PAHs in the Soils of a Mature,Mixed-Deciduous (Quercus-Fraxinus) Woodland and the Surrounding Pasture

A survey of PAHs in the soils of a mature,mixed-deciduous woodland and the surrounding pasturewas conducted along two transects. PAH `profiles'were not significantly different in the woodland soilcompared with the pasture. ΣPAH concentrations in thewoodland soil were significantly higher than soil fromthe surrounding pasture by a factor of 1.5–3 (P < 0.01), indicating enhanced deposition of PAHs to thesoil under the canopy via leaf litter, stemflow and/or through-fall. A deposition `edge effect' was onlyobserved at the windward edge of the canopy where thenumber and density of aerial and basal stems washighest (P < 0.05). The influence of predominantwest/south-westerly winds was observable in the lackof an edge effect at the leeward edges, and the higherΣPAH concentrations in the predominantly leewardpasture compared to the windward pasture (P < 0.05).