Pollen analysis and the vegetational history of Barra and South Uist in the Outer Hebrides, Scotland.

This study examines contemporary vegetation, pollen taphonomy and Holocene vegetation history across east-west trending environmental transects in the southern Outer Hebridean islands of South Uist and Barra. The pollen depositionalc haracteristicso f sixteenp lant communities are described and modern pollen deposition is found to reflect the distribution of major vegetation types on the islands. The history of Holocene vegetation is investigated at a number of sites which include exposed west coast inter-tidal peat deposits, wooded loch islands and pre-peat soils associated with archaeological features. These studies indicate that Holocene vegetation development followed a pattern typical for the region at similar latitudes. The early post-glacial vegetation mosaic of Empetrum heath, herb-rich grassland and dwarf shrub communities was progressivly altered by the subsequent establishment of predominantly deciduous woodlands. The pollen diagrams record an ordered sequence of tree migration to the islands in which Betula then Corylus were the first colonists followed later by Ulmus, Quercus, Pinus Alnus and Fraxinus. The scales of analysis employed in the study indicate that very local' pollen deposition is a characteristic of the islands' micro-fossil record - a feature which could be exploited in further archaeologically related studies. Woodland appears to have persisted in sheltered locations until c. 5,000 B. P. A gradual reduction of woodland from c. 5,000 B. P. was accompanied by an expansion of the herb-rich grassland and blanket bog communitiues which had been present on the islands from the early Holocene After c 4,000 B.P .w oodland decline accelerateda nd the grasslanda nd blanket peat communities increased to attain their present dominance in the islands vegetation. The vegetation changes recorded in the pollen diagrams are attributed to a combination of factors changing environmental conditions - such as the pedological effects of Holocene climatic conditions, sea level rise and human impacts. There is no archaeological evidence for mesolithic occupation of the islands, however at a point in the 'early' Holocene a brief episode of fluctuating woodland disturbance, charcoal and 'cereal type' pollen is noted at one east coast site, Loch Hellisdale. This data contributes to an increasing body of information which suggests some mesolithic presence along the eastern coast of South Uist

A tale of struggles: an evaluation framework for transitioning from individually usable to community-useful online deliberation tools

In this paper, we discuss the importance of providing socio-technical support for technology-mediated public interest debates and outline the principles that need to be considered to ensure healthy and fruitful deliberation in online discussion processes. We highlight the challenge of transitioning from individually usable only to community-useful online deliberation tools and we propose a 4-layer evaluation framework for online deliberation technologies that take into consideration usability, discussion quality, debate quality, and societal context, under the prism of participants’ sensemaking. We present a new online deliberation tool (BCause), enhanced with computational aids for sensemaking support that conforms with our evaluation framework guidelines. We also present the hurdles encountered in two use case applications of BCause and reflect on the real-world challenges of deploying a novel deliberation tool within real communities

Next generation ice core technology reveals true minimum natural levels of lead (Pb) in the atmosphere: insights from the Black Death

Current policies to reduce lead pollution in the air are based on the assumption that pre-industrial levels of lead in the air were negligible, safe or non-existent. This trans-disciplinary article shows that this is not the case, using ‘next-generation’ laser technology in climate science, in combination with detailed historical and archaeological records in as many as 7 languages, from all over Europe. We show that lead levels in the air have been elevated for the past 2000 years, except for a single 4-year period. This 4-year period corresponds with the largest known pandemic ever to ravage western Europe (the Black Death), resulting in a 40-50% reduction in population. This unprecedented historic population collapse was accompanied by dramatic economic collapse that halted lead mining and smelting, and related emissions in the air. This trans-disciplinary study is a collaboration led by Harvard University and the Climate Change Institute at the University of Maine, and researchers from the University of Heidelberg (Germany) and the University of Nottingham (UK). It uses next-generation technology and expertise in history, climate science, archaeology and toxicology, brought to bear in a highly detailed contribution to planetary health, with crucial implications for public health and environmental policy, and the history of human exposure to lead

Spatial variation of wetland woods in the latitudinal transition to arid regions: a multiscale approach

In order to investigate the occurrence of wetland woods in the latitudinal transition to arid regions in south-western Europe, we studied species patterns (richness and abundance), examined floristic differences between woods along the latitudinal gradient, and determined the relative influence of the underlying environmental drivers of plant variation at various scales

Networking expertise: Discursive coalitions and collaborative networks of experts in a public creationism controversy in the UK

Experts do play a particular role in public socio-scientific debates, even more so if they form heterogeneous coalition with other actors and experts. A case study about a public science education controversy surrounding the teaching of evolution/creationism in the UK press is used to investigate in detail how connections and coalitions between experts and other actors involved in the controversy emerged and played out. The research focuses on the question of what role collaborative and other networks of experts played in terms of influence, visibility, credibility, consensus and weight of argument. Issues that are considered in the research are the status of the members of the coalitions forming during the debate and how it is displayed in media representations and letters and petitions, and also how these networks and coalitions of experts perform in relation to each other

The European Modern Pollen Database (EMPD) project

Modern pollen samples provide an invaluable research tool for helping to interpret the quaternary fossil pollen record, allowing investigation of the relationship between pollen as the proxy and the environmental parameters such as vegetation, land-use, and climate that the pollen proxy represents. The European Modern Pollen Database (EMPD) is a new initiative within the European Pollen Database (EPD) to establish a publicly accessible repository of modern (surface sample) pollen data. This new database will complement the EPD, which at present holds only fossil sedimentary pollen data. The EMPD is freely available online to the scientific community and currently has information on almost 5,000 pollen samples from throughout the Euro-Siberian and Mediterranean regions, contributed by over 40 individuals and research groups. Here we describe how the EMPD was constructed, the various tables and their fields, problems and errors, quality controls, and continuing efforts to improve the available dat