88 research outputs found

    Enhancing beetle and spider communities in agricultural grasslands: the roles of seed addition and habitat management

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    Over three years, a replicated block design was used to investigate the effects of seed mixtures (grasses only; grasses and legumes; grasses, legumes and non-legume forbs), establishment techniques and long term management on beetle and spider communities of grassland swards. We quantified trophic links between phytophagous beetles and their host plants to assess the effect of these seed mixtures and management practices on food web structure. When managed under low intensity cutting regimes the most diverse seed mixture supported the highest biomass of beetles and spiders (c. 3.6 kg ha−1). Species richness of predatory beetles, phytophagous beetles and spiders were all increased by the sowing of legumes, although the addition of other forbs tended to result in at most modest further increases in invertebrate species richness. Analysis of food web structure suggests that the number of host plants utilised by beetles was greatest within the most diverse seed mixtures, but that this declined rapidly after the establishment year. We demonstrate that by sowing cheap and simple seed mixtures agriculturally improved grasslands can be managed to support increased diversity of spiders and beetles. While seed mixtures do not necessarily need to be of the highest diversity to achieve these benefits, the inclusion of legumes does appear to be crucial. The lower costs of intermediate diversity seed mixtures increase appeal to farmers, increasing the likely uptake of these methodologies in voluntary agri-environment schemes

    Lattice-switch Monte Carlo

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    We present a Monte Carlo method for the direct evaluation of the difference between the free energies of two crystal structures. The method is built on a lattice-switch transformation that maps a configuration of one structure onto a candidate configuration of the other by `switching' one set of lattice vectors for the other, while keeping the displacements with respect to the lattice sites constant. The sampling of the displacement configurations is biased, multicanonically, to favor paths leading to `gateway' arrangements for which the Monte Carlo switch to the candidate configuration will be accepted. The configurations of both structures can then be efficiently sampled in a single process, and the difference between their free energies evaluated from their measured probabilities. We explore and exploit the method in the context of extensive studies of systems of hard spheres. We show that the efficiency of the method is controlled by the extent to which the switch conserves correlated microstructure. We also show how, microscopically, the procedure works: the system finds gateway arrangements which fulfill the sampling bias intelligently. We establish, with high precision, the differences between the free energies of the two close packed structures (fcc and hcp) in both the constant density and the constant pressure ensembles.Comment: 34 pages, 9 figures, RevTeX. To appear in Phys. Rev.

    Historical, local and landscape factors determine the success of grassland restoration for arthropods

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    In Europe, extensively managed grasslands have undergone large-scale declines due to intensive agriculture and abandonment. Their restoration supports arthropod biodiversity within farming systems. We investigated limiting factors for arthropod establishment during grassland restoration across a chronosequence of 52 restoration sites established by either natural regenerating or direct seeding. Our study covered 363 arthropod species of 10 orders, including detritivores, herbivores, predators and pollinators. These were sampled using pitfall traps, suction sampling and transect walks. The similarity of plant communities on restoration sites to target species rich grasslands was positively correlated with the similarity of the arthropod communities to these same grasslands. There was evidence that restoration sites located in landscapes suffering from historic large-scale loss of species rich grassland (1930–2015) had lower success in replicating the composition of arthropod communities and supported the lowest levels of species richness. The age of the restoration site was a predictor of restoration success for some trophic levels. For example, predator species richness was greatest in the oldest restoration sites. However, this was only the case were sites were either of large size or located in landscapes with the lowest historic loss of species rich grassland. Impacts of within site management also affected arthropod communities. The annual frequency of cutting negatively affected detritivores species richness, and selected against traits including herbivore monophagy. Overall arthropod species richness was positively correlated with sward height. These results emphasise the relative importance of the success with which the floral community is replicated, as well as landscape and management factors, during grassland restoration. This has implications for future agri-environmental schemes. In particular, achieving high quality within-site management that maximises establishment of the plant communities needs to be the initial focus of any restoration program

    Problematising parent–professional partnerships in education

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    The value of, and need for, parent–professional partnerships is an unchallenged mantra within policy relating to ‘special educational needs’. In spite of this, partnerships continue to be experienced as problematic by both parents and professionals. This paper brings together the different perspectives of two disability researchers: one a parent of a disabled child while the other was a teacher for 20 years of children with the label autism. The paper deconstructs the concept of partnership and then, drawing on the expertise of parents, suggests how enabling and empowering parent–professional relationships might be achieved

    Problematising parent–professional partnerships in education

    Get PDF
    The value of, and need for, parent–professional partnerships is an unchallenged mantra within policy relating to ‘special educational needs’. In spite of this, partnerships continue to be experienced as problematic by both parents and professionals. This paper brings together the different perspectives of two disability researchers: one a parent of a disabled child while the other was a teacher for 20 years of children with the label autism. The paper deconstructs the concept of partnership and then, drawing on the expertise of parents, suggests how enabling and empowering parent–professional relationships might be achieved

    Country-specific effects of neonicotinoid pesticides on honey bees and wild bees

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    Neonicotinoid seed dressings have caused concern world-wide. We use large field experiments to assess the effects of neonicotinoid-treated crops on three bee species across three countries (Hungary, Germany, and the United Kingdom). Winter-sown oilseed rape was grown commercially with either seed coatings containing neonicotinoids (clothianidin or thiamethoxam) or no seed treatment (control). For honey bees, we found both negative (Hungary and United Kingdom) and positive (Germany) effects during crop flowering. In Hungary, negative effects on honey bees (associated with clothianidin) persisted over winter and resulted in smaller colonies in the following spring (24% declines). In wild bees (Bombus terrestris and Osmia bicornis), reproduction was negatively correlated with neonicotinoid residues. These findings point to neonicotinoids causing a reduced capacity of bee species to establish new populations in the year following exposure

    Characterization factors to assess land use impacts on pollinator abundance in life cycle assessment

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    While wild pollinators play a key role in global food production, their assessment is currently missing from the most commonly used environmental impact assessment method, Life Cycle Assessment (LCA). This is mainly due to constraints in data availability and compatibility with LCA inventories. To target this gap, relative pollinator abundance estimates were obtained with the use of a Delphi assessment, during which 25 experts, covering 16 nationalities and 45 countries of expertise, provided scores for low, typical, and high expected abundance associated with 24 land use categories. Based on these estimates, this study presents a set of globally generic characterization factors (CFs) that allows translating land use into relative impacts to wild pollinator abundance. The associated uncertainty of the CFs is presented along with an illustrative case to demonstrate the applicability in LCA studies. The CFs based on estimates that reached consensus during the Delphi assessment are recommended as readily applicable and allow key differences among land use types to be distinguished. The resulting CFs are proposed as the first step for incorporating pollinator impacts in LCA studies, exemplifying the use of expert elicitation methods as a useful tool to fill data gaps that constrain the characterization of key environmental impacts.Industrial EcologyEnvironmental Biolog

    Community-led comparative genomic and phenotypic analysis of the aquaculture pathogen Pseudomonas baetica a390T sequenced by Ion semiconductor and Nanopore technologies

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    Pseudomonas baetica strain a390T is the type strain of this recently described species and here we present its high-contiguity draft genome. To celebrate the 16th International Conference on Pseudomonas, the genome of P. baetica strain a390T was sequenced using a unique combination of Ion Torrent semiconductor and Oxford Nanopore methods as part of a collaborative community-led project. The use of high-quality Ion Torrent sequences with long Nanopore reads gave rapid, high-contiguity and -quality, 16-contig genome sequence. Whole genome phylogenetic analysis places P. baetica within the P. koreensis Glade of the P. fluorescens group. Comparison of the main genomic features of P. baetica with a variety of other Pseudomonas spp. suggests that it is a highly adaptable organism, typical of the genus. This strain was originally isolated from the liver of a diseased wedge sole fish, and genotypic and phenotypic analyses show that it is tolerant to osmotic stress and to oxytetracycline.Microbial Biotechnolog
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