<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pinho, P</style></author><author><style face="normal" font="default" size="100%">Llop, E</style></author><author><style face="normal" font="default" size="100%">Ribeiro, M C</style></author><author><style face="normal" font="default" size="100%">Cruz, C</style></author><author><style face="normal" font="default" size="100%">Soares, A</style></author><author><style face="normal" font="default" size="100%">Pereira, M J</style></author><author><style face="normal" font="default" size="100%">Branquinho, C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Tools for determining critical levels of atmospheric ammonia under the influence of multiple disturbances</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental Pollution</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Air Pollutants</style></keyword><keyword><style  face="normal" font="default" size="100%">Air Pollutants: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">ammonia</style></keyword><keyword><style  face="normal" font="default" size="100%">Ammonia: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Atmosphere</style></keyword><keyword><style  face="normal" font="default" size="100%">Atmosphere: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodiversity</style></keyword><keyword><style  face="normal" font="default" size="100%">Critical thresholds</style></keyword><keyword><style  face="normal" font="default" size="100%">Environmental Monitoring</style></keyword><keyword><style  face="normal" font="default" size="100%">Environmental Monitoring: methods</style></keyword><keyword><style  face="normal" font="default" size="100%">Eutrophication</style></keyword><keyword><style  face="normal" font="default" size="100%">Functional groups</style></keyword><keyword><style  face="normal" font="default" size="100%">Global change</style></keyword><keyword><style  face="normal" font="default" size="100%">lichens</style></keyword><keyword><style  face="normal" font="default" size="100%">Lichens: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Lichens: classification</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><publisher><style face="normal" font="default" size="100%">Elsevier Ltd</style></publisher><volume><style face="normal" font="default" size="100%">188</style></volume><pages><style face="normal" font="default" size="100%">88-93</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Critical levels (CLEs) of atmospheric ammonia based on biodiversity changes have been mostly calculated using small-scale single-source approaches, to avoid interference by other factors, which also influence biodiversity. Thus, it is questionable whether these CLEs are valid at larger spatial scales, in a multi- disturbances context. To test so, we sampled lichen diversity and ammonia at 80 sites across a region with a complex land-cover including industrial and urban areas. At a regional scale, confounding factors such as industrial pollutants prevailed, masking the CLEs. We propose and use a new tool to calculate CLEs by stratifying ammonia concentrations into classes, and focusing on the highest diversity values. Based on the significant correlations between ammonia and biodiversity, we found the CLE of ammonia for Mediterranean evergreen woodlands to be 0.69 mgm?3, below the previously accepted value of 1.9 mgm?3, and below the currently accepted pan-European CLE of 1.0 mgm?3</style></abstract><accession-num><style face="normal" font="default" size="100%">24568792</style></accession-num></record></records></xml>