<?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%">Theobald, M R</style></author><author><style face="normal" font="default" size="100%">Dias, T</style></author><author><style face="normal" font="default" size="100%">Tang, Y S</style></author><author><style face="normal" font="default" size="100%">Cruz, C</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a.</style></author><author><style face="normal" font="default" size="100%">Máguas, C</style></author><author><style face="normal" font="default" size="100%">Sutton, M</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%">Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands</style></title><secondary-title><style face="normal" font="default" size="100%">Biogeosciences</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">atmospheric ammonia</style></keyword><keyword><style  face="normal" font="default" size="100%">Critical levels</style></keyword><keyword><style  face="normal" font="default" size="100%">Critical loads</style></keyword><keyword><style  face="normal" font="default" size="100%">lichen functional-groups</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean evergreen woodlands (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">n deposition</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">1205-1215</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Nitrogen (N) has emerged in recent years as a key factor associated with global changes, with impacts on biodiversity, ecosystems functioning and human health. In order to ameliorate the effects of excessive N, safety thresholds such as critical loads (deposition ﬂuxes) and levels (concentrations) can be established. Few studies have assessed these thresholds for semi-natural Mediterranean ecosystems. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands. We have considered changes in epiphytic lichen communities, one of the most sensitive comunity indicators of excessive N in the atmosphere. Based on a classiﬁcation of lichen species according to their tolerance to N we grouped species into response functional groups, which we used as a tool to determine the critical loads and levels. This was done for a Mediterranean climate in evergreen cork-oak woodlands, based on the relation between lichen functional diversity and modelled N deposition for critical loads and measured annual atmospheric ammonia concentrations for critical levels, evaluated downwind from a reduced N source (a cattle barn). Modelling the highly signiﬁcant relationship between lichen functional groups and annual atmospheric ammonia concentration showed the critical level to be below 1.9 µg m−3 , in agreement with recent studies for other ecosystems. Modelling the highly signiﬁcant relationship between lichen functional groups and N deposition showed that the critical load was lower than 26 kg (N) ha−1 yr−1 , which is within the upper range established for other semi-natural ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should aid development of policies to protect Mediterranean woodlands from the initial effects of excessive N.</style></abstract></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%">Francaviglia, R.</style></author><author><style face="normal" font="default" size="100%">Gataleta, L.</style></author><author><style face="normal" font="default" size="100%">Marchionni, M.</style></author><author><style face="normal" font="default" size="100%">Trinchera, A.</style></author><author><style face="normal" font="default" size="100%">Aromolo, R.</style></author><author><style face="normal" font="default" size="100%">Benedetti, A.</style></author><author><style face="normal" font="default" size="100%">Nisini, L.</style></author><author><style face="normal" font="default" size="100%">Morselli, L.</style></author><author><style face="normal" font="default" size="100%">Brusori, B.</style></author><author><style face="normal" font="default" size="100%">Olivieri, P.</style></author><author><style face="normal" font="default" size="100%">Bernardi, E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil quality and vulnerability in a Mediterranean natural ecosystem of Central Italy.</style></title><secondary-title><style face="normal" font="default" size="100%">Chemosphere</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acidification</style></keyword><keyword><style  face="normal" font="default" size="100%">Atmospheric depositions</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological indicators</style></keyword><keyword><style  face="normal" font="default" size="100%">Critical loads</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil organic carbon</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/14987944</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">55</style></volume><pages><style face="normal" font="default" size="100%">455 - 466</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Wet and dry atmospheric depositions and soil chemical and microbiological properties were determined in a Mediterranean natural ecosystem of Central Italy near Rome (Castelporziano Estate). The monitoring of depositions permitted us to quantify the exceedances of S and N compounds (expressed as eqH(+)ha(-1)year(-1)) over the critical loads of acidity. Critical loads, i.e. the quantity of a substance which a part of the environment can tolerate without adverse effects occurring, were determined adopting the level 0 methodology following the UN/ECE Convention on Long-range Transboundary Air Pollution. Deposition data were available for the period 1992-1997, and acidity exceedances were referred to the main vegetation types present in the area. Results showed that most part of the Estate has a medium degree of vulnerability to acidification, and the corresponding risk of acidification deriving from the exceedances of atmospheric deposition was rather low. The study of soil chemical and microbiological properties included mainly total soil organic carbon (SOC), microbial biomass-C, biomass-C/SOC, soil respiration, and metabolic quotient (qCO2). Soil organic C metabolism has been discussed on the basis of the results from eight sampling sites.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 14987944</style></notes></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%">Francaviglia, R</style></author><author><style face="normal" font="default" size="100%">Gataleta, L</style></author><author><style face="normal" font="default" size="100%">Marchionni, M</style></author><author><style face="normal" font="default" size="100%">Trinchera, A</style></author><author><style face="normal" font="default" size="100%">Aromolo, R</style></author><author><style face="normal" font="default" size="100%">Benedetti, A</style></author><author><style face="normal" font="default" size="100%">Nisini, L</style></author><author><style face="normal" font="default" size="100%">Morselli, L</style></author><author><style face="normal" font="default" size="100%">Brusori, B</style></author><author><style face="normal" font="default" size="100%">Olivieri, P</style></author><author><style face="normal" font="default" size="100%">Bernardi, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil quality and vulnerability in a Mediterranean natural ecosystem of Central Italy.</style></title><secondary-title><style face="normal" font="default" size="100%">Chemosphere</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acidification</style></keyword><keyword><style  face="normal" font="default" size="100%">Atmospheric depositions</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological indicators</style></keyword><keyword><style  face="normal" font="default" size="100%">Critical loads</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil organic carbon</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">55</style></volume><pages><style face="normal" font="default" size="100%">455-466</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Wet and dry atmospheric depositions and soil chemical and microbiological properties were determined in a Mediterranean natural ecosystem of Central Italy near Rome (Castelporziano Estate). The monitoring of depositions permitted us to quantify the exceedances of S and N compounds (expressed as eqH(+)ha(-1)year(-1)) over the critical loads of acidity. Critical loads, i.e. the quantity of a substance which a part of the environment can tolerate without adverse effects occurring, were determined adopting the level 0 methodology following the UN/ECE Convention on Long-range Transboundary Air Pollution. Deposition data were available for the period 1992-1997, and acidity exceedances were referred to the main vegetation types present in the area. Results showed that most part of the Estate has a medium degree of vulnerability to acidification, and the corresponding risk of acidification deriving from the exceedances of atmospheric deposition was rather low. The study of soil chemical and microbiological properties included mainly total soil organic carbon (SOC), microbial biomass-C, biomass-C/SOC, soil respiration, and metabolic quotient (qCO2). Soil organic C metabolism has been discussed on the basis of the results from eight sampling sites.</style></abstract><accession-num><style face="normal" font="default" size="100%">14987944</style></accession-num></record></records></xml>