Magnetic Field Generation in Stars

Enormous progress has been made on observing stellar magnetism in stars from the main sequence through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which remains one of the main unanswered questions in astrophysics. In this chapter we review recent work in this area of research. In particular, we look at the fossil field hypothesis which links magnetism in compact stars to magnetism in main sequence and pre-main sequence stars and we consider why its feasibility has now been questioned particularly in the context of highly magnetic white dwarfs. We also review the fossil versus dynamo debate in the context of neutron stars and the roles played by key physical processes such as buoyancy, helicity, and superfluid turbulence,in the generation and stability of neutron star fields. Independent information on the internal magnetic field of neutron stars will come from future gravitational wave detections. Thus we maybe at the dawn of a new era of exciting discoveries in compact star magnetism driven by the opening of a new, non-electromagnetic observational window. We also review recent advances in the theory and computation of magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo theory. These advances offer insight into the action of stellar dynamos as well as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field generation in stars to appear in Space Science Reviews, Springe

Looking forward through the past: identification of 50 priority research questions in palaeoecology

1. Priority question exercises are becoming an increasingly common tool to frame future agendas in conservation and ecological science. They are an effective way to identify research foci that advance the field and that also have high policy and conservation relevance. 2. To date, there has been no coherent synthesis of key questions and priority research areas for palaeoecology, which combines biological, geochemical and molecular techniques in order to reconstruct past ecological and environmental systems on time-scales from decades to millions of years. 3. We adapted a well-established methodology to identify 50 priority research questions in palaeoecology. Using a set of criteria designed to identify realistic and achievable research goals, we selected questions from a pool submitted by the international palaeoecology research community and relevant policy practitioners. 4. The integration of online participation, both before and during the workshop, increased international engagement in question selection. 5. The questions selected are structured around six themes: human–environment interactions in the Anthropocene; biodiversity, conservation and novel ecosystems; biodiversity over long time-scales; ecosystem processes and biogeochemical cycling; comparing, combining and synthesizing information from multiple records; and new developments in palaeoecology. 6. Future opportunities in palaeoecology are related to improved incorporation of uncertainty into reconstructions, an enhanced understanding of ecological and evolutionary dynamics and processes and the continued application of long-term data for better-informed landscape management

Interpretation and modelling : geology, to support the development of an Integrated Site Descriptive Model

Taking into account the experiences of sister organisations and best practice in other sectors such as oil and gas it is anticipated that the characterisation of the site will best be undertaken by the development and progressive updating of a single integrated Site Descriptive Model, i.e. a model describing the geometry, properties of the bedrock and water, and the associated interacting processes and mechanisms, which will be used to address the information requirements of all the end users (NDA 2010). Such an approach will ensure that • The understanding of the different aspects of the geosphere such as the geology, hydrogeology and hydrochemistry is developed in a consistent manner; and • The different end users base their design and assessments on the same understanding and evidence base. There are several elements to the preparation of a Site Descriptive Model, including: • Definition of the volume of ground that needs to be included in the model; • Subdivision of the model into geometric units so as to permit the description of spatial variability in a meaningful manner; and • Assignment of parameters (values and/or statistical distributions) to the defined geometric units. It is anticipated that, in a similar way to the approach adopted by SKB and Posiva, the integrated Site Descriptive Model will be divided into parts comprising clearly defined disciplines which may form either chapters or discipline-based models. The discipline-based models that are likely to be developed for UK sites comprise the following: • Geology; • Hydrogeology; • Hydrochemistry; • Geotechnical; • Transport properties; • Thermal properties; and • Biosphere. The Site Descriptive Model will provide the understanding of the characteristics of the site, sufficient to allow further qualitative and quantitative modelling to be undertaken as part of the development of the Environmental Safety Case

Developing an indicator of the abundance, extent and impact of invasive non-native species. Final report

This report describes an indicator of the abundance, extent and impact of invasive non-native species in Great Britain. The main ideas and options for the abundance indicator and for the impact indicator are considered. A third type of indicator, the annual rate of establishment of new non-native species, is outlined, with provisional data presented only for England. Most of the options for the abundance indicator do not in fact measure abundance, but use either frequency in samples or frequency in recording scheme data as a substitute. An exception is the Breeding Bird Survey, for which numbers of individuals are counted. Several well-recorded groups of organisms have no non-native species (e.g. butterflies and lichens) or exceedingly few non-native species (macro-moths). Datasets selected for the abundance indicator were the Breeding Bird Survey (birds and mammals), Countryside Survey (vascular plants), British Bryological Society data (bryophytes) and Marine Biological Society data (marine organisms). From samples of records in each species group, the non-native component was calculated as proportion of all species sampled. This provided a temporal trend in non-native proportions, which were calculated separately for England, Scotland and Wales. The GB trend was derived by combining the trends for each component country, weighted by the area of each. Finally, the overall trend was calculated as a weighted geometric mean of trends for each species group, converted to an index by dividing by a constant to start at 1 in the baseline year 1990. The weights applied were birds 20%, mammals 20%, vascular plants 30%, bryophytes 10% and marine organisms 20%. There were no suitable datasets from the freshwater environment. No direct measure of impact could feasibly be calculated for all invasive species in Great Britain. As a substitute, an indicator based on the extent of occupation by invasive species was adopted. The methodology for the indicator was based on a scheme developed by the Belgian Forum on Invasive Species. First, a list of the most invasive species was compiled, using a simplified environmental impact assessment protocol to assign species to threat categories. Then the extent of each invasive species was scored for 1960, 1970, 1980, 1990, 2000 and 2007, on a 5-point scale ranging from 0 (absent) to 4 (present in more than half the territory). Extent scores were added to obtain the indicator. Over the period 1990-2007, the mean indexed proportion of records of non-native species in samples of birds, mammals, plants and marine life rose by 23%. Except for mammals, the absolute proportion was still only about 1% of the total. The assessment protocol assigned 49 species in Great Britain to the highest threat category. There were 3 marine plants, 16 marine animals, 4 freshwater plants, 8 freshwater animals, 8 terrestrial plants and 10 terrestrial animals. Over the period 1990-2007, the summed extent scores of these invasive non-native species rose by 40%. The increase of invasive species was particularly large in the freshwater and marine environments. Although non-native species are a potential threat, they are still only a small proportion of the animals and plants to be found in most of the land area and coasts of Great Britain. Vertebrates stand out as the most invasive group. For all groups of organisms reported here, England was the country most affected by non-native species. Scotland was the least affected. Wales was intermediate. In 2008, values of the impact indicator for the three countries were respectively 135, 73 and 95. Most species groups showed a trend over time towards an increasingly non-native biota. If the indicator is to be developed further, the main priority is to include freshwater species in the abundance component. Because the list of invasive species depends on expert judgement, it needs to be reviewed and if necessary updated at regular intervals. Further analytical work is desirable, to improve the signal obtained from recording scheme data

The Waterways Bird Survey An evaluation and appraisal of its future role

SIGLEAvailable from British Library Document Supply Centre-DSC:7218.47425(22) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A comparison of breeding bird numbers along canals with and without a close season for fishing

SIGLEAvailable from British Library Document Supply Centre-DSC:7218.47425(W193) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A comparison of breeding bird numbers along canals with and without a close season for fishing

A report to the Environment AgencySIGLEAvailable from British Library Document Supply Centre-DSC:2354.730(211) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A review of large-scale generic population monitoring schemes in Europe

SIGLEAvailable from British Library Document Supply Centre-DSC:2354.730(165) / BLDSC - British Library Document Supply Centre2. ed.GBUnited Kingdo

A field validation of some Common Birds Census techniques

2.50Available from British Library Document Supply Centre- DSC:3490.375F(CST--498)(microfiche) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo