Análisis del comportamiento de Mus spretus en la selección, manejo y gestión de bellotas del género Quercus

Las especies del género Quercus son de gran valor ecológico y económico, por lo que han sido objeto de numerosos estudios científicos relacionados con la conservación y gestión forestal. Una de las fases más limitantes en la regeneración natural de quercíneas en ambientes mediterráneos es la fase de reclutamiento, para lo que es necesario previamente que las semillas alcancen micrositios favorables para poder germinar y establecerse, jugando un papel crucial en dicho proceso los dispersantes. El efecto de los roedores en la configuración de las comunidades de quercíneas dependerá de sus preferencias a la hora de seleccionar bellotas, de su conducta en el manejo y procesado durante su consumo, y del comportamiento del roedor en la gestión de las bellotas en los almacenes; aspectos todos ellos que se analizan en el presente estudio. Para ello se diseñaron ocho experimentos de laboratorio con el objetivo de evaluar de forma explícita el comportamiento de cinco Mus spretus sin experiencia previa en el consumo de bellotas. Los resultados muestran que el ratón moruno selecciona las bellotas en función de la especie disponible, pero no existe una relación clara con el tamaño de la bellota, existiendo otros factores que pueden influir en la selección como la concentración de taninos o la dureza del endocarpio. El análisis del comportamiento en la gestión de almacenes sugiere que Mus spretus utiliza despojos de bellotas para evitar los robos en las madrigueras y, así, preservar las bellotas enteras y mejor conservadas. La evaluación de la forma y manejo de las bellotas en el consumo indican que Mus spretus sigue unas conductas destinadas a preservar el embrión, ligado este comportamiento a la especie de Quercus. Los experimentos muestran una significativa preferencia por las bellotas de Quercus ilex, lo que ayudaría a explicar su dominancia en los bosques mixtos compuestos por especies de Quercus.Departamento de Producción Vegetal y Recursos ForestalesMáster en Investigación en Ingeniería para la Conservación y Uso Sostenible de Sistemas Forestale

Predicting potential wildfire severity across Southern Europe with global data sources

.The large environmental and socioeconomic impacts of wildfires in Southern Europe require the development of efficient generalizable tools for fire danger analysis and proactive environmental management. With this premise, we aimed to study the influence of different environmental variables on burn severity, as well as to develop accurate and generalizable models to predict burn severity. To address these objectives, we selected 23 wildfires (131,490 ha) across Southern Europe. Using satellite imagery and geospatial data available at the planetary scale, we spatialized burn severity as well as 20 pre-burn environmental variables, which were grouped into climatic, topographic, fuel load-type, fuel load-moisture and fuel continuity predictors. We sampled all variables and divided the data into three independent datasets: a training dataset, used to perform univariant regression models, random forest (RF) models by groups of variables, and RF models including all predictors (full and parsimonious models); a second dataset to analyze interpolation capacity within the training wildfires; and a third dataset to study extrapolation capacity to independent wildfires. Results showed that all environmental variables determined burn severity, which increased towards the mildest climatic conditions, sloping terrain, high fuel loads, and coniferous vegetation. In general, the highest predictive and generalization capacities were found for fuel load proxies obtained though multispectral imagery, both in the individual analysis and by groups of variables. The full and parsimonious models outperformed all, the individual models, models by groups, and formerly developed predictive models of burn severity, as they were able to explain up to 95%, 59% and 25% of variance when applied to the training, interpolation and extrapolation datasets respectively. Our study is a benchmark for progress in the prediction of fire danger, provides operational tools for the identification of areas at risk, and sets the basis for the design of pre-burn management actions.S

Relevance of UAV and sentinel-2 data fusion for estimating topsoil organic carbon after forest fire

[EN] The evaluation at detailed spatial scale of soil status after severe fires may provide useful information on the recovery of burned forest ecosystems. Here, we aimed to assess the potential of combining multispectral imagery at different spectral and spatial resolutions to estimate soil indicators of burn severity. The study was conducted in a burned area located at the northwest of the Iberian Peninsula (Spain). One month after fire, we measured soil burn severity in the field using an adapted protocol of the Composite Burn Index (CBI). Then, we performed soil sampling to analyze three soil properties potentially indicatives of fire-induced changes: mean weight diameter (MWD), soil moisture content (SMC) and soil organic carbon (SOC). Additionally, we collected post-fire imagery from the Sentinel-2A MSI satellite sensor (10–20 m of spatial resolution), as well as from a Parrot Sequoia camera on board an unmanned aerial vehicle (UAV; 0.50 m of spatial resolution). A Gram-Schmidt (GS) image sharpening technique was used to increase the spatial resolution of Sentinel-2 bands and to fuse these data with UAV information. The performance of soil parameters as indicators of soil burn severity was determined trough a machine learning decision tree, and the relationship between soil indicators and reflectance values (UAV, Sentinel-2 and fused UAV-Sentinel-2 images) was analyzed by means of support vector machine (SVM) regression models. All the considered soil parameters decreased their value with burn severity, but soil moisture content, and, to a lesser extent, soil organic carbon discriminated at best among soil burn severity classes (accuracy = 91.18 %; Kappa = 0.82). The performance of reflectance values derived from the fused UAV-Sentinel-2 image to monitor the effects of wildfire on soil characteristics was outstanding, particularly for the case of soil organic carbon content (R2 = 0.52; RPD = 1.47). This study highlights the advantages of combining satellite and UAV images to produce spatially and spectrally enhanced images, which may be relevant for estimating main impacts on soil properties in burned forest areas where emergency actions need to be applied.S

Mapping Soil Burn Severity at Very High Spatial Resolution from Unmanned Aerial Vehicles

ArtículoThe evaluation of the effect of burn severity on forest soils is essential to determine the impact of wildfires on a range of key ecological processes, such as nutrient cycling and vegetation recovery. The main objective of this study was to assess the potentiality of different spectral products derived from RGB and multispectral imagery collected by unmanned aerial vehicles (UAVs) at very high spatial resolution for discriminating spatial variations in soil burn severity after a heterogeneous wildfire. In the case study, we chose a mixed-severity fire that occurred in the northwest (NW) of the Iberian Peninsula (Spain) in 2019 that affected 82.74 ha covered by three different types of forests, each dominated by Pinus pinaster, Pinus sylvestris, and Quercus pyrenaica. We evaluated soil burn severity in the field 1 month after the fire using the Composite Burn Soil Index (CBSI), as well as a pool of five individual indicators (ash depth, ash cover, fine debris cover, coarse debris cover, and unstructured soil depth) of easy interpretation. Simultaneously, we operated an unmanned aerial vehicle to obtain RGB and multispectral postfire images, allowing for deriving six spectral indices. Then, we explored the relationship between spectral indices and field soil burn severity metrics by means of univariate proportional odds regression models. These models were used to predict CBSI categories, and classifications were validated through confusion matrices. Results indicated that multispectral indices outperformed RGB indices when assessing soil burn severity, being more strongly related to CBSI than to individual indicators. The Normalized Difference Water Index (NDWI) was the best-performing spectral index for modelling CBSI (R2cv = 0.69), showing the best ability to predict CBSI categories (overall accuracy = 0.83). Among the individual indicators of soil burn severity, ash depth was the one that achieved the best results, specifically when it was modelled from NDWI (R2cv = 0.53). This work provides a useful background to design quick and accurate assessments of soil burn severity to be implemented immediately after the fire, which is a key factor to identify priority areas for emergency actions after forest fires.S

Transhumant Sheep grazing enhances ecosystem multifunctionality in productive mountain grasslands: a case study in the Cantabrian Mountains

.Understanding the effects of traditional livestock grazing abandonment on the ability of mountain grasslands to sustain multiple ecosystem functions (ecosystem multifunctionality; EMF) is crucial for implementing policies that promote grasslands conservation and the delivery of multiple ecosystem services. In this study, we evaluated the effect of short- and long-term transhumant sheep abandonment on EMF through a grazing exclusion experiment in a grassland of the Cantabrian Mountains range (NW Spain), where transhumant sheep flocks graze in summer. We considered four key ecosystem functions, derived from vegetation and soil functional indicators measured in the field: (A) biodiversity function, evaluated from total plant species evenness, diversity and richness indicators; (B) forage production function, evaluated from cover and richness of perennial and annual herbaceous species indicators; (C) carbon sequestration function, evaluated from woody species cover and soil organic carbon indicators; and (D) soil fertility function, evaluated from NH4C-N, NO3-N, P and K content in the soil. The EMF index was calculated by integrating the four standardized ecosystem functions through an averaging approach. Based on linear mixed modeling we found that grazing exclusion induced significant shifts in the considered individual ecosystem functions and also on EMF. Long-term livestock exclusion significantly hindered biodiversity and forage production functions, but enhanced the carbon sequestration function. Conversely, the soil fertility function was negatively affected by both short- and long-term grazing exclusion. Altogether, grazing exclusion significantly decreased overall EMF, especially in long-term livestock exclusion areas, while the decline in EMF in short-term exclusions with respect to grazed areas was marginally significant. The results of this study support the sustainability of traditional transhumance livestock grazing for promoting the conservation of grasslands and their ecosystem function in mountain regions.S

Silica-based powders and monoliths with bimodal pore systems

Porous pure and doped silicas with pore sizes at two length scales (meso/macroporous) have been prepared and shaped both as powders and monoliths through a one-pot surfactant assisted procedure by using a simple template agent and starting from atrane complexes as inorganic precursors.El Haskouri, Jamal, [email protected] ; Latorre Saborit, Julio, [email protected] ; Beltran Porter, Aurelio, [email protected] ; Beltran Porter, Daniel, [email protected] ; Amoros del Toro, Pedro Jose, [email protected]

Generalized “one-pot” preparative strategy to obtain highly functionalized silica-based mesoporous spherical particles

In this work we present a synthesis strategy for the preparation of Stöber-type mesoporous particles functionalized with inorganic species. The procedure is based on a combination of the Atrane and the Stöber methods. Both as a source of silicon and of the incorporated heteroelements (Fe, Zn, Al, Ti) the corresponding atrane complexes are used as hydrolytic reagents. These complexes are easily formed by reaction with triethanolamine. Mesoporosity is achieved using surfactant micelles as templates. Obtaining uniform spherical particles is achieved by optimizing the amount of water-ethanol in the reaction medium. The particle sizes have been modulated by controlling simple parameters such as reaction time or temperature. The incorporation of inorganic species is on many occasions incompatible with the preservation of spherical morphology, resulting in heterogeneous particles in shape and size and even phase segregation for high functionalization degrees. The methodology that we propose makes it possible to achieve a high concentration of highly dispersed heteroelements (even at molecular level), maintaining, to a large extent, both sphericity and particle size homogeneity. The Si/M molar ratios achieved are significantly lower (greater functionalization) than those usually reported in the literature. The strategy is generalizable for the incorporation of a great variety of elements, and specially for first row transition elements

Laser Shock Processing: An Advanced Technique for Improving the Surface and Mechanical Properties of Metallic Alloys

Profiting by the increasing availability of laser sources delivering intensities above 10 9W/cm2 with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is being consolidating as an effective technology for the improvement of surface and mechanical resistance properties of metals and is being developed as a practical process amenable to production engineering. The main acknowledged advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Following a short description of the theoretical/computational and experimental methods developed by the authors for the predictive assessment and experimental implementation of LSP treatments, experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (specifically steels and Al and Ti alloys) under different LSP irradiation conditions are presented. In particular, the analysis of the residual stress profiles obtained under different irradiation parameters and the evaluation of the corresponding induced surface properties and fatigue life enhancement are presented

Induction of Through-Thickness Compressive Residual Stresses and Application to the Mitigation of the Effect of Surface Defects on the Fatigue Life of Thin Metal Plates by LSP

Laser Shock Processing (LSP) is developed as a technique allowing the effective induction of residual stresses fields in metallic materials allowing a high degree of surface material protection against fatigue crack propagation, abrasive wear, chemical corrosion and other failure conditions, what makes the technique specially suitable and competitive with presently use techniques for the treatment of heavy duty components in the aeronautical, nuclear and automotive industries. In particular, the treatment of thin plates for, i.e., the aeronautical industry, is still a topic not fully addressed by the current industrial approaches. The desired induction of through-thickness compressive RSs fields is generally difficult to achieve due to the local + global deformations induced by highenergy- per-pulse processing systems.The authors have directly envisaged this problem by means of their coupled predictive + experimental methodology and have obtained successful results. In a combined way, the highly beneficial effect of LSP treatments has been demonstrated in the extension of life of thin Al2024-T351 test specimens with induced surface notches

Pobreza en la ocupación e instrumentos de reacción

Unión Europea,Ministerio de Economía y Competitividad y el Fondo Europeo de Desarrollo Regional DER2015-63701-C3-1-