this by its high surface-to-volume ratio and feathery leaves, which reduce the laminar boundary layer surrounding theleaves. Conversely, dust-associated PAH may be easily washed off from large, flat and thin leaves like those of Populus or Fagus. The interspecies comparison of
PAH accumulation in three Plantago species by Bakker et al. (1999) also indicated the importance of leaf hairs to scavenge PAHs from the air.