Forest connectivity restoration through reforestation: an integrated methodology for prioritizing agricultural lands and selecting reforestation species

Forest connectivity restoration is a major goal in natural resource planning. Given the high amount of abandoned cultivated lands, setting efficient methods for the reforestation of agricultural lands offers a good opportunity to face this issue. However, reforestations must be carefully planned, which poses two main challenges. In first place, to determine those agricultural lands that, once reforested, would meet more effectively the planning goals. As a further step, in order to grant the success of the activity, it is fairly advisable to select those tree species that are more adapted to each particular environment. Here we intend to give response to both requirements by proposing a sequential and integrated methodology that has been implemented in two Spanish forest districts, which are formed by several landscape types that were previously defined and characterized. Using the software Conefor Sensinode, a powerful tool for quantifying habitat availability that is based on graph theory concepts, we determined the landscapes where forest planning should have connectivity as a major concern and, afterwards, we detected the agricultural patches that would contribute most to enhance connectivity if they were reforested. The subsequent reforestation species assessment was performed within these priority patches. Using penalized logistic regressions we fitted ecological niche models for the Spanish native tree species. The models were trained with species distribution data from the Spanish Forest Map and used climatic and lithological variables as predictors. Model predictions were used to build ordered lists of suitable species for each priority patch. The lists include dominant and non dominant tree species and allow adding biodiversity goals to the reforestation planning. The result of this combined methodology is a map of agricultural patches that would contribute most to uphold forest connectivity if they were reforested and a list of suitable tree species for each patch ordered by occurrence probability. Therefore the proposed methodology may be useful for suitable and efficient forest planning and landscape designing

Continuous monitoring of mining induced strain in a road pavement using fiber Bragg grating sensors

Abstrakt Få samhällsproblem har under de senaste åren mött så allmän uppmärksamhet som ungdomsbrottsligheten. Den polisanmälda ungdomsbrottsligheten har i stort sett följt brottslighetens utvecklingskurva avseende antal begångna brott, denna kurva visar en tydlig ökning sedan efterkrigstiden. Detta är en komparativ uppsats som är inriktad på ungdomsbrottsligheten i två av Malmö stadsdelar där vi undersöker antalet polisanmälda ungdomar till socialtjänsten mellan åren 2007-2009. Vi har studerat vilka brott ungdomarna var anmälda, analyserat brottstrender och i den mån det var möjligt granskat hur könsfördelningen har sett ut. Vi har undersökt vilka insatser som tillämpas från socialtjänstens håll för att motverka ungdomsbrottslighet samt förhindra fortsatt brottslighet hos redan polisanmälda ungdomar samt granska hur socialsekreterare vid våra undersökningsverksamheter upplever och uppfattar ungdomsbrottsligheten. Våra resultat har delvis ställts i relation till hur ungdomsbrottsligheten enligt tidigare forskning och redan befintlig statistik ser ut i Sverige. Vi har i uppsatsen använt oss av kvalitativ och kvantitativ datainsamlingsmetod samt ställt analysavsnitt och diskussionsavsnitt i relation till tidigare forskning och den av Travis Hirschis konstruerade teorin om sociala band. Studiens resultat visar bland annat att antalet polisanmälningar till socialtjänsterna har ökat, att killar begår fler brott än tjejer, att brottstyperna skiljer sig åt beroende på kön samt att ett mindre antal ungdomar ansvarar för en stor del av socialtjänsternas inkomna polisanmälningar

Forest landscape ecology and biodiversity maintenance: application to forest resources planning in spanish rural landscapes

Spanish Forestry Act enhances the development of tools for planning and monitoring forestry uses in land units beyond local forest boundaries. This requirement implies a new approach at a higher to forest ecosystem organisation level. Landscape level approach includes knowledge of composition, structure and function of different landscape elements and land uses related to a forested matrix in a region. Nowadays there are some ongoing projects from different public and private institutions aiming to settle the methodological basis and research requirements for appropriate design and monitoring of forest landscape regions. We are reporting aims and preliminary results related to one of these projects involving two characteristic forested areas in central Spain: pine forests of Burgos‐ Soria region and different forest types located in High Tajo Valley. Main topics are: • Forest landscape and area delineation criteria. • Overlook of main digital data sources for the region related to non biotic and biotic components. • Settlement of main habitat, ecosystem and landscape typologies. • Research on main grain and landscape unit size for evaluating landscape indices. Evaluation of landscape structure in relation with some frequent disturbance sources (wild fires, floods and others). • Baseline definition for monitoring diversity related to representative groups of plant and animal species. • Settlement of habitat structure for some focal species existing in the area. • Evaluation of silviculture and management in relation with biodiversity maintenance at landscape level. Methodological routines are based on GIS geo‐databases and simulation programs that includes several digital information sources and field data related to habitat distribution, species composition, silviculture, disturbances impact,… One of the outputs of this project is a methodological guide for delineation, sustainable management and monitoring the forest landscapes in Mediterranean Spain

Analysis of a distributed fiber-optic temperature sensor using single-photon detectors

We demonstrate a high-accuracy distributed fiber-optic temperature sensor using superconducting nanowire single-photon detectors and single-photon counting techniques. Our demonstration uses inexpensive single-mode fiber at standard telecommunications wavelengths as the sensing fiber, which enables extremely low-loss experiments and compatibility with existing fiber networks. We show that the uncertainty of the temperature measurement decreases with longer integration periods, but is ultimately limited by the calibration uncertainty. Temperature uncertainty on the order of 3 K is possible with spatial resolution of the order of 1 cm and integration period as small as 60 seconds. Also, we show that the measurement is subject to systematic uncertainties, such as polarization fading, which can be reduced with a polarization diversity receiver

Dispersive properties of quasi-phase-matched optical parametric amplifiers

The dispersive properties of non-degenerate optical parametric amplification in quasi-phase-matched (QPM) nonlinear quadratic crystals with an arbitrary grating profile are theoretically investigated in the no-pump-depletion limit. The spectral group delay curve of the amplifier is shown to be univocally determined by its spectral power gain curve through a Hilbert transform. Such a constraint has important implications on the propagation of spectrally-narrow optical pulses through the amplifier. In particular, it is shown that anomalous transit times, corresponding to superluminal or even negative group velocities, are possible near local minima of the spectral gain curve. A possible experimental observation of such effects using a QPM Lithium-Niobate crystal is suggested.Comment: submitted for publicatio

Diseño de una tolva y de un extrusor para alimentar una impresora 3D a partir de pellet

Treball Final de Grau en Enginyeria Mecànica. Codi: EM1047. Curs acadèmic: 2020/2021Actualmente se generan más de 300 millones de toneladas de residuos plásticos (Greenpeace, 2021) cada año, lo cual supone una grave amenaza para el medioambiente en general y para los océanos en particular. En consecuencia, urge no solo reducir la cantidad de plástico que se pone en circulación, sino también encontrar formas eficaces de reutilizar el ya existente. En este proyecto se diseñará una alternativa viable para la reutilización de dichos plásticos con el fin de darles una segunda vida útil y reducir los residuos que, de otra manera, se tratarían de formas menos sostenibles. El objeto de este proyecto es el diseño de una extrusora de pellet, un nuevo tipo de impresora que hace uso de residuos de plástico para la generación de filamento que posteriormente será extruido