Comment on: “Peatland carbon stocks and burn history: Blanket bog peat core evidence highlights charcoal impacts on peat physical properties and long-term carbon storage”, by A. Heinemeyer, Q. Asena, W.L. Burn and A.L. Jones (Geo: Geography and Environment. 2018; e00063)

A recent paper by Heinemeyer et al. (2018) in this journal has suggested that the use of prescribed fire may enhance carbon accumulation in UK upland blanket bogs. We challenge this finding based on a number of concerns with the original manuscript including the lack of an unburned control, insufficient replication, unrecognised potential confounding factors, and potentially large inaccuracies in the core dating approach used to calculate carbon accumulation rates. We argue that burn‐management of peatlands is more likely to lead to carbon loss than carbon gain

Application of compact laser-driven accelerator X-ray sources for industrial imaging

X-rays generated by betatron oscillations of electrons in a laser-driven plasma accelerator were characterised and applied to imaging industrial samples. With a 125TW laser, a low divergence beam with 5.2±1.7 × 107photonsmrad−2 per pulse was produced with a synchrotron spectrum with a critical energy of 14.6±1.3keV. Radiographs were obtained of a metrology test sample, battery electrodes, and a damage site in a composite material. These results demonstrate the suitability of the source for non-destructive evaluation applications. The potential for industrial implementation of plasma accelerators is discussed

Overriding water table control on managed peatland greenhouse gas emissions

Global peatlands store more carbon than is naturally present in the atmosphere1,2. However, many peatlands are under pressure from drainage-based agriculture, plantation development and fire, with the equivalent of around 3% of all anthropogenic greenhouse gases emitted from drained peatland3–5. Efforts to curb such emissions are intensifying through the conservation of undrained peatlands and rewetting of drained systems6. Here we report CO2 eddy covariance data from 16 locations and CH4 data from 41 locations in the British Isles, and combine them with published data from sites across all major peatland biomes. We find that the mean annual effective water-table depth (WTDe; that is, the average depth of the aerated peat layer) overrides all other ecosystem- and management-related controls on greenhouse gas fluxes. We estimate that every 10 cm of reduction in WTDe could reduce the net warming impact of CO2 and CH4 emissions (100-year Global Warming Potentials) by at least 3 t CO2e ha-1 yr-1, until WTDe is < 30 cm. Raising water levels further would continue to have a net cooling effect until WTDe is < 10 cm. Our results suggest that greenhouse gas emissions from peatlands drained for agriculture could be greatly reduced without necessarily halting their productive use. Halving WTDe in all drained agricultural peatlands, for example, could reduce emissions by the equivalent of over 1% of global anthropogenic emissions

Defra Lowland Peat 2: Managing agricultural systems on lowland peat for decreased greenhouse gas emissions whilst maintaining agricultural productivity. Report to Defra for Project SP1218

DescriptionThis report describes the results of the Defra "Lowland Peat 2" project, which ran from 2019 to 2023. This Project assessed the opportunities and challenges of managing lowland agricultural peat for reduced greenhouse gas emissions, providing evidence to support Departmental Net Zero ambitions, as well as help inform policy linked to the England Peat Action Plan (2021). Key findings include a detailed review of the opportunities and challenges for paludiculture (wetland-based agriculture) as a potential emissions mitigation measure; additional review scoping the societal impacts of lowland peat drainage, with a focus on the impacts of long-term subsidence; analyses from what is believed to be the largest network of flux towers on agricultural peatlands globally, suggesting that raising water levels could help to mitigate peat GHG emissions, and if correctly optimised may not lead to yield declines.The report also explores the role of "regenerative" farming measures in reducing peat GHGs.ObjectiveThe project assessed the opportunities and challenges of managing lowland agricultural peat for reduced greenhouse gas emissions. Primarily work in this area looks to support priorities of net zero, climate adaptation and mitigation, national food security, water security, and protection of biodiversity and habitats.. Following the earlier Lowland Peat 1 project (2014-2017) which generated fundamental data on GHG emissions from a range of contrasting lowland peat sites across England and Wales, the project focused primarily on developing and testing options to mitigate these emissions, whilst maintaining the agricultural productivity of lowland peatlands. The project coincided with a number of major peatland-related policy initiatives across the UK, including the Committee on Climate Change's 6th Carbon Budget and Net Zero Strategy, the England Peat Action Plan, and the Defra Lowland Agricultural Peat Task Force. Interim results from the project have fed into many of these initiatives, as well as to an update of emission factors for cropland and grassland on peat in the UK?s National Atmospheric Emissions Inventory

Population genomics of an outbreak of the potato late blight pathogen, <i>Phytophthora infestans</i>, reveals both clonality and high genotypic diversity

An outbreak of the potato late blight pathogen Phytophthora infestans in Denmark was characterized in order to resolve the population structure and determine to what extent sexual reproduction was occurring. A standard set of microsatellite simple sequence repeats (SSRs) and single nucleotide polymorphism (SNP) markers generated using restriction site‐associated DNA sequencing (RAD‐seq) were employed in parallel. A total of 83 individuals, isolated from seven different potato fields in 2014, were analysed together with five Danish whole‐genome sequenced isolates, as well as two Mexican individuals used as an outgroup. From a filtered dataset of 55 288 SNPs, population genomics analyses revealed no sign of recombination, implying clonality. In spite of this, multilocus genotypes were unique to individual potato fields, with little evidence of gene flow between fields. Ploidy analysis performed on the SNPs dataset indicated that the majority of isolates were diploid. These contradictory results with clonality and high genotypic diversity may suggest that rare sexual events likely still contribute to the population. Comparison of the results generated by SSRs vs SNPs data indicated that large marker sets, generated by RAD‐seq, may be advised going forward, as it provides a higher level of genetic discrimination than SSRs

Experimental signatures of the quantum nature of radiation reaction in the field of an ultraintense laser

The motion of an electron in an external field of arbitrary intensity is one of the most fundamental outstanding problems in electrodynamics. Remarkably, there is no unanimously accepted theoretical solution for high intensities and little or no experimental data to date. The basic challenge is the inclusion of the self-interaction of the electron with the fields emitted by the electron itself -- the so-called radiation reaction (RR). As is well known, solutions exist for specific parameter ranges. At low field-strength, where RR is negligible, the equation of motion is the well-known Lorentz equation. At higher field-strength in the classical limit the Landau-Lifshitz equation is the accepted solution. For the strongest fields a full quantum description is required and this is currently the subject of active research. We report on the first experimental evidence of strong radiation reaction during the interaction of a relativistic electron beam with an intense laser field

Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction

A representational predicament for a subordinate vis-à-vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. © 2013 Copyright Taylor and Francis Group, LLC