@article {1273, title = {Diversity and sensitivity of epiphytes to oxides of nitrogen in London}, journal = {Environmental Pollution }, volume = {146}, year = {2007}, pages = {299-310}, abstract = {This study investigated the distribution and diversity of epiphytes in London in relation to NO(x) using fine-scale atmospheric dispersion modelling. The survey recorded over 3000 epiphytes from 334 trees (Fraxinus excelsior) representing 74 lichen, 14 moss, 7 fungal and 3 algal species. There was a significant inverse relationship between diversity and NO(x). Diversity declined where NO(x) exceeded 70 microg m(-3) and NO2 exceeded 40 microg m(-3), suggesting a phytotoxic effect. However, there was a significant positive relationship between NO(x) and lichen abundance due to the ubiquitous distribution of pollution tolerant species, mainly associated with eutrophication. A scale of lichen sensitivity to NO(x) has been derived.}, author = {Davies, L. and Bates, J.W. and Bell, J.N.B. and James, P.W. and Purvis, O.W.} } @book {727, title = {Lichen Flora of Great Britain and Ireland}, year = {1992}, pages = {710}, publisher = {The Natural History Museum}, organization = {The Natural History Museum}, address = {London}, author = {Purvis, O.W. and Coppins, B.J. and Hawksworth, D.L. and James, P. and Moore, D.M.} }