Validation of microsatellite markers for cytotype discrimination in the model grass Brachypodium distachyon

Brachypodium distachyon (2n = 2x = 10) is a small annual grass species where the existence of three different cytotypes (10, 20 and 30 chromosomes) has long been regarded as a case of autopolyploid series, with x = 5. However, it has been demonstrated that the cytotypes assumed to be polyploids represent two separate Brachypodium species recently named as B. stacei (2n = 2x = 20) and B. hybridum (2n = 4x = 30). The aim of this study was to find a PCR-based alternative approach that could replace standard cytotyping methods (i. e., chromosome counting and flow cytometry) to characterize each of the three Brachypodium species. We have analyzed with four microsatellite (SSR) markers eighty-three Brachypodium distachyon-type lines from varied locations in Spain, including the Balearic and Canary Islands. Within this set of lines, 64, 4 and 15 had 10, 20 and 30 chromosomes, respectively. The surveyed markers produced cytotype-specific SSR profiles. So, a single amplification product was generated in the diploid samples, with non-overlapping allelic ranges between the 2n = 10 and 2n = 20 cytotypes, whereas two bands, one in the size range of each of the diploid cytotypes, were amplified in the 2n = 30 lines. Furthermore, the remarkable size difference obtained with the SSR ALB165 allowed the identification of the Brachypodium species by simple agarose gel electrophoresis

Valoración de escenarios futuros a través de la conectividad del paisaje

En este trabajo se presenta una metodología SIG de valoración de la conectividad del paisaje aplicada a la valoración de escenarios futuros para el Área Metropolitana de Granada. Esta metodología será empleada para realizar un análisis comparado de las pérdidas de conectividad que los tres escenarios introducen unos con respecto a otros y se revela, junto con la generación de escenarios futuros como un instrumento útil para ayudar en la toma de decisiones en lo que respecta a las formas, lugares e intensidades del crecimiento urbano.This paper presents a GIS methodology to assess landscape connectivity through urban growth scenarios in the Metropolitan Area of Granada. This methodology will be useful to assess landscape connectivity loss in a compared evaluation of the scenarios. Thus, this evaluation will be show as a useful tool, combined with the scenario simulation, to help in the metropolitan decision making process

Shoreline change patterns in sandy coasts. A case study in SW Spain

Coastal changes on sandy shorelines are continuous and occur at diverse spatial and temporal scales. Gaining knowledge on beach change processes increases our capability tomanage risks, especially shoreline erosion, affecting the increasing population living in coastal areas. Processes and factors involved in medium- and short-term beach changes depend on the morphological and dynamic characteristics of the coast. In this work, the decadal behaviour of 58 sandy beaches along the 150 km long South-Atlantic coast of Spain, between the Guadalquivir rivermouth and the Strait of Gibraltar, is analysed in order to investigate the relationships between shoreline change patterns and the diverse morphological and dynamic factors controlling beach evolution in the area. For this purpose, georectified aerial photographs spanning the period 1956–2008 were compared in a GIS environment to calculate rates of shoreline change. Short-term evolution of beach profiles was also analysed in selected areas of interest. Results show that the study area exhibits a great variety of shoreline evolution trends, with erosion prevailing in the northern and central sectors and stability or even accretion in the southern sector. In general, sediment availability is the main factor determining coastal erodibility in the area, largely conditioned by the reduction in fluvial sediment supply caused by river basin regulation. Nearshore bathymetry also has a great significance, as it controls wave refraction-diffraction patterns and wave energy concentration on certain zones. Human interventions on the coast also represent a major influence on beach erodibility in the study area. Severe detrimental effects are caused at certain points by shore-normal engineering structures blocking longshore drift. Additionally extensive urban development in backbeach environments has a significant influence on the sediment budget at certain areas. On the basis of these results, a morphological and evolutionary classification of sandy beaches is proposed taking into account the way beach morphology influences erosion/accretion processes. Rectilinear beaches and enclosed beaches typically show dynamic equilibrium or even accretion trends, whereas reef-supported beaches tend to be dominated by erosion. Headland-bay beaches show complex evolution patterns greatly influenced by local conditions, such as specific shoaling processes or local winds. This classification is useful not only in forecasting general shoreline behaviour in the near future, but also in selecting the most appropriate type of intervention when managing retreating coasts

Design and simulation of metropolitan urban growth demands scenarios

La generación y simulación de escenarios exploratorios externos es un instrumento útil en los procesos de planificación y toma de decisiones, de especial relevancia en el ámbito territorial y metropolitano (Peterson et al, 2003; Pettit y Pullar, 2004; Luca, 2007; Carsjens, 2009), cuyo calado en el proceso de planificación en España es escaso hasta la fecha (Valenzuela, Aguilera, Soria y Molero, 2008). En este artículo se presenta un modelo basado en Dinámica de Sistemas para estimar las demandas de nuevo suelo urbano en ámbitos metropolitanos. El modelo se ha desarrollado concretamente para dos ámbitos metropolitanos españoles (Región Urbana de Madrid y Aglomeración Urbana de Granada) para los cuales se ha realizado un proceso de calibración individual, Una vez calibrado el modelo para dichos ámbitos, y a través del planteamiento de tres escenarios futuros, se han simulado las posibles tendencias de las demandas de ocupación urbana que podrían derivarse de las premisas establecidas en cada escenario, con unos resultados satisfactorios. Dichos resultados podrán ser empleados en otros trabajos que permitirán localizar espacialmente, mediante modelos de simulación espacial, las demandas estimadas, para mostrar y evaluar posibles consecuencias espaciales y territoriales de los procesos de crecimiento metropolitano.The design and development of future explorative external scenarios are useful tools for the spatial planning and even more for the metropolitan planning (Peterson et al, 2003; Pettit y Pullar, 2004; Luca, 2007; Carsjens, 2009). However, spatial planning policy and practices in Spain lack of this instruments (Valenzuela, Aguilera, Soria y Molero, 2008) This paper shows a System Dynamics-based model designed to estimate urban growth demands in metropolitan areas. This model has been specifically developed for Madrid and Granada metropolitan areas (Spain), where the model has been calibrated. After the calibration, three future urban growth demands scenarios has been designed and simulated using the model developed. The urban growth demands obtained may be used in later research to spatially locate that demands using spatial simulation models.Peer Reviewe

Neogene activity of the Barrancas Bancas Fault and its relationship with Hydrothermal and volcanic activity

The chronology and nature of the Neogene-Cuaternary deformation in the Central Volcanic Zone (CVZ) in the north of Chile is partially unclear. Some authors have identified compression in isolated areas of the western slopes of the Altiplano-Puna Plateau between the 23,5 and 25ºS, which deformed Miocene and Pliocene deposits (e.g. Gonzalez et al., 2009). In this context, Barrancas Blancas fault, located in the western limit of the Western Cordillera, outcrops in a scarp oriented NS and represents a record of the tectonic activity during the Miocene (Gardeweg et al., 1993). This fault affects to Pampa de Mulas gravels (23,6±1,6 Ma) and Rio Frio Ignimbrites (17,3± 1,7 Ma), and is covered by Miocene-to-Holocene alluvial deposits. In the eastern side of Punta Negra Salar was emplaced the Monognetic Punta Negra volcano, located over the Barrancas Blanca-Fault scarp (10±0,8 Ma) and immediately to the south of Punta Negra volcano, travertine deposits are present in the footwall of Barrancas Blancas fault (10-2 Ma; Quade et al., 2017). This work presents the preliminary results from geomorphologic and stratigraphic data, and structural analysis from Barrancas Blancas fault, and the sediment wedge related with the fault scarpament. These results were combined with geochronological data from magmatic and hydrothermal related rocks/minerals, with the objetive to rebuild the activity of Barrancas Blancas fault and its relation with the magmatic activity during Miocene-Pliocene. Our results show that Barrancas Blancas fault has reverse displacement during Lower Miocene, which caused folding of the Rio Frio ignimbrite and Pampa de Mulas Formation. This period has a maximum age of 11,7 Ma and can be related to the local uplift of the Altiplano-Puna plateau. Using a cinematic analysis, we have identified a period with transtensional activity for Barrancas Blancas fault, which had been coeval with magmatic/hydrothermal activity, the last represented by monogenetic (Punta Negra volcano, ca. 10 Ma) and geothermal activity. The hydrothermal activity in the Barrancas Blancas fault would have lasted until to ca. 2 Ma, coeval with the depositation of alluvial fans related with the scarp backward movement. Our hypothesis suggests that transtensional activity of the Barrancas Blancas fault is related with the uplift and local collapse of the Altiplano