<?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%">Ruiz Sinoga, Jose Damian</style></author><author><style face="normal" font="default" size="100%">Pariente, Sarah</style></author><author><style face="normal" font="default" size="100%">Diaz, Asuncion Romero</style></author><author><style face="normal" font="default" size="100%">Martinez Murillo, Juan Francisco</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variability of relationships between soil organic carbon and some soil properties in Mediterranean rangelands under different climatic conditions (South of Spain)</style></title><secondary-title><style face="normal" font="default" size="100%">Catena</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cation exchange capacity</style></keyword><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">desertification</style></keyword><keyword><style  face="normal" font="default" size="100%">Pluviometric gradient</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil degradation</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%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0341816211001184</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">94</style></volume><pages><style face="normal" font="default" size="100%">17 - 25</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Changes in land use and vegetation cover affect various soil properties, including the soil organic carbon (SOC) pool and the transfer of atmospheric CO2 to terrestrial landscapes. In natural or quasi-natural conditions a reduction in biomass increases the risk of erosion, and can reduce the stored soil organic matter content. This can cause (i) consolidation of low levels of organic carbon stored in the soil; (ii) reduction in the levels of organic carbon because of the onset of erosion processes; and (iii) differing rates of recovery of the soil in response to environmental factors including precipitation, which is a principal agent of indirect recharge of soil organic matter. Few comparable studies have analyzed the reduction of SOC because of erosion, and assessed how this contributes to the loss of soil as vegetation cover decreases. This is particularly the case in semiarid Mediterranean environments, where erosion is one of the main causes of soil degradation. This study presents the results of an experiment carried out along a pluviometric gradient from humid to semiarid Mediterranean conditions, in southern Spain. The study involved two soil depths at ﬁve ﬁeld sites having similar lithology, slope and aspect, but differ in vegetation cover and composition related to their location along the gradient. We used soil cation exchange capacity (CEC) as an indicator of soil degradation. The results showed that: a) SOC decreased with decreasing rainfall; b) SOC is greater at the soil surface than at depth; c) CEC is a good indicator of the degradation of soil surface formations, as it is directly related to the SOC storage capacity; and d) the so-called “Mediterranean mountain” landscape, with sparse and mixed vegetation composed of scrubland and woodland species, is a good organic carbon sink with direct implications in relation to climate change.</style></abstract><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</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%">Mariscal-Sancho, Ignacio</style></author><author><style face="normal" font="default" size="100%">Peregrina, Fernando</style></author><author><style face="normal" font="default" size="100%">Mendiola, Maria A</style></author><author><style face="normal" font="default" size="100%">Santano, Jesus</style></author><author><style face="normal" font="default" size="100%">Espejo, Rafael</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Exchange Complex Composition in Mediterranean Ultisols Under Various Types of Vegetation and Soil Uses</style></title><secondary-title><style face="normal" font="default" size="100%">SOIL SCIENCE</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">organic carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil quality</style></keyword><keyword><style  face="normal" font="default" size="100%">storage bases</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><publisher><style face="normal" font="default" size="100%">LIPPINCOTT WILLIAMS &amp; WILKINS</style></publisher><pub-location><style face="normal" font="default" size="100%">530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA</style></pub-location><volume><style face="normal" font="default" size="100%">174</style></volume><pages><style face="normal" font="default" size="100%">339-345</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied the dynamics of texture, bulk density, exchangeable bases, acidity, and aluminum in the uppermost Surface 50 con of Mediterranean Ultisols under natural vegetation at variable degradation stages and tinder different soil uses in the Canamero's rana formation (southwest Spain). The areas studied included a cork oak grove (the climax vegetation in the area), a field densely covered by Cistus ladaniferus L., a field with 55% covered by Cistus crispus L. and C. ladaniferus, a field with 10% covered by bushes of the same type as the previous one, and a field with grass and occasional Cistus bushes. All of these fields with bushes were extensively cultivated with rye (Secale. cereale L.) and then abandoned 45, 35, 12, and 6 years, respectively, before the study. Finally, we selected an olive grove that had been under continuous tillage for the previous 65 years. The total organic matter content decreased, starting from the virgin soil, under cork oaks, to the most heavily degraded soil (that under olive trees), whereas the bulk density increased. The total contents of exchangeable Ca, Mg, Na, and K significantly decreased in the same trend as organic matter. In contrast, the amount of aluminum extracted by 1N KCl, Al(K), remained essentially constant or even increased with increasing soil degradation. This resulted in a markedly decreased Ca/Al(K) ratio in the topmost 5 cm of soil, which had a strong adverse effect on crop productivity and natural plant recovery after the soils were abandoned.</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%">Mariscal-Sancho, Ignacio</style></author><author><style face="normal" font="default" size="100%">Peregrina, Fernando</style></author><author><style face="normal" font="default" size="100%">Mendiola, Maria A.</style></author><author><style face="normal" font="default" size="100%">Santano, Jesus</style></author><author><style face="normal" font="default" size="100%">Espejo, Rafael</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Exchange Complex Composition in Mediterranean Ultisols Under Various Types of Vegetation and Soil Uses</style></title><secondary-title><style face="normal" font="default" size="100%">SOIL SCIENCE</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">organic carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil quality</style></keyword><keyword><style  face="normal" font="default" size="100%">storage bases</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">174</style></volume><pages><style face="normal" font="default" size="100%">339 - 345</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied the dynamics of texture, bulk density, exchangeable bases, acidity, and aluminum in the uppermost Surface 50 con of Mediterranean Ultisols under natural vegetation at variable degradation stages and tinder different soil uses in the Canamero's rana formation (southwest Spain). The areas studied included a cork oak grove (the climax vegetation in the area), a field densely covered by Cistus ladaniferus L., a field with 55% covered by Cistus crispus L. and C. ladaniferus, a field with 10% covered by bushes of the same type as the previous one, and a field with grass and occasional Cistus bushes. All of these fields with bushes were extensively cultivated with rye (Secale. cereale L.) and then abandoned 45, 35, 12, and 6 years, respectively, before the study. Finally, we selected an olive grove that had been under continuous tillage for the previous 65 years. The total organic matter content decreased, starting from the virgin soil, under cork oaks, to the most heavily degraded soil (that under olive trees), whereas the bulk density increased. The total contents of exchangeable Ca, Mg, Na, and K significantly decreased in the same trend as organic matter. In contrast, the amount of aluminum extracted by 1N KCl, Al(K), remained essentially constant or even increased with increasing soil degradation. This resulted in a markedly decreased Ca/Al(K) ratio in the topmost 5 cm of soil, which had a strong adverse effect on crop productivity and natural plant recovery after the soils were abandoned.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA&lt;br/&gt;publisher: LIPPINCOTT WILLIAMS &amp; WILKINS</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%">Garcia, C.</style></author><author><style face="normal" font="default" size="100%">Hernandez, T.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biological and biochemical indicators in derelict soils subject to erosion</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biochemical parameters (PG)</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological indicators</style></keyword><keyword><style  face="normal" font="default" size="100%">derelict soils</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil degradation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1997///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0038071796002945</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">29</style></volume><pages><style face="normal" font="default" size="100%">171 - 177</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n 21 derelict soils from a semi-arid Spanish Mediterranean area, with a lithological sub- strate of Ioams, submitted to a high degree of erosion, several biological and biochemical properties in- dicative of the soil degradation leve1 were determined. The organic matter content of these soils was very low (mean value = 11.8 g kg-‘), approximately one-third of the average value for organic matter content of natura1 soils in the same zone. Biological properties such as basal respiration and biomass C also had low values and were positively correlated with the organic matter content. Low values for de- hydrogenajse and catalase activity were indicative of low biological activity of the degraded soils. A positive correlation was found between the hydrolases related with the N, P, C and S cycles (urease, proteases, fl-glucosidase and arylsulphatase), as wel1 as between these hydrolases and the organic matter content. Principal component analysis showed that ah the variables studied, except catalase and qCOr, had a similar behaviour. There was a negative correlation between many of the properties studied and electrical conductivity, which agreed with the higher degree of biological and biochemical degradation found in gypsiferous soils with a higher salt content. Arylsulphatase and p-glucosidase activity were the hydrolases most affected by soil erosion processes</style></abstract><issue><style face="normal" font="default" size="100%">2</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%">García, C</style></author><author><style face="normal" font="default" size="100%">Hernández, T</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biological and biochemical indicators in derelict soils subject to erosion</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biochemical parameters (PG)</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological indicators</style></keyword><keyword><style  face="normal" font="default" size="100%">derelict soils</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil degradation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><volume><style face="normal" font="default" size="100%">29</style></volume><pages><style face="normal" font="default" size="100%">171-177</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n 21 derelict soils from a semi-arid Spanish Mediterranean area, with a lithological sub- strate of Ioams, submitted to a high degree of erosion, several biological and biochemical properties in- dicative of the soil degradation leve1 were determined. The organic matter content of these soils was very low (mean value = 11.8 g kg-‘), approximately one-third of the average value for organic matter content of natura1 soils in the same zone. Biological properties such as basal respiration and biomass C also had low values and were positively correlated with the organic matter content. Low values for de- hydrogenajse and catalase activity were indicative of low biological activity of the degraded soils. A positive correlation was found between the hydrolases related with the N, P, C and S cycles (urease, proteases, fl-glucosidase and arylsulphatase), as wel1 as between these hydrolases and the organic matter content. Principal component analysis showed that ah the variables studied, except catalase and qCOr, had a similar behaviour. There was a negative correlation between many of the properties studied and electrical conductivity, which agreed with the higher degree of biological and biochemical degradation found in gypsiferous soils with a higher salt content. Arylsulphatase and p-glucosidase activity were the hydrolases most affected by soil erosion processes</style></abstract></record></records></xml>