275 research outputs found

    Functionality of wet grasslands as green infrastructure

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    Habitat loss is a global issue that affects land cover patterns, ecological processes and the distribution and abundance of species. As a result, many conservation approaches have appeared, such as the European Union’s green infrastructure (GI) policy and UNESCO’s Biosphere Reserve (BR) concept. Both are being applied in southern Sweden’s Kristianstad Vattenrike Biosphere Reserve (KVBR). Despite concentrated conservation efforts at a local scale to conserve biodiversity, focal grasslands and waders have declined. This calls for the assessment of outputs within the KVBR in terms of both knowledge production and its dissemination, as well as the consequences of management on the ground (Paper I). Focusing on supporting the KVBRs’ work and wader conservation in general, this thesis studied how anthropogenic factors affect the land cover patterns and processes of wet grasslands for waders. Over the past two centuries land use and land cover change have reduced the KVBR’s area of functional grassland habitat by >98% (Paper II). Whilst loss and degradation of wet grassland habitats is considered a primary reason of wader decline in Europe, predator–prey relationships have been proposed as a secondary reason. Using several wet grassland landscapes across Northern Europe, predator-prey relationships were explored (Paper III, IV & V). Firstly, the distribution and abundance of avian predators is determined by resource diversity and anthropogenic factors of a landscape at multiple spatial scales. Secondly, predator abundance and predation pressure were positively correlated, and linked to different wet grassland developmental stages in Northern Europe. Thus, based on the studies contained in this thesis, changes to both land cover patterns and ecological processes play a vital role for the maintenance of wet grasslands as functional GI. Finally, the multiple landscape case study approach employed in this thesis is a novel macroecological tool that encourages knowledge production and learning for functional GI

    A combinatorial formula for homogeneous moments

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    We establish a combinatorial formula for homogeneous moments and give some examples where it can be put to use. An application to the statistical mechanics of interacting gauged vortices is discussed.Comment: 8 pages, LaTe

    Effects of Forestry Intensification and Conservation on Green Infrastructures: A Spatio-Temporal Evaluation in Sweden

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    There is a rivalry between policies on intensification of forest management to meet the demands of a growing bioeconomy, and policies on green infrastructure functionality. Evaluation of the net effects of different policy instruments on real-world outcomes is crucial. First, we present data on final felling rates in wood production landscapes and stand age distribution dynamic in two case study regions, and changes in dead wood amounts in Sweden. Second, the growth of formally protected areas was compiled and changes in functional connectivity analysed in these regions, and the development of dead wood and green tree retention in Sweden was described. The case studies were the counties Dalarna and Jamtland (77,000 km(2)) representing an expanding frontier of boreal forest transformation. In the wood production landscape, official final felling rates averaged 0.84%/year, extending the regional timber frontier. The amount of forest <60 years old increased from 27-34% in 1955 to 60-65% in 2017. The amounts of dead wood, a key forest naturalness indicator, declined from 1994 to 2016 in north Sweden, and increased in the south, albeit both at levels far below evidence-based biodiversity targets. Formal forest protection grew rapidly in the two counties from 1968 to 2020 but reached only 4% of productive forests. From 2000 to 2019, habitat network functionality for old Scots pine declined by 15-41%, and Norway spruce by 15-88%. There were mixed trends for dead wood and tree retention at the stand scale. The net result of the continued transformation of near-natural forest remnants and conservation efforts was negative at the regional and landscape levels, but partly positive at the stand scale. However, at all three scales, habitat amounts were far below critical thresholds for the maintenance of viable populations of species, let alone ecological integrity. Collaboration among stakeholder categories should reject opinionated narratives, and instead rely on evidence-based knowledge about green infrastructure pressures, responses, and states

    Macroecology of North European Wet Grassland Landscapes: Habitat Quality, Waders, Avian Predators and Nest Predation

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    Wet grassland degradation is a global issue that involves both altered land cover patterns and ecological processes, which affect the distribution and abundance of species. The sharp decline in European wader bird (Charadrii) populations is a good example. The aim of this study is to test the hypothesis that the anthropogenic developmental stage of wet grassland habitats and landscapes drives avian nest predator abundance, and thus the predation pressure on nests, which is a major cause of wader bird declines. Using a macroecological approach we selected six wet grassland landscapes representing a gradient in both grassland habitat development and breeding wader population status in four European countries (Belarus, Iceland, Lithuania and Sweden). We (1) mapped wader and avian predator assemblages in multiple wet grassland patches in each landscape, (2) used artificial nests to estimate the relative rate of egg predation, and (3) analyzed relationships between nest predation pressure, corvid nest predators versus raptors, nest loss and the stage of wet grassland habitat and landscape development. We found (1) inverse relationships between the abundance of corvids and waders, as well as between wet grassland developmental stage and waders, and (2) a positive correlation between the probability of nest loss and the density of corvid birds. In conclusion, we found a clear macroecological pattern linking habitat quality, wader populations, nest predators and nest predation. These linkages stress the importance of including nest predation as a factor limiting wader bird populations, and that corvid control or management may be useful management tools

    Challenges and Solutions for Forest Biodiversity Conservation in Sweden: Assessment of Policy, Implementation Outputs, and Consequences

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    Swedish policies aim at conserving biological production, biodiversity, cultural heritage and recreational assets. This requires compositionally and structurally functional networks of representative habitats, the processes that maintain them, and resilient ecosystems. The term green infrastructure (GI) captures this. We review (1) policy concerning forest biodiversity conservation from the 1990s; (2) the implementation outputs, including the formulation of short-term and evidence-based long-term goals for protected areas, education, and the development of hierarchical spatial planning; (3) the consequences in terms of formally protected and voluntarily set-aside forest stands, as well as conservation management and habitat restoration. We assess the successes and failures regarding policy, outputs and consequences, discuss challenges to be addressed, and suggest solutions. Policies capture evidence-based knowledge about biodiversity, and evidence-based conservation planning as an output. However, the desired consequences are not met on the ground. Thus, the amount of formally protected and voluntary set-aside forests are presently too low, and have limited quality and poor functional connectivity. GI functionality is even declining because of forestry intensification, and insufficient conservation. Challenges include limited collaborative learning among forest and conservation planners, poor funding to conserve forest habitats with sufficient size, quality and connectivity, and national politics that ignores evidence-based knowledge. As solutions, we highlight the need for diversification of forest management systems with a landscape perspective that matches forest owner objectives and regional social-ecological contexts. This requires integrative approaches to knowledge production, learning and spatial planning

    Prohibiting public drinking in an urban area: determining the impacts on police, the community and marginalised groups

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    With public drinking laws proliferating across urban areas over the past 15 years, this project evaluated the implementation of these laws, their effectiveness, and their impact on a range of target groups including police, residents, traders, local health and welfare workers, and potentially marginalised groups. Overview Public drinking laws have proliferated across urban areas over the past 15 years; however, there have been very few evaluations of their impacts and effectiveness. The purpose of this project was to evaluate public drinking laws across three diverse inner-urban local government areas (LGAs) of Melbourne: the Cities of Yarra, Darebin and Maribyrnong. The objectives of this project were to evaluate the implementation of public drinking laws, the effectiveness of these laws and the impact of these laws on a range of target groups including police, residents, traders, local health and welfare workers, and potentially marginalised groups. The evaluation produced equivocal findings in relation to whether public drinking laws reduced congregations of drinkers (with differing findings across municipalities) and there was no evidence that these laws reduced alcohol-related crime or harm. However, public drinking laws do make residents feel safer and improve the amenity of an area from the perspective of residents and traders. The evaluation found that public drinking laws often result in negative impacts to marginalised individuals and this requires more consideration in the implementation and enforcement of these laws. It is important that public drinking laws are carefully considered, implemented and enforced (with local council officers and police liaising collaboratively to respond to the needs of the individual community) and are coupled with community-specific social inclusion strategies

    On Eigenvalue Decompactification in QCD1+1_{1+1}

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    The question whether it is necessary to decompactify the gauge eigenvalue degrees of freedom in QCD1+1_{1+1} is addressed. A careful consideration of the dynamics governing these degrees of freedom leads to the conclusion that eigenvalue decompactification is not necessary due to the curvature on the space of eigenvalues.Comment: 4 revtex pages; replaced version contains some additional footnotes and a changed final comment on the path integral pictur

    A note on the (1, 1,..., 1) monopole metric

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    Recently K. Lee, E.J. Weinberg and P. Yi in CU-TP-739, hep-th/9602167, calculated the asymptotic metric on the moduli space of (1, 1, ..., 1) BPS monopoles and conjectured that it was globally exact. I lend support to this conjecture by showing that the metric on the corresponding space of Nahm data is the same as the metric they calculate.Comment: 12 pages, latex, no figures, uses amsmath, amsthm, amsfont

    Decompactification of space or time in large N QCD_2

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    QCD_2 with fundamental quarks on a cylinder is solved to leading order in the 1/N expansion, including the zero mode gluons. As a result of the non-perturbative dynamics of these gauge degrees of freedom, the compact space-time direction gets effectively decompactified. In a thermodynamic interpretation, this implies that there is no pressure of order N and that the chiral condensate of order N is temperature independent. These findings are consistent with confinement of quarks, rule out both chiral and deconfining phase transitions in the finite temperature 't Hooft model, and help to resolve some controversial issues in the literatureComment: Latex2e, 8 pages, no figur
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