Carbon Storage and Distribution in a Temperate Saltmarsh – A case study of the Ribble Estuary, UK

Temperate saltmarshes serve as important stores of blue carbon and climatic regulators, however little is currently known about the contemporary carbon storage capacities of UK saltmarshes. This study quantifies the carbon storage capacity of the saltmarshes in the Ribble estuary and analyses the influence of elevation, gradient and watercourse proximity on carbon distribution. The study specifically focusses on carbon stored within the ‘active section’ which is comprised of the above-ground biomass and surface organic layer, defined as the ‘active layer’ in this research. Overall, the findings indicate that 1.26 x 107 kg and 12.9 x 107 kg (3.s.f) of carbon is stored within the above-ground biomass and active layer sediment respectively, although carbon is unevenly distributed between the sub-environments that comprise the saltmarshes of the Ribble. Whilst elevation, gradient and watercourse proximity are recognised to exert an interconnected influence on sub-environment and carbon distribution, only gradient and watercourse proximity were found to be statistically significant. In all sub-environments watercourse proximity exhibits a standardised influence between 50.1% and 72.0% greater than gradient. The overall distribution findings rebuke the simple elevation ramp model of distribution and support the theory that saltmarsh sub-environment and carbon distribution is controlled by a multitude of interconnected ecogeomorphological factors. The study also highlights the overall active section carbon storage capacity of the Ribble saltmarshes could decrease by 23.8%, 30.7% or 30.9% of the 2012 capacity by 2100 under the respective RCP 2.6, 4.5 and 8.5 (50th percentile) sea level rise scenarios. There is also the potential for greater degradation and carbon loss to occur as result of sea level rise driven headward expansion of creeks given the significant influences of watercourse proximity and gradient on sub-environment distribution. Therefore, it is important future shoreline management policies are adapted to limit future degradation in order to allow the saltmarshes of the Ribble to continue to act as an important store of blue carbon

A Multidisciplinary Analysis of Coastal Storms in Western Britain, 1800-2020

This multidisciplinary study combines environmental science and environmental history to improve storm understanding in Western Britain from 1800 to 2020. Storms have persistently impacted coastal communities, infrastructure and environments in this region and climate change is predicted to increase storm threats and impacts. A sedimentological study analysed saltmarsh storm impacts in Carmarthen Bay. High magnitude storm surge deposition in 1954, 1977 and 1981 was identified through sedimentological, meteorological and tidal gauge analyses. The results show storm surges irregularly contributed to sustaining saltmarsh elevation suggesting the value of continued research into saltmarsh storm impacts. An archival newspaper analysis produced a comprehensive original storm database from 1800 to 2020. Three environmental history investigations followed. The first investigation analysed a major storm using the concept of storm subcultures. The 1859 Royal Charter Storm and the ensuing developments in storm prediction were analysed. Storm catastrophes were shown to evoke long-term social, political and cultural responses. The event changed storm understanding and prediction with long-term community and governance implications. The analysis highlighted the importance of inclusive decision making and adaptive storm subcultures. The second study employed statistical and qualitative newspaper analyses of written storm representations from 1800 to 1953. Rapidly declining religious storm interpretations and progressively increasing scientific interpretations reflected changing beliefs in Britain. The analysis showed that epistemological change profoundly affected public storm representations and understandings. A contemporary study analysed meteorological, tidal gauge and newspaper data from Storms Ciara and Dennis. While the storms were climate anomalies and the short-term response was effective, shortcomings in long-term climate change-related government policies likely enhanced vulnerability and therefore policy adaptation was recommended. Multidisciplinary research ultimately improves the understanding of the often interconnected community and environmental storm impacts and can inform inclusive and effective response. Further multidisciplinary research can therefore contribute towards enhancing resilience to increasing storm threats

Uncovering the natural variability of araucariacean exudates from ex situ and in situ tree populations in New Caledonia using FTIR spectroscopy

Background Understanding the natural variability of plant resins is crucial for evaluating the chemical information stored in ambers that may support inferring palaeoenvironmental conditions. However, even among extant resin-producing plants, the variation of resinous exudates within and between tree genera and species is still poorly understood. Methods We analysed plant exudates from across the Araucariaceae in New Caledonia using Fourier-transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR). Both, wild (in situ) and arboretum grown (ex situ) populations were used to uncover the effects of intergeneric, inter- and intraspecific variation of the araucariacean plants on the resin chemistry. Results We show that even resins from the same species in the same habitat do have natural (intraspecific) chemical variation. Some of the variation can result from the degree of resin polymerisation, but this is not the only source of variation. Wild sourced resins have greater natural intraspecific chemical variation than the arboretum sourced ones. Interspecific and intergeneric differences were not easy to distinguish in the resins sampled. This has strong implications for the evaluation of the chemical information from worldwide ambers: multiple samples should be analysed to give a more accurate picture of the natural chemical variation present and how this may or may not overlap with the chemistries of other resin types. Additionally we discovered that the Araucariacean species can produce up to three distinct types of exudate (gum, resin, and gum resin). This is the first time that gum resins have been identified and characterized with FTIR-ATR. We also provide a guide on how to distinguish the exudate types when using FTIR-ATR.Peer reviewe

Fabrication and Characterization of Borosilicate Glasses Containing Alpha-Radionuclides and Silver From Conversion and Mixed-Oxide Facilities Proposed for Russia

Liquid and solid radioactive wastes are formed during conversion of plutonium metal to oxide and during fabrication of weapons-grade plutonium into mixed-oxide (MOX) fuel. In Russia, these wastes are to be processed for disposition by immobilization in either borosilicate glass or cement matrices depending upon the waste stream-specific radionuclide contents. Vitrification is planned for the liquid high-level waste raffinate stream containing the bulk of the Am-241 produced from Pu-241 decay. Previous work on the Russian MOX Fuel Fabrication Facility (R-MFFF) by the Public Joint Stock Corporation (TVEL) [1] showed that this waste stream may contain significant amounts of silver derived from the electrochemical dissolution of PuO2 using a Ag(II) catalyst. The work reported here further investigated silver solubility limits, which, if exceeded in a production glass melter, allow discrete silver grains to form in the glass and also deposit over time on the bottom of a joule-heated ceramic melter. In melters with immersed electrodes, such as the Russian EP-100 for phosphate glasses or the US Duratek DP-100 type melters for borosilicate glasses that are being considered for use at the Siberian Chemical Combine (SCC) Tomsk site, the undissolved silver could cause a short circuit and an unacceptable production melter failure. The silver solubility limit of 3.85 wt% Ag{sub 2}O in liquid, alpha-bearing wastes determined in this work will guide the production scale use of borosilicate glass compositions, and effectively increase the capacity of the ceramic melters and reduce the total volume of solidified vitrified wastes at SCC Tomsk that require storage prior to geologic disposal

Sedimentological archives of coastal storms in South-West Wales, UK

High magnitude coastal storms have persistently threatened human communities and environments. In the British Isles their frequency and magnitude are predicted to increase in the future with advancing climate change. This study analyses sedimentological evidence from south-west Wales to assess the impacts of high magnitude coastal storms in vulnerable coastal saltmarshes in the Three Rivers Estuarine Complex, Carmarthen Bay. Storm surge saltmarsh deposits were identified following geochemical and particle size analyses and dated using radionuclides ¹³⁷Cs and ²¹⁰Pb. The sedimentological evidence is compared with regional tidal gauge and meteorological records to assess variability in storm recording and corroborate the storms which produced the sedimentological deposits. Three episodes of high magnitude saltmarsh storm surge deposition are identified in 1954, 1977 and 1981. Evidence of storm erosion or alternative forms of storm deposition were not present. The sedimentological evidence highlights the comparative rarity of major depositional events in the saltmarshes between 1929 and 2019. The recorded depositional events combined with organic accretion have contributed to maintaining saltmarsh elevation relative to sea level. There remains uncertainty surrounding the storm impacts on the saltmarshes of the Three Rivers Estuarine Complex. When the future 21st century threats of increasing regional atmospheric storminess and sea level rise are considered along with predictions of saltmarsh degradation, this study suggests further research is required to explore the sedimentological storm impacts. This could contribute to sustaining the vulnerable coastal saltmarsh environments and the important ecosystem services they provide

Homotopy colimits and global observables in Abelian gauge theory

We study chain complexes of field configurations and observables for Abelian gauge theory on contractible manifolds, and show that they can be extended to non-contractible manifolds by using techniques from homotopy theory. The extension prescription yields functors from a category of manifolds to suitable categories of chain complexes. The extended functors properly describe the global field and observable content of Abelian gauge theory, while the original gauge field configurations and observables on contractible manifolds are recovered up to a natural weak equivalence