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We consider how the stoichiometry and energy content of organic matter reservoirs and fluxes through and from a peatland enable the fluxes and storage of carbon within a peatland to be constrained. We include the elemental composition of the above‐ and below‐ground biomass, litter, the peat profile, and the dissolved and particulate organic matter within a blanket bog in northern England for which the C budget has previously been measured. The study shows, based only on the elemental composition, and calculation of oxidation and energy contents, that: (a) Dissolved organic carbon (DOC) in first‐order streams is significantly more oxidized than in peat pore water but that there was no significant difference in organic carbon oxidation state down the peat profile; (b) The occurrence and speciation of N uptake and release in the peatland with N used and recycled can be predicted; (c) The relatively high oxidation state of DOC in stream water acts as an endpoint for peat‐forming reactions; (d) Methanogenesis does not result in deep peat formation as its requirement for energy consumes too much organic matter to form residual peat at depth; (e) Sulfate reduction does occur during the formation of deep peat; (f) Organic matter elemental composition could be constrained to within three bounding equations though the proportions of carbon species could not be specified. (g) The formation of deep peat in this catchment could only be achieved if the dissolved organic matter (DOM) in the peat pore water is the dominant electron acceptor and energy source in the production of residual organic matter; however, it is unclear as to the flux of DOM up or down the peat profile. Plain Language Summary: Peatlands are a vital terrestrial carbon store and so understanding their carbon budget has been a common measure of the health of those peatlands. Measuring carbon budgets a long and expensive process. However, we propose that the reactions of organic matter in peatlands must be constrained, like all chemical reactions, by stoichiometry and by enthalpy. Using elemental analysis of peat organic matter this study could reconstruct the C budget of a peatland and show which reactions are the most important. Key Points: Study applies rules of stoichiometry and enthalpy balance to understand carbon budgets of peatlandsMethanogenesis does not result in deep peat formation as it requires too much energy to form residual organic matter at depthDeep peat formation could only be achieved if the dissolved organic matter in the peat pore water was the dominant electron acceptor [ABSTRACT FROM AUTHOR]

Non-destructive testing (NDT) is a quality control measure designed to ensure the safety of products according to established variability thresholds. With the development of advanced technologies and a lack of formalised knowledge of the state-of-the-art, the National Composites Centre, Bristol, has identified that the increasing complexity of composite products will lead to some severe inspection challenges. To address the apparent knowledge gap and understand system complexity, a formulaic approach to introduce intelligence and improve the robustness of NDT operations is presented. The systemic development of a high-fidelity knowledge base (KB) involves the establishment of a capability matrix that maps material, component, and defect configuration to the capabilities and limitations of selected detection methods. Population and validation are demonstrated through the experimental testing of reference standards and evaluated against an assessment criteria. System complexity in ultrasonic testing operations focusses on capturing the inherent risks in inspection and the designation of evidence-based path plans for automation platforms. Anticipated deployment of the validated applicability data within the KB will allow for road-mapping of the inspection technique development and will provide opportunities for knowledge-based decision making. Moreover, the KB highlights the need for Design for Inspection, providing measurable data that the methodology should not be ignored. [ABSTRACT FROM AUTHOR]

Long-term datasets of integrated environmental variables, co-located together, are relatively rare. The UK Environmental Change Network (ECN) was launched in 1992 and provides the UK with its only long-term integrated environmental monitoring and research network for the assessment of the causes and consequences of environmental change. Measurements, covering a wide range of physical, chemical, and biological "driver" and "response" variables are made in close proximity at ECN terrestrial sites using protocols incorporating standard quality control procedures. This paper describes the datasets (there are 19 published ECN datasets) for these co-located measurements, containing over 20 years of data (1993–2015). The data and supporting documentation are freely available from the NERC Environmental Information Data Centre under the terms of the Open Government Licence using the following DOIs. Meteorology Meteorology: 10.5285/fc9bcd1c-e3fc-4c5a-b569-2fe62d40f2f5 (Rennie et al., 2017a) Biogeochemistry Atmospheric nitrogen chemistry: 10.5285/baf51776-c2d0-4e57-9cd3-30cd6336d9cf (Rennie et al., 2017b) Precipitation chemistry: 10.5285/18b7c387-037d-4949-98bc-e8db5ef4264c (Rennie et al., 2017c) Soil solution chemistry: 10.5285/b330d395-68f2-47f1-8d59-3291dc02923b (Rennie et al., 2017d) Stream water chemistry: 10.5285/fd7ca5ef-460a-463c-ad2b-5ad48bb4e22e (Rennie et al., 2017e) Stream water discharge: 10.5285/8b58c86b-0c2a-4d48-b25a-7a0141859004 (Rennie et al., 2017f) Invertebrates Moths: 10.5285/a2a49f47-49b3-46da-a434-bb22e524c5d2 (Rennie et al., 2017g) Butterflies: 10.5285/5aeda581-b4f2-4e51-b1a6-890b6b3403a3 (Rennie et al., 2017h) Carabid beetle: 10.5285/8385f864-dd41-410f-b248-028f923cb281 (Rennie et al., 2017i) Spittle bugs: 10.5285/aff433be-0869-4393-b765-9e6faad2a12b (Rennie et al., 2018) Vegetation Baseline: 10.5285/a7b49ac1-24f5-406e-ac8f-3d05fb583e3b (Rennie et al., 2016a) Coarse grain: 10.5285/d349babc-329a-4d6e-9eca-92e630e1be3f (Rennie et al., 2016b) Woodland: 10.5285/94aef007-634e-42db-bc52-9aae86adbd33 (Rennie et al., 2017j) Fine grain: 10.5285/b98efec8-6de0-4e0c-85dc-fe4cdf01f086 (Rennie et al., 2017k) Vertebrates Frogs: 10.5285/4d8c7dd9-8248-46ca-b988-c1fc38e51581 (Rennie et al., 2017l) Birds (Breeding bird survey): 10.5285/5886c3ba-1fa5-49c0-8da8-40e69a10d2b5 (Rennie et al., 2017m) Birds (Common bird census): 10.5285/8582a02c-b28c-45d2-afa1-c1e85fba023d (Rennie et al., 2017n) Bats: 10.5285/2588ee91-6cbd-4888-86fc-81858d1bf085 (Rennie et al., 2017o) Rabbits and deer: 10.5285/0be0aed3-f205-4f1f-a65d-84f8cfd8d50f (Rennie et al., 2017p) [ABSTRACT FROM AUTHOR]

Peatlands are important reserves of terrestrial carbon and biodiversity, and given that many peatlands across the UK and Europe exist in a degraded state, their conservation is a major area of concern and a focus of considerable research. Aerial surveys are valuable tools for habitat mapping and conservation and provide useful insights into their condition. We investigate how SfM photogrammetry-derived topography and habitat classes may be used to construct an estimate of carbon loss from erosion features in a remote blanket bog habitat. An autonomous, unmanned, aerial, fixed-wing remote sensing platform (Quest UAV 300™) collected imagery over Moor House, in the Upper Teesdale National Nature Reserve, a site with a high degree of peatland erosion. The images were used to generate point clouds into orthomosaics and digital surface models using SfM photogrammetry techniques, georeferenced and subsequently used to classify vegetation and peatland features. A classification of peatbog feature types was developed using a random forest classification model trained on field survey data and applied to UAV-captured products including the orthomosaic, digital surface model and derived surfaces such as topographic index, slope and aspect maps. Using the area classified as eroded peat and the derived digital surface model, we estimated a loss of 438 tonnes of carbon from a single gully. The UAV system was relatively straightforward to deploy in such a remote and unimproved area. SfM photogrammetry, imagery and random forest modelling obtained classification accuracies of between 42% and 100%, and was able to discern between bare peat, saturated bog and sphagnum habitats. This paper shows what can be achieved with low-cost UAVs equipped with consumer grade camera equipment and relatively straightforward ground control, and demonstrates their potential for the carbon and peatland conservation research community. [ABSTRACT FROM AUTHOR]

Long-term datasets of integrated environmental variables, co-located together, are relatively rare. The UK Environmental Change Network (ECN) was launched in 1992 and provides the UK with its only long-term integrated environmental monitoring and research network for the assessment of the causes and consequences of environmental change. Measurements, covering a wide range of physical, chemical and biological "driver" and "response" variables are made in close proximity at ECN terrestrial sites using protocols incorporating standard quality control procedures. This paper describes the datasets (there are nineteen published ECN datasets) for these co-located measurements, containing over twenty years of data (1993–2015). The data and supporting documentation are freely available from the NERC Environmental Information Data Centre under the terms of the Open Government Licence using the following DOI’s: Meteorology Meteorology: https://doi.org/10.5285/fc9bcd1c-e3fc-4c5a-b569-2fe62d40f2f5 (Rennie et al., 2017a) Biogeochemistry Atmospheric nitrogen chemistry: https://doi.org/10.5285/baf51776-c2d0-4e57-9cd3-30cd6336d9cf (Rennie et al., 2017b) Precipitation chemistry: https://doi.org/10.5285/18b7c387-037d-4949-98bc-e8db5ef4264c (Rennie et al., 2017c) Soil solution chemistry: https://doi.org/10.5285/b330d395-68f2-47f1-8d59-3291dc02923b (Rennie et al., 2017d) Stream water chemistry: https://doi.org/10.5285/fd7ca5ef-460a-463c-ad2b-5ad48bb4e22e (Rennie et al., 2017e) Stream water discharge: https://doi.org/10.5285/8b58c86b-0c2a-4d48-b25a-7a0141859004 (Rennie et al., 2017f) Invertebrates Moths: https://doi.org/10.5285/a2a49f47-49b3-46da-a434-bb22e524c5d2 (Rennie et al., 2017g) Butterflies: https://doi.org/10.5285/5aeda581-b4f2-4e51-b1a6-890b6b3403a3 (Rennie et al., 2017h) Carabid beetle: https://doi.org/10.5285/8385f864-dd41-410f-b248-028f923cb281 (Rennie et al., 2017i) Spittle bugs: https://doi.org/10.5285/aff433be-0869-4393-b765-9e6faad2a12b (Rennie et al., 2018) Vegetation Baseline: https://doi.org/10.5285/a7b49ac1-24f5-406e-ac8f-3d05fb583e3b (Rennie et al., 2016a) Coarse grain: https://doi.org/10.5285/d349babc-329a-4d6e-9eca-92e630e1be3f (Rennie et al., 2016b) Woodland: https://doi.org/10.5285/94aef007-634e-42db-bc52-9aae86adbd33 (Rennie et al., 2017j) Fine grain: https://doi.org/10.5285/b98efec8-6de0-4e0c-85dc-fe4cdf01f086 (Rennie et al., 2017k) Vertebrates Frogs: https://doi.org/10.5285/4d8c7dd9-8248-46ca-b988-c1fc38e51581 (Rennie et al., 2017l) Birds (Breeding bird survey): https://doi.org/10.5285/5886c3ba-1fa5-49c0-8da8-40e69a10d2b5 (Rennie et al., 2017m) Birds (Common bird census): https://doi.org/10.5285/8582a02c-b28c-45d2-afa1-c1e85fba023d (Rennie et al., 2017n) Bats: https://doi.org/10.5285/2588ee91-6cbd-4888-86fc-81858d1bf085 (Rennie et al., 2017o) Rabbits and deer: https://doi.org/10.5285/0be0aed3-f205-4f1f-a65d-84f8cfd8d50f (Rennie et al., 2017p). [ABSTRACT FROM AUTHOR]

Rewilding is currently being proposed as a means of enhancing the conservation value of marginal land in many parts of the world. This is especially true in the British uplands where rewilding will almost certainly involve either a reduction in livestock grazing, or its complete removal. The aim of reducing stock numbers would be to reverse the degradation of these ecosystems that has been caused by past over‐grazing. However, little is known about the likely outcomes, or the time‐scales over which such ecosystem recovery might occur. Here, we report preliminary results from a recent study of eight sites at Moor House NNR in the north‐Pennines, where permanent plots with‐ and without‐sheep grazing were established between 1954 and 1967 on a range of typical upland plant communities. Soils and vegetation were sampled, and their chemical properties analysed; for vegetation an assessment of the herbage quality for animal nutrition was also made. No significant differences in soil properties, above‐ground biomass and nutritional status of the vegetation was detected that could be attributed to sheep grazing removal. The only significant effect associated with grazing removal was a reduced digestibility of the vegetation (greater acid detergent fibre concentration) where sheep were removed. These results show that a rewilding strategy that relies only on reducing sheep numbers will have very little impact on ecosystem recovery in terms of soil or herbage chemistry over short‐ to medium‐term time‐scales. Rewilding policies, therefore, attempting to restore ecosystems degraded by over‐grazing must, therefore, be viewed as long‐term (>50 y). Herbage biomass was related to elevation: presence/absence of sheep grazing had almost no effect on soil or plant nutrition. [ABSTRACT FROM AUTHOR]

Abstract: The transformations and transitions of organic matter into, through, and out of an ecosystem must obey the second law of thermodynamics. This study considered the transition in the solid components of the organic matter flux through an entire ecosystem. Organic matter samples were taken from each organic matter reservoir and fluvial transfer pathway in a 100% peat‐covered catchment (Moor House National Nature Reserve, North Pennines, UK) and were analyzed by elemental analysis and bomb calorimetry. The samples analyzed were as follows: bulk aboveground and belowground biomass; individual plant functional types (heather, mosses, and sedges); plant litter layer; peat soil; and samples of particulate and dissolved organic matter (POM and DOM). Samples were compared to standards of lignin, cellulose, and plant protein. It was possible to calculate: enthalpy of formation ( Δ H f OM); entropy of formation ( Δ S f OM); and Gibbs free energy of formation ( Δ G f OM) for each of the samples and standards. The increase (decreasing negative values) in Δ G f OM through the ecosystem mean that for all but litter production, the transformations through the system must be balanced by production of low (large negative values) Δ G f OM products, not only CO2 or CH4 but also DOM. The change in Δ G f OM down the peat profile shows that reaction of the soil organic matter decreases or even ceases at depth and the majority of the reaction has occurred above 40 cm below the surface. This approach represents a new objective way to test and trace organic matter transformations in and through an ecosystem. [ABSTRACT FROM AUTHOR]

The effect of prescribed burning for conservation management of plant communities is controversial for moorlands growing on peat. These ecosystems provide many services that may be damaged by fire, hence it is important to fully assess its impact on all aspects of ecosystem structure and function experimentally over relatively long time-scales. This paper describes change in community composition, major plant species, and plant functional types on moorland on peat in upland Britain over 60 years subject to 3 burning treatments after an initial burn in 1954/1955: no further burn and burning at 10- and 20-year intervals (all ± sheep grazing). Data were analysed using multivariate and univariate methods. Vegetation composition and individual species abundance reflected the degree of disturbance. The least disturbed was dominated by Calluna vulgaris and pleurocarpous mosses, whereas the most disturbed treatment (burned every 10 years) had greater Eriophorum vaginatum, Sphagnum spp., acrocarpous mosses, liverworts, and lichens. The 20-year treatment was intermediate in response disturbance. Repeated burning increased species abundance-weighted Ellenberg values for moisture, reaction, light through time, and fertility; the exception was the 10-year rotation for fertility. These confirm that prescribed burning is not deleterious to peat-forming species (Eriophorum spp. and Sphagnum spp.), indeed these species were found in greater abundance in frequently burned treatments. It also confirms that a no-burn policy will lead to increasing dominance of C. vulgaris, a flammable, fire-adapted shrub, which increases summer wildfire risk. These results inform conservation management policy for moorland vegetation growing on peat; for this site, a 20-year prescribed burning rotation is recommended. [ABSTRACT FROM AUTHOR]

Abstract: Peatlands can accumulate organic matter into long‐term carbon (C) storage within the soil profile. This study used solid‐state 13C nuclear magnetic resonance (13C‐NMR) to investigate the transit of organic C through a peatland ecosystem to understand the molecular budget that accompanies the long‐term accumulation of C. Samples of biomass, litter, peat soil profile, particulate organic matter, and dissolved organic matter (DOM) were taken from the Moor House National Nature Reserve, a peat‐covered catchment in northern England where both the dry matter and C budget for the ecosystem were known. The results showed that: The interpretation of the 13C‐NMR spectra shows that polysaccharides are preferentially removed through the ecosystem, while lignin components are preferentially retained and come to dominate the organic matter accumulated at depth in the profile. The DOM is derived from the oxidation of both biomass and the degradation of lignin, while the particulate organic matter is derived from erosion of the peat profile. The DOM is differentiated by its proportion of oxidized functional groups and not by its aromatic content. The changes in functionality leading to DOM production suggest side chain oxidation resulting in C‐C cleavage/depolymerisation of lignin, a common reaction within white rot fungi. The 13C‐NMR budget shows that O‐alkyl functional groups are disproportionately lost between primary production and accumulation in the deep peat, while C‐alkyl functional groups are disproportionately preserved. The carbon lost as gases (CO2 and CH4) was estimated to be composed of 93% polysaccharide‐derived carbon and 7% lignin‐derived carbon. [ABSTRACT FROM AUTHOR]

The importance of peatlands is being increasingly recognized internationally for both the conservation of biodiversity and the provision of ecosystem services; strategies are being developed world-wide to help maintain their integrity. Prescribed burning has been highlighted as a threat with considerable debate over its use as it is perceived to produce a Calluna vulgaris monoculture and a decline in preferred peat-forming species., We investigated the impact of prescribed burning on vegetation composition and diversity in a long-term experiment at Moor House NNR in northern England. The study comprised a comparison between no-burn reference plots last burned in ca. 1924 and an experiment where all plots were burned in 1954/5. Within the experiment, the effects of very light sheep grazing vs. no grazing and three burning rotations (no-burn since 1954/5, repeat-burning at 10- and 20-year intervals) were tested., Calluna vulgaris and Hypnum jutlandicum cover and bryophyte species richness increased in the least-disturbed, no-burn reference plots, but bryophyte cover did not. Lichen diversity declined., Within the formal experiment, low-intensity sheep grazing had little impact but there were substantive changes produced by the different burning rotations. There was divergence between the burning rotation treatments with the least-disturbed, no-burn treatment changing towards a C. vulgaris- H. jutlandicum community, whereas the most-disturbed 10-year rotation had a much greater abundance of both Eriophorum and Sphagnum spp., Synthesis and applications. Our findings suggest that blanket-bog vegetation on peat responds to prescribed burning in a complex manner. Where burn return interval is long (>20 years), C. vulgaris becomes dominant and there was no evidence that preferred peat-forming species ( Eriophorum/Sphagnum) increased. Where burn return interval is short (10 years), E. vaginatum/ Sphagnum abundance increased. We found no evidence to suggest that prescribed burning was deleterious to the abundance of peat-forming species; indeed, it was found to favour them. These results inform conservation management policy for blanket bogs in the UK and more generally for future wildfire-mitigation strategies on dwarf-shrub-dominated peatlands elsewhere. Some lessons for the management of long-term experimental studies are also discussed. [ABSTRACT FROM AUTHOR]

Persistence of HIV DNA presents a major barrier to the complete control of HIV infection under current therapies. Most studies suggest that cells with latently integrated HIV decay very slowly under therapy. However, it is much more difficult to study the turnover and persistence of HIV DNA during active infection. We have developed an "escape clock" approach for measuring the turnover of HIV DNA in resting CD4+ T cells. This approach studies the replacement of wild-type (WT) SIV DNA present in early infection by CTL escape mutant (EM) strains during later infection. Using a strain-specific real time PCR assay, we quantified the relative amounts of WT and EM strains in plasma SIV RNA and cellular SIV DNA. Thus we can track the formation and turnover of SIV DNA in sorted resting CD4+ T cells. We studied serial plasma and PBMC samples from 20 SIV-infected Mane-A*10 positive pigtail macaques that have a signature Gag CTL escape mutation. In animals with low viral load, WT virus laid down early in infection is extremely stable, and the decay of this WT species is very slow, consistent with findings in subjects on anti-retroviral medications. However, during active, high level infection, most SIV DNA in resting cells was turning over rapidly, suggesting a large pool of short-lived DNA produced by recent infection events. Our results suggest that, in order to reduce the formation of a stable population of SIV DNA, it will be important either to intervene very early or intervene during active replication. [ABSTRACT FROM AUTHOR]

Several letters to the editor are presented in response to articles in previous issues including "NHS laboratories can provide a service to the pharmaceutical industry: a personal experience," "Gender differences in urinary excretion rates of cortisol and androgen metabolites," and "Evaluation of effect of analytical imprecision in maternal serum screening for Down's syndrome."

It is a common assumption that species' ranges are limited by their physiological tolerances to climatic factors. Biotic factors, such ascompetition, are rarely considered. We investigated the distributions of Ulex minor and U. gallii at three spatial scales - from geographic ranges to individual heaths - to examine whether the species are negatively associated, as predicted by the hypothesis that the ranges of the species are limited by competition with each other. Distribution maps for the British Isles and France (100-400 km2 survey units) show the two species have largely separated, but slightly overlapping ranges. A region of range overlap on the heaths of Dorset,southern England was mapped using 4 ha survey squares. There was strong negative association between the species, and the heaths could bedivided into zones where one species was dominant. There was some indication of edaphic differences between the U. minor-dominated zones and the U. gallii zones. The few heaths where the species co-occurredwere surveyed using 4 m2 quadrats placed along transects.Usually one species was widespread over the heath, while the other occurred in patches. The species were strongly negatively associated in all transects. Therefore, the two species showed strong negative associations at three mapping scales. Apparent co-occurrences detectedat one spatial scale largely disappeared when species were mapped atfiner scales, emphasizing the fractal nature of distributions. This provides evidence that the distributions of the two species are not independent and that they cannot co-exist, and therefore that their ranges are limited by competition. Over their ranges, competitive superiority is probably determined by the climate. At the range boundariesin the region of overlap, climate is not important, but other physical factors such as edaphic conditions may determine the outcome of competition. [ABSTRACT FROM AUTHOR]