<?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><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%">Baldantoni, Daniela</style></author><author><style face="normal" font="default" size="100%">Fagnano, Massimo</style></author><author><style face="normal" font="default" size="100%">Alfani, Anna</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Tropospheric ozone effects on chemical composition and decomposition rate of Quercus ilex L. leaves.</style></title><secondary-title><style face="normal" font="default" size="100%">The Science of the total environment</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: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Air Pollutants: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Air Pollutants: toxicity</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%">Carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Cellulose: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Decaying leaf composition</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Lignin</style></keyword><keyword><style  face="normal" font="default" size="100%">Lignin: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Lignin: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean area</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrogen: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrogen: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Ozone</style></keyword><keyword><style  face="normal" font="default" size="100%">ozone exposure</style></keyword><keyword><style  face="normal" font="default" size="100%">Ozone: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Ozone: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Ozone: toxicity</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: metabolism</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">Elsevier B.V.</style></publisher><volume><style face="normal" font="default" size="100%">409</style></volume><pages><style face="normal" font="default" size="100%">979-984</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We determined the effects of tropospheric ozone on the chemical composition of Quercus ilex L. leaves and their decomposition, with a view to assessing the influence of ozone on nutrient cycling and the sustainability of Mediterranean holm oak forests. Forming one of the most widespread thermophilous vegetation communities in the area, Q. ilex is a dominant and widespread evergreen oak in the Mediterranean, where concentrations of tropospheric ozone are particularly high. The dynamics of carbon, nitrogen, lignin and cellulose concentrations were monitored for six months during the decomposition of leaves from plants subjected to controlled ozone exposure in open-top chambers. Ozone-exposed leaves, compared to unexposed leaves, showed no significant differences in C, N, lignin and cellulose concentrations prior to the incubation in mesocosms. However, during decomposition, leaves from plants exposed to ozone lost C significantly more slowly and showed a higher C/N ratio than unexposed leaves. Ozone exposure significantly slowed down the decomposition rate, indicating a negative effect of tropospheric ozone on nutrient cycling, which may reduce long-term sustainability of the holm oak forest.</style></abstract><accession-num><style face="normal" font="default" size="100%">21167557</style></accession-num></record><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%">Kesselmeier, J</style></author><author><style face="normal" font="default" size="100%">Bode, K</style></author><author><style face="normal" font="default" size="100%">Gerlach, C</style></author><author><style face="normal" font="default" size="100%">Jork, E.-M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Exchange of atmospheric formic and acetic acids with trees and crop plants under controlled chamber and purified air conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acetic acid</style></keyword><keyword><style  face="normal" font="default" size="100%">assimilation</style></keyword><keyword><style  face="normal" font="default" size="100%">Atmosphere</style></keyword><keyword><style  face="normal" font="default" size="100%">crop plants</style></keyword><keyword><style  face="normal" font="default" size="100%">exchange of volatile organic compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">formic acid</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">organic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Plants</style></keyword><keyword><style  face="normal" font="default" size="100%">Transpiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">32</style></volume><pages><style face="normal" font="default" size="100%">1765-1775</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the exchange of formic and acetic acids between the atmosphere and various tree species such as beech (Fagus sylvatica L.), ash (Fraxinus excelsior L.), spruce (Picea abies L.) Karst, holm oak (Quercus ilex L.), and birch (Betula pendula L.). and some crop-plant species such as corn (Zea mays, var. Banjo), pea (Pisum sativum, var. Solara), barley (Hordeum vulgare, var. Igri) and oat (Avena sativa, var. Wiesel). All experiments were done with dynamic enclosures ßushed with puriÞed oxidant-free air, containing only low or controlled amounts of the two acids. SigniÞcant and light-triggered emission of both acids from all tree species was observed. For one tree species (ash) a seasonal large increase in fall due to early leaf decomposition was found. The standard emission factors (30¡C and PAR&quot;1000 kmol m2 s~1) given as (nmol m~2 min~1) for acetic and formic acids, respectively, were 8.1 and 29.7 (ash, autumn), 1.0 and 3.3 (ash, summer), 0.9 and 1.4 (beech), 0.7 and 1.45 (spruce), 1.9 and 2.4 (Holm oak) and 1.7 and 6.7 (birch). Rough estimation of global annual emissions range between 20 and 130 Gmol formic acid and 10 and 33 Gmol acetic acid. These numbers reßect a 15Ð30% contribution by forest emissions to the continental organic acid budget. As compared to the global total NMHC emissions low molecular weight organic acids are of minor importance. In contrast to the trees, none of the crop-plant species investigated showed an emission, but always a clear deposition of both acids. Both emission from trees as well as uptake by the agricultural plants could be related to transpiration rates and leaf conductances</style></abstract></record></records></xml>