133 research outputs found

    Computing crustal deformation of the Iberian Peninsula

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    Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2022, Tutor: Giorgi KhazaradzeCrustal deformation studies are useful to comprehend on-going geological processes and enhance seismic hazard assessment studies. These studies require large GPS data sets, covering a wide temporal and spatial range, besides further complex computation and analysis. We present a three-dimensional crustal deformation velocity map of the Iberian Peninsula with improved spatial resolution. The results show a regional clockwise rotation of the peninsula, as well as a northward velocity trend in the eastern Betics. An explanation could involve a rigidly rotating lithospheric block along with a viscous coupling between Nubia and Eurasia plates. The results are coherent with earlier studies and will serve as a basis for future researc

    Ús i gestió del territori a la mediterrània: implicacions en la matèria orgànica del sòl

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    Land use and management in Mediterranean ecosystems: implications for soil organic matter. - In the Mediterranean basin, soils have been intensively used to supply food, raw materials and energy. Here we aim to interpret the current status of Mediterranean soils by considering their long history of human use. Mediterranean soils are characterized by their poverty of organic matter and frequent carbonate content. Classical studies indicate that carbonates may favor the retention of soil organic matter. As historic soil data is lacking, we have focused on studying the distribution of organic matter across contrasting land uses. We have seen that soil organic matter poverty mainly affects agricultural soils and pastures (mostly shrublands and grassy swards). In contrast, soil organic matter content in forest soils is very rich, especially in the case of carbonatic soils. However, high levels of organic matter in carbonatic soils are not found in arable or pasture soils. Moreover, pastures contain soil organic matter levels very similar to those of arable soils, particularly in carbonatic soils. In Mediterranean lands the lack of soil structure and the presence of carbonates may jeopardize soil aggradation after the cessation of agricultural practices. In this context soil protection strategies should be adapted to Mediterranean ecosystems in order to better withstand climate change

    Land use and management in Mediterranean ecosystems: implications for soil organic matter.

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    In the Mediterranean basin, soils have been intensively used to supply food, raw materials and energy. Here we aim to interpret the current status of Mediterranean soils by considering their long history of human use. Mediterranean soils are characterized by their poverty of organic matter and frequent carbonate content. Classical studies indicate that carbonates may favor the retention of soil organic matter. As historic soil data is lacking, we have focused on studying the distribution of organic matter across contrasting land uses. We have seen that soil organic matter poverty mainly affects agricultural soils and pastures (mostly shrublands and grassy swards). In contrast, soil organic matter content in forest soils is very rich, especially in the case of carbonatic soils. However, high levels of organic matter in carbonatic soils are not found in arable or pasture soils. Moreover, pastures contain soil organic matter levels very similar to those of arable soils, particularly in carbonatic soils. In Mediterranean lands the lack of soil structure and the presence of carbonates may jeopardize soil aggradation after the cessation of agricultural practices. In this context soil protection strategies should be adapted to Mediterranean ecosystems in order to better withstand climate change

    Analysis of soil carbon in Spanish agricultural soils: relevant aspects in relation to the organic farming reconversion in the Mediterranean area

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    Los niveles de carbono orgánico en suelos agrícolas son especialmente relevantes en los modelos de gestión que se basan en la reserva orgánica de nutrientes. La disminución de materia orgánica que ocurre en los suelos roturados puede en algunos casos determinar la degradación del suelo. Este hecho puede ser especialmente relevante en condiciones climáticas límite (secas y semiáridas). A partir del análisis de una base de datos de suelos españoles se discute la distribución del C en el horizonte superficial de suelo según el clima y según el uso. Para cada área climática, mediante comparación entre suelos forestales y agrícolas se observa que los suelos de clima semiárido presentan una mayor resistencia a la pérdida de C y una menor resiliencia que los suelos de climas más húmedos. Este hecho nos hace pensar que los suelos semiáridos pueden estar cerca de los umbrales de degradación y que por lo tanto su gestión debería evitar les pérdidas de materia orgánica.Organic carbon levels in agricultural soils are specially relevant in the management models based on the organic reserve of the soil. Losses of soil organic matter that occur associated to tillage practices can enhance, in some cases, soil degradation. This fact may be specially relevant in dry and semiarid climates. By analysing a soil data base of the Spanish forest and agricultural soils we discuss the distribution of C in the soil surface horizon across climates and land uses. In each climatic area, by comparing forest with agricultural soils we found that soils in semiarid climate show greater resistance to soil C losses and lower resilience than soils of wetter climates. This fact suggest that semiarid soils can be at or near soil degradation thresholds and thus its management should avoid any losses of soil organic matter.Este trabajo ha sido posible gracias a un convenio establecido entre la Dirección General de Evaluación Ambiental del Ministerio de Medio Ambiente y la Universidad de Barcelona

    Joan Basset: edició i estudi de cinc esparses amoroses

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    Treballs Finals de Grau de Filologia Catalana, Facultat de Filologia, Universitat de Barcelona, Curs: 2019-2020, Tutors: Anna Alberni Jordà, Albert Soler Llopart[cat] Joan Basset és un dels poetes més prolífics i originals del Cançoner Vega-Aguiló. Com que és un autor encara força desconegut, aquest treball pretén acostar la seva figura i obra a un públic actual. En primer lloc, s'ha recollit i sintetitzat la bibliografia que parla de l'autor per fer-ne un estat de la qüestió que ha de ser útil tant per introduir el personatge com per senyalar les llacunes biogràfiques i contextuals que encara caldria omplir. En segon lloc, s'han seleccionat les cinc esparses amoroses del poeta com a tast representatiu de la seva poètica i se n'han elaborat diferents productes editorials: una edició diplomàtica, una de crítico-interpretativa i, finalment, una d'actualitzada. D'aquesta manera, es pretén abraçar un públic molt divers que podria estar interessat per la poesia medieval.[eng] Joan Basset is one of the most productive and original poets of the Vega-Aguiló compilation. As he still is an unknown author, the aim of this work is to approach his profile and lyrical work to an actual reader. In the first place, it is assembled a status of the issue based on the literary works about the poet and his poetical context. This compilation pretends to be an introduction into the world of the poet and, what is more, a base for a future more deep study about his figure. In the second place, five love esparses have been selected as a representation of the poetic frame of the poet. Different editorial products have been elaborated of the same five poems: a diplomatic edition, an interpretative and critic edition and, finally, a contemporary version. The diversity of the offer wants to be an attraction for the different possible public of Middle Age literature

    Crop yield, weed infestation and soil fertility responses to contrasted ploughing intensity and manure additions in a Mediterranean organic crop rotation

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    Conservation agriculture and organic farming are two alternative strategies that aim to improve soil quality and fertility in arable cropping systems through the deployment of different practices, that are rarely combined. While conservation agriculture practices include reducing tillage intensity and maintaining soil cover all year round to prevent soil erosion, organic farming focuses on nutrient recycling, using farmyard manure and green manure to enhance soil quality. However, these practices are not free from side-effects, such as increasing weed infestation or limited nutrient availability. Therefore it is necessary to explore the sustainability of their combination under local environmental constraints. The objectives of this study were to evaluate the effects of tillage type (mouldboard vs. chisel ploughing), fertilization and green manure on soil parameters (SOC, N, bulk density, carbon stocks, and soil microbial biomass Cmic and Nmic), weed abundance and crop yields in a four-year rotation of spelt, chickpea, winter wheat and lentil in the Mediterranean region (Catalonia, Spain). Tillage and green manure did not affect crop yields or weed biomass, although during the last year of the experiment, plots with mouldboard ploughing had less weed biomass and higher lentil biomass. Fertilization was the most important factor, increasing the cereal yields, SOC, N and soil microbial biomass (Cmic and Nmic) content of the soil. However, fertilization did not favour chickpea and lentil crops because weed competition limited legume crop growth. Overall, there was a loss of SOC and a reduction of carbon stocks over the four years of the trial in the soil because of the deep soil tillage (25 cm) and low crop productivity irrespective of tillage type. In contrast, N content increased in all of the plots and was enhanced by fertilization. The use of chisel plough stratified the distribution of SOC and N in the surface layers (0-10 cm). Both Cmic and Cmic/SOC ratio increased in fertilized treatments, suggesting an increased lability of SOC. The application of more stabilized organic matter may be a better practice to build up soil organic matter and to maintain crop yields in organic farming systems

    Impact of olive saplings and organic amendments on soil microbial communities and effects of mineral fertilization

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    Plant communities and fertilization may have an impact on soil microbiome. Most commercial olive trees are minerally fertilized, while this practice is being replaced by the use of organic amendments. Organic amendments can both fertilize and promote plant growth-promoting organisms. Our aims were (i) to describe the changes in soil bacterial and fungal communities induced by the presence of young olive trees and their interaction with organic amendments and (ii) to compare the effects of mineral and organic fertilization. We set up two parallel experiments in pots using a previously homogenized soil collected from a commercial olive orchard: in the first one, we grew olive saplings in unamended and organically amended soils with two distinct composts and compared these two soils incubated without a plant, while in the second experiment, we comparatively tested the effects of organic and mineral fertilization. OTUs and the relative abundances of bacterial and fungal genera and phyla were analyzed by 16S rRNA and ITS1 gene amplicon using high-throughput sequencing. Basal respiration and substrate-induced respiration were measured by MicroRespTM. The effects of the different treatments were analyzed in all phyla and in the 100 most abundant genera. The presence of olive saplings increased substrate-induced respiration and bacterial and fungal richness and diversity. Organic amendments greatly affected both bacterial and fungal phyla and increased bacterial richness while not affecting fungal richness. Mineral fertilization increased the relative abundance of the less metabolically active bacterial phyla (Actinobacteria and Firmicutes), while it reduced the most metabolically active phylum, Bacteroidetes. Mineral fertilization increased the relative abundance of three N2-fixing Actinobacteria genera, while organic fertilization only increased one genus of Proteobacteria. In organically and minerally fertilized soils, high basal respiration rates were associated with low fungal diversity. Basidiomycota and Chytridiomycota relative abundances positively correlated with basal respiration and substrate-induced respiration, while Ascomycota correlated negatively. Indeed, the Ascomycota phyla comprised most of the fungal genera decreased by organic amendments. The symbiotrophic phylum Glomeromycota did not correlate with any of the C sources. The relative abundance of this phylum was promoted by the presence of plants but decreased when amending soils with composts

    La restauración ecológica aplicada a la minería a cielo abierto en Cataluña

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    En la minería a cielo abierto, la revegetación es el objetivo principal de las tareas de restauración ecológica y puede evaluarse desde diferentes enfoques. El aspecto paisajístico ha sido hasta la fecha el más ampliamente valorado y frecuentemente suele asimilarse a la presencia de vegetación que disminuye el impacto visual de estas zonas.La frase 'está verde' simboliza y resume todo un conjunto de prioridades y una primera etapa de implementación de la ley 12/1981 de la legislación catalana.De hecho, naturalizar los taludes resultantes del cese de la extracción de recursos minerales no es una tarea fácil. El tipo de vegetación obtenido difiere en muchos casos de la vegetación de los sistemas natural es del entorno y genera una disfunción en el contexto paisajístico y ecológico [...]

    The Gallecs trial, a mid-term experiment on reduced tillage, fertilisation and green manure in Mediterranean dryland arable cropping systems

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    Conservation agriculture and organic farming are two alternative strategies aimed at improving soil fertility in arable cropping systems through reducing tillage intensity, maintaining year-round soil cover and increasing nutrient recycling, using farmyard and green manures. However, the reduction of tillage intensity can increase weed infestation and decrease nutrient availability. The mid-term "Gallecs" trial (Catalonia) was established in autumn 2011 at Gallecs, a periurban agricultural area near Barcelona. The effects of tillage (mouldboard versus chisel ploughing), fertilisation by farmyard manure (without versus with) and green manure (without versus with) on soil fertility indicators, weed abundance and grain crop yields were studied in a 4-years cereal-legume rotation for human consumption under organic farming conditions in the Mediterranean region (Catalonia, Spain)

    Crop yield, weed infestation and soil fertility responses to contrasted ploughing intensity and manure additions in a Mediterranean organic crop rotation

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    Conservation agriculture and organic farming are two alternative strategies that aim to improve soil quality and fertility in arable cropping systems through reducing tillage intensity, maintaining soil cover and increasing nutrient recycling, using farmyard and green manures. However, these practices can increase weed infestation or decrease nutrient availability. The objectives of this study were to evaluate the effects of tillage type (mouldboard vs. chisel ploughing), fertilization and green manure on soil parameters (SOC, N, bulk density, carbon stocks, and soil microbial biomass Cmic and Nmic), weed abundance and crop yields in a four-year rotation of spelt, chickpea, winter wheat and lentil in the Mediterranean region (Catalonia, Spain). Tillage and green manure did not affect crop yields or weed biomass, although during the last year of the experiment, plots with mouldboard ploughing had less weed biomass and higher lentil biomass. Fertilization was the most important factor, increasing the cereal yields, SOC, N and soil microbial biomass (Cmic and Nmic) content of the soil. However, fertilization did not favour chickpea and lentil crops because weed competition limited legume crop growth. Overall, there was a loss of SOC and a reduction of carbon stocks over the four years of the trial in the soil because of the deep soil tillage (25 cm) and low crop productivity irrespective of tillage type. In contrast, N content increased in all of the plots and was enhanced by fertilization. The use of chisel plough stratified the distribution of SOC and N in the surface layers (0-10 cm). Both Cmic and Cmic/SOC ratio increased in fertilized treatments, suggesting an increased lability of SOC. The application of more stabilized organic matter may be a better practice to build up soil organic matter and to maintain crop yields in organic farming systems
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