<?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%">Ceballos, Antonio</style></author><author><style face="normal" font="default" size="100%">Cerdà, A.</style></author><author><style face="normal" font="default" size="100%">Schnabel, Susanne</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">RUNOFF PRODUCTION AND EROSION PROCESSES ON A DEHESA IN WESTERN SPAIN*</style></title><secondary-title><style face="normal" font="default" size="100%">Geographical Review</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">erosion</style></keyword><keyword><style  face="normal" font="default" size="100%">land use</style></keyword><keyword><style  face="normal" font="default" size="100%">rainfall simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">runoff</style></keyword><keyword><style  face="normal" font="default" size="100%">Spain</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://onlinelibrary.wiley.com/doi/10.1111/j.1931-0846.2002.tb00147.x/abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">92</style></volume><pages><style face="normal" font="default" size="100%">333 - 353</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Runoff generation and soil erosion were investigated at the Guadalperal6n ex- perimental watershed (western Spain), within the land-use system known as dehesa, or open, managed evergreen forests. Season and type of surface were found to control runoff and soil- loss rates. Five soil units were selected as representative of surface types found in the study area: hillslope grass, bottom grass, tree cover, sheep trails, and shrub cover. Measurements were made in various conditions with simulated rainfall to gain an idea of the annual varia- tion in runoff and soil loss. Important seasonal differences were noted due to surface cover and moisture content of soil, but erosion rates were determined primarily by runoff. Surfaces covered with grass and shrubs always showed less erosion; surfaces covered with holm oaks showed higher runoff rates, due to the hydrophobic character of the soils. Concentrations of runoff sediment during the siniulations confirmed that erosion rates at the study site de- pended directly on the sediment available on the soil surface</style></abstract><issue><style face="normal" font="default" size="100%">3</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%">Ceballos Barbancho, A.</style></author><author><style face="normal" font="default" size="100%">Shanabel, S.</style></author><author><style face="normal" font="default" size="100%">Cerdà, A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Estudio de la variabilidad temporal y espacial de la pérdida de suelo en la dehesa (Extremadura, SO España) mediante lluvia simulada</style></title><secondary-title><style face="normal" font="default" size="100%">Geographicalia</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">rainfall simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">runoff</style></keyword><keyword><style  face="normal" font="default" size="100%">Season</style></keyword><keyword><style  face="normal" font="default" size="100%">sediment concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">soil loss</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dialnet.unirioja.es/servlet/articulo?codigo=257338</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">19 - 36</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The inain objective of this paper is to study the influence of the seasonal variability of tlze antecedent conditions in soil losses in a dehesa ecosystem, as well as an approach to its spatial variability. The experimental layout includes forty rainfall simulation experiments carried out in two different situa- tions: first on dry conditions, with degraded vegetation, and, second on wet con- ditions, with an important vegetation cover. The results indicate that the highest sediiilent concentrations are located in situations with bare soils, due to the effect of the drought and the soil remo- ved by grazing animals. The control of the process depends more to tlie sediment available on the soil surface than to the runoff transport capacity. From an spatial point of view, it liighlights the contrast between tlie low los- ses registered in the valley bottoms and the highest values measured in tlie areas more frequented by the livestock, where the degradation of the vege- tation cover and the removal of tlie soil material are continuous. Finally, although the rate of soil loss in the dehesa is low, it is important froin a qua- litative point of view because it affects to the inost fertile horizon in the soil profile</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%">Cerdà, A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil aggregate stability under different Mediterranean vegetation types</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%">Aggregate stability</style></keyword><keyword><style  face="normal" font="default" size="100%">Laboratory test</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">Vegetation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0341816298000411</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">32</style></volume><pages><style face="normal" font="default" size="100%">73 - 86</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The influence of vegetation type on soil erodibility was studied by means of aggregate stability measurements using the Modified Emerson Water Dispersion Test MEWDT , water-drop impacts . . . CND and TDI and Ultrasonic Disruption UD methods on soils from north-facing slopes of the mountain range of La Serra Grossa in the eastern Iberian Peninsula. Soils with similar characteristics but covered by the main plant species at the study area were selected. Quercus ilex woodland showed the most resistant soil aggregates followed by Q. coccifera and Pistacea lentiscus scrubland, Brachypodium retusum grassland and Pinus halepensis woodland. Aggregates developed beneath dwarf shrubs like Rosmarinus officinalis, Thymus Íulgaris, Ulex parÍiflorus and Anthyllis cystisoides were least resistant. The different methods and tests applied are useful to study the soil aggregate stability. The MEWDT and TDI tests showed only minor differences between samples due to the high aggregate resistance and the low energy applied by these tests. CND and UD tests are considered to be more suitable for resistant Mediterranean soil developed on limestone due to the greater energy applied. Aggregates tested from an initially moist pF1 condition were always more stable than air dried aggregates. Rangeland management . after disturbances by fire, agriculture or grazing, etc. should try to establish natural woodland Q. ilex. in order to get the most stable soil. Alternative vegetation cover to the climax vegetation that give high aggregate stability are Q. coccifera and P. lentiscus scrublands. Immediately after disturbance, B. retusum grassland seems to be the best option for soil protection.</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%">Cerdà, A.</style></author><author><style face="normal" font="default" size="100%">Schnabel, S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil hydrological response under simulated rainfall in the Dehesa land system (Extremadura, SW Spain) under drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Earth Surface Processes and Landforms</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">hydrophobicity</style></keyword><keyword><style  face="normal" font="default" size="100%">rainfall simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil hydrology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1096-9837(199803)23:3&lt;195::AID-ESP830&gt;3.0.CO;2-I/abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">23</style></volume><pages><style face="normal" font="default" size="100%">195 - 209</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil hydrology was investigated in the Guadelperalón experimental watershed in order to determine the inﬂuence of land use and vegetation cover on runoff and inﬁltration within the Dehesa land system. Five soil–vegetation units were selected: (1) tree cover, (2) sheep trials, (3) shrub cover, (4) hillslope grass and (5) bottom grass. The results of the simulated rainfall experiments performed at an intensity of 53·6mm h −1 during one hour on plots of 0·25m 2 , and the water drop penetration time test indicate the importance of water repellency in the Dehesa land system under drought conditions. Low inﬁltration rates (c. 9–44mm h −1 ) were found everywhere except at shrub sites and in areas with low grazing pressure. Soil water repellency greatly reduced inﬁltration, especially beneath Quercus ilex canopies, where fast ponding and greater runoff rates were observed. The low vegetation cover as a consequence of a prolonged drought and grazing pressure, in conjunction with the soil water repellency, induces high runoff rates (15–70 per cent). In spite of this, macropore ﬂuxes were found in different locations, beneath trees, on shrub-covered surfaces, as well as at sites with a dominance of herbaceous cover. Discontinuity of the runoff ﬂuxes due to variations in hydrophobicity causes preferential ﬂows and as a consequence deeper inﬁltration, especially where macropores are developed</style></abstract></record></records></xml>