Reintroduction of Quercus petraea and Quercus pyrenaica mediated by nurse shrubs on reclaimed coal wastes in Northern Spain

La facilitación entre plantas permite a una especie persistir en ambientes difíciles, pero se necesita conocer mejor sus efectos como técnica de restauración de la cobertura vegetal en ecosistemas antrópicos degradados. Así, se realizó un experimento para determinar si los arbustos nodriza (Genista florida y Cytisus scoparius) y la protección ante herbívoros beneficiaría la reintroducción de Quercus petraea y Q. pyrenaica en una mina de carbón restaurada en el norte de España. Los arbustos mejoraron la emergencia, supervivencia y crecimiento de plántulas y bellotas, reduciendo el efecto de la sequía estival. La edad y la tolerancia al estrés de la especie también afectaron a los resultados, siendo mejores para las plántulas de Q. pyrenaica. Así, la reintroducción de especies forestales en áreas mineras debería considerar la influencia de los arbustos nodriza, la fase de vida y la tolerancia al estrés de la especie a introducir para optimizar la restauración.Producción Vegetal y Recursos ForestalesMáster en Investigación en Ingeniería para la Conservación y Uso Sostenible de Sistemas Forestale

Estructura genética, filogeografía, variación adaptativa y especiación en árboles tropicales del género Symphonia

The genetic structure within a species is the result of the levels of the genetic diversity and its spatial distribution. Also, it depends significantly on the specific evolutionary history experienced by the species. Thus, to disentangle the overlapping evolutionary processes acting at different levels in a species or a taxon, it will be necessary to work at different spatial scales and at different taxonomic levels as complementary approaches. The study of the fine-scale spatial genetic structure in plants (the micro scale approach) will imply to work at the shortest spatial scales and to capture detailed information on the spatial distribution of genotypes at within-population scale. The analysis at this scale will help to detect mainly evolutionary and ecological processes more related to short‐term periods of time and/or smaller spatial scales such as habitat fragmentation and other disturbances, efficiency of dispersal mechanisms or gene dispersal distances. On the other side, the study of the genetic structure at wider scales (the macro scale approach), including both geographical and taxonomic (i.e., speciation) points of view, will usually imply to detect larger spatio-temporal processes and to work with deeper evolutionary timescales. In this sense, the spatial genetic structure within a species at this macro scale will be the result of different historical and contemporary influences such as connectivity across the range of the species and landscape barriers, environmental adaptation, demographic history or climatic events, among others. Finally, if we include the taxonomic perspective in the analysis of genetic structure in a group of closely related species, we will be able to analyse the processes leading to speciation, which also may involve those previously mentioned.La estructura genética que presenta una especie es el resultado de sus niveles de diversidad genética, así como de su distribución espacial. Además, depende significativamente de la historia evolutiva específica que ha sufrido la especie. Así, para desentrañar los procesos evolutivos que actúan simultáneamente a diferentes niveles en una especie o taxon, será necesario trabajar mediante enfoques complementarios, orientados a diferentes escalas espaciales y a diferentes niveles taxonómicos. El estudio de la estructura genética espacial a pequeña escala en plantas (un enfoque en escala micro) implicará trabajar en las escalas espaciales más pequeñas, así como recoger información detallada de la distribución espacial de genotipos dentro de las poblaciones. El análisis a esta escala ayudará a detectar principalmente procesos evolutivos y ecológicos relacionados principalmente con periodos de tiempo cortos y/o a escala espacial pequeña, tales como fragmentación de hábitats y otras perturbaciones, eficiencia de los mecanismos de dispersión o distancias de dispersión genética. Por otro lado, el estudio de la estructura genética a escala más amplia (un enfoque en escala macro), incluyendo los puntos de vista geográfico y taxonómico (es decir, de especiación), normalmente implicará detectar procesos espacio-temporales más amplios y trabajar con escalas evolutivas de tiempo más largas. En este sentido, la estructura genética espacial de una especie a escala macro será el resultado de diferentes influencias históricas y contemporáneas, tales como la conectividad a lo largo de la distribución de la especie, las barreras del paisaje, la adaptación al medio, la historia demográfica o los eventos climáticos, entre otros. Finalmente, si incluímos la perspectiva taxonómica en el análisis de la estructura genética de un grupo de especies muy relacionadas, podremos ser capaces de analizar los procesos que conducen a la especiación, entre los cuales se pueden encontrar también los ya previamente mencionados.Doctorado en Conservación y Uso Sostenible de Sistemas Forestale

Visual-based Guidance System for a 6-DOF Robot

The idea of this bachelor’s thesis is to develop a position-based visual servoing system with two webcams that allows an anthropomorphic robot ABB IRB 120 with six degrees of freedom (DOF) to be guided in real time by an operator, by triangulating a specific target moved within the field of view (FOV) of a machine vision system. For this kind of motion control based on visual data input, termed visual servoing control, we need a stereo vision system to acquire the images of the target since three-dimensional information is required to perform object tracking with six DOF. These images are processed by a MATLAB ap-plication running in a remote PC. The current coordinates of the target referred to the left camera reference frame are extracted from the images and sent through an Ethernet connec-tion to the robot controller, which is programmed to receive the vectors and move its tool centre point (TCP) to the demanded position within its workspace.Grado en Ingeniería en Electrónica Industrial y Automátic

Frugivore species maintain their structural role in the trophic and spatial networks of seed dispersal interactions

1. Trophic relationships have inherent spatial dimensions associated with the sites where species interactions, or their delayed effects, occur. Trophic networks among interacting species may thus be coupled with spatial networks linking species and habitats whereby animals connect patches across the landscape thanks to their high mobility. This trophic and spatial duality is especially inherent in processes like seed dispersal by animals, where frugivores consume fruit species and deposit seeds across habitats. 2. We analysed the frugivore–plant interactions and seed deposition patterns of a diverse assemblage of frugivores in a heterogeneous landscape in order to determine whether the roles of frugivores in network topology are correlated across trophic and spatial networks of seed dispersal. 3. We recorded fruit consumption and seed deposition by birds and mammals during 2 years in the Cantabrian Range (N Spain). We then constructed two networks of trophic (i.e. frugivore–plant) and spatial (i.e. frugivore–seed deposition habitat) interactions and estimated the contributions of each frugivore species to the network structure in terms of nestedness, modularity and complementary specialization. We tested whether the structural role of frugivore species was correlated across the trophic and spatial networks, and evaluated the influence of each frugivore abundance and body mass in that relationship. 4. Both the trophic and the spatial networks were modular and specialized. Trophic modules matched medium-sized birds with fleshy-fruited trees, and small bird and mammals with small-fruit trees and shrubs. Spatial modules associated birds with woody canopies, and mammals with open habitats. Frugivore species maintained their structural role across the trophic and spatial networks of seed dispersal, even after accounting for frugivore abundance and body mass. 5. The modularity found in our system points to complementarity between birds and mammals in the seed dispersal process, a fact that may trigger landscape-scale secondary succession. Our results open up the possibility of predicting the consumption pattern of a diverse frugivore community, and its ecological consequences, from the uneven distribution of fleshy-fruit resources in the landscape

A framework for the practical science necessary to restore sustainable, resilient, and biodiverse ecosystems

Demand for restoration of resilient, self-sustaining, and biodiverse natural ecosystems as a conservation measure is increasing globally; however, restoration efforts frequently fail to meet standards appropriate for this objective. Achieving these standards requires management underpinned by input from diverse scientific disciplines including ecology, biotechnology, engineering, soil science, ecophysiology, and genetics. Despite increasing restoration research activity, a gap between the immediate needs of restoration practitioners and the outputs of restoration science often limits the effectiveness of restoration programs. Regrettably, studies often fail to identify the practical issues most critical for restoration success. We propose that part of this oversight may result from the absence of a considered statement of the necessary practical restoration science questions. Here we develop a comprehensive framework of the research required to bridge this gap and guide effective restoration. We structure questions in five themes: (1) setting targets and planning for success, (2) sourcing biological material, (3) optimizing establishment, (4) facilitating growth and survival, and (5) restoring resilience, sustainability, and landscape integration. This framework will assist restoration practitioners and scientists to identify knowledge gaps and develop strategic research focused on applied outcomes. The breadth of questions highlights the importance of cross-discipline collaboration among restoration scientists, and while the program is broad, successful restoration projects have typically invested in many or most of these themes. Achieving restoration ecology's goal of averting biodiversity losses is a vast challenge: investment in appropriate science is urgently needed for ecological restoration to fulfill its potential and meet demand as a conservation tool

The Multiple Tasks Endured by PI3K during neural tube development

[eng] Development of the spinal cord involves coordination between exposure to localized extracellular signals and controlled activation of intracellular signaling pathways. This way, neuroepithelial cells firstly proliferate apically to increase the progenitor pool and, later on, initiate neurogenic divisions giving rise to a variety of neuronal cell types. Class IA PI3Ks are heterodimeric enzymes (catalytic+regulatory subunits) activated by receptors tyrosine kinase (RTKs) or G protein coupled receptors (GPCRs) that, upon extracellular stimuli, modulate diverse target proteins through local production of PtdIns(3,4,5)P3 lipids. Vertebrates express three Class IA catalytic subunits (p110-alpha, p110-beta, and p110-delta), all important for the development of the central nervous system. However, it is unclear to what extent these p110-alpha isoforms have overlapping or distinct biological roles, and what exact functions they hold in neural development. Analysis of PI3Kalpha (p110-alpha-alpha+regulatory subunit) expression in the embryonic spinal cord revealed abundant mRNA and protein levels in cycling progenitors followed by restriction of PI3K-alpha exclusively to differentiating neurons. To examine the role of PI3K-alpha in progenitors and neurons, we interfered with normal PI3K-alpha regulation by expressing active mutants or knocking down of p110-alpha-alpha in the chicken neural tube. Loss of p110-alpha resulted in high apoptotic rates in both progenitors and neurons, sustaining a role for PI3K-alpha in neural survival as seen in other studies. Instead, uncontrolled upregulation of PI3K-alpha activity resulted in severely disrupted neural tubes, with abnormal cell masses in the luminal face of the neuroepithelium and ectopic mitosis. Additionally, we observed alterations in the neural lamination characterized by basement membrane breaches followed by enhanced neural migration and misoriented axonal growth. A thorough analysis of the tissue unveiled loss of polarity as the main cellular mechanism driving the luminal structural aberrations, suggesting a major role of PI3K-alpha in neuroepithelial apico basal polarity. Moreover, the rescue of the depolarization phenotype with a dominant negative form of RhoA proposes local regulation of the Rho family of small GTPases as the molecular mechanism responsible for the PIP3 dependent regulation of adherens junction dynamics. Alternatively, we found the neural overmigration caused by excess of PI3K-alpha activity explained by increased basal accumulation of PIP3, leading to actin based membrane protrusions and basement membrane breaches. Coherently, when we assessed the neural positioning after p110-alpha knock down, we detected neurons inserted in the proliferative layer and reduction of the neuronal cytoskeletal component beta III tubulin, suggesting that PI3K-alpha also modulates morphological maturation and apico basal positioning of differentiating neurons. Interestingly, PIP3 induced overmigration seemed to be carried out through local activation of other two members of the Rho GTPases, Cdc42 and Rac1. These results shed some light upon the PI3K-alpha/PIP3 specific roles during early neural tube development, stressing out its function in cell polarity. Furthermore, we propose a mechanism that may partially explain how the PI3K-alpha /PIP3 signaling is able to control different types of polarity corresponding to different developmental moments. This could help to understand the initial events leading to some neurodevelopmental disorders caused by hyperactivation of PI3K signaling.[spa] El desarrollo de la médula espinal requiere una fina coordinación entre señales extracelulares y la activación de vías intracelulares específicas. De este modo se da una primera fase de proliferación de las células neuroepiteliales en la zona apical para aumentar el número de progenitores y una segunda fase de neurogénesis, a partir de la cual se originan diferentes tipos de neuronas. La clase IA de las PI3Ks se encuentra implicada en la transducción de señales a través de receptores tirosina quinasa (RTKs) o receptores acoplados a proteínas G (GPCRs). En respuesta a estímulos extracelulares, controlan la actividad de distintas proteínas diana a través de la producción local de lípidos PtdIns(3,4,5)P3. La clase IA de las PI3Ks, formada por enzimas heterodiméricas, consta de tres tipos de subunidades catalíticas (p110-alfa, p110-beta y p110-delta). Todas ellas son importantes para el desarrollo del sistema nervioso, sin embargo no están claras las funciones específicas de cada isoforma. El análisis de la expresión de PI3K a nivel de RNAm y proteína en la médula espinal embrionaria reveló una expresión diferencial según el estadío, siendo alta en progenitores antes de la neurogénesis y restringida a neuronas en estadíos más tardíos. Para estudiar su función en progenitores y neuronas, transfectamos formas activas de PI3K-alfa o suprimimos transitoriamente la p110-alfa en el tubo neural de embriones de pollo. La pérdida de p110-alfa provocó una alta tasa de apoptosis en ambas poblaciones, revelando su importancia en supervivencia. La sobreexpresión de la PI3K-alfa activa, en cambio, generó disrupciones muy severas del tejido neural caracterizadas por la presencia de masas celulares en la pared ventricular y mitosis ectópicas. En el lado basal, se observaron alteraciones en la laminación neuronal con células atravesando la lámina basal y crecimiento axonal aberrante. Nuestros resultados apuntan hacia la pérdida de polaridad como la principal causa de las aberraciones estructurales apicales, indicando que la PI3K-alfa tiene una función en la regulación de la polaridad apico basal. Asimismo, la PI3K-alfa parece implicada en la maduración del citoesqueleto neural y en el posicionamiento de las neuronas en el eje apico basal, funciones parcialmente mediadas por miembros de las Rho GTPasas

Natural forest expansion on reclaimed coal mines in Northern Spain the role of native shrubs as suitable microsites

The characterization of suitable microsites for tree seedling establishment and growth is one of the most important tasks to achieve the restoration of native forest using natural processes in disturbed sites. For that, we assessed the natural Quercus petraea forest expansion in a 20-year-old reclaimed open-cast mine under sub-Mediterranean climate in northern Spain, monitoring seedling survival, growth, and recruitment during 5 years in three contrasting environments (undisturbed forest, mine edge, and mine center). Seedling density and proportion of dead branches decreased greatly from undisturbed forest towards the center of the mine. There was a positive effect of shrubs on Q. petraea seedling establishment in both mine environments, which increase as the environment undergoes more stress (from the mine edge to the center of the mine), and it was produced by different shrub structural features in each mine environment. Seedling survival reduction through time in three environments did not lead to a density reduction because there was a yearly recruitment of new seedlings. Seedling survival, annual growth, and height through time were greater in mine sites than in the undisturbed forest. The successful colonization patterns and positive neighbor effect of shrubs on natural seedlings establishment found in this study during the first years support the use of shrubs as ecosystem engineers to increase heterogeneity in micro-environmental conditions on reclaimed mine sites, which improves late-successional Quercus species establishment. © 2015, Springer-Verlag Berlin Heidelberg

Hybridization and species delimitation of Symphonia (Clusiaceaea) in Madagascar

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