Evolution of the landscape of Madeira Island: long-term vegetation dynamics

The aim of this thesis was to evaluate historical change of the landscape of Madeira Island and to assess spatial and temporal vegetation dynamics. In current research diverse “retrospective techniques”, such as landscape repeat photography, dendrochronology, and research of historical records were used. These, combined with vegetation relevés, aimed to gather information about landscape change, disturbance history, and vegetation successional patterns. It was found that landscape change, throughout 125 years, was higher in the last five decades manly driven by farming abandonment, building growth and exotic vegetation coverage increase. Pristine vegetation was greatly destroyed since early settlement and by the end of the nineteenth century native vegetation was highly devastated due to recurrent antropogenic disturbances. These actions also helped to block plant succession and to modify floristical assemblages, affecting as well as species richness. In places with less hemeroby, although significant growth of vegetation of lower seral stages was detected, the vegetation of most mature stages headed towards unbalance between recovery and loss, being also very vulnerable to exotic species encroachment. Recovery by native vegetation also occurred in areas formerly occupied by exotic plants and agriculture but it was almost negligible. Vegetation recovery followed the successional model currently proposed, attesting the model itself. Yet, succession was slower than espected, due to lack of favourable conditions and to recurrent disturbances. Probable tempus of each seral stage was obtained by growth rates of woody taxa estimated through dendrochronology. The exotic trees which were the dominant trees in the past (Castanea sativa and Pinus pinaster) almost vanished. Eucalyptus globulus, the current main tree of the exotic forest is being replaced by other cover types as Acacia mearnsii. The latter, along with Arundo donax, Cytisus scoparius and Pittosporum undulatum are currently the exotic species with higher invasive behaviour. However, many other exotic species have also proved to be highly pervasive and came together with the ones referred above to prevent native vegetation regeneration, to diminish biological diversity, and to block early successional phases delaying native forest recovery.ARDITI; Rumos; QRE

Representation of diatom communities by fossil assemblages in Loch Fleet, Galloway, Scotland

Fossil assemblages of diatom valves from lake sediments are used as a record of former diatom communities. Past water quality, for example pH, can be inferred from the composition of these assemblages. However, the relationship between mixtures of diatom valves in lake sediment and the diatom communities from which they are formed is not necessarily a direct one. In order to test the representative quality of fossil assemblages, valve assemblages in recent sediment have been compared with the contemporary diatom flora of a lake. Loch Fleet, Galloway, Scotland was an acidified lake. Experimental liming of the lake catchment produced changes in water quality and a consistently higher pH has been maintained. The marked response of diatom species to changing water quality provided a means of tracing events from living communities to the fossil assemblage. Diatom periphyton and plankton were sampled during a 20 month period and in addition archived material was available. These samples were compared with fossil diatom assemblages from sediment cores and from sediment traps taken during the same period

Linking deep seabed structure to biodiversity: an exploration of seamounts and deeper reefs in the South and Western Indian Ocean

Environmental heterogeneity, understood as spatial or temporal variability in environmental conditions, influences biodiversity and ecosystem processes over multiple scales, including at the deep seabed. However, as a result of the inaccessibility of the ocean beyond conventional SCUBA depth (> 30 m), key knowledge gaps remain on the biotic and abiotic patterns that influence the occurrence and distribution of seabed-associated taxa, habitats and resulting ecological processes and ecosystem services. Although seabed and habitat mapping documents seabed environmental and habitat heterogeneity, very little research explicitly quantifies it to draw conclusions on its ecological consequences. To study the character and effect of environmental heterogeneity on biodiversity and marine ecological processes in the deep sea, this thesis explored the potential of combining existing seabed and habitat mapping practices with the theoretical framework and analytical techniques from land- and seascape ecology. This thesis first reviews seascape ecology and its potential to study the ecological implications of environmental heterogeneity at the deep seabed, and identifies theoretical focal areas for the application of tools and concepts from seascape ecology deeper than 30 m (Chapter 1: Introduction). The objectives of this thesis, based on these focal areas, can be divided in three main themes: 1) characterising spatial heterogeneity using spatial pattern metrics; 2) assessing the ecological relevance of spatial heterogeneity quantified using spatial pattern metrics; and 3) applying this knowledge to inform environmental management. Objectives are addressed through a set of case studies that provide the opportunity to explore the multi-scale relationship between seabed structure and ecology in habitats at seamounts (km-m scale, Chapter 2 and 3) and reefs found between 30 m-250 m on atoll slopes (m-cm scale, Chapter 4 and 5) in theWestern Indian Ocean. Case studies test specific ecological hypotheses using spatial pattern metrics quantifying seascape composition, configuration and terrain structure, which function as predictors for the occurrence and distribution of benthic assemblages and demersal fish. Chapter 2 combines habitat mapping and spatial pattern metrics from seascape ecology to quantitatively test for and compare differences in seascape composition and configuration between five seamounts on the Southwest Indian Ridge (SWIR). Results quantitatively demonstrate that seamounts are highly variable in morphology, even when part of the same geological feature. As heterogeneity in the relative proportion and spatial relationships of habitats may influence ecological functioning, habitat mappers and marine managers focusing on representational protection of seamounts could benefit from such spatially-explicit approaches to quantify seabed heterogeneity. Chapter 3 examines the influence of multi-scale seabed spatial heterogeneity on 15 commercially important fish families at three SWIR seamounts, focusing on patch affinity, patch complexity, patch size and seascape aggregation. Although strongly driven by site and depth, demersal fish respond to unique combinations of seascape composition, configuration and terrain structure depending on their family. Further, seascape composition and configuration (i.e. habitat size, shape and structural connectivity) had higher predictive power than terrain derivatives commonly used in developing proxies for deepwater fish biodiversity. These outcomes indicate the importance of incorporating spatial pattern metrics when identifying environmental predictors of fish distributions and suitable habitat in deep-sea environments. Chapter 4 tests whether multi-scale geomorphology can act as a reliable spatial proxy for deeper reef assemblage (30 m-250 m) distribution. It found that assemblage occurrence and distribution is determined by a combination of environmental parameters, explained by the functional characteristics of each assemblage. Depth and structural complexity were main predictors, and broad scale predictors (25 m) proved more informative than finer scale predictors (2 m). Findings addressed geographical gaps in our knowledge of the distribution of deeper reef habitats and generated insights into ecological relationships. Complex geomorphological structures, including terraces and paleoshorelines, supported particularly high densities of mesophotic benthic assemblages and could be considered priority habitats for management. Chapter 5 investigates the effect of fine-scale (cm-m) environmental heterogeneity on fish associated with mesophotic reefs (30 m-120 m). Spatial pattern metrics quantifying benthic composition, configuration and terrain structure were extracted from transect terrain models and orthomosaics produced with Structure-from-Motion (SfM) photogrammetry. In addition to known drivers (depth and geographic location), results show a combination of fine-scale seascape metrics of terrain structure, patch composition and patch configuration best explains mesophotic fish assemblage structure. Overall, sites with steep slopes and high terrain complexity hosted highest fish abundance and biomass. Across case studies, spatial pattern metrics allowed quantification and comparison of seascape structure and functioned as reliable predictors for the occurrence and distribution of benthic assemblages and demersal fish at deeper reefs and seamounts in the Western Indian Ocean. Overall, spatial pattern metrics facilitated a better understanding of biodiversity-environment relationships in heterogeneous environments, in some cases functioning as the main explanatory variable. This thesis therefore recommends their further application in deep sea ecology, monitoring and ecosystembased management and conservation, whilst accounting for the biological phenomenon under consideration and scale- and context dependency in survey and analysis

Fabricate 2020

Fabricate 2020 is the fourth title in the FABRICATE series on the theme of digital fabrication and published in conjunction with a triennial conference (London, April 2020). The book features cutting-edge built projects and work-in-progress from both academia and practice. It brings together pioneers in design and making from across the fields of architecture, construction, engineering, manufacturing, materials technology and computation. Fabricate 2020 includes 32 illustrated articles punctuated by four conversations between world-leading experts from design to engineering, discussing themes such as drawing-to-production, behavioural composites, robotic assembly, and digital craft

AI in Museums: Reflections, Perspectives and Applications

Artificial intelligence is becoming an increasingly important topic in the cultural sector. While museums have long focused on building digital object databases, the existing data can now become a field of application for machine learning, deep learning and foundation model approaches. This goes hand in hand with new artistic practices, curation tools, visitor analytics, chatbots, automatic translations and tailor-made text generation. With a decidedly interdisciplinary approach, the volume brings together a wide range of critical reflections, practical perspectives and concrete applications of artificial intelligence in museums, and provides an overview of the current state of the debate

Palaeoeology sedimentology and depositional environments of the middle lias of North Yorkshire.

PhDThe shallow marine Yorkshire Middle Lias (Lower Jurassic) sequence comprises two formations, the lowermost (Staithes Formation) consisting of interbedded bioturbated siltstones and thin sheet sandstones and the uppermost (cleveland Ironstone Formation) comprising bioturbated shales, siltstones and Minette-type oolitic ironstones. Two new subdivisions, the Penny Nab and Old Nab Members, are proposed for the Cleveland Ironstone Formation. Lithofacies distributions during Staithes Formation times reflected the gradual progradation, retreat and transgressive reworking of a barrier island complex. Sand was eroded from the barriers by powerful storm waves and entrained along narrow paths further out on the shelf by offshore flowing storm surge ebb currents. Temporal changes in these paths were mainly responsible for the vertical lithofacies transitions within the sequence. In early Cleveland Ironstone Formation times four phases of shoreline progradation were each terminated by transgression induced sedimentation breaks, leading to the deposition of four shale - silt stone - ironstone "punctuated aggradational cycles". During these breaks and throughout late Cleveland Ironstone Formation times there was a drastic reduction in terrigenous siliciclastic influx into the basin of deposition but concomitantly increased input of colloidal reduced iron compounds. Ironstones formed by nearshore flocculation and concentration of iron hydroxides and their reaction with detrital kaolinite (within the guts of benthic marine organisms) to form chamosite, which was subsequently incorporated into ooliths. Residual iron hydroxides were converted to siderite during early burial diagenesis. Both quantitative and qualitative analysis of the macrofauna and ichnofauna has led to the recognition of fourteen recurrent nonrandom "associations" of body and trace fossils. These represent the incompletely preserved, biased but in situ relics of Middle Lias benthic comunities. Their compositions and distributions were mainly controlled by substrate grain size and consistency, the availability of microsubstrates for attachment purposes, food availability and bottom water turbidity and dissolved oxygen content

Large-scale riverine biodiversity patterns and dam effects on Spanish rivers

Hydrological alteration caused by dams, changing climates, and land use-cover changes produce pervasive effects on freshwater ecosystems and undermine the delivery of essential ecosystem services. Riverine ecosystems are particularly vulnerable to these stressors, with alarming biodiversity loss rates. In this context, the primary goal of this PhD thesis is to explore spatial biodiversity patterns in Spanish rivers and how dams and reservoirs modify them. Using the taxonomy and traits of diatom, macroinvertebrate, and fish communities, we evaluated the role of key environmental gradients and spatial distances (i.e. dispersal-related processes) in structuring biological communities in near-pristine streams throughout Spain. In streams impacted by irrigation and hydropower dams in the north of the country, we investigated the ecological responses in mountain areas and in a control-impact design. The study's findings provide useful insights into the development of effective conservation efforts directed towards global change drivers and the different dams' operational schemes.La alteración hidrológica provocada por presas, el cambio climático y cambios en el uso del suelo producen efectos generalizados en los ecosistemas de agua dulce y ponen en riesgo servicios ecosistémicos esenciales. Los ecosistemas fluviales son especialmente vulnerables a estos factores de estrés, con tasas de pérdida de biodiversidad alarmantes. En este contexto, el objetivo principal de esta tesis doctoral es explorar los patrones espaciales de biodiversidad en los ríos españoles y cómo las presas y embalses los modifican. Utilizando taxonomía y rasgos de diatomeas, macroinvertebrados y peces, evaluamos el papel de los gradientes ambientales y las distancias espaciales (es decir, procesos relacionados con la dispersión) en la estructura de las comunidades biológicas en ríos prístinos de toda España. En ríos afectados por presas de regadío e hidroeléctricas en el norte del país, investigamos las respuestas ecológicas en zonas de montaña y en un diseño de control-impacto. Las conclusiones del estudio aportan una perspectiva útil para el desarrollo de estrategias de conservación eficaces dirigidos a los impulsores del cambio global y adaptados a los diferentes esquemas operativos de las presas.Finally, the accomplishment of this work has only been possible thanks to the Spanish Ministry for the Ecological Transition for providing the biological monitoring data and the European Union’s Horizon 2020 research and innovation programme, which funded the EuroFlow project under the Marie Skłodowska-Curie grant agreement No 765553

Estimation des capacités comportementales des larves de poissons et leurs implications pour la phase larvaire : un cas d'étude d'espèces démersales de Méditerranée Nord-Occidentale

Most coastal fish species have a bipartite life history, with a demersal phase as juvenile and adult and a pelagic larval phase. Dispersal is often limited to this pelagic phase, which is also the phase experiencing the highest mortality rates. Predicting the connectivity between populations remains difficult because not all processes determining larval fish survival and transport during the pelagic phase are understood. Besides the environmental conditions that may influence the journey of fish larvae in the open ocean, these tiny organisms possess high behavioural abilities (swimming, orientating, etc.) that have the potential to shape their dispersal. However, the vast majority of in situ observations of these behaviours have been conducted in tropical environments and very little data exists on temperate Perciformes fish larvae. In this dissertation, we aim to describe the ecology and behavioural abilities of fish larvae from the Mediterranean Sea, a temperate environment where they have never been studied.The first part of this dissertation describes the distribution of young fish larvae along an inshore-offshore transect crossing an hydrological front. We also describe their diel vertical migration and predatoravoidance behaviour. The high-frequency imaging techniques used to capture their distribution at miscroscale generated huge amount of data. It lead us to modify an automatic classification method to reduce the time required to processes these kind of data. The second part focuses on the settlement phase, when fish larvae come back to the coast at the end of their pelagic journey. To shed light on the factors influencing the settlement process, we monitored the supply of fish larvae to a coastal habitat, on a weekly basis for three years and at higher frequency over shorter periods of time. Additionally, we tested the in situ orientation abilities of the most abundant species, focusing on large scale orientation mechanisms. In the laboratory, we measured the swimming speeds of several species, including the ones tested for orientation. Then, we implemented these observed behaviours in a biophysical model to explore their combined influence on settlement rate. To finish, we discuss on how larval fish behaviour may influence survival throughout the pelagic larval phase and insist on the importance of considering behaviour to improve larval dispersal models.La majorité des espèces de poissons côtiers a un cycle de vie comprenant une phase juvénile et adulte démersale et une phase larvaire pélagique. Cette seconde phase représente l’unique opportunité de dispersion pour de nombreuses espèces mais est soumise à une forte mortalité. Aujourd’hui, il est toujours délicat de prédire la connectivité entre les populations car tous les processus influençant la survie et le transport des larves durant leur phase pélagique ne sont pas encore décrits. Les larves de poissons possèdent des capacités comportementales non-négligeables (de nage, d’orientation, etc.) qui pourraient leur permettre de contrôler leur dispersion au cours de leur épisode pélagique. Cependant, les observations in situ de ces comportements ont principalement été faites en milieu tropical. Elles sont nettement plus rares en milieu tempéré, notamment chez les poissons Perciformes. Dans cette thèse, nous cherchons à décrire l’écologie et les capacités comportementales des larves de poissons en Mer Méditerranée Nord-Occidentale, un milieu tempéré où elles n’ont pas encore été décrites.La première partie de cette thèse vise à décrire la distribution des jeunes stades larvaires le long d’un transect côte-large traversant un front hydrologique. Nous nous intéressons également à leurs comportements de migration nycthémérale et d’évitement des prédateurs. La méthode d’imagerie utilisée pour décrire leur distribution à microéchelle génèrant des quantités de données considérables, nous avons développé une méthode de classification automatique pour accélérer le traitement de ce type de données. La seconde partie se concentre sur la phase d’installation, c’est-à-dire lorsque les larves arrivent à la côte à la fin de leur phase pélagique. Nous avons suivi l’arrivée des larves à la côte afin de déterminer les périodes d’installation des différentes espèces ainsi que les facteurs influençant leur arrivée. Nous avons également testé in situ les capacités d’orientation des espèces les plus abondantes, en se focalisant sur les mécanismes d’orientation à large échelle. En laboratoire, nous avons mesuré les vitesses de nage de plusieurs espèces, incluant celles testées pour l’orientation. Nous avons ensuite implémenté ces comportements observés dans un modèle biophysique afin de tester leur l’influence combinée sur le taux d’installation. Pour finir, nous discutons de l’influence que peut avoir le comportement sur la survie des larves de poissons tout au long de la phase pélagique, ainsi que de l’importance de sa prise en compte dans les modèles de dispersion