Some indirect effects of air pollution on bark-living invertebrates.
Describes further study of the ecosystem on the boles of mature, free-standing Fraxinus excelsior trees in three districts in Newcastle upon Tyne, which represent a gradient of increasing SO2 and smoke pollution. [Cf. F.A. 32 No. 2653.] Autotrophs (algae, lichens) were gradually eliminated with increasing pollution, and there was a parallel decline in the number and diversity of herbivores (mainly psocids). Carnivorous and omnivorous insects did not diminish in numbers, because of cross-links with other habitats. KEYWORDS: air pollution \ air pollution \ effects \ vegetation \ plant populations \ air pollution \ gases \ fumes HCl, HF, SO2