N. Fenner

N. Fenner
Bangor University · School of Biological Sciences

About

69
Publications
29,868
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6,684
Citations
Citations since 2016
29 Research Items
3759 Citations
20162017201820192020202120220200400600
20162017201820192020202120220200400600
20162017201820192020202120220200400600
20162017201820192020202120220200400600

Publications

Publications (69)
Article
Iron (Fe) oxides promote carbon store stability in conventional (aerated) soils, and yet emerging evidence shows that Fe may also contribute to C decomposition in at redox interfaces. Mineral soil addition is common during peatland cultivation, but high content of Fe in mineral soil may lead to carbon loss upon flooding of agricultural peatlands (e...
Article
Full-text available
Peatland reservoirs are global hotspots for drinking water provision and are likely to become more important as demand per capita rises and the climate changes. Dissolved organic carbon (DOC) is associated with harmful disinfection byproducts and reduced aesthetic quality, and its removal is the major treatment cost. Littoral zones are known to be...
Article
Full-text available
Northern peatlands store ~30% of the world’s soil carbon. This carbon sequestration is due to slow decomposition, as illustrated by ancient wooden artefacts and ‘bog bodies’ preserved over millennia. Such artefacts suggest that carbon could be captured externally and stored long term in peat. However, whether such carbon would remain stable followi...
Article
Full-text available
There have been widespread attempts to rewet peatlands in Europe and elsewhere in the world to restore their unique biodiversity as well as their important function as nutrient and carbon sinks. However, changes in hydrological regime and therefore oxygen availability likely alter the abundance of enzyme-inhibiting polyphenolic compounds, which hav...
Article
Nitrogen deposition and tropospheric ozone are important drivers of vegetation damage, but their interactive effects are poorly understood. This study assessed whether long-term nitrogen deposition altered sensitivity to ozone in a semi-natural vegetation community. Mesocosms were collected from sand dune grassland in the UK along a nitrogen gradie...
Article
Full-text available
Modern wheat cultivars are increasingly sensitive to ground level ozone, with 7–10% mean yield reductions in the northern hemisphere. In this study, three of the genome donors of bread wheat, Triticum urartu (AA), T. dicoccoides (AABB), and Aegilops tauschii (DD) along with a modern wheat cultivar (T. aestivum ‘Skyfall’), a 1970s cultivar (T. aesti...
Article
Full-text available
Dune slacks are biodiverse seasonal wetlands which experience considerable fluctuations in water table depths. They are subject to multiple threats such as eutrophication and climate change, and the interactions of both of these pressures are poorly understood. In this study we measured the impact of groundwater nitrogen contamination, as ammonium...
Article
Mowing is a common management technique employed in Europe and North America to manage seral wetland plant communities to: (a) prevent development to late succession, (b) minimise internal eutrophication and (c) conserve biodiversity. However, little is known about the effect mowing has on water quality, and the duration of any effects. Therefore,...
Article
Full-text available
Peat represents a globally significant pool of sequestered carbon. However, peatland carbon stocks are highly threatened by anthropogenic climate change, including drought, which leads to a large release of carbon dioxide. Although the enzymatic mechanisms underlying drought-driven carbon release are well documented, the effect of drought on peatla...
Article
Full-text available
Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about mi...
Article
Full-text available
Chlorination of drinking water protects humans from water-born pathogens, but it also produces low concentrations of dibromoacetonitrile (DBAN), a common disinfectant by-product found in many water supply systems. DBAN is not mutagenic but causes DNA breaks and elevates sister chromatid exchange in mammalian cells. The WHO issued guidelines for DBA...
Article
Algal blooms resulting from the eutrophication of surface waters represent a significant ecological and water treatment issue. The potential for wetland systems to act as sinks for various types of pollutants indicates their potential for mitigating algal blooms. Although nutrient uptake in terrestrial treatment wetland systems has received substan...
Article
Dune slacks are biodiverse seasonal wetlands which experience considerable fluctuation in water table depth. They are under threat from eutrophication and lowered water tables due to climate change and water abstraction. The biological effects caused by the interactions of these pressures are poorly understood, particularly on soil processes. We us...
Book
Full-text available
The distribution and function of microorganisms are of crucial importance for the flow of matter in the Earth's biogeochemical cycles. Effects of microbial communities on the carbon and nitrogen cycles are particularly important for producing climate gases such as CO(2), CH(4), or N(2)O. However, the biogeochemical cycles are reversely impacted by...
Chapter
Peatlands contain more than double the amount of carbon than is found in the biomass of the world's forests. Such stores are due to the build-up of dead plant material, resulting from restraints on microbial decomposition in the peat-substrate: in particular the inhibitory effects of phenolic compounds create an 'enzymic latch' on the breakdown of...
Article
Globally important U.K. fens are in poor condition, principally due to abandonment, following cessation of traditional mowing and grazing in recent decades. In the absence of management, rich fen flora are displaced as a result of succession. This leads to an increase in competitive species and subsequent biomass accumulation. In order to reverse t...
Article
Drained peatland catchments are reported to produce more colored, dissolved organic carbon (DOC)-rich water, presenting problems for potable water treatment. The blocking of peatland drainage ditches to restore the water table is increasingly being considered as a strategy to address this deterioration in water quality. However, the effect of ditch...
Article
Numerous catchment characteristics including topography, geology, soil and vegetation are reported to exert a strong influence on mean surface water properties. The present study employs a geographical information system (GIS) approach to examine, for the first time, the relationship between reservoir water quality [dissolved organic carbon (DOC) c...
Article
Extensive areas of European peatlands have been drained by digging ditches in an attempt to improve the land, resulting in increased carbon dioxide fluxes to the atmosphere and enhanced fluvial dissolved organic carbon (DOC) concentrations. Numerous peatland restoration projects have been initiated which aim to raise water tables by ditch blocking,...
Article
Nutrients and faecal contaminants can enter wetland systems in a number of ways, with both biological and potentially human-health implications. In this study we used a combination of inorganic chemistry, dissolved organic matter (DOM) fluorescence and Escherichiacoli and total coliform (TC) count techniques to study the sources and multiple pathwa...
Article
Peatlands are large terrestrial stores of carbon, and sustained CO2 sinks, but over the last century large areas have been drained for agriculture and forestry, potentially converting them into net carbon sources. More recently, some peatlands have been re-wetted by blocking drainage ditches, with the aims of enhancing biodiversity, mitigating floo...
Conference Paper
Fens are minerotrophic peatlands that provide ecosystem services such as water purification and climate regulation. In order for fens to perform optimally, the presence of peat forming primary producers that maintain nutrient cycling and sequester carbon are vital. However, in recent decades, UK fens have degraded largely due to cessation of tradit...
Article
Dune slacks are seasonal wetlands, high in biodiversity, which experience considerable within-year and between-year variations in water-table. They are subject to many pressures including climate change, land use change and eutrophication. Despite their biological importance and the threats facing them, the hydrological and nutrient parameters that...
Article
Absorbance in the UV or visible spectrum (UV-vis) is commonly used as a proxy for DOC concentrations in waters draining upland catchments. To determine the appropriateness of different UV-vis measurements we used surface and pore water samples from two Welsh peatlands in four different experiments: (i) an assessment of single wavelength proxies (1...
Article
Throughout the last two centuries peatlands have been subject to extensive drainage, typically through the digging of ditches. Ecosystem restoration now focusses on damming or infilling these ditches to increase biodiversity and to provide a range of ecosystem services such as carbon sequestration and water provision. We surveyed 60 bog pools creat...
Article
Peatland catchments store vast amounts of carbon. Humic lakes and pools are the primary receptacles for terrigenous carbon in these meta-ecosystems, representing sequestration hotspots; boreal lakes alone store ca. 120 Pg C. But little is known about the mechanisms that preserve aquatic carbon stocks. Here, we determined the regulatory pathway of d...
Article
Concentrations of dissolved organic carbon (DOC) in soil and stream waters in upland catchments are widely monitored, in part due to the potential of DOC to form harmful by-products when chlorinated during treatment of water for public supply. DOC can be measured directly, though this is expensive and time-consuming. Light absorbance in the UV–vis...
Article
Full-text available
Terrestrial and oceanic ecosystems contribute almost equally to the sequestration of ca 50 per cent of anthropogenic CO(2) emissions, and already play a role in minimizing our impact on Earth's climate. On land, the majority of the sequestered carbon enters soil carbon stores. Almost one-third of that soil carbon can be found in peatlands, an area...
Article
Global warming is expected to have greater impacts on northern peatlands in coming decade than most other ecosystems. Bacterial and methanogen communities in peatlands play a role in greenhouse gas emissions, and provide a feedback to global climate change. We investigated 3-degree warming effects on gas emissions (CO2 and CH4) and bacterial and me...
Article
Full-text available
Peatlands store vast amounts of organic carbon, amounting to approximately 455 Pg. Carbon builds up in these water-saturated environments owing to the presence of phenolic compounds-which inhibit microbial activity and therefore prevent the breakdown of organic matter. Anoxic conditions limit the activity of phenol oxidase, the enzyme responsible f...
Article
Restoration of drained peatlands has been promoted to reduce gaseous and aquatic carbon losses; however, there are conflicting reports as to its effectiveness. Here we report “hotspots” of organic matter decomposition as a result of rewetting a drained peatland in Wales, at the field-scale, in the medium/long-term with implications for water qualit...
Article
Summary1. In Europe, grassland agriculture is one of the dominant land uses. A major aim of European agri-environment policy is the management of grassland for botanical diversity conservation and restoration, together with the delivery of ecosystem services including soil carbon (C) sequestration.2. To test whether management for biodiversity rest...
Article
Drainage for forestry has been amongst the most extensive of land management practices applied to northern latitude peatlands, particularly in northern Europe. Extracellular phenol oxidases play an important role in the carbon cycle of soils. This study investigated the effects of long-term (45 years) drainage for forestry upon surface peat extrace...
Article
The effects of elevated atmospheric CO2 (eCO2) and water table draw-down on soil carbon sequestration in an ombrotrophic bog ecosystem were examined. Peat monoliths (11 cm diameter, 25 cm deep) with intact bog vegetation were exposed to ambient or elevated (ambient + 200 mg l−1) atmospheric CO2, combined with a natural water table (level with the p...
Chapter
Full-text available
Long-term increases in dissolved organic carbon (DOC) release from peatlands to British aquatic ecosystems are widely acknowledged, and are now confirmed to occur in a wide variety of boreal and subboreal settings. Depth to water table is probably the single most important hydrological factor governing that DOC generation and will modulate the resp...
Article
Peat drainage, a common land-use practice in Europe, has been associated with habitat degradation and increased particulate and dissolved carbon release. In the UK, peatland drain blockage has been encouraged in recent years as a management practice to preserve peatland habitats and to reduce fluvial carbon loss and municipal water discoloration. D...
Article
The frequency of drought is anticipated to increase in wetland ecosystems as global warming intensifies. However, information on microbial communities involved in greenhouse gas emissions and their responses to drought remains sparse. We compared the gene abundance of eubacterial 16S rRNA, nitrite reductase (nirS) and methyl coenzyme M reductase (m...
Article
Natural moisture limitation during summer drought can constitute a stress for microbial communities in soil. Given globally predicted increases in drought frequency, there is an urgent need for a greater understanding of the effects of drought events on soil microbial processes. Using a long-term field-scale drought manipulation experiment at Cloca...
Article
Extracellular phenol oxidases play an important role in the soil carbon cycle. The effects of a field-scale summer drought manipulation on extracellular litter and soil phenol oxidase activity, soluble phenolic compounds and dissolved organic carbon concentrations were examined for an upland Calluna heathland on a peaty podsol in North Wales. Litte...
Article
Northern peatlands are important stores of carbon and reservoirs of biodiversity that are vulnerable to global change. However, the carbon dynamics of individual peatland plant species is poorly understood, despite the potential for rising atmospheric CO2 to affect the vegetation’s contribution to overall ecosystem carbon function. Here, we examine...
Article
Peatlands export more dissolved organic carbon (DOC) than any other biome, contributing 20% of all terrestrial DOC exported to the oceans. Both warming and elevated atmospheric CO2 (eCO2) can increase DOC exports, but their interaction is poorly understood. Peat monoliths were, therefore, exposed to eCO2, warming and eCO2 + warming (combined). The...
Article
Full-text available
Peat bogs have historically represented exceptional carbon (C) sinks because of their extremely low decomposition rates and consequent accumulation of plant remnants as peat. Among the factors favoring that peat accumulation, a major role is played by the chemical quality of plant litter itself, which is poor in nutrients and characterized by polyp...
Article
The temperature dependence of chemical reaction rates and microbial metabolism mean that temperature is a key factor regulating soil trace gas emissions and hydrochemistry. Here we evaluated a novel approach for studying the thermal response of soils, by examining the effects of temperature on gas emissions and hydrochemistry in (a) peat and (b) so...
Article
Thermal gradient apparatus has been used to study enzyme activity and carbon cycling in peat collected seasonally from a Northern upland peatland. A thermal optimum was observed in the peat where maximum carbon-cycling enzyme activities (phenol oxidase and b-glucosidase), phenolic compound concentrations, dissolved organic carbon (DOC) concentratio...
Article
Northern peatlands store ca. 1/3 of the world's soil organic carbon and this is attributed to low decomposition rates as a result of waterlogged, anaerobic conditions and high levels of phenolic substances. Climate change models predict both an increase in summer droughts and increased rainfall, depending on region, but information on the effect of...
Article
Wetlands play a key role in global biogeochemical cycles, and as such, the effects of global climatic changes on these systems are of great importance. In this study, we assessed impacts of elevated CO(2) on soil enzyme activities in different types of wetlands. We hypothesised that elevated CO(2), by increasing DOC supply into the soil, would modi...
Article
Unique peatland properties, such as their ability to preserve intact ancient human remains (bog bodies) and to store globally significant quantities of atmospheric CO2, can be attributed to their low rates of enzymic decomposition. Peatland soils are normally devoid of molecular oxygen in all, but the uppermost layer, and thus enzymes such as pheno...
Article
Full-text available
Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increa...
Article
Full-text available
Over half of the world's peat originated from Sphagnum, representing 10–15% of the terrestrial carbon stock. However, information regarding the release and exudation of organic carbon by living Sphagnum plants into the surface peat is scarce. In this study, we examined the contribution of recent Sphagnum subnitens (Russ. and Warnst.) photosynthate...
Article
Full-text available
Tranvik and Jansson question our proposed link between temperature and DOC export, on the basis of spatial patterns of DOC concentration, confounding effects of hydrology, and apparently conflicting observations from other regions.
Article
Dissolved organic matter in the oceans represents one of the biosphere's principal stores of organic carbon. A large proportion of this matter is drained from the continents — particularly from northern peatlands, which contain 20% of the global soil carbon1. Freeman et al.2 have suggested that rising temperatures may enhance this transport of diss...
Article
Warmer conditions may be to blame for the exodus of peatland carbon to the oceans.
Article
Demand for water from catchments dominated by upland peat as a source of drinking water supplies in the UK is likely to increase in the future as demand per capita continues to rise (Thomsen 1990) and/or summer droughts increase in frequency (Arnell 1992). Concern has been expressed in recent years over rising colour levels (related to dissolved or...

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Projects

Projects (3)
Project
Determining the significance of wetland-derived DOC (dissolved organic carbon) in water treatment - particularly in the context of our changing climate
Project
Investigating the value of wetlands in the treatment of water pollution
Project
DOM in aquatic ecosystems