Aspects of microbial communities in peatland carbon cycling under changing climate and land use pressures

This is the final version. Available on open access from the Finnish Peatland Society via the DOI in this record. Globally, major efforts are being made to restore peatlands to maximise their resilience to anthropogenic climate change, which puts continuous pressure on peatland ecosystems and modifies the geography of the environmental envelope that underpins peatland functioning. A probable effect of climate change is reduction in the waterlogged conditions that are key to peatland formation and continued accumulation of carbon (C) in peat. C sequestration in peatlands arises from a delicate imbalance between primary production and decomposition, and microbial processes are potentially pivotal in regulating feedbacks between environmental change and the peatland C cycle. Increased soil temperature, caused by climate warming or disturbance of the natural vegetation cover and drainage, may result in reductions of long-term C storage via changes in microbial community composition and metabolic rates. Moreover, changes in water table depth alter the redox state and hence have broad consequences for microbial functions, including effects on fungal and bacterial communities especially methanogens and methanotrophs. This article is a perspective review of the effects of climate change and ecosystem restoration on peatland microbial communities and the implications for C sequestration and climate regulation. It is authored by peatland scientists, microbial ecologists, land managers and non-governmental organisations who were attendees at a series of three workshops held at The University of Manchester (UK) in 2019–2020. Our review suggests that the increase in methane flux sometimes observed when water tables are restored is predicated on the availability of labile carbon from vegetation and the absence of alternative terminal electron acceptors. Peatland microbial communities respond relatively rapidly to shifts in vegetation induced by climate change and subsequent changes in the quantity and quality of below-ground C substrate inputs. Other consequences of climate change that affect peatland microbial communities and C cycling include alterations in snow cover and permafrost thaw. In the face of rapid climate change, restoration of a resilient microbiome is essential to sustaining the climate regulation functions of peatland systems. Technological developments enabling faster characterisation of microbial communities and functions support progress towards this goal, which will require a strongly interdisciplinary approach.Natural Environment Research Council (NERC

From Romantic Gothic to Victorian Medievalism: 1817 and 1877

"The Cambridge History of the Gothic was conceived in 2015, when Linda Bree, then Editorial Director at Cambridge University Press, first suggested the idea to us

The development and application of new computational tools for working with viral metagenomic data

Next generation, high throughput sequencing has revolutionised the way in which we are able to view the microbial world. We have now generated a large volume of metagenomic sequence data describing viruses and bacteria in diverse environments across the planet. These data require computational processing in order to be used in further analysis. Manipulating the data in the way a bioinformatician wants is often a major difficulty in a metagenomic research. There are two reasons for this. One is that, as the field is nascent, there are many useful data processing tasks that do not yet have published computational tools. A second is that the computational tools that have been published to date are often poorly documented and complicated making them difficult to use in a routine application. Research in this thesis focusses on developing simple computational tools for managing viral metagenomic data. Viral metagenomic data presents the bioinformatician with specific difficulties owing to its size, poor quality and largely novel sequence content. Four new computational tools for managing viral metagenomic data are presented and benchmarked here. Three of these tools expedite everyday researching tasks, automating a process that would otherwise be done manually. The fourth, VHost-Classifier, allows a new scientific question to be asked using viral metagenomic data. In the final chapter VHost-Classifier is applied to analyse viruses published in the NCBI taxonomy database by host organism. The results reveal a large anthropocentric bias in viral sequencing.Science, Faculty ofMicrobiology and Immunology, Department ofGraduat

The effect of drainage and drain-blocking on the molecular and microbial composition of blanket bog peat

Over the last century researchers have acquired substantial evidence that water table regime is a fundamental determinant of peatland health. Peatland health refers to the ability of a peatland to perform essential ecosystem functions for humanity, including but not limited to, carbon sequestration, water filtration, flooding prevention and sustenance of high biodiversity. Undrained peatlands with a high, stable water table level perform these services better than drained peatlands. The question is, why? The molecular and microbial composition of peat determines the physical (e.g. bulk density) and biological (e.g. enzyme activity) properties of peat which are responsible for ecosystem functioning. Peatland drainage changes the molecular and microbial composition of peat. This results in peatlands that no longer perform the essential ecosystem functions listed above. The consequences for humanity are serious: carbon release driving global warming, flooding, fresh water pollution and loss of biodiversity. The primary aim of this work is to develop a better deterministic understanding of how peatland drainage changes the molecular and microbial characteristics of peat, and whether restoration attempts through drain-blocking have been successful in reverting these changes. To this end, peat cores were extracted from drained, undrained, and drain-blocked regions of four UK blanket bogs and analysed using a range of complementary chemical and biological techniques. The drain-blocked regions were restored between six and nineteen years prior to sampling. Analysis of water-logger data confirmed that the water table level was deeper below the peat surface in drained regions of bogs than undrained bogs. Drain-blocking showed limited success at raising the water table to undrained levels. In situ field recordings made at the time of sampling showed that drainage caused profound shifts in vegetation cover, from Sphagnum mosses to drier-tolerant vascular plants such as heaths and sedges. In three out of four blanket bogs there was a recovery of Sphagnum in drain-blocked peat. The lack of recovery in one bog is likely to have resulted from the initial severity of drainage. Physiochemical and enzyme assays undertaken using low-resolution methods found that drained peat had higher bulk density, carbon percentage, phenol content and hydrolase activity and lower pH and oxygen percentage. In general, drain-blocked peat showed physicochemical values closer to undrained peat with the exception of bulk density and carbon content. The extent of physiochemical recovery was not clearly linked to time elapsed since drain-blocking. An increase in phenol content due to drainage was also observed by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis of peat porewaters. FT-ICR MS analysis showed a notable increase in the diversity of oxy-aromatic phytochemical compounds in drained pore waters which caused the entire molecular pool to increase in mean aromaticity. Drain-blocked peat had mean aromaticity values in between undrained and drain-blocked peat, however the effect of drain-blocking, although not clearly linked to time, was highly dependent on site. Finally, metataxonomic analysis of bacteria and archaea using high-throughput sequencing of the 16S rRNA gene from DNA extracts found that undrained peat had a distinct microbial community composition compared to drain-blocked and drained peat. Furthermore, there was a high degree of similarity between DNA and RNA communities in the site with the longest time since drain-blocking which indicated stable community composition over the recent past (DNA is representative of both living and dead organisms, whereas RNA is only representative of only living organisms). Together, these results indicated that drain-blocked communities were stuck in a stable drained-like state that species from undrained communities found hard to re-colonise. Overall, drainage caused fundamental changes to peat at every level of analysis. In general, differences between undrained and drained peat were most evident in peat sampled from 20 to 50 cm compared to surface peat. The effects of drain-blocking varied by site. On the whole, drain-blocked peat showed more undrained-like characteristics in the field and low-resolution datasets and more drained-like characteristics in the high-resolution data. There was a notable lack of change in the microbial community of drained-block peat. This work demonstrates that drain-blocking blanket bogs is partially successful in changing to the molecular composition of peat back to an undrained state, but at the time-scales studied was not successful at changing the microbial composition of peat

The Theatrical Gothic in the Nineteenth Century

Despite its seeming defeat at the hands of the new melodrama and, later, the emerging stage realism, the Gothic continued to stalk the stage long into the nineteenth century. Shape-shifting and refusing to die outright, the Gothic mode would inform melodrama, domestic drama, sensation drama and even the emerging realist dramas to the end of the century. Moreover, whilst according to hegemonic narratives of theatre history, the new modes of realism would claim a victorious precedence over the drama of the shudder, this chapter argues that as the fin de siècle loomed, attempts to repress the Gothic on stage were met with an increasingly Gothic representation of the theatre itself within the wider popular and literary imagination