Evaluación de los procesos de formación de suelo en terrenos graníticos del Mediterráneo

Soil is one of the most important natural systems that support the development of life and is part of fundamental processes that make our planetary ecosystem work. It is well known that the factors that intervene in the formation of the soil are climate, bedrock, relief, biota and time. However, despite the numerous studies related to soil formation, little is known about these processes due to the immense complexity in which they are integrated. This study identifies and investigates in detail the different soil-forming processes in the study area located in a rocky Mediterranean landscape. Specifically, the processes that have been studied have been biological such as bioturbation, physical such as erosiondeposit and physical weathering. These processes are related to the spatial distribution of carbon stored in the soil, which has also been part of this study. The spatial distribution of carbon stocks in the soil is highly variable in the study area, as well as bulk density and stoniness. The variable that controls the spatial distribution of the stoniness is the slope, demonstrating the influence of the erosion. The spatial distribution of the carbon content and carbon stocks in the soil depend on vegetation cover and insolation. Bioturbation has been studied in soil profiles at different depths along a steeply inclined slope using the IRSL (Infrared Stimulated Luminescence) luminescence technique used on sand sized feldspar grains for the first time for this purpose. This technique has made it possible to identify the age of the sample at different depths and an effective soil mixing rate that takes into account only those grains that have ever been exposed to the soil surface. This has allowed, for the first time, to identify the border between the mobile regolith and the saprolite because the grains close to the border have never visited the surface.The soil age at different depths previously calculated has been used to determine the bioturbation, erosion and deposition rates along the slope through a new analytical solution of the advection-diffusion equation. Physical weathering has been assessed in the horizons of ten soil profiles by comparing rock fragmentation field data with different models. In this way, the patterns governing rock fragmentation were established in six profiles. The rest of the profiles did not fit any of these models because they are characterized by armouring effect on the surface, i.e. the surface horizon contains larger size of rocks than the lower one due to the removal of fine particles produced by erosion. The study presented here is a great advance in the knowledge of these soil-forming processes and can be implemented in other studies of the same type. In the future, this study could be compared with the results that would be obtained from erosion rates using other methods (10Be or 137Cs), completed with an estimation of the chemical processes in the study area and, finally, useful for the calibration and validation of both the new soil formation model that will be developed linked to the work developed in this thesis, as explained in chapter six, and other soil formation and landscape evolution models to better understand the connection between pedology and geomorphological processes.El suelo es uno de los sistemas naturales más importantes que sustentan el desarrollo de la vida y forma parte de procesos fundamentales que hacen funcionar nuestro ecosistema planetario. Es bien sabido que los factores que intervienen en la formación del suelo son el clima, la roca madre, relieve, biota y el tiempo. Sin embargo, a pesar de los numerosos estudios relacionados con la formación del suelo, poco es conocido sobre estos procesos debido a la inmensa complejidad en la que se integran. Este estudio identifica y profundiza en el conocimiento de varios procesos formadores del suelo en la zona de estudio situada en un ambiente Mediterráneo. Específicamente, los procesos que se han estudiado han sido biológicos como la bioturbación, físicos como la erosión-depósito y la meteorización física. Estos procesos están relacionados con la distribución espacial de carbono almacenado en el suelo, la cual también ha formado parte de este estudio. La distribución espacial del carbono almacenado en el suelo ha resultado ser muy variable en la zona de estudio, caracterizada por ser rocosa, al igual que la densidad aparente y la pedregosidad. Las variables que controlan la distribución espacial de la pedregosidad es la pendiente, demostrándose la influencia de la misma en la erosión. La distribución espacial del contenido de carbono y carbono almacenado en el suelo dependen de la cobertura vegetativa y de la insolación. La bioturbación se ha estudiado en perfiles de suelo a distintas profundidades a lo largo de una ladera con pronunciada pendiente, a través de la técnica de luminiscencia IRSL (Infrared Stimulated Luminescence) usada en granos de feldespato tamaño arena por primera vez para dicho fin. Esta técnica ha permitido identificar la edad de la muestra a diferentes profundidades y una tasa efectiva de mezcla del suelo que tiene en cuenta sólo los granos que alguna vez vieron la luz en la superficie del suelo. Esto ha hecho posible que, por primera vez, se haya identificado el borde entre el regolito móvil y el saprolito debido a que los granos cercanos a esta franja nunca han visitado la superficie. La edad del suelo a diferentes profundidades anteriormente calculada ha sido usada para determinar las tasas de bioturbación, erosión y depósito a lo largo de la ladera a través de una nueva solución analítica de la ecuación advección-difusión. La meteorización física ha sido evaluada en los horizontes de diez perfiles de suelo comparando los datos de campo de fragmentación de rocas con diferentes modelos. De esta forma, se establecieron los patrones que rigen la fragmentación de partículas en seis perfiles. El resto de los perfiles no se ajustaron a ninguno de estos modelos por estar caracterizados por el efecto armouring en la superficie, es decir, el horizonte superficial contiene un tamaño de rocas mayor que el inferior debido a la eliminación de las partículas finas producida por la erosión. El estudio presentado aquí es un gran avance para el conocimiento de estos procesos formadores del suelo y puede ser implementado en otros estudios de la misma índole. En el futuro, este estudio podrá ser comparado con los resultados que se obtendrían de tasas de erosión usando otros métodos (10Be or 137Cs), ser completado con una estimación de los procesos químicos en el área de estudio y, por último, podría ayudar a la calibración y validación tanto del nuevo modelo de formación de suelo que se pretende desarrollar vinculado al trabajo desarrollado en esta tesis, tal y como se explica en el capítulo seis, como de otros modelos de formación de suelo y evolución de paisaje para entender mejor la conexión entre la pedología y los procesos geomorfológicos

The Effect of Tree-Uprooting on the Soil Spatial Complexity in an Old-Growth Temperate Forest, Central Europe

The formation of spatial pedocomplexity in forested landscapes is an issue that has not yet been comprehensively resolved. This study analysed the effects of tree disturbances on the spatial variability of soil chemical properties in order to explain the spatial pedocomplexity in one of the oldest forest reserves in Europe. A total of 1545 sites over an area of 74 ha were assessed in terms of soil taxonomy, morphology, and profiles. We quantified the spatial autocorrelation of soil chemical properties and analysed the effects of soil disturbance regimes on soil chemical properties in both the surface and subsurface layers using geostatistics and redundancy analysis, respectively. A paired difference test revealed that the factors involved in the soil formation of the two layers are different. The neoformation of the surface layer proceeds rapidly after soil disturbance and, therefore, some formerly disturbed surface layers become mature above immature subsurface layers. The effect of tree disturbances on soil chemical properties was significant for totally decomposed treethrows. Treethrow density partially explained the variation in soil chemical properties in both layers, but even more so in the subsurface layer. This study further elucidates the impact of treethrows on soils and shows that they are an important driver of soil spatial pedocomplexity

Testing one-loop galaxy bias: Cosmological constraints from the power spectrum

We investigate the impact of different assumptions in the modeling of one-loop galaxy bias on the recovery of cosmological parameters, as a follow-up of the analysis done in the first paper of the series at fixed cosmology. To carry out these tests we focus on the real-space galaxy-power spectrum from a set of three different synthetic galaxy samples whose clustering properties are meant to match the ones of the CMASS and LOWZ catalogs of BOSS and the SDSS Main Galaxy Sample. We investigate the relevance of allowing for either short range nonlocality or scale-dependent stochasticity by fitting the real-space galaxy autopower spectrum or the combination of galaxy-galaxy and galaxy-matter power spectrum. From a comparison among the goodness of fit (χ2), unbiasedness of cosmological parameters (FoB), and figure of merit (FoM) of the model, we find that a simple four-parameter model (linear, quadratic, cubic nonlocal bias, and constant shot noise) with fixed quadratic tidal bias provides a robust modeling choice for the autopower spectrum of the three galaxy samples, up to kmax ¼ 0.3h Mpc−1 and for an effective volume of 6h−3 Gpc3. Instead, a joint analysis of the two observables fails at larger scales, and a model extension with either higher derivatives or scale-dependent shot noise is necessary to reach a similar kmax, with the latter providing the most accurate and stable results. Throughout the majority of the paper, we fix the description of the nonlinear matter evolution using a hybrid perturbative-N-body approach, RESPRESSO, that was found in the first paper to be the closest performing to the measured matter spectrum. We also test the impact of different modeling assumptions based on perturbative approaches, such as galilean-invariant Renormalised Perturbation Theory (gRPT) and effective field theory (EFT). In all cases, we find the inclusion of scale-dependent shot noise to increase the range of validity of the model in terms of FoB and χ2. Interestingly, these model extensions with additional free parameters do not necessarily lead to an increase in the maximally achievable FoM for the cosmological parameters ðh; Ωch2; AsÞ, which are generally consistent with those of the simpler model at smaller kmax

Dead or Alive: Drivers of Wind Mortality Initiate Multiple Disturbance Regime in a Temperate Primeval Mountain Forest

The driving forces of tree mortality following wind disturbances of mountain mixed European temperate forests belongs among issues not comprehensively resolved. Hence, we aimed to elucidate the key factors of tree resistance to historical severe disturbance events in the Boubínský Primeval Forest, one of the oldest forest reserves in the Czech Republic. By using spatially explicit tree census, dendrochronological and soil data, we study spatial and temporal patterns of past disturbances and mathematically compared selected characteristics of neighboring trees that were killed by a severe storm in 2017 and those that remained undisturbed. The tendency of trees toward falling was primarily driven edaphically, limiting severe events non-randomly to previously disturbed sites occupied by hydromorphic soils and promoting the existence of two spatially-separated disturbance regimes. While disturbed trees usually recruited in gaps and experienced only one severe release event, surviving trees characteristically regenerated under the canopy and were repeatedly released. Despite the fact that disturbed trees tended to reach both lower ages and dimensions than survivors, they experienced significantly higher growth rates. Our study indicates that slow growth with several suppression periods emerged as the most effective tree strategy for withstanding severe windstorms, dying of senescence in overaged life stage. Despite the selective impact of the Herwart storm on conifer population, we did not find any difference in species sensitivity for most characteristics studied. We conclude that the presence of such ancient, high-density wood trees contributes significantly to the resistance of an entire stand to severe storms

COMET: Clustering Observables Modelled by Emulated perturbation Theory

In this paper we present COMET, a Gaussian process emulator of the galaxy power spectrum multipoles in redshift-space. The model predictions are based on one-loop perturbation theory and we consider two alternative descriptions of redshift-space distortions: one that performs a full expansion of the real- to redshift-space mapping, as in recent effective field theory models, and another that preserves the non-perturbative impact of small-scale velocities by means of an effective damping function. The outputs of COMET can be obtained at arbitrary redshifts (up to $z \sim 3$), for arbitrary fiducial background cosmologies, and for a large parameter space that covers the shape parameters $\omega_c$, $\omega_b$, and $n_s$, as well as the evolution parameters $h$, $A_s$, $\Omega_K$, $w_0$, and $w_a$. This flexibility does not impair COMET's accuracy, since we exploit an exact degeneracy between the evolution parameters that allows us to train the emulator on a significantly reduced parameter space. While the predictions are sped up by at least two orders of magnitude, validation tests reveal an accuracy of $0.1\,\%$ for the monopole and quadrupole ($0.3\,\%$ for the hexadecapole), or alternatively, better than $0.25\,\sigma$ for all three multipoles in comparison to statistical uncertainties expected for the Euclid survey with a tenfold increase in volume. We show that these differences translate into shifts in mean posterior values that are at most of the same size, meaning that COMET can be used with the same confidence as the exact underlying models. COMET is a publicly available Python package that also provides the tree-level bispectrum multipoles in redshift-space and Gaussian covariance matrices.Comment: 18 pages, 10 figures; for the COMET Python package, see https://gitlab.com/aegge/comet-em

Rapid diagnosis of the geospatial distribution of intertidal macroalgae using large-scale UAVs

Macroalgae have been used as indicators of the health of coastal ecosystems, they function as sinks of CO2 and are essential contributors to primary production. With the increase in anthropogenic activities, it is crucial to assess the impact of such activities on these ecosystems. As traditional surveying techniques, although accurate, are time-consuming and their area coverage is limited, novel techniques are required to monitor the coverage and diversity of intertidal macroalgae. We propose a methodology using the free-source Semi-Automatic Classification Plugin from QGIS to use UAV and multispectral cameras for the spatiotemporal monitoring of intertidal macroalgae. We also compared the performance of six classifiers: Minimum Distance (MD), Maximum Likelihood (ML), Spectral Angle Mapping (SAM), Multi-Layer Perceptron (MLP), Random Forest (RF) and Support Vector Machine (SVM), for three types of macroalgae classification: general, taxonomical groups and species. As proof of concept, an intertidal rocky shore in a marine protected area (NW Spain) was studied for four months. RF and SVM achieved similar results, with both being recommended for the general (OASVM = 97.4±1.7 and OARF = 98.3±1.7) and taxonomical groups (OASVM = 91.6±1.9 and OARF = 89.2±4.5). SVM and ML were found to be more suitable for species classification (OASVM = 77.4±11.4 and OAML = 74.2±9.7). SAM and MLP provided the least performant species classifiers because of the overlap in the macroalgae spectral signatures. The plugin showed limitations when tuning the input parameters of the MLP classifier and did not let to add a validation dataset. Additionally, we present an open-access GIS web application, Alganat 2000 GIS web, to facilitate the monitoring and management of coastal areas. We conclude that the proposed methodology using the SVM or ML classifiers is an effective tool for assessing intertidal macroalgal assemblages. Its easy and rapid implementation is beneficial for researchers who are not very familiar with coding and machine learning frameworks and reduces the time and cost of fieldwork. As future work, we propose the combination of the multispectral bands with topographic and spectral indices and to research the application of deep learning models to the classification of intertidal macroalgaeAgencia Estatal de Investigación | Ref. PRTR-C17.I1Universidade de Vigo/CISU

Multimedia platform for the efficient management of water and the use of hydric resources from a multidisciplinary point of view in engineering degrees

En este proyecto de innovación docente se ha realizado una red social sobre la gestión eficiente del agua involucrando a diferentes asignaturas de los grados en ingeniería Mecánica, Eléctrica, Electrónica Industrial, Agroalimentaria y del Medio Rural e Ingeniería Civil. En este entorno virtual se ha creado un laboratorio virtual sobre comportamiento de un canal hidrodinámico. Esta aplicación representa una alternativa barata y eficiente, donde el estudiante simula los fenómenos a estudiar como si los observase en un laboratorio tradicional. Por lo tanto, es una herramienta de autoaprendizaje, donde el alumno puede alterar las variables de entrada, configurar nuevos experimentos, aprender el manejo de instrumentos y personalizarlos. Además, la simulación en el laboratorio virtual ha permitido obtener una visión más intuitiva de aquellos fenómenos que en su realización manual no aportan suficiente claridad gráfica. Finalmente, se ha realizado un debate sobre tema de actualidad de los recursos hídricos que ha tenido una muy buena valoración por parte del alumnado.In this teaching innovation project, a social network about the efficient management of water has been carried out, involving different subjects of the degrees in Mechanical, Electrical, Electronic, Agrofood, Rural and Civil Engineering. In this virtual environment, a virtual laboratory (VL) of hydrodynamic channel behavior has been created. This application represents an economical and efficient alternative, where the student simulates the processes to be studied as if they were observed in a traditional laboratory. Therefore, VL represents a self-learning tool, where the student can alter the input variables, configure new experiments, learn how to use instruments and customize them. In addition, the simulation in the virtual laboratory has allowed to obtain a more intuitive vision of those phenomena that in their manual realization do not provide enough graphic clarity. Finally, an academic debate has been carried out about current topic of water resources that received an excellent evaluation by students

Ecoestabilidad femenina y malnutrición severa infantil: Evidencia a partir de intervenciones de ayuda humanitaria de Acción Contra el Hambre en países africanos, Asiáticos y Latinoamericanos

Introducción: Evidencias previas han reportado diferencias en la condición nutricional de niños y niñas pertenecientes a la misma comunidad y sometidos a idénticas condiciones de privación alimentaria. El objetivo del presente trabajo es analizar las diferencias sexuales en prevalencia de malnutrición severa en menores de 5 años, sometidos a situación de crisis alimentaria. Métodos: Se analizaron datos recogidos en intervenciones de ayuda humanitaria llevadas a cabo por Acción Contra el Hambre entre 2002 y 2010 en 24 países. Dichas intervenciones se efectuaron en poblaciones de Africa, Latinoamérica y Asia que se encontraban en situación de grave crisis alimentaria. La muestra se compone de un total de 367.258 menores (186,156 niños y 181,102 niñas) con edad (E) entre 6 y 59 meses. Se midió el peso (P) y la talla (T) siguiendo la metodología SMART y se estimó la prevalencia de severo bajo peso (P/E <-3DE), desnutrición aguda severa (P/T <-3DE) y desnutrición crónica severa (T/E <-3DE) de acuerdo a los estándares de la OMS. Resultados: Para el total de la muestra, la proporción de niños con severo bajo peso fue de 9,8% en comparación al 7,3% de niñas (p <0.001). La desnutrición aguda severa afectó al 3,9% de los niños frente al 2,5% de las niñas (p <0.001). Las diferencias también fueron notables en la des-nutrición crónica: el 19, 5% de los niños frente al 15% de las niñas (p<0,001) presentaron crecimiento retardado. Conclusiones: Los resultados avalan la idea de la deno-minada eco-estabilidad femenina, de acuerdo a la cual, las mujeres serian menos sensibles a los factores externos que modulan el desarrollo ontogénico, mientras los varones se ve-rían más negativamente afectados por las agresiones medio-ambientales

Multi-platform experiments, numerical simulations and data science techniques for generation of new altimetric products: focus on mesoscale and sub- mesoscale variability (MANATEE – OSTST proposal)

Trabajo presentado en la Ocean Surface Topography Science Team Meeting (OSTST), celebrada online del 19 al 23 de octubre de 2020

Coupled C, H, N, S and Fe biogeochemical cycles operating in the continental deep subsurface of the Iberian Pyrite Belt

Microbial activity is a major contributor to the biogeochemical cycles that make up the life support system of planet Earth. A 613 m deep geomicrobiological perforation and a systematic multi-analytical characterization revealed an unexpected diversity associated with the rock matrix microbiome that operates in the subsurface of the Iberian Pyrite Belt (IPB). Members of 1 class and 16 genera were deemed the most representative microorganisms of the IPB deep subsurface and selected for a deeper analysis. The use of fluorescence in situ hybridization allowed not only the identification of microorganisms but also the detection of novel activities in the subsurface such as anaerobic ammonium oxidation (ANAMMOX) and anaerobic methane oxidation, the co-occurrence of microorganisms able to maintain complementary metabolic activities and the existence of biofilms. The use of enrichment cultures sensed the presence of five different complementary metabolic activities along the length of the borehole and isolated 29 bacterial species. Genomic analysis of nine isolates identified the genes involved in the complete operation of the light-independent coupled C, H, N, S and Fe biogeochemical cycles. This study revealed the importance of nitrate reduction microorganisms in the oxidation of iron in the anoxic conditions existing in the subsurface of the IPBFP7 Ideas: European Research Council, Grant/Award Number: ERC Advanced Grant #250-35