Mid and late Holocene forest fires and deforestation in the subalpine belt of the Iberian range, northern Spain

26 Pags.- 6 Figs.- 2 Tabls. The definitive version is available at: http://link.springer.com/journal/11629The conversion of subalpine forests into grasslands for pastoral use is a well-known phenomenon, although for most mountain areas the timing of deforestation has not been determined. The presence of charcoal fragments in soil profiles affected by shallow landsliding enabled us to date the occurrence of fires and the periods of conversion of subalpine forest into grasslands in the Urbión Mountains, Iberian Range, Spain. We found that the treeline in the highest parts of the northwestern massifs of the Iberian Range (the Urbión, Demanda, Neila, and Cebollera massifs) is currently between 1500 and 1600 m a.s.l., probably because of pastoral use of the subalpine belt, whereas in the past it would have reached almost the highest divides (at approximately 2100–2200 m a.s.l.). The radiocarbon dates obtained indicate that the transformation of the subalpine belt occurred during the Late Neolithic, Chalcolithic, Bronze Age, Iron Age, and Middle Ages. Forest clearing was probably moderate during fires prior to the Middle Ages, as the small size of the sheep herds and the local character of the markets only required small clearings, and therefore more limited fires. Thus, it is likely that the forest recovered burnt areas in a few decades; this suggests the management of the forest and grasslands following a slash-and-burn system. During the Middle and Modern Ages deforestation and grassland expansion affected most of the subalpine belt and coincided with the increasing prevalence of transhumance, as occurred in other mountains in the Iberian Peninsula (particularly the Pyrenees). Although the occurrence of shallow landslides following deforestation between the Neolithic and the Roman Period cannot be ruled out, the most extensive shallow landsliding processes would have occurred from the Middle Ages until recent times.Support for this research was provided by the projects INDICA (CGL2011- 27753-C02-01 and -02) and DINAMO2 (CGL2012-33063), funded by the Spanish Ministry of Economy and Competitiveness.Peer reviewe

La Política Agraria Común en el alto Guadiana: Evolución de recursos hídricos y de cultivos

[EN] There are clear links between supports from the Common Agricultural Policy (CAP) and the overexploitation of aquifers in the upper basin of the Guadiana River. Historically, European supports to agriculture have been linked to the production, which has resulted in the 169 municipalities in the study area, a strong trend towards the expansion of irrigation lands. The implementation of the Single Payment in 2003 implies a decoupling of production supports, going to charge the beneficiaries of supports a subsidy equal to the average of that perceived during the last three years, i.e. from 2003 payments are maintained even though production is zero. However, there are still many payments linked to production, known as coupled payments (primarily those associated with livestock, woody crops, arable crops and irrigated land). These are the ones with higher capacity to affect the environment, and therefore they are which have been considered in this study (except livestock, no directly related to overexploitation of aquifers). To make this paper, ArcGis program has been used, superimposing or comparing different thematic layers: Protected areas, overexploited aquifers and vulnerable areas to nitrates pollution in the Upper Guadiana, the percentage of irrigated hectares in several municipalities, the irrigated area devoted to arable crops and woody crops, and finally support levels of the Common Agricultural Policy (CAP) in each of the selected sectors and for each of the municipalities in the Upper Guadiana in 2009. It is noteworthy that the municipalities with the highest percentage of irrigated area, especially vineyard, receive higher levels of subsidies, despite of using water from overexploited aquifers. In contrast, supports to organic farming are scarce as compensation income from aquifers. This suggests that CAP subsides coupled to woody crops (mainly the vineyard) and herbaceous crops are detrimental for the environmental quality of the study area, especially water resources. As a positive factor it was found that a percentage of one of the two pillars of the CAP (EAFRD) is devoted for investment axes of Environment and Rural Development. © Universidad de La Rioja.[ES] Existen claras relaciones entre las ayudas procedentes de la Política Agraria Común (PAC) y la sobreexplotación de acuíferos en la cuenca alta del rio Guadiana. Históricamente las ayudas de Europa a la agricultura han estado ligadas a la producción, lo que ha ocasionado, en los 169 municipios pertenecientes a la zona de estudio, una fuerte tendencia a la expansión del regadío. La implantación del Pago Único en 2003 implica un desacoplamiento de las ayudas a la producción, pasando a cobrar, los perceptores de las ayudas, un subsidio equivalente a la media de lo percibido durante los tres últimos anos, es decir que a partir de 2003 los pagos se mantienen aunque la producción sea nula. No obstante, aun existen muchos pagos ligados a la producción, conocidos como pagos acoplados (básicamente los asociados a la ganadería, cultivos leñosos, cultivos herbáceos y regadío). Estos son los que tienen una mayor capacidad para afectar al medio ambiente y son, por lo tanto, los que se han tenido en cuenta en este estudio (salvo la ganadería por no relacionarse directamente con la sobreexplotación de acuíferos). Para realizar este trabajo se ha utilizado el programa ArcGis, superponiendo o comparando capas de distintas temáticas: Espacios Naturales Protegidos, Acuíferos Sobreexplotados y Zonas Vulnerables a la Contaminación por Nitratos en el Alto Guadiana, el porcentaje de hectáreas en regadío en los distintos términos municipales, la superficie en regadío dedicada a cultivos herbáceos y cultivos leñosos, y por ultimo, los niveles de ayudas de la Política Agraria Común (PAC) en cada uno de los sectores elegidos y para cada uno de los municipios del Alto Guadiana, en el ano 2009. Entre las conclusiones destaca el hecho de que los municipios con mayor porcentaje de superficie de regadío, especialmente viñedos, reciben los mayores niveles de ayudas a pesar de utilizar agua de acuíferos sobreexplotados. En cambio, las ayudas a la agricultura ecológica son escasas al igual que la compensación por renta de acuíferos. Esto sugiere que las ayudas de la PAC acopladas a cultivos leñosos (fundamentalmente el viñedo) y herbáceos actúan en detrimento de la calidad ambiental de la zona de estudio, muy especialmente de los recursos hídricos. Como nota positiva se ha observado que un alto porcentaje de uno de los dos pilares de la PAC (fondos FEADER) va destinado a los ejes de inversión de Medio Ambiente y Desarrollo Rural.Peer Reviewe

Comparación de la peligrosidad por riesgos naturales en núcleos de población consolidados y nuevas zonas de expansión urbanística de la provincia de Zaragoza

10 páginasPeer reviewe

Cambios en el piso subalpino de las montañas mediterráneas

6 páginas, fotos a color.Peer reviewe

La dinámica de un cauce torrencial en relación con cambios en la cuenca. El ejemplo del río Ijuez

22 páginas. Presentación elaborada para las II Jornadas IPErinas, celebradas el 12 de diciembre de 2013.Peer reviewe

Errores frecuentes en las medidas de la erosión del suelo

22 páginas.- Presentación elaborada para las III Jornadas IPErinas, celebradas el 11 de diciembre de 2014.Peer reviewe

Landscape changes and land degradation in the subalpine belt of the Central Spanish Pyrenees

11 Pags.- 8 Figs.- 9 Tabls.As with other mountain areas in Europe, the subalpine belt of the Central Spanish Pyrenees (approximately 1600–2200 m a.s.l.) has undergone constant deforestation since the Neolithic era and particularly during the Late Middle Ages, in favour of livestock management and grazing in summer. This furthered the rise of transhumance between the lowlands and the highlands. The abrupt change in land cover triggered a variety of geomorphic processes and landforms that partially contributed to land degradation and an increase in erosion and sediment yield: shallow landslides, solifluction lobes, soil creeping, terracettes, parallel deep incisions (henceforth: gullies) and stone-banked lobes. The main factors explaining the location of the various landforms are elevation, gradient, aspect, plant cover, soil characteristics, and the topographic index. The statistical analysis clearly separates two types of landforms: (i) shallow landslides, solifluction lobes, and areas of soil creeping, located at relatively low elevations, deep soils and fairly gentle gradients; and (ii) terracettes, gullies and stone-banked lobes, which are generally found at high elevations, on thin soils, north-facing slopes and steep gradients. The declining livestock pressure from the beginning of the 19th century, and particularly from the mid-20th century, explains the progressive re-colonization of the subalpine belt by forest and the reduction in shallow landslides over the last few decades. Most likely, this forest recovery will continue in the near future, with the hydrological, geomorphological and biogeographical consequences still being far from understood.This research was supported by the MANMOUNT (PID2019-105983RB-100) project, funded by the Spanish Ministry of Science and FEDER and by the Research Group from the Aragón Government E02_17E.Peer reviewe