250 research outputs found

    What are the costs and benefits of using aerial photography to survey habitats in 1km squares?

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    Undertaking a field survey, such as the Countryside Survey (Carey et al., 2008) or the Welsh Glastir Monitoring and Evaluation Programme (GMEP) (Emmett and GMEP team, 2014), is a relatively expensive and time consuming way of collecting habitat data in comparison with remotely sensed techniques. In order to assess the information gained from a field survey in relation to the information that can be gained from aerial photography, a short project has been undertaken with the following objectives: • To measure the time taken to survey a 1km square using aerial photography (for a range of different and UK representative landscape types) • To measure the accuracy and level of detail of data derived using this method relative to data collected using field survey • To provide an idea of time costs associated with each of the methods • To determine the extent to which Priority Habitats can be assessed using remotely sensed methods in addition to Broad Habitats

    Is it time for a socio-ecological revolution in agriculture?

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    Sustainable intensification is touted as the future for agricultural land management in a world demanding greater food production. Agricultural practices remain primarily driven by the ‘intensification’ and not the ‘sustainable’ agenda. To turn this around requires clear evidence from ecologists about the nature of farming systems, the fundamental underpinning role of natural resources and ecological processes within them and the provision of feasible alternatives. Alternative ecologically based farming systems must reflect current wider food systems and the actors engaged in them with ecologists playing a key role in advocating change; from international global agreements which force political change, through changes in focus for agri-businesses, to decision-making by individual land owners

    Changes in the frequency of common plant species across linear features in Wales from 1990 to 2016: implications for potential delivery of ecosystem services

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    In 2016, 21 1km squares recorded in Wales as part of the Countryside Survey of Great Britain were revisited. One hundred and thirty seven quadrats alongside linear features that had all been recorded in the same place in 1990, 1998 and 2007 were re-found and the plant species compositions recorded. Changes in individual species frequency were analysed and the results summarised by a number of ecosystem services and one disservice whose delivery are linked to functionally important species being present. Results indicated a continuation of a trend toward increased shading and woody cover seen between the first Countryside Survey in 1978 and the last in 2007. Most species showed no significant change in frequency suggesting that the significant directional trend seems only to have impacted a subset of the species present. A greater sample size would be required to capture impacts on a larger number of species including a wider range of Common Standards Monitoring (CSM) positive indicator species that may find refuge on the linear network in lowland Wales. Having grouped species by the ecosystem services they help deliver, we found that injurious weeds (an ecosystem disservice to food production) either declined or remained stable, a greater number of butterfly larval food plants decreased than increased and there was a net decline in potential nectar yield. Consistent with the successional trend, increasing species in these service-providing groups tended to be tall or shade-tolerant herbs and tree species. Decreasing species tended to be short, shade-intolerant forbs

    Does nature conservation enhance ecosystem services delivery?

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    Whilst a number of studies have examined the effects of biodiversity conservation on the delivery of ecosystems, they have been often limited by the scope of the ecosystem services (ES) assessed and often suffer from confounding spatial issues. This paper examines the impacts of nature conservation (designation) on the delivery of a full suite of ES across nine case-studies in the UK, using expert opinion. The case-studies covered a range of habitats and explore the delivery of ES from a ‘protected site’ and a comparable ‘non-protected’ site. By conducting pair-wise comparisons between comparable sites our study is one of the first to attempt to mitigate confounding cause and effect factors in relation to spatial context in correlative studies. Protected sites delivered higher levels of ecosystem services than nonprotected sites, with the main differences being in the cultural and regulating ecosystem services. Against expectations, there was no consistent negative impact of protection on provisioning services across the case-studies. Whilst the analysis demonstrated general patterns and differences in ecosystem delivery between protected and non-protected sites, the individual responses in each case-study highlights the importance of the social, biophysical, economic and temporal context of individual protected areas and the associated management

    Identifying effective approaches for monitoring national natural capital for policy use

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    In order to effectively manage natural resources at national scales national decision makers require data on the natural capital which supports the delivery of ecosystem services (ES). Key data sources used for the provision of national natural capital metrics include Satellite Remote Sensing (SRS), which provides information on land cover at an increasing range of resolutions, and field survey, which can provide very high resolution data on ecosystem components, but is constrained in its potential coverage by resource requirements. Here we combine spatially representative field data from a historic national survey of Great Britain (Countryside Survey (CS)) with concurrent low resolution SRS data land cover map within modelling frameworks to produce national natural capital metrics. We present three examples of natural capital metrics; top soil carbon, headwater stream quality and nectar species plant richness which show how highly resolved, but spatially representative field data can be used to significantly enhance the potential of low resolution SRS land cover data for providing national spatial data on natural capital metrics which have been linked to ecosystem services (ES). We discuss the role of such metrics in evaluations of ecosystem service provision and areas of further development to improve their utility for stakeholders

    Modeling the Subsurface Structure of Sunspots

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    While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There are two main hypotheses for the subsurface structure of sunspots: the monolithic model and the cluster model. Local helioseismology is the only means by which we can investigate subphotospheric structure. However, as current linear inversion techniques do not yet allow helioseismology to probe the internal structure with sufficient confidence to distinguish between the monolith and cluster models, the development of physically realistic sunspot models are a priority for helioseismologists. This is because they are not only important indicators of the variety of physical effects that may influence helioseismic inferences in active regions, but they also enable detailed assessments of the validity of helioseismic interpretations through numerical forward modeling. In this paper, we provide a critical review of the existing sunspot models and an overview of numerical methods employed to model wave propagation through model sunspots. We then carry out an helioseismic analysis of the sunspot in Active Region 9787 and address the serious inconsistencies uncovered by \citeauthor{gizonetal2009}~(\citeyear{gizonetal2009,gizonetal2009a}). We find that this sunspot is most probably associated with a shallow, positive wave-speed perturbation (unlike the traditional two-layer model) and that travel-time measurements are consistent with a horizontal outflow in the surrounding moat.Comment: 73 pages, 19 figures, accepted by Solar Physic

    Spectral Line Selection for HMI: A Comparison of Fe I 6173 and Ni I 6768

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    We present a study of two spectral lines, Fe I 6173 Angstroms and Ni I 6768 Angstroms, that were candidates to be used in the Helioseismic and Magnetic Imager (HMI) for observing Doppler velocity and the vector magnetic field. The line profiles were studied using the Mt. Wilson Observatory, the Advanced Stokes Polarimeter and the Kitt Peak McMath telescope and one meter Fourier transform spectrometer atlas. Both Fe I and Ni I profiles have clean continua and no blends that threaten instrument performance. The Fe I line is 2% deeper, 15% narrower and has a 6% smaller equivalent width than the Ni I line. The potential of each spectral line to recover pre-assigned solar conditions is tested using a least-squares minimization technique to fit Milne-Eddington models to tens of thousands of line profiles that have been sampled at five spectral positions across the line. Overall, the Fe I line has a better performance than the Ni I line for vector magnetic field retrieval. We selected the Fe I spectral line for use in HMI due to its better performance for magnetic diagnostics while not sacrificing velocity information

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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