Browsing by Subject "Erosion"
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- PublicationOpen AccessErosión del suelo en plantaciones de cítricos en laderas. Valle del Riu Canyoles, Valencia(Servicio de Publicaciones - Universidad de Murcia, 2007) Cerdà, Artemi; Bodí, Merche B.; Hevilla-Cucarella, Enrique B.Durante las últimas décadas el cultivo de cítricos en el Mediterráneo se ha trasladado desde las zonas bajas a las laderas en busca de un mayor confort térmico. Todo ello ha sido posible por la introducción del riego localizado, potenciado por la presión urbanística de las zonas llanas, y fomentado por la reducción de costes en los bombeos de aguas subterráneas. Las nuevas plantaciones ocupan ahora espacios de elevada pendiente donde las pérdidas de suelo suelen ser graves. A pesar del cambio en la localización de los cultivos -de llanuras a laderas- se siguen laboreando intensamente los suelos y/o aplicando herbicidas con el fi n de eliminar las malas hierbas. La agricultura de conservación y la agricultura ecológica pueden ayudar a detener las elevadas pérdidas de suelo. Experimentos con lluvia simulada (60 mm h-1) en campos de cítricos del valle de Montesa (Valencia) donde se han aplicado herbicidas (residual y sistémico), laboreo, cubiertas de paja y abono verde permiten cuantifi car tasas de erosión muy distintas según el manejo aplicado. La tasa de erosión en los campos donde se aplicó la cubierta de paja y el abono verde fue nula, mientras que el campo laboreado alcanzó los 10 g m-2 h-1, y en aquellos tratados con herbicidas la pérdida de suelo osciló entre 37 y 58 g m-2 h-1.
- PublicationOpen AccessErosión y desertificación.-Retroceso erosivo en la cuenca del río Nacimiento en la Vega Baja del Segura: Evaluación y seguimiento utilizando herramientas SIGRodríguez Juan, J. E.; Universidad de MurciaABSTRACT In this paper, we are tried to know the most significant erosion processes that affect the study area selected in the last 50 years, according to the different land uses in the study area, as well as the lithologic formation of them. To do this we have used GIS technology (Geographic Information Systems) to compare the erosion processes of the different periods of study and for data collection in a thematic cartography. Generally are reliefs that are colonized by natural vegetation, but the main area are soils that have been deforested and plowed. Will be in the latter ones which will generate more concentrated runoff and soil loss. In the comparative analysis between the different frames, we observed that the anthropic practices have degrees of erosion and loss of superficial material alarming. Erosion processes are more pressing in cultivated soils where runoff concentrated in rills, gully erosion, piping processes and off the slopes are the most evident expressions of loss of soil.
- PublicationOpen AccessErosión y desertificación.-Understanding the erosion of semi-arid landscapes subject to vegetation change: a combined approach using monitoring, isotope and c analysis.Brazier, R.E.; Turnbull, L.; Bol, R.; Dixon, L.; Wainwright, J.; Universidad de MurciaABSTRACT The degradation of grasslands is a common problem across semi-arid areas worldwide. Over the last 150 years much of the South-Western USA has experienced significant land degradation, with desert grasslands becoming dominated by shrubs and concurrent changes in runoff and erosion which are thought to propagate further the process of degradation. Field-based experiments were carried out to determine how runoff and erosion vary at stages over a transition from a black grama (Bouteloua eriopoda) grassland to creosotebush (Larrea tridentata) shrubland at the Sevilleta NWR LTER site in New Mexico. δ13C and δ15N analyses were carried out to investigate the age and potential provenance of eroded sediment
- PublicationOpen AccessMorfología Fluvial.-El matorral como protector del suelo y los recursos hídricos en la Sierra de Enguera. Valencia. España. Implicaciones económicas de su manejo.Cerdà, A.; Jiménez-Morena, A.; Bodí, M.B.; Universidad de MurciaAbstract John Thornes found that scrubland (matorral) was a key factor to control soil erosion on Mediterranean mountains. His research works inspired many scientist that researched the impact of scrubland changes and management on semiarid ecosystems. An experiment carried out on the El Teularet-Sierra de Enguera experimental station in 2004 show the erosion rates on a 30-years abandoned orchard with dense vegetation cover of Ulex parviflorus and Cistus albidus and a 20-year old fire affected Maquia with Quercus coccifera, Pistacia lentiscus and Juniperus oxycedrus. The 8 (4 at each treatment) plots (1, 2, 4 and 16 m2) under 715 mm of natural rainfall contributed with low runoff, sediment concentration and soil erosion. These measurements confirm the John Thornes� idea: matorral is an efficient vegetation cover protection on Mediterranean ecosystems.esentat
- PublicationOpen AccessMorfología Fluvial.-El papel de la vegetación de pinar y de matorral en la regeneración de los suelos afectados por los incendios forestales. Efectos hidrológicos y erosivos en el año posterior al incendioCerdá, A.; Bodí, M.B.; Doerr, S.H.; Mataix-Solera, J.; Universidad de MurciaABSTRACT Forest fires provide an excellent opportunity to understand the relationship between vegetation and erosion. This is because changes in vegetation and erosion processes and rates are highly dynamics after the fire. Through simulated rainfall and WDPT (Water Drop Penetration Time) tests the soil water repellency and the runoff and erosion rates after a fire in the Serra Grossa Range, Eastern Spain, was measured. Sampling (six plots) was carried out in October 2002 and July 2003, under wet and dry conditions respectively. The results show high losses of soil and water during the October 2002 measurements for both vegetation covers: pine (Pinus halepensis) and scrubland (Ulex parviflorus y Cistus albidus). However, during the July 2003 measurements, the pine forest area continues to show high rates of erosion while the shrub is drastically reduced as the runoff was lower. This was due to the higher soil water repellency on the pine covered soils, what caused the increase in runoff and the acceleration of erosion processes. Therefore, the type of vegetation influences the erosive processes, which must be taken into account in forest policy.
- PublicationOpen AccessLa producción de biomasa y sus efectos en los procesos erosivos en un ecosistema semiárido del S. E. de España*(Murcia: Universidad de Murcia, Servicio de Publicaciones, 1987) Fisher, G. C.; Romero Díaz, María Asunción; López Bermúdez, Francisco; Thornes, J. B.; Francis, C.; Facultad de BiologíaThe effects of vegetation on soil erosion occur partly through the controls which surface plant litter and incorporated organic matter exercise over hydrological and geomorphological processes. The relationships between litter and other components of a dry Mediterranean ecosystem have been measured since November 1983 to Fehruary 1986 on a sloping site with eroding mar! soils about 30 Km from Murcia. Results are presented here for hiomass, litter production and litter composition for severa! perennial shrubs on this site. Litter and soil characteristics were found to vary rapidly over short distances ( < lm). Litter fall from perennial shruhs usually peaks in spring and early summer, but generally surface litter variation is poorly correlated with the amount of vegetation cover and soil moisture amounts. The stronger links between vegetation cover and soil organic matter suggest an importan! role for root biomass as a major and strongly localized source of organic matter on this site.