<?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%">D'Orazio, Valeria</style></author><author><style face="normal" font="default" size="100%">Traversa, Andreina</style></author><author><style face="normal" font="default" size="100%">Senesi, Nicola</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Forest soil organic carbon dynamics as affected by plant species and their corresponding litters: a fluorescence spectroscopy approach</style></title><secondary-title><style face="normal" font="default" size="100%">PLANT AND SOILPLANT AND SOIL</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Fluorescence spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest soils and litters</style></keyword><keyword><style  face="normal" font="default" size="100%">humic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil organic carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">Total luminescence spectroscopy</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">374</style></volume><pages><style face="normal" font="default" size="100%">473-484</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effect of forest cover distribution and plant litter input on soil organic carbon were analyzed to better understand the dynamics of carbon cycling across ecosystems on the ``Natural Oriented Reserve Bosco delle Pianelle{''}. Fluorescence spectroscopy represents a very useful tool to characterize soil organic matter properties, since it allows to directly monitor the molecular status of a fluorophore depending on its chemical environment, as well as on its structure, substituents of the aromatic moieties, and molecular weight. Here, fluorescence analysis was performed on humic acids isolated from four litters (HALs) and their underlying soils (HAs) at three depths. All samples were collected from a protected forest area, Southern Italy, under different plant covering: Quercus ilex L. (Q), mixed Carpinus betulus L. and Carpinus orientalis Mill. (CC), Pinus halepensis L. (P), and mixed Quercus trojana Webb. and Quercus ilex L. (QQ). Data obtained showed a fast decomposition process for P and QQ litters, with HAs in the underlying soils characterized by the presence of simple, highly fluorescent structural components also in the deepest layers. On the contrary, a slow decomposition process was observed for Q and CC litters, whose underlying soil HAs were characterized by an increasing aromatic polycondensation and humification degree from the surface to the deepest layers, as supported by low values of fluorescence intensity and high wavelength maxima. Results obtained indicate that P and QQ species promote C accumulation and stock in the underlying soils, thanks to a greater decomposition of their litter, and fluorescence spectroscopy is a very simple and suitable method to evaluate the influence of three species distribution on soil organic carbon pools.</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%">Duarte, Regina M. B. O.</style></author><author><style face="normal" font="default" size="100%">Fernández-Getino, Ana P.</style></author><author><style face="normal" font="default" size="100%">Duarte, Armando C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Humic acids as proxies for assessing different Mediterranean forest soils signatures using solid-state CPMAS 13C NMR spectroscopy</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%">CPMAS 13C NMR spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest soils</style></keyword><keyword><style  face="normal" font="default" size="100%">humic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Soils signature</style></keyword><keyword><style  face="normal" font="default" size="100%">Structural characterization</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0045653512015445http://www.ncbi.nlm.nih.gov/pubmed/23332874</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">91</style></volume><pages><style face="normal" font="default" size="100%">1556 - 1565</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Humic acids (HAs) of four representative forest soils profiles from Central Spain (two with different vegetation – pine and oak – but same parent material – granitie, and two with same vegetation – holm oak – but different parent material – granite and limestone) were investigated by solid-state cross polarization with magic angle spinning 13C nuclear magnetic resonance (NMR) spectroscopy. The objectives included the investigation of the impact of different forest properties on HA composition, assessing how the structural characteristics of the HA vary with soil depth, and evaluating the role of HA as surrogates for mapping the different forest soils signatures using structural data derived from 13C NMR spectroscopy. On average, alkyl C is the dominant C constituent (38–48% of the total NMR peak area) in all HA samples, followed by aromatic (12–22%) and O-alkyl C (12–19%), and finally carboxyl C (7.0–10%). The NMR data also indicated that HA composition is likely to be differently affected by the soil physico-chemical properties and type of forest vegetation. The structural characteristics of the HA from soil under oak did not differ broadly downward in the profile, whereas soil HA under pine forest exhibits a somewhat higher recalcitrant nature as a consequence of a higher degree of decomposition. The soil HA from holm oak forests differed from the other two forest soils, exhibiting a progressive decomposition of the alkyl C structures with increasing depth, while the carbohydrate-like indicator (O-alkyl C) is apparently being protected from mineralization in the horizons below the ground level. Overall, these differences in soil HA NMR signatures are an important diagnostic tool for understanding the role of different soil environmental factors on the structural composition of HA from Mediterranean forest soils.</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier Ltd&lt;br/&gt;accession-num: 23332874</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%">Aranda, V.</style></author><author><style face="normal" font="default" size="100%">Oyonarte, C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Characteristics of organic matter in soil surface horizons derived from calcareous and metamorphic rocks and different vegetation types from the Mediterranean high-mountains in SE Spain</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Soil Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">humic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean environments</style></keyword><keyword><style  face="normal" font="default" size="100%">pine trees reforestations</style></keyword><keyword><style  face="normal" font="default" size="100%">soil organic matter quality</style></keyword><keyword><style  face="normal" font="default" size="100%">surface horizon</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S1164556306000185</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">247 - 258</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A study was carried out on some basic characteristics of the organic matter in the surface horizons of soils from the two different geological (calcareous and acid metamorphic rocks) and ecological systems under a Mediterranean climate in Southeast Spain. The results show some noticeable differences in soil organic matter composition. This is likely due to typical Mediterranean climate and well adapted vegetation. There is a tendency towards a greater stability for the soil humus formed under slightly alkaline soil in comparison to the slightly acidic environment. The samples taken from the latter environment have a higher content in free organic matter, a lower content in total extractable humin and a greater relative proportion of aliphatic chains and lignin in the humic acids. The results also suggest some differences caused by the type of vegetation (forest and scrubland ecosystems) in the soil humus chemistry, with a more obvious negative effect under reforestations with species of Pinus in an acidic soil environment (a higher content in free organic matter, lesser presence of fungal-derived perylenequinonic pigments in the humic acids, and a higher content in little evolved forms of nitrogen and lignin in the humic acids). In general the organic matter under scrubland and Quercus vegetation is more decomposed and the humus is more evolved than under Pinus vegetation.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue></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%">Aranda, V</style></author><author><style face="normal" font="default" size="100%">Oyonarte, C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Characteristics of organic matter in soil surface horizons derived from calcareous and metamorphic rocks and different vegetation types from the Mediterranean high-mountains in SE Spain</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Soil Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">humic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean environments</style></keyword><keyword><style  face="normal" font="default" size="100%">pine trees reforestations</style></keyword><keyword><style  face="normal" font="default" size="100%">soil organic matter quality</style></keyword><keyword><style  face="normal" font="default" size="100%">surface horizon</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">247-258</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A study was carried out on some basic characteristics of the organic matter in the surface horizons of soils from the two different geological (calcareous and acid metamorphic rocks) and ecological systems under a Mediterranean climate in Southeast Spain. The results show some noticeable differences in soil organic matter composition. This is likely due to typical Mediterranean climate and well adapted vegetation. There is a tendency towards a greater stability for the soil humus formed under slightly alkaline soil in comparison to the slightly acidic environment. The samples taken from the latter environment have a higher content in free organic matter, a lower content in total extractable humin and a greater relative proportion of aliphatic chains and lignin in the humic acids. The results also suggest some differences caused by the type of vegetation (forest and scrubland ecosystems) in the soil humus chemistry, with a more obvious negative effect under reforestations with species of Pinus in an acidic soil environment (a higher content in free organic matter, lesser presence of fungal-derived perylenequinonic pigments in the humic acids, and a higher content in little evolved forms of nitrogen and lignin in the humic acids). In general the organic matter under scrubland and Quercus vegetation is more decomposed and the humus is more evolved than under Pinus vegetation.</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%">González-Vila, F L</style></author><author><style face="normal" font="default" size="100%">Almendros, G</style></author><author><style face="normal" font="default" size="100%">Martin, F</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">An evaluation of the differences in the composition of humic acids in soils under oak and pine forest by GC-MS after mild degradation</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Forest soils</style></keyword><keyword><style  face="normal" font="default" size="100%">humic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Lipids</style></keyword><keyword><style  face="normal" font="default" size="100%">mild degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">resin acids</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1987</style></year></dates><volume><style face="normal" font="default" size="100%">103</style></volume><pages><style face="normal" font="default" size="100%">83-88</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Significant differences were found in the products released after eight samples of humic acids (HA's) isolated from soils under mediterranean pine and oak forests underwent mild degradation. A number of compounds, including typical degradation products of lignins, were found exclusively in the HA's from the soils under pine forests. The aliphatic constituents were more firmly retained in the HA's under oak, which presented mean values for aromatic acids lower than the humic samples from pine forests. Different types of diterpene resin acids were also found amongst the mild degradation products of HA's from the studied areas.</style></abstract></record></records></xml>