Vegetación dispersa y flujos de vertiente en clima semiárido

[Resumen] Se revisa la información disponible sobre la generación y dinámica de los mosaicos de vegetación-suelo desnudo en clima semiárido y su relación con los flujos de vertiente. Muchos de los datos utilizados se obtuvieron en el área experimental de Rambla Honda (Almería) que opera en el marco del proyecto MEDALUS de la Comisión de las Comunidades Europeas. Las conclusiones indican que la diferenciación de las propiedades del suelo entre las fases veegtadas y desnudas se refuerza con el tiempo. Las primeras se convierten en "islas de fertilidad" y núcleos activos de sucesión, mientras que las segundas sufren una progresiva degradación. Los rodales de vegetación obtienen agua de las áreas desnudas adyacentes, de manera que ambas constituyen unidades funcionales, cuya forma y distribución espacial resulta de interacciones entre el crecimiento de las plantas y los flujos de escorrentía y sedimentos a lo largo de las vertientes.[Abstract] A review is made on the available information about the origin and dynamics of vegetation-bare soil mosaics in semi-arid climate and their relation with runoff and sediment fluxes. Data come mostly from the Rambla Honda field site which is being operated under the Medalus project from the Commission of European Communities. Main conclusions show that differences in the soil properties between vegetated and bare patches are self-reinforced with time. The former become "fertility islands" and active successional spots, while the latter suffer a progressive degradation. Vegetated patches obtaln water from neighbour bare areas so that both become functional units. Shapes and spatial patterns of such units result from interactions between plant growth and downhill fluxes of water and sediments

A neuro-scientific approach to enviroment care

Grass-root feedback to public agencies’ policies for coping with global change threats is poor and reactive. Concurrently, human population becomes more urban, isolated from nature and unable to take personal decisions about it. Therefore, helping societal involvement and proactive behavior towards nature is a crucial challenge nowadays. This paper intends to explore the role of emotions in support of a positive interaction in human/ environment systems, to assess their evolutionary changes and ways to eventually readdress its trend. For that purpose, the latest neuroscientific findings are applied to disentangle the nature impact on the human emotional system by comparing the present people’s attitudes to those from pre-agrarian cultures. This knowledge allows drawing guidelines to improve people´s concern to care for the environment.La retroalimentación “grass-root” para las políticas de los organismos públicos que tienen como objetivo enfrentarse a las amenazas del cambio global es pobre y reactiva. Al mismo tiempo, la población humana se vuelve más urbana, aislada de la naturaleza e incapaz de tomar decisiones personales al respecto. Por lo tanto, ayudar a la participación social y al comportamiento proactivo hacia la naturaleza es en la actualidad un desafío crucial. Este artículo intenta explorar el papel de las emociones en apoyo de una interacción positiva entre los sistemas humanos/ambientales, con el objeto de evaluar sus cambios evolutivos y caminar finalmente hacia una reorientación de su tendencia. Con este propósito, se aplican las últimas conclusiones neurocientíficas para desentrañar el impacto de la naturaleza en el sistema emocional humano, comparando las actitudes de las personas actuales con las de las culturas preagrarias. Este conocimiento permite diseñar pautas que mejoren la preocupación de las personas por el cuidado del medio ambiente

Variaciones sedimentarias durante el Eoceno medio en la sierra de Andía (Navarra)

In this paper, tkie stratigraphical and lithological character- istics of the Middle Eocene are established, in the Sierra de Andia (Navarra, Spain). Examples of the cross-stratification are described and the directional data analyzed. A study of the basin evolution is elaborated. It is pro- posed a correlation with the youngest sediments of the Sierra de Urbasa, situated more to the West

Analysis of effective resistance calculation methods and their effect on modelling evapotranspiration in two different patches of vegetation in semi-arid SE Spain

International audienceEffective parameters are of major importance in modelling surface fluxes at different scales of spatial heterogeneity. Different ways to obtain these effective parameters for their use in meso-scale and GCM models have been studied. This paper deals with patch-scale heterogeneity, where effective resistances were calculated in two patches with different vegetation (Retama sphaerocarpa (L.) Boiss shrubs, and herbaceous plants) using different methods: aggregating soil and plant resistances in parallel, in series or by an average of both. Effective aerodynamic resistance was also calculated directly from patch fluxes. To assess the validity of the different methods used, the Penman-Monteith equation was used with effective resistances to estimate the total ?E for each patch. The ?E estimates found for each patch were compared to Eddy Covariance system measurements. Results showed that for effective surface resistances, parallel aggregation of soil and plant resistances led to ?E estimates closer to the measured ?E in both patches (differences of around 10%). Results for effective aerodynamic resistances differed depending on the patch considered and the method used to calculate them. The use of effective aerodynamic resistances calculated from fluxes provided less accurate estimates of ?E compared to the measured values, than the use of effective aerodynamic resistances aggregated from soil and plant resistances. The results reported in this paper show that the best way of aggregating soil and plant resistances depends on the type of resistance, and the type of vegetation in the patch

Analysis of effective resistance calculation methods and their effect on modelling evapotranspiration in two different patches of vegetation in semi-arid SE Spain

Effective parameters are of major importance in modelling surface fluxes at different scales of spatial heterogeneity. Different ways to obtain these effective parameters for their use in meso-scale and GCM models have been studied. This paper deals with patch-scale heterogeneity, where effective resistances were calculated in two patches with different vegetation (Retama sphaerocarpa (L.) Boiss shrubs, and herbaceous plants) using different methods: aggregating soil and plant resistances in parallel, in series or by an average of both. Effective aerodynamic resistance was also calculated directly from patch fluxes. To assess the validity of the different methods used, the Penman-Monteith equation was used with effective resistances to estimate the total λE for each patch. The λE estimates found for each patch were compared to Eddy Covariance system measurements. Results showed that for effective surface resistances, parallel aggregation of soil and plant resistances led to λE estimates closer to the measured λE in both patches (differences of around 10%). Results for effective aerodynamic resistances differed depending on the patch considered and the method used to calculate them. The use of effective aerodynamic resistances calculated from fluxes provided less accurate estimates of λE compared to the measured values, than the use of effective aerodynamic resistances aggregated from soil and plant resistances. The results reported in this paper show that the best way of aggregating soil and plant resistances depends on the type of resistance, and the type of vegetation in the patch.This work received financial support from several different research projects: the PROBASE (ref.: CGL2006-11619/HID) and CANOA (ref.: CGL2004-04919-C02-01/HID) projects funded by the Spanish Ministry of Education and Science; and the BACAEMA (“Balance de carbono y de agua en ecosistemas de matorral mediterráneo en Andalucía: Efecto del cambio climático”, RNM-332) and CAMBIO (“Efectos del cambio global sobre la biodiversidad y el funcionamiento ecosistémico mediante la identificación de áreas sensibles y de referencia en el SE ibérico”, RNM 1280) projects funded by the regional government Junta de Andalucía. The first author enjoyed a pre-doctoral grant from the Spanish Ministry of Science and Technology

Mass fluxes, biogeochemistry and currents: Components for dynamics of particle fluxes in the Blanes submarine canyon (Northwestern Mediterranean)

XV Seminario Ibérico de Química Marina, Vigo, 22-24 de febrero de 2010N

Sources and sinks of nutrients and pollutants in Cullera Bay

[EN] Water quality plays a very important role in the ecological balance and economic development of coastal and estuarine areas. However, these areas have been progressively degraded in recent decades due to different factors, including an increase in nutrient and pollutant loads introduced into the system, which may cause eutrophication problems. This paper analyzes the water quality of one such area, Cullera Bay, located on the Spanish Mediterranean coast. This study focuses on the main sources and sinks of pollutant substances and the relationship between the distribution of these substances within the bay and local meteorological and oceanographic conditions. Two main sources of nutrients and pollutants were identified: the discharges of the Júcar River and the marine outfall, although other secondary sources are also present. The river discharge varies greatly depending on the season. The freshwater it carries is very rich in nutrients due to the presence of fertilizers and pesticides from its agricultural use. The domestic wastewater discharged through the marine outfall is occasionally untreated, particularly in the summer, when the tourist population increases and the capacity of the water treatment plant is exceeded. This study is based on data recorded during nine field campaigns carried out in the area in 2002 and 2003 and numerical simulations of hydrodynamics and pollutant dispersion. By analyzing the field data and the numerical simulation results, wind is identified as the main driving factor in the bay because the other possible driving factors either have negligible effects (tide), affect only a very localized area (waves, usual river discharges) or are infrequent (storm surges, river floods).The European Community funded this study as a part of the ECOSUD ‘‘Estuaries and Coastal Areas. Basis and Tools for a More Sustainable Development’’ (reference no. ICA4-CT-2001-10027) and AQUAS ‘‘Water quality and sustainable aquaculture. Links and implications’’ (reference no. INCOCT-2005-015105) projects. It was also funded by the Spanish Ministry of Science and Technology, through the project ‘‘Desarrollo y optimizacio´n de te´cnicas para gestionar los vertidos de aguas residuales de emisarios submarinos (ARTEMISA)’’(Reference no. REN2003-07585-C02-01/MAR).Sierra, J.; Mösso, C.; González Del Rio Rams, J.; Mestres, M.; Cupul, L.; Sánchez-Arcilla, A.; Rodilla Alamá, M.... (2007). Sources and sinks of nutrients and pollutants in Cullera Bay. Journal of Coastal Research. SI47:31-39. doi:10.2112/1551-5036-47.sp1.31S3139SI4

Cenozoic deformation of Iberia: a model for intraplate mountain building and basin development based on analogue modelling

Inferences from analogue models support lithospheric folding as the primary response to large-scale shortening manifested in the present day topography of Iberia. This process was active from the late Oligocene-early Miocene during the Alpine orogeny and was probably enhanced by reactivation of inherited Variscan faults. The modeling results confirm the dependence of fold wavelength on convergence rate and hence the strength of the layers of the lithosphere such that fold wavelength is longest for fast convergence rates favoring whole lithosphere folding. Folding is associated with the formation of dominantly pop-up type mountain ranges in the brittle crust and thickening of the ductile layers in the synforms of the buckle folds by flow. The mountain ranges are represented by upper crustal pop-ups forming the main topographic relief. The wavelengths of the topographic uplifts, both, in model and nature suggest mechanical decoupling between crust and mantle. Moreover, our modeling results suggest that buckling in Iberia took place under rheological conditions where the lithospheric mantle is stronger than the lower crust. The presence of an indenter, inducing oblique shortening in response to the opening of the King's Trough in the north western corner of the Atlantic Iberian margin controls the spacing and obliquity of structures. This leads to the transfer of the deformation from the moving walls towards the inner part of the model, creating oblique structures in both brittle and ductile layers. The effect of the indenter, together with an increase on the convergence rate produced more complex brittle structures. These results show close similarities to observations on the general shape and distribution of mountain ranges and basins in Iberia, including the Spanish Central System and Toledo Mountains.Peer reviewe