ORCID Profile
0000-0002-1482-4209
Current Organisations
University of Western Australia
,
Murdoch University
,
Bangor University
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Publisher: Springer Science and Business Media LLC
Date: 09-06-2021
DOI: 10.1038/S41598-021-91498-4
Abstract: In grazing systems, urine patches deposited by livestock are hotspots of nutrient cycling and the most important source of nitrous oxide (N 2 O) emissions. Studies of the effects of urine deposition, including, for ex le, the determination of country-specific N 2 O emission factors, require natural urine for use in experiments and face challenges obtaining urine of the same composition, but of differing concentrations. Yet, few studies have explored the importance of storage conditions and processing of ruminant urine for use in subsequent gaseous emission experiments. We conducted three experiments with sheep urine to determine optimal storage conditions and whether partial freeze-drying could be used to concentrate the urine, while maintaining the constituent profile and the subsequent urine-derived gaseous emission response once applied to soil. We concluded that filtering of urine prior to storage, and storage at − 20 °C best maintains the nitrogen-containing constituent profile of sheep urine s les. In addition, based on the 14 urine chemical components determined in this study, partial lyophilisation of sheep urine to a concentrate represents a suitable approach to maintain the constituent profile at a higher overall concentration and does not alter sheep urine-derived soil gaseous emissions.
Publisher: Springer Science and Business Media LLC
Date: 06-10-2012
Publisher: Wiley
Date: 03-04-2015
DOI: 10.1002/LNO.10084
Publisher: Elsevier BV
Date: 08-2014
Publisher: Informa UK Limited
Date: 04-07-2022
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.SCITOTENV.2014.10.100
Abstract: Routine bacterial monitoring of shellfish beds using indicator species is a common global practice designed to prevent human consumption of contaminated shellfish products. However, current bacteriological monitoring procedures which focus on the quantification of faecal indicator organisms (FIOs) as a proxy for microbial pollution may not be representative of total bacterial contamination levels present in shellfish harvesting areas. The objective of this study was to critically assess the accuracy of current monitoring strategies by quantifying the spatial (lateral and longitudinal distance) and temporal (seasonality and tidal state) concentrations of FIOs (Escherichia coli and total coliforms) within a single intertidal commercially harvested shellfish bed. Spatial and temporal FIO dynamics, including the effects of tidal state and seasonality, were quantified in mussel flesh and sediment s les from a single intertidal mussel (Mytilus edulis) bed. Our results confirmed that FIO concentrations across a shellfish bed were heterogeneous over larger spatial and temporal scales, but showed no relation to the concentrations of autochthonous bacteria, such as Vibrio spp., or the physico-chemical parameters of the sediment. These results have important implications for both public health and the economic prosperity of the shellfish industry, and demonstrate the importance of accommodating both spatial and temporal fluctuations in routine bacteriological monitoring protocols. We conclude that current FIO monitoring procedures may not accurately represent levels of microbial contamination within shellfish harvesting areas and that more robust microbiological testing procedures need developing.
Publisher: Wiley
Date: 10-10-2013
DOI: 10.1111/GCB.12338
Abstract: We investigated how the legacy of warming and summer drought affected microbial communities in five different replicated long-term (>10 years) field experiments across Europe (EU-FP7 INCREASE infrastructure). To focus explicitly on legacy effects (i.e., indirect rather than direct effects of the environmental factors), we measured microbial variables under the same moisture and temperature in a brief screening, and following a pre-incubation at stable conditions. Specifically, we investigated the size and composition of the soil microbial community (PLFA) alongside measurements of bacterial (leucine incorporation) and fungal (acetate in ergosterol incorporation) growth rates, previously shown to be highly responsive to changes in environmental factors, and microbial respiration. We found no legacy effects on the microbial community size, composition, growth rates, or basal respiration rates at the effect sizes used in our experimental setup (0.6 °C, about 30% precipitation reduction). Our findings support previous reports from single short-term ecosystem studies thereby providing a clear evidence base to allow long-term, broad-scale generalizations to be made. The implication of our study is that warming and summer drought will not result in legacy effects on the microbial community and their processes within the effect sizes here studied. While legacy effects on microbial processes during perturbation cycles, such as drying-rewetting, and on tolerance to drought and warming remain to be studied, our results suggest that any effects on overall ecosystem processes will be rather limited. Thus, the legacies of warming and drought should not be prioritized factors to consider when modeling contemporary rates of biogeochemical processes in soil.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 12-2016
Publisher: Springer Science and Business Media LLC
Date: 19-10-2021
DOI: 10.1007/S10021-021-00715-8
Abstract: The response of soil microbial communities to a changing climate will impact global biogeochemical cycles, potentially leading to positive and negative feedbacks. However, our understanding of how soil microbial communities respond to climate change and the implications of these changes for future soil function is limited. Here, we assess the response of soil bacterial and fungal communities to long-term experimental climate change in a heathland organo-mineral soil. We analysed microbial communities using Illumina sequencing of the 16S rRNA gene and ITS2 region at two depths, from plots undergoing 4 and 18 years of in situ summer drought or warming. We also assessed the colonisation of Calluna vulgaris roots by ericoid and dark septate endophytic (DSE) fungi using microscopy after 16 years of climate treatment. We found significant changes in both the bacterial and fungal communities in response to drought and warming, likely mediated by changes in soil pH and electrical conductivity. Changes in the microbial communities were more pronounced after a longer period of climate manipulation. Additionally, the subsoil communities of the long-term warmed plots became similar to the topsoil. Ericoid mycorrhizal colonisation decreased with depth while DSEs increased however, these trends with depth were removed by warming. We largely ascribe the observed changes in microbial communities to shifts in plant cover and subsequent feedback on soil physicochemical properties, especially pH. Our results demonstrate the importance of considering changes in soil microbial responses to climate change across different soil depths and after extended periods of time.
Publisher: Wiley
Date: 08-2013
DOI: 10.1136/VR.101660
Publisher: Springer Science and Business Media LLC
Date: 19-07-2012
Publisher: Elsevier BV
Date: 05-2023
Publisher: Frontiers Media SA
Date: 11-2016
Publisher: Springer Science and Business Media LLC
Date: 14-04-2016
Publisher: Springer Science and Business Media LLC
Date: 11-03-2016
Publisher: American Chemical Society (ACS)
Date: 02-05-2013
DOI: 10.1021/ES400183Z
Abstract: Options for the storage and disposal of animal carcasses are extremely limited in the EU after the introduction of the EU Animal By-products Regulations (ABPR EC/1774/2002), leading to animosity within the livestock sector and the call for alternative methods to be validated. Novel storage technologies such as bioreduction may be approved under the ABPR provided that they can be shown to prevent pathogen proliferation. We studied the survival of Enterococcus faecalis, Salmonella spp., E. coli O157 and porcine parvovirus in bioreduction vessels containing sheep carcasses for approximately 4 months. The vessels were operated under two different scenarios: (A) where the water within was aerated and heated to 40 °C, and (B) with no aeration or heating, to simulate vessel failure. Microbial analysis verified that pathogens were contained within the bioreduction vessel and indeed reduced in numbers with time under both scenarios. This study shows that bioreduction can provide an effective and safe on-farm storage system for livestock carcasses prior to ultimate disposal. The findings support a review of the current regulatory framework so that bioreduction is considered for approval for industry use within the EU.
Publisher: Elsevier BV
Date: 08-2019
Publisher: Elsevier BV
Date: 05-2018
Publisher: Springer Science and Business Media LLC
Date: 11-05-2021
Publisher: Springer Science and Business Media LLC
Date: 08-04-2017
Publisher: Wiley
Date: 23-12-2014
DOI: 10.1002/ECE3.1244
Publisher: Elsevier BV
Date: 11-2019
Publisher: Wiley
Date: 30-05-2013
DOI: 10.1111/NPH.12320
Abstract: The high degree to which plant roots compete with soil microbes for organic forms of nitrogen ( N ) is becoming increasingly apparent. This has culminated in the finding that plants may consume soil microbes as a source of N , but the functional significance of this process remains unknown. We used 15 N ‐ and 14 C ‐labelled cultures of soil bacteria to measure rates of acquisition of microbes by sterile wheat roots and plants growing in soil. We compared these rates with acquisition of 15 N delivered as nitrate, amino acid monomer ( l ‐alanine) and short peptide ( l ‐tetraalanine), and the rate of decomposition of [ 14 C ] microbes by indigenous soil microbiota. Acquisition of microbe 15 N by both sterile roots and roots growing in soil was one to two orders of magnitude slower than acquisition of all other forms of 15 N . Decomposition of microbes was fast enough to account for all 15 N recovered, but approximately equal recovery of microbe 14 C suggests that microbes entered roots intact. Uptake of soil microbes by wheat ( Triticum aestivum ) roots appears to take place in soil. If wheat is typical, the importance of this process to terrestrial N cycling is probably minor in comparison with fluxes of other forms of soil inorganic and organic N .
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-8609
Abstract: & & Sufficient nitrogen fertilisation is essential for obtaining the crop yields required to feed the growing population. Moreover, nitrogen applied to fields is often lost to a number of processes including denitrification, surface run-off and leaching. These processes can damage the local ecology and contaminate water supplies. Additionally, nitrogen lost as ammonia gas and the large energy input required to synthesize ammonia are both large contributors to global greenhouse gas emissions. Choosing fertilisation strategies to optimise the proportion of nitrogen taken up by crops (nitrogen use efficiency) can reduce the production of ammonia and the pollution of water supplies.& & & & We developed a mathematical model that describes the movement of water and multiple nitrogen species in soil at the field scale over a growing season. The model was then used to assess the nitrogen use efficiency of varying fertilisation strategies. We consider the effects of a number of biological, chemical, and physical processes including: root growth, root uptake, the transformation of nitrogen between different nitrogen species, and the effect of soil water movement on nitrogen transport. The resulting model is comprised of a coupled system of partial and ordinary differential equations that describe the mathematical interplay between nitrogen transport, water movement, and root uptake, which were solved numerically using a finite element approach. Numerical experiments were conducted to determine how nitrogen uptake efficiency was affected by different fertilisation strategies. We examine numerous cases by varying the quantity of fertiliser applied to the soil and the fertiliser application times.& & & & The numerical experiments suggest that, under uniform rainfall rates, the optimal fertilisation times (within the bounds of typical times found in agriculture) can result in 25% more nitrogen uptake than the worst strategies. However, there were large time periods, 28 days for the first application and 10 days for the second, which resulted in close-to-optimal nitrogen use efficiency. The results of this study, in addition to crop health and past and predicted rainfall, could be taken into consideration by farmers while choosing fertilisation times to optimise nitrogen uptake efficiency.& &
Publisher: Wiley
Date: 17-03-2022
DOI: 10.1111/GCB.16152
Abstract: Drained, lowland agricultural peatlands are greenhouse gas (GHG) emission hotspots and a large but vulnerable store of irrecoverable carbon. They exhibit soil loss rates of ~2.0 cm yr −1 and are estimated to account for 32% of global cropland emissions while producing only 1.1% of crop kilocalories. Carbon dioxide emissions account for % of their terrestrial GHG emissions and are largely controlled by water table depth. Reducing drainage depths is, therefore, essential for responsible peatland management. Peatland restoration can substantially reduce emissions. However, this may conflict with societal needs to maintain productive use, to protect food security and livelihoods. Wetland agriculture strategies will, therefore, be required to adapt agriculture to the wetland character of peatlands, and balance GHG mitigation against productivity, where halting emissions is not immediately possible. Paludiculture may substantially reduce GHG emissions but will not always be viable in the current economic landscape. Reduced drainage intensity systems may deliver partial reductions in the rate of emissions, with smaller modifications to existing systems. These compromise systems may face fewer hurdles to adoption and minimize environmental harm until societal conditions favour strategies that can halt emissions. Wetland agriculture will face agronomic, socio‐economic and water management challenges, and careful implementation will be required. Diversity of values and priorities among stakeholders creates the potential for conflict. Successful implementation will require participatory research approaches and co‐creation of workable solutions. Policymakers, private sector funders and researchers have key roles to play but adoption risks would fall predominantly on land managers. Development of a robust wetland agriculture paradigm is essential to deliver resilient production systems and wider environmental benefits. The challenge of responsible use presents an opportunity to rethink peatland management and create thriving, innovative and green wetland landscapes for everyone's future benefit, while making a vital contribution to global climate change mitigation.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Springer Science and Business Media LLC
Date: 21-12-2015
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.SCITOTENV.2017.12.250
Abstract: Nitrification inhibitors (NIs) such as dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP) provide an opportunity to reduce losses of reactive nitrogen (Nr) from agricultural ecosystems. To understand the fate and efficacy of these two inhibitors, laboratory-scale experiments were conducted with
Publisher: Wiley
Date: 24-06-2014
DOI: 10.1111/PCE.12376
Abstract: The readily available global rock phosphate (P) reserves may run out within the next 50-130 years, causing soils to have a reduced P concentration which will affect plant P uptake. Using a combination of mathematical modelling and experimental data, we investigated potential plant-based options for optimizing crop P uptake in reduced soil P environments. By varying the P concentration within a well-mixed agricultural soil, for high and low P (35.5-12.5 mg L(-1) respectively using Olsen's P index), we investigated branching distributions within a wheat root system that maximize P uptake. Changing the root branching distribution from linear (evenly spaced branches) to strongly exponential (a greater number of branches at the top of the soil) improves P uptake by 142% for low-P soils when root mass is kept constant between simulations. This causes the roots to emerge earlier and mimics topsoil foraging. Manipulating root branching patterns, to maximize P uptake, is not enough on its own to overcome the drop in soil P from high to low P. Further mechanisms have to be considered to fully understand the impact of P reduction on plant development.
Publisher: Elsevier BV
Date: 11-2017
Publisher: Springer Science and Business Media LLC
Date: 29-03-2016
Publisher: Wiley
Date: 12-12-2017
DOI: 10.1002/ECO.1928
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 11-2022
Publisher: Springer Science and Business Media LLC
Date: 09-03-2017
Publisher: Springer Science and Business Media LLC
Date: 19-10-2017
Publisher: Oxford University Press (OUP)
Date: 21-07-2014
DOI: 10.1111/JAM.12596
Abstract: To determine the risk associated with the use of carcase storage vessels on a scrapie infected farm. A stochastic quantitative risk assessment was developed to determine the rate of accumulation and fate of scrapie in a novel low-input storage system. For an ex le farm infected with classical scrapie, a mean of 10(3·6) Ovine Oral ID50 s was estimated to accumulate annually. Research indicates that the degradation of any prions present may range from insignificant to a magnitude of one or two logs over several months of storage. For infected farms, the likely partitioning of remaining prion into the sludge phase would necessitate the safe operation and removal of resulting materials from these systems. If complete mixing could be assumed, on average, the concentrations of infectivity are estimated to be slightly lower than that measured in placenta from infected sheep at lambing. This is the first quantitative assessment of the scrapie risk associated with fallen stock on farm and provides guidance to policy makers on the safety of one type of storage system and the relative risk when compared to other materials present on an infected farm.
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-473
Abstract: Extreme weather events such as prolonged flooding and extended drought are predicted to increase in frequency and intensity due to climate change. Drying and rewetting influence soil nutrient cycling and greenhouse gas emissions, particularly where nutrient inputs are high such as in agricultural systems. Flooding and drought events therefore directly influence climate change, nutrient fate and nutrient use efficiency. Soil wetting events can stimulate nitrous oxide (N2O) hot moments (disproportionately high emission rates over a short temporal period). Antecedent soil moisture conditions influence these hot moments, however this relationship and the mechanisms underlying it are not yet fully understood.Characterisation of N2O hot moments in response to current and future climatic conditions is essential to inform land management practices and nutrient application regimes. This work explores the relationship between hydrological events and resultant hot moment dynamics, and aims to elucidate the mechanisms fundamental to these processes.In this study, soil s les were subjected to four treatment conditions (n=5) for a 14-day dry period: 5%, 20%, 35% and 50% water filled pore space (WFPS). After this period, all soils were fertilised (100 kg N ha-1 ammonium nitrate) and simultaneously wetted to 90% WFPS for a further 14 days, to stimulate an N2O hot moment. Gas emissions (N2O, CO2, CH4) and soil chemistry (NO3-, NH4+, dissolved organic carbon) were analysed throughout the 28-day incubation, and untargeted metabolomics analysis was conducted on day 14 of the dry period.Our results showed hot moments to intensify under pre-drought conditions, with 5% and 20% WFPS considered a drought, versus 35% and 50% WFPS considered moist. For the first time, we showed extreme drought (5% WFPS) to significantly influence hot moment dynamics compared with moderate drought and moist conditions, with emissions occurring more abruptly and to a greater intensity over a 3-day, versus 14-day, timeframe. Possible explanations for this shift include microbial osmolyte accumulation during drought and secretion upon rewetting, resulting in a labile C pool (immediate C availability) microbial cell death during drought or rewetting (immediate C availability via necromass) or shifts in microbial community structure, or gene expression rate, following rewetting. Untargeted metabolomics analysis is being conducted to determine the extent of osmolyte accumulation between treatments, including the nature of said osmolytes for indication of species likely involved in accumulation, and to probe any disparities in active microbial metabolic pathways, and therefore function, between treatments.In summary, our results indicate antecedent conditions to significantly influence N2O hot moments following wetting, with extreme droughts appearing to shift biogeochemical process dynamics compared with dry-to-moist conditions. Microbial activity, function and substrate availability may play explanatory roles in this shift, with untargeted metabolomics promising a powerful tool to probe underlying functional mechanisms.
Publisher: Springer Science and Business Media LLC
Date: 22-03-2017
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 2014
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.SYAPM.2014.06.001
Abstract: The Fibrobacteres phylum contains two described species, Fibrobacter succinogenes and Fibrobacter intestinalis, both of which are prolific degraders of cellulosic plant biomass in the herbivore gut. However, recent 16S rRNA gene sequencing studies have identified novel Fibrobacteres in landfill sites, freshwater lakes and the termite hindgut, suggesting that members of the Fibrobacteres occupy a broader ecological range than previously appreciated. In this study, the ecology and ersity of Fibrobacteres was evaluated in 64 s les from contrasting environments where cellulose degradation occurred. Fibrobacters were detected in 23 of the 64 s les using Fibrobacter genus-specific 16S rRNA gene PCR, which provided their first targeted detection in marine and estuarine sediments, cryoconite from Arctic glaciers, as well as a broader range of environmental s les. To determine the phylogenetic ersity of the Fibrobacteres phylum, Fibrobacter-specific 16S rRNA gene clone libraries derived from 17 s les were sequenced (384 clones) and compared with all available Fibrobacteres sequences in the Ribosomal Database Project repository. Phylogenetic analysis revealed 63 lineages of Fibrobacteres (95% OTUs), with many representing as yet unclassified species. Of these, 24 OTUs were exclusively comprised of fibrobacters derived from environmental (non-gut) s les, 17 were exclusive to the mammalian gut, 15 to the termite hindgut, and 7 comprised both environmental and mammalian strains, thus establishing Fibrobacter spp. as indigenous members of microbial communities beyond the gut ecosystem. The data highlighted significant taxonomic and ecological ersity within the Fibrobacteres, a phylum circumscribed by potent cellulolytic activity, suggesting considerable functional importance in the conversion of lignocellulosic biomass in the biosphere.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 2023
DOI: 10.1016/J.ENVPOL.2022.120556
Abstract: Bioplastics (biodegradable plastics) potentially offer an encouraging alternative to conventional (petroleum-based) plastics. In practice, bioplastics inevitably generate a large number of bio-microplastics (bio-MPs, diameter <5 mm) during the degradation progress. However, the impact of bio-MPs on plant and soil health within agroecosystems remains incomplete. Here, a field study was conducted to investigate the effect of two shapes (fiber and powder) of pure polylactic acid (PLA) bio-MPs on oat (Avena sativa L.) and soybean (Glycinemax (L.) Merr.) growth and soil health. Our results showed that PLA application at a representative soil loading rate of 0.2% (w/w) had no significant effect on soil enzyme activities, soil physicochemical properties (soil water content, pH, etc.), root characteristics, plant biomass, and crop yield. Thus, we conclude that soil quality, plant health, and ecosystem multifunctionality were not affected by PLA over one growing season (5 months) in the presence of either bio-MP shape (fiber and powder) for either crop species (oat and soybean). Overall, PLA based bio-MPs may not pose a significant threat to agroecosystem functions in the short term (days to months) in the field, thus may provide a viable environmentally benign solution to replace traditional non-biodegradable plastics in agroecosystems.
Publisher: Elsevier BV
Date: 09-2014
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 20-11-2017
DOI: 10.1038/S41564-017-0062-X
Abstract: The emergence of high-throughput DNA sequencing methods provides unprecedented opportunities to further unravel bacterial bio ersity and its worldwide role from human health to ecosystem functioning. However, despite the abundance of sequencing studies, combining data from multiple in idual studies to address macroecological questions of bacterial ersity remains methodically challenging and plagued with biases. Here, using a machine-learning approach that accounts for differences among studies and complex interactions among taxa, we merge 30 independent bacterial data sets comprising 1,998 soil s les from 21 countries. Whereas previous meta-analysis efforts have focused on bacterial ersity measures or abundances of major taxa, we show that disparate licon sequence data can be combined at the taxonomy-based level to assess bacterial community structure. We find that rarer taxa are more important for structuring soil communities than abundant taxa, and that these rarer taxa are better predictors of community structure than environmental factors, which are often confounded across studies. We conclude that combining data from independent studies can be used to explore bacterial community dynamics, identify potential 'indicator' taxa with an important role in structuring communities, and propose hypotheses on the factors that shape bacterial biogeography that have been overlooked in the past.
Publisher: American Society for Microbiology
Date: 26-06-2018
DOI: 10.1128/MSYSTEMS.00025-18
Abstract: Enteric viruses cause gastrointestinal illness and are commonly transmitted through the fecal-oral route. When wastewater is released into river systems, these viruses can contaminate the environment. Our results show that we can use viromics to find the range of potentially pathogenic viruses that are present in the environment and identify prevalent genotypes. The ultimate goal is to trace the fate of these pathogenic viruses from origin to the point where they are a threat to human health, informing reference-based detection methods and water quality management.
Publisher: Elsevier BV
Date: 03-2016
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-8848
Abstract: Micro and macroplastics, produced from plastic mulch film and polytunnels, are contaminants of growing concern in agricultural settings. However, their impact on nitrogen (N) cycling and partitioning in plant-soil-microbial systems, critical to soil health and food security, is poorly understood. The differing impact of conventional plastics (e.g. low density polyethylene LDPE) and emerging biodegradable plastics on microbially-mediated N transformations is also unclear, especially with accumulation over long timescales. In this mesocosm-scale study, spring barley (Hordeum vulgare L.) was exposed to macro (1 x 1 cm) or microplastic ( 500 & #956 m) produced from LDPE or biodegradable (polylactic acid olybutylene adipate terephthalate (PLA/PBAT) 15%/85% w/w) plastic mulch at concentrations equivalent to 1 (0.02%), 10 (0.2%) and 20 (0.4% LDPE only) years of plastic mulch film use. Mesocosms were fertilised with ammonium nitrate (40 kg N ha& #8722 , 20 atom%15N), and partitioning of 15N-labelled fertiliser into plant biomass, soil and leachate yielded a partial mass balance. Soil-N partitioning was probed via diffusion of extractable ammonium and nitrate, and compound-specific 15N-stable isotope analyses of soil microbial protein. Barley chlorophyll content and growth were used to determined effects on plant health. Plant health parameters were not effected by increasing concentrations of micro or macroplastic, however, there were concentration-dependent decreases in plant 15N uptake. This was linked to increased leached nitrogen for biodegradable and LDPE micro- and macroplastic, due to changes in physical pore flow pathways. This was also observed for total soil 15N, while varying patterns in soil 15N partitioning between plastic type, size and concentrations revealed potential complexities of impacts of N cycling for macro and microplastics. Assimilation into soil microbial protein was higher for biodegradable plastics, which we associate with early-stage degradation. Microbial assimilation in the presence of LDPE was a function of abiotic impacts on leaching, with suppression of inorganic N transformations. While micro- and macroplastics altered soil N cycling, the limited impacts on plant health indicated the threshold for negative effects was not reached at agriculturally relevant concentrations during early-stage barley growth. However, changes in soil N cycling and available N will impact nitrogen use efficiency and soil organic matter dynamics. Thus, the differing impacts of conventional and biodegradable macro and microplastics, and effects of accumulation, must be considered in risk assessments for agricultural plastics.&
Publisher: Springer Science and Business Media LLC
Date: 18-09-2013
Publisher: Elsevier BV
Date: 07-2014
Publisher: Wiley
Date: 26-07-2021
Publisher: Elsevier BV
Date: 09-2021
Publisher: Frontiers Media SA
Date: 17-10-2017
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-11148
Abstract: & & Peatlands cover three percent of the global land surface. However, they store significant amounts of carbon (C), approximately 30%. Peatlands are drained to support agricultural production. It& #8217 s estimated that agriculture exploits approximately 20% of peatlands worldwide. The exploited peatlands are significant emitters of carbon dioxide (CO& sub& & /sub& ) and nitrous oxide (N& sub& & /sub& O). In Europe, agriculture is the second largest contributor of greenhouse gas (GHG) emissions. In addition to GHG emissions, we are fast losing productive peatlands it& #8217 s estimated by 2050, a third of productive peatlands will be lost. Loss of productive peatlands will affect productivity and food security.& & & & To prolong use of peatlands, ploughing in of crop residue, either from the previous season or specially grown crop, is often considered a mitigation option. Nevertheless, there is concern that fresh organic matter (FOM) might accelerate decomposition of existing organic. This study assesses effects of FOM on the emissions of CO& sub& & /sub& , methane (CH& sub& & /sub& ) and N& sub& & /sub& O in a cultivated peatland. A mesocosm experiment was carried out using intact cores with added FOM and manipulated water table (WT), -20 and -50 cm.& & & & The results show there is an effect of both WT and FOM on emissions. CO& sub& & /sub& , CH& sub& & /sub& , and N& sub& & /sub& O emissions differ in the different WT treatments. The -20 cm cores produced more methane than the -50 cm.& It is evident that leaving crop residue and then ploughing it in does not have the desired effect as it led to increased emissions.& &
Publisher: Elsevier BV
Date: 02-2014
Publisher: Springer Science and Business Media LLC
Date: 25-01-2016
DOI: 10.1038/SREP20018
Abstract: Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ~10%. However, intense summer drought, superimposed on the experiment, that began in 2003 and peaked in 2005 caused an unexpected erosion of resilience and a shift to an ASS both for the experimental drought manipulation and control plots, impairing the soil from rewetting in winter. Measurements outside plots, with vegetation removal, showed no evidence of moisture shifts. Further independent evidence supports our findings from historical soil moisture monitoring at a long-term upland hydrological observatory. The results herald the need for a new paradigm regarding our understanding of soil structure, hydraulics and climate interaction.
Publisher: Frontiers Media SA
Date: 24-02-2016
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 08-2022
Publisher: JMIR Publications Inc.
Date: 28-10-2022
DOI: 10.2196/43891
Publisher: Cold Spring Harbor Laboratory
Date: 07-06-2023
DOI: 10.1101/2023.06.07.544003
Abstract: Understanding the ersity and composition of ecological communities is a key component in predicting future bio ersity responses to environmental change and implications for ecosystem health. Linking across the domains of life and trophic levels is also essential for understanding whole-ecosystem dynamics but is often challenging to perform and limited in scope. In particular, it is unclear to what extent cross-domain correlations in bio ersity are determined by common abiotic drivers or species interactions. Here we analyse data from a unique bio ersity dataset gathered across a variety of oceanic temperate terrestrial habitats comprising 300 sites with co-located soil microbial, plant, bird and pollinator surveys along with climate and soil physicochemical information. Soil microbial groups are analysed using metabarcoding of the 16S, ITS and 18S DNA regions, allowing in depth characterisation of microbial community composition and ersity. Using Bayesian hierarchical regression models, we show that a positive correlation between plant ersity and soil bacterial and fungal ersity is actually driven by non-linear responses to changing soil pH, with the exception of AM fungi which show positive associations with plant ersity at low soil pH. However, positive associations between plant ersity and bird, and pollinator ersity persisted after accounting for changes in climate. The composition of soil bacteria, fungi, bees, butterflies and birds are all impacted by the plant community in conjunction with edaphic factors. The heterotrophic protistan community strongly tracks the bacterial community in both ersity and composition. The residual associations between taxa after accounting for environmental variation in a joint species distribution model revealed cross-domain correlations. Overall, our results comprehensively show the differential responses, linkages and ergences of cross-Kingdom ersity and composition in aboveground-belowground ecological communities to environmental and biotic properties.
Publisher: Cold Spring Harbor Laboratory
Date: 30-06-2021
DOI: 10.1101/2021.06.28.448043
Abstract: Grassland ecosystems form 30-40% 1 of total land cover and provide essential ecosystem services, including food production, flood mitigation and carbon storage 2 . Their productivity is closely related to soil microbial communities 3 , yet the role of viruses within these critical ecosystems is currently undercharacterised 4 and in particular, our knowledge of soil RNA viruses is significantly limited 5 . Here, we applied viromics 6 to characterise soil RNA viral communities along an altitudinal productivity gradient of peat, managed grassland and coastal soils. We identified 3,462 viral operational taxonomic units (vOTUs) and assessed their spatial distribution, phylogenetic ersity and potential host ranges. Soil types exhibited showed minimal similarity in viral community composition, but with -fold more vOTUs shared between managed grassland soils when compared with peat or coastal soils. Phylogenetic analyses of viral sequences predicted broad host ranges including bacteria, plants, fungi, vertebrates and invertebrates, contrasting with soil DNA viromes which are typically dominated by bacteriophages 7 . RNA viral communities therefore likely have the ability to influence soil ecosystems across multiple trophic levels. Our study represents an important step towards the characterisation of terrestrial RNA viral communities and the intricate interactions with their hosts, which will provide a more holistic view of the biology of economically and ecologically important terrestrial ecosystems.
Publisher: Oxford University Press (OUP)
Date: 02-06-2014
DOI: 10.1111/JAM.12534
Abstract: The aim of this study was to determine if domestic cooking practices can reduce concentrations of norovirus (NoV) and F-specific RNA (FRNA) bacteriophage in experimentally contaminated mussels. Mussels (n = 600) contaminated with NoV and FRNA bacteriophage underwent four different cooking experiments performed in triplicate at ~70°C and >90°C. Concentrations of infectious FRNA bacteriophage (using a plaque assay) were compared with concentrations of FRNA bacteriophage and NoV determined using a standardised RT-qPCR. Initial concentrations of infectious FRNA bacteriophage (7·05 log10 PFU g(-1) ) in mussels were not significantly reduced in simmering water (~70°C) however, cooking at higher temperatures (>90°C) reduced infectious FRNA bacteriophage to undetected levels within 3 min. Further investigation determined the time required for a 1-log reduction of infectious FRNA bacteriophage at 90°C to be 42 s therefore a >3-log reduction in infectious virus can be obtained by heating mussel digestive tissue to 90°C for 126 s. Domestic cooking practices based on shell opening alone do not inactivate infectious virus in mussels, however, cooking mussels at high temperatures is effective to reduce infectious virus concentrations and the risk of illness in consumers. The data will contribute towards evidence-based cooking recommendations for shellfish to provide a safe product for human consumption.
Publisher: Elsevier BV
Date: 04-2014
Publisher: Springer Science and Business Media LLC
Date: 13-05-2015
Publisher: Emerald
Date: 03-08-2015
Abstract: – Food poisoning attributable to the home generates a large disease burden, yet is an unregulated and largely unobserved domain. Investigating food safety awareness and routine practices is fraught with difficulties. The purpose of this paper is to develop and apply a new survey tool to elicit awareness of food hazards. Data generated by the approach are analysed to investigate the impact of oberservable heterogeneity on food safety awareness. – The authors develop a novel Watch-and-Click survey tool to assess the level of awareness of a set of hazardous food safety behaviours in the domestic kitchen. Participants respond to video footage stimulus, in which food hazards occur, via mouse clicks/screen taps. This real-time response data is analysed via estimation of count and logit models to investigate how hazard identification patterns vary over observable characteristics. – User feedback regarding the Watch-and-Click tool approach is extremely positive. Substantive results include significantly higher hazard awareness among the under 60s. People who thought they knew more than the average person did indeed score higher but people with food safety training/experience did not. Vegetarians were less likely to identify four of the five cross-contamination hazards they observed. – A new and engaging survey tool to elicit hazard awareness with real-time scores and feedback is developed, with high levels of user engagement and stakeholder interest. The approach may be applied to elicit hazard awareness in a wide range of contexts including education, training and research.
Publisher: Elsevier BV
Date: 09-2015
Publisher: Wiley
Date: 25-08-2016
DOI: 10.1111/SUM.12295
Abstract: Dissolved organic matter ( DOM ) in soil solution represents a complex mixture of organic molecules and plays a central role in carbon and nitrogen cycling in plant–microbial–soil systems. We tested whether excitation–emission matrix ( EEM ) fluorescence spectroscopy can be used to characterize DOM and support previous findings that the majority of DOM is of high molecular weight ( MW ). EEM fluorescence spectroscopy was used in conjunction with MW fractionation to characterize DOM in soil solution from a grassland soil land management gradient in North Wales, UK . Data analysis suggested that three distinct fluorescence components could be separated and identified from the EEM data. These components were identified as being of humic‐like or fulvic‐like origin. Contrary to expectations, the majority of the fluorescence signal occurred in the small MW ( kDa) fraction, although differences between soils from the differently managed grasslands were more apparent in larger MW fractions. We conclude that following further characterization of the chemical composition of the fluorophores, EEM has potential as a sensitive technique for characterizing the small MW phenolic fraction of DOM in soils.
Publisher: Elsevier BV
Date: 07-2016
Publisher: Elsevier BV
Date: 08-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4EM00031E
Abstract: Review of the interaction of human microbial pathogens, nutrients and flocs from rivers to coasts.
Publisher: Elsevier BV
Date: 10-2013
Publisher: Research Square Platform LLC
Date: 15-09-2020
DOI: 10.21203/RS.3.RS-62137/V1
Abstract: The discharge of wastewater-derived viruses in aquatic environments impacts catchment-scale virome composition and is a potential hazard to human health. Here, we used viromic analysis of RNA and DNA virus-like particle preparations to track virus communities entering and leaving wastewater treatment plants and the connecting river catchment system and estuary. We found substantial viral ersity and geographically distinct virus communities associated with different wastewater treatment plants. River and estuarine water bodies harboured more erse viral communities in downstream locations, influenced by tidal movement and proximity to wastewater treatment plants. Shellfish and beach sand were enriched in viral communities when compared with the surrounding water, acting as entrapment matrices for virus particles. We reconstructed ,000 partial viral genomes into 10,149 species-level groups, dominated by dsDNA and (+)ssRNA bacteriophages (Caudovirales and Leviviridae). We identified 73 (partial) genomes comprising six families that could pose a risk to human health Astroviridae, Caliciviridae (sapovirus), Picornaviridae (cocksackievirus), Reoviridae (rotavirus), Parvoviridae and Circoviridae. Based on the pattern of viral incidence, we observe that wastewater-derived viral genetic material is commonly deposited in the environment, but due to fragemented nature of these viral genomes, the risk to human health is low, and is more likely driven by community transmission, with wastewater-derived viruses subject to cycles of dilution, enrichment and virion degradation influenced by local geography, weather events and tidal effects. Our data illustrate the utility of viromic analyses for wastewater- and environment-based epidemiology, and we present a conceptual model for the circulation of viruses in a freshwater catchment.
Publisher: Elsevier BV
Date: 12-2014
Publisher: Copernicus GmbH
Date: 28-04-2021
DOI: 10.5194/ISMC2021-11
Abstract: & & Half of the nitrogen applied to arable-fields is lost through several processes linked to soil moisture. Low soil moisture limits nitrogen mobility reducing nitrogen-uptake while wetter conditions can increase nitrogen leaching. Rainfall ultimately governs soil moisture and the fate of nitrogen in soil. However, the interaction between rainfall and nitrogen use efficiency (NUE) remains poorly understood.& & & & We developed a field-scale modelling platform that describes coupled water and nitrogen transport, root growth and uptake, rainfall, the nitrogen-cycle and leaching to assess the NUE of split fertilisations with realistic rainfall patterns. The model was solved for every possible split fertilisation timing in 200+ growing seasons to determine optimal timings. Two previous field trials regarding rainfall and NUE had contrasting results: wetter years have enhanced fertiliser loss and drier years reduced plant nitrogen uptake. By choosing appropriate fertilisation timings in the model we could recreate the two contrasting trends and maintain variability in the data. However, we found by choosing other fertilisation timings we could mitigate the leaching in wetter years. Optimised timings could increase plant nitrogen uptake by up to 35% compared to the mean in dry years. Plant uptake was greatest under drier conditions due to mitigated leaching, but less likely to occur due to low nitrogen mobility. Optimal fertilisation timings varied dramatically depending on the rainfall patterns. Historic and projected rainfall patterns from 1950-2069 were used in the model. We found optimal NUE has a decrease from 2022-2040 due to increased heavy rainfall events and optimal fertilisation timings are later in the season but varied largely on a season-to-season basis.& & & & The results are a step towards achieving improved nitrogen efficiency in agriculture by using the & #8216 at the right time& #8217 agronomic-strategy in the & #8216 Rs& #8217 of improved nitrogen fertilisation. Our results can help determine nitrogen fertilisation timings in changing climates.& &
Publisher: Elsevier BV
Date: 05-2018
DOI: 10.1016/J.SCITOTENV.2017.12.179
Abstract: Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a erse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7-17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research is required to critically test this across a wider range of ecosystems.
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-8648
Abstract: & & & & Soil microbial communities contribute many ecosystem services including soil structure maintenance, crop synergy, and carbon sequestration. However, it is not fully understood how the health of microbial communities is effected by fertilization at the pore scale. This study investigates the nature of nitrogen (N) transport and reactions at the soil pore scale in order to better understand the influence of soil structure and moisture content on microbial community health. Using X-ray Computed Tomography (XRCT) scans, we reconstructed a microscale description of a dry soil-pore geometry as a computational mesh. Solving two-phase water/air models produced pore-scale water distributions at 15, 30 and 70% water-filled pore volume. The model considers ammonium (NH& sub& & /sub& & sup& +& /sup& ), nitrate (NO& sub& & /sub& & sup& -& /sup& ) and dissolved organic N (DON), and includes N immobilization, ammonification and nitrification processes, as well as diffusion in soil-solution. We simulated the dissolution of a fertilizer pellet and a pore scale N cycle at the three different water saturation conditions. To aid interpretation of the model results, microbial activity at a range of N concentrations was quantified experimentally using labelled C to infer microbial activity based on CO& sub& & /sub& respiration measurements in bulk soil. The pore-scale model showed that the diffusion and concentration of N in water films is critically dependent upon soil moisture and N species. We predicted that the maximum NH& sub& & /sub& & sup& +& /sup& and NO& sub& & /sub& & sup& -& /sup& concentrations in soil solution around the pellet under low water saturation conditions (15%) are in the order of 1x10& sup& & /sup& and 1x10& sup& & /sup& mol m& sup& -3& /sup& respectively (1-10 M), and under higher water saturation conditions (70%) where on the order of 2x10& sup& & /sup& and 1x10& sup& & /sup& mol m& sup& -3& /sup& , respectively (0.1-1 M). Supporting experimental evidence regarding microbial respiration suggests that these concentrations at the pore-scale would be sufficient to reduce microbial activity in the zone immediately around the fertilizer pellet (ranging from 0.9 to 3.8 mm depending on soil moisture status), causing a major loss of soil biological activity by up to 90%. This model demonstrates the importance of pore-scale processes in regulating N movement in soil with special capability to predict the effects of fertilizers on rhizosphere-scale processes and the root microbiome.& & & / &
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.ENVPOL.2013.04.019
Abstract: The addition of calcium carbonate to catchments or watercourses--liming--has been used widely to mitigate freshwater acidification but the abatement of acidifying emissions has led to questions about its effectiveness and necessity. We conducted a systematic review and meta-analysis of the impact of liming streams and rivers on two key groups of river organisms: fish and invertebrates. On average, liming increased the abundance and richness of acid-sensitive invertebrates and increased overall fish abundance, but benefits were variable and not guaranteed in all rivers. Where B-A-C-I designs (before-after-control-impact) were used to reduce bias, there was evidence that liming decreased overall invertebrate abundance. This systematic review indicates that liming has the potential to mitigate the symptoms of acidification in some instances, but effects are mixed. Future studies should use robust designs to isolate recovery due to liming from decreasing acid deposition, and assess factors affecting liming outcomes.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 10-2020
Publisher: Springer Science and Business Media LLC
Date: 12-11-2013
DOI: 10.1007/S11356-013-2272-Y
Abstract: Recycled waste wood is being increasingly used for energy production however, organic and metal contaminants in by-products produced from the combustion yrolysis residue may pose a significant environmental risk if they are disposed of to land. Here we conducted a study to evaluate if highly polluted biochar (from pyrolysis) and ash (from incineration) derived from Cu-based preservative-treated wood led to different metal (e.g., Cu, As, Ni, Cd, Pb, and Zn) bioavailability and accumulation in sunflower (Helianthus annuus L.). In a pot experiment, biochar at a common rate of 2 % w/w, corresponding to ∼50 t ha(-1), and an equivalent pre-combustion dose of wood ash (0.2 % w/w) were added to a Eutric Cambisol (pH 6.02) and a Haplic Podzol (pH 4.95), respectively. Both amendments initially raised soil pH, although this effect was relatively short-term, with pH returning close to the unamended control within about 7 weeks. The addition of both amendments resulted in an exceedance of soil Cu statutory limit, together with a significant increase of Cu and plant nutrient (e.g., K) bioavailability. The metal-sorbing capacity of the biochar, and the temporary increase in soil pH caused by adding the ash and biochar were insufficient to offset the amount of free metal released into solution. Sunflower plants were negatively affected by the addition of metal-treated wood-derived biochar and led to elevated concentration of metals in plant tissue, and reduced above- and below-ground biomass, while sunflower did not grow at all in the Haplic Podzol. Biochar and ash derived from wood treated with Cu-based preservatives can lead to extremely high Cu concentrations in soil and negatively affect plant growth. Identifying sources of contaminated wood in waste stream feedstocks is crucial before large-scale application of biochar or wood ash to soil is considered.
Publisher: Elsevier BV
Date: 09-2015
Publisher: Frontiers Media SA
Date: 2013
Publisher: Elsevier BV
Date: 08-2016
Publisher: Springer Science and Business Media LLC
Date: 19-06-2017
Publisher: Wiley
Date: 11-2016
Abstract: Storing livestock manure is the primary stage of manure management where microbial processes and chemical reactions result in the release of methane (CH 4 ), nitrous oxide (N 2 O), ammonia (NH 3 ), and carbon dioxide (CO 2 ). This study examined the reduction of CH 4 emissions from slurry storage under two temperatures (cool [10°C] and warm [30°C]) when a glucose‐rich substrate (brewing sugar) and activated effective microorganisms were applied at 10% (w/w) and 5% (v/w), respectively. Brewing sugar addition influenced microbial anaerobic respiration, resulting in a reduction of slurry pH to .0, through “self‐acidification” caused by lactic acid production. Subsequently, CH 4 emissions were significantly reduced by 87 and 99% in the cool and warm environments, respectively. The effective microorganism treatment did not change the chemical characteristics of the slurry but reduced CH 4 emissions by 17 and 27% ( P 0.05) in the cool and warm environments, respectively. These results suggest that self‐acidification after addition of a carbon source may be a promising alternative to slurry acidification using concentrated acids. Glucose addition leads to slurry self‐acidification by lactic acid production. Self‐acidification of slurry (pH .0) reduced CH 4 emissions by %. Bio‐augmentation with effective microorganisms reduced CH 4 emissions by 17–27%.
Publisher: Wiley
Date: 23-12-2014
DOI: 10.1111/GCB.12784
Abstract: Increasing atmospheric carbon dioxide ( CO 2 ) concentration is both a strong driver of primary productivity and widely believed to be the principal cause of recent increases in global temperature. Soils are the largest store of the world's terrestrial C. Consequently, many investigations have attempted to mechanistically understand how microbial mineralisation of soil organic carbon ( SOC ) to CO 2 will be affected by projected increases in temperature. Most have attempted this in the absence of plants as the flux of CO 2 from root and rhizomicrobial respiration in intact plant‐soil systems confounds interpretation of measurements. We compared the effect of a small increase in temperature on respiration from soils without recent plant C with the effect on intact grass swards. We found that for 48 weeks, before acclimation occurred, an experimental 3 °C increase in sward temperature gave rise to a 50% increase in below ground respiration (ca. 0.4 kg C m −2 Q 10 = 3.5), whereas mineralisation of older SOC without plants increased with a Q 10 of only 1.7 when subject to increases in ambient soil temperature. Subsequent 14 C dating of respired CO 2 indicated that the presence of plants in swards more than doubled the effect of warming on the rate of mineralisation of SOC with an estimated mean C age of ca. 8 years or older relative to incubated soils without recent plant inputs. These results not only illustrate the formidable complexity of mechanisms controlling C fluxes in soils but also suggest that the dual biological and physical effects of CO 2 on primary productivity and global temperature have the potential to synergistically increase the mineralisation of existing soil C.
Publisher: Elsevier BV
Date: 02-2018
Publisher: Elsevier BV
Date: 06-2013
Publisher: MDPI AG
Date: 03-03-2017
DOI: 10.3390/F8030070
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-9464
Abstract: The flux of nutrients into rivers is rising due largely to inputs from the expansion and intensification of agriculture along with inputs from treatment of human waste. This trend is set to continue due to changing climate and increasing population while we attempt to balance food security and environmental impact. While water quality legislation focuses on inorganic nutrients due to their bioavailability, the proportion of the total nitrogen (N) flux, which is organic in its molecular composition is important in many riverine systems. Despite this, the impact of organic N on ecosystem function is currently poorly understood. Here we address part of this knowledge gap using compound-specific stable isotope probing to investigate the extent to which dissolved organic matter substrates are bioavailable to stream biota and if they can be directly assimilated.Stable isotope probing was used to identify and quantify the routes of biotic uptake of organic N and carbon (C) into stream biota. Here, we added 15N labelled (nitrate, ammonium, glucosamine, sheep urine) and doubly labelled (15N/13C) substrates (glutamic acid, urea, glycine) to in-stream mesocosms containing water and epilithon, and bryophyte communities from the River Conwy North Wales, UK. S les of epilithon and bryophyte were removed from the incubations after 2, 6, 12, 24 and 48 h and rates of assimilation of the labelled substrate were determined using bulk 15N/13C, followed by compound-specific 15N/13C analysis of extracted amino acids. This method allowed us to demonstrate the assimilation of labelled organic substrates into newly biosynthesised proteinaceous amino acids and to determine if they were utilised as intact organic molecules.The findings showed that the majority of the organic N substrates tested were directly bioavailable for utilisation as intact molecules by the stream biota, except for urea where transformation occurred before uptake. The data also showed that there were differences in the rates of assimilation both between the organic substrates added and between the epilithon and bryophyte communities. This work illustrates the analytical power of using doubly labelled 13C, 15N compounds in a stable isotope probing experiment, as the ability to trace the utilisation of both the N and C simultaneously had provided significant new insights in the biotic assimilation of organic-N substrates. Our findings confirm the importance of organic nutrients in ecosystem function and the need for changes to water quality legislation to reflect this.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 28-07-2017
DOI: 10.1038/S41598-017-06082-6
Abstract: Ecological thresholds, which represent points of rapid change in ecological properties, are of major scientific and societal concern. However, very little research has focused on empirically testing the occurrence of thresholds in temperate terrestrial ecosystems. To address this knowledge gap, we tested whether a number of bio ersity, ecosystem functions and ecosystem condition metrics exhibited thresholds in response to a gradient of forest dieback, measured as changes in basal area of living trees relative to areas that lacked recent dieback. The gradient of dieback was s led using 12 replicate study areas in a temperate forest ecosystem. Our results provide novel evidence of several thresholds in bio ersity (namely species richness of ectomycorrhizal fungi, epiphytic lichen and ground flora) for ecological condition (e.g. sward height, palatable seedling abundance) and a single threshold for ecosystem function (i.e. soil respiration rate). Mechanisms for these thresholds are explored. As climate-induced forest dieback is increasing worldwide, both in scale and speed, these results imply that threshold responses may become increasingly widespread.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Springer Science and Business Media LLC
Date: 15-12-2013
Publisher: Wiley
Date: 26-02-2015
DOI: 10.1111/GCBB.12246
Publisher: Informa UK Limited
Date: 28-11-2016
Publisher: Elsevier BV
Date: 05-2013
Publisher: Wiley
Date: 17-09-2012
DOI: 10.1111/GCBB.12007
Publisher: Springer Science and Business Media LLC
Date: 21-04-2021
DOI: 10.1038/S41586-021-03523-1
Abstract: Global peatlands store more carbon than is naturally present in the atmosphere
Publisher: Elsevier BV
Date: 04-2014
Publisher: Wiley
Date: 02-06-2020
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.JHAZMAT.2014.05.053
Abstract: Pyrolysis or combustion of waste wood can provide a renewable source of energy and produce byproducts which can be recycled back to land. To be sustainable requires that these byproducts pose minimal threat to the environment or human health. Frequently, reclaimed waste wood is contaminated by preservative-treated timber containing high levels of heavy metals. We investigated the effect of feedstock contamination from copper-preservative treated wood on the behaviour of pyrolysis-derived biochar and combustion-derived ash in plant-soil systems. Biochar and wood ash were applied to soil at typical agronomic rates. The presence of preservative treated timber in the feedstock increased available soil Cu however, critical Cu guidance limits were only exceeded at high rates of feedstock contamination. Negative effects on plant growth and soil quality were only seen at high levels of biochar contamination (>50% derived from preservative-treated wood). Negative effects of wood ash contamination were apparent at lower levels of contamination (>10% derived from preservative treated wood). Complete removal of preservative treated timber from wood recycling facilities is notoriously difficult and low levels of contamination are commonplace. We conclude that low levels of contamination from Cu-treated wood should pose minimal environmental risk to biochar and ash destined for land application.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.WATRES.2016.09.002
Abstract: Bivalve shellfish have the capacity to accumulate norovirus (NoV) from waters contaminated with human sewage. Consequently, shellfish represent a major vector for NoV entry into the human food chain, leading to gastrointestinal illness. Identification of areas suitable for the safe cultivation of shellfish requires an understanding of NoV behaviour upon discharge of municipal-derived sewage into coastal waters. This study exploited the potential of edible mussels (Mytilus edulis) to accumulate NoV and employed the ISO method for quantification of NoV within mussel digestive tissues. To evaluate the spatial spread of NoV from an offshore sewage discharge pipe, mesh cages of mussels were suspended from moorings deployed in a 9 km
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JENVMAN.2018.11.113
Abstract: Peat soils represent an important global carbon (C) sink, but can also provide a highly fertile medium for growing horticultural crops. Sustainable crop production on peat soils involves a trade-off between ensuring food security and mitigating typically high greenhouse gas (GHG) emissions and rates of soil C loss. An alternative approach to resource intensive field-based monitoring of GHG fluxes for all potential management scenarios is to use a process-based model driven by existing field data to estimate emissions. The aim of this study was to evaluate the suitability of the Denitrification-Decomposition (DNDC) model for estimating emissions of CO
Publisher: Elsevier BV
Date: 09-2016
Publisher: Springer Science and Business Media LLC
Date: 08-04-2022
DOI: 10.1038/S43705-022-00110-X
Abstract: The distribution and ersity of RNA viruses in soil ecosystems are largely unknown, despite their significant impact on public health, ecosystem functions, and food security. Here, we characterise soil RNA viral communities along an altitudinal productivity gradient of peat, managed grassland and coastal soils. We identified 3462 viral contigs in RNA viromes from purified virus-like-particles in five soil-types and assessed their spatial distribution, phylogenetic ersity and potential host ranges. Soil types exhibited minimal similarity in viral community composition, but with -fold more viral contigs shared between managed grassland soils when compared with peat or coastal soils. Phylogenetic analyses predicted soil RNA viral communities are formed from viruses of bacteria, plants, fungi, vertebrates and invertebrates, with only 12% of viral contigs belonging to the bacteria-infecting Leviviricetes class. 11% of viral contigs were found to be most closely related to members of the Ourmiavirus genus, suggesting that members of this clade of plant viruses may be far more widely distributed and erse than previously thought. These results contrast with soil DNA viromes which are typically dominated by bacteriophages. RNA viral communities, therefore, have the potential to exert influence on inter-kingdom interactions across terrestrial biomes.
Publisher: Elsevier BV
Date: 08-2013
Publisher: Springer Science and Business Media LLC
Date: 03-12-2013
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 12-2016
Publisher: Springer Science and Business Media LLC
Date: 04-02-2016
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-22358
Abstract: & & The ability of an agricultural soil to function and sustainably provide an increasing food supply for a rapidly increasing global population has become of vital worldwide importance. Traditionally, soil health has been determined on a physico-chemical basis with biological characteristics often being ignored. Although several biological methods have been proposed, to date, none of these methods adequately indicate soil health. One method proposed to correct these circumstances is profiling or fingerprinting the volatile organic compounds (VOCs) from soil. VOCs in soils originate from a large variety of biological sources microbial, fungal, animal- and plant-derived. These volatilomes are vital to plant/fungi-microbe and animal/human-microbe interactions and therefore offer a potential reactive, functional diagnostic tool to determine soil health by investigating the intra and interspecies interactions.& & & & The standard methodology for VOC profiling has been solid phase microextraction (SPME). This automated VOC extraction method allows the monitoring of the community structure, physiological state, and activity of any microbial community in a soil without the need of manual extraction or cultivation procedures. Other common techniques that could be used to monitor the VOC fingerprints from soils include high capacity sorptive extraction (HCSE) or thermal desorption using sorbent-packed tubes for passive, in-situ s ling of soil gas.& & & & Combining each of these techniques with an innovative cryogen-free focussing and pre-concentration trap has two main advantages:& & & ol& & li& All extraction techniques can run on a single platform without the need to change the hardware.& /li& & li& Single (SPME-trap) and multiple extractions (SPME-trap with enrichment) can be carried out automatically on a single s le to increase the analytical sensitivity, thus achieving a comprehensive VOC profile.& /li& & /ol& & & In this microcosm study, soils were treated in three different ways and their VOC profiles investigated. A & #8216 good& #8217 soil comprised of brown earth and compost, a & #8216 medium& #8217 soil of unaltered brown earth and a & #8216 bad& #8217 soil of brown earth held under eutrophic anaerobic conditions. 2 g of each soil was analysed with SPME-trap, SPME-trap with enrichment, HCSE and sorbent tubes. Both a targeted (phenol, p-cresol, isophorone, indole and trans-& #946 -ionone) and untargeted approach indicates that there are significant differences between the different soil types. By increasing the sensitivity of the untargeted approach with SPME-trap enrichment, this study was able to extend the number of VOCs identified, allowing a much more comprehensive VOC profile and possibility to determine the actual functions of specific VOC produced by the soil microbial community.& &
Publisher: Springer Science and Business Media LLC
Date: 23-03-2017
Publisher: Elsevier BV
Date: 2016
Publisher: Informa UK Limited
Date: 05-10-2017
Publisher: Oxford University Press (OUP)
Date: 02-08-2014
DOI: 10.1093/JXB/ERU284
Publisher: Elsevier BV
Date: 04-2018
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 05-2021
Publisher: Springer Science and Business Media LLC
Date: 10-10-2016
Publisher: JMIR Publications Inc.
Date: 28-10-2022
Abstract: he COVID-19 pandemic necessitated rapid real-time surveillance of epidemiological data to advise governments and the public, but the accuracy of these data depend on myriad auxiliary assumptions, not least accurate reporting of cases by the public. Wastewater monitoring has emerged internationally as an accurate and objective means for assessing disease prevalence with reduced latency and less dependence on public vigilance, reliability, and engagement. How public interest aligns with COVID-19 personal testing data and wastewater monitoring is, however, very poorly characterised. his study assesses the associations between internet search volume data relevant to COVID-19, public healthcare statistics and national-scale wastewater monitoring of SARS-CoV-2 across South Wales, UK over time to investigate how interest in the pandemic may reflect the prevalence of SARS-CoV-2, as detected by national testing and wastewater monitoring. elative search volume data from Google Trends for search terms linked to the COVID-19 pandemic were extracted and compared against government-reported COVID-19 statistics and RT-qPCR SARS-CoV-2 data generated from wastewater in South Wales, UK, using multivariate linear models and correlation analysis. astewater monitoring data suggests that prevalence of the virus exceeded that reported in self-testing national reports. Google search volumes surrounding the COVID-19 pandemic also decreased across the same period, potentially suggesting a reduction in public interest is reflected in lower volumes of self-testing and reporting with consequential loss of accuracy of those data. astewater monitoring presents a valuable means for assessing population-level prevalence of SARS-CoV-2. The importance of such monitoring is increasingly clear as a means of objectively assessing the prevalence of COVID-19 despite the dynamic interest and participation of the public. Increased accessibility of wastewater monitoring data to the public, as is the case for other national data, may enhance public engagement with these forms of monitoring.
Publisher: Wiley
Date: 09-09-2018
DOI: 10.1111/NPH.15433
Abstract: Despite considerable attention over the last 25 yr, the importance of early protein breakdown products to plant nitrogen (N) nutrition remains uncertain. We used rhizosphere injection of
Publisher: Informa UK Limited
Date: 28-02-2014
DOI: 10.1080/09593330.2014.885585
Abstract: Bioreduction is a novel method for the on-farm storage of fallen stock in a vessel containing water that is heated and aerated, prior to disposal. The combination of a mesophilic temperature and high bacterial population leads to rapid degradation of carcasses due to microbial and enzymatic breakdown of protein material and ultimately the reduction in volume of waste to be disposed. The system could, however, be improved if more was known about the changes that occur during a bioreduction cycle. Pig carcasses were placed within two commercial-scale bioreduction vessels (BVs) (6.5 m3 capacity) and the changes in physicochemical parameters, enzymatic activity, gas emissions and microbial communities were analysed over 56 days. Analyses showed that each vessel displayed different physicochemical parameters. The microbial communities within both vessels were also distinct, though they converged between days 28 and 42 before again erging. Of the enzymes assayed, acetylesterases showed the highest activity during initial stages, with a subsequent increase in lipase towards the end. All other enzymes showed little activity in comparison. Despite active aeration of the vessels, conditions were redox-constrained, leading to the emission of gases associated with anaerobic conditions, namely NH3 and H2S. It was concluded that no single parameter governed the biochemical processes and that each BV will have its own unique microbial population and hence rate of decomposition. Further work is needed to increase the rate of bioreduction through bioaugmentation or developing enzyme additives.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 11-2019
Publisher: Springer Science and Business Media LLC
Date: 13-06-2015
Publisher: Elsevier BV
Date: 09-2022
Publisher: Public Library of Science (PLoS)
Date: 14-03-2014
Publisher: Public Library of Science (PLoS)
Date: 14-11-2014
Publisher: Elsevier BV
Date: 02-2018
Publisher: Springer Science and Business Media LLC
Date: 15-08-2012
Publisher: Elsevier BV
Date: 02-2018
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/AN15613
Abstract: Ruminant urine nitrogen (N) concentration and volume are important parameters influencing the size and N loading rate of urine patches deposited to soil. Such parameters can influence N cycling and emissions of the greenhouse gas, nitrous oxide (N2O) from grazed grassland, yet, there is limited information on the effect of these parameters within typical ranges reported for sheep. We used an automated, high-frequency gas monitoring system to investigate N2O emissions from varying urine N application rates and patch sizes under field conditions. Using artificial sheep urine, we manipulated urine N concentration to provide two urine N application rates (4 and 16 g N/L equivalent to 200 and 800 kg N/ha). We investigated the effect of urine patch size with equal N application rates (4 × 125 cm2 vs 500 cm2, at 200 and 800 kg N/ha) and the effect of patch size with unequal N application rates, but the same total amount of N applied (62.5 mL over 125 cm2 at 800 kg N/ha and 250 mL over 500 cm2 at 200 kg N/ha). Cumulative emissions of N2O generally increased with N loading rate, whether applied as one large urine patch or four smaller ones. Cumulative N2O emissions increased when the N was applied in four smaller urine patches compared with one large patch this difference was significant at 800 kg N/ha, but not at 200 kg N/ha. When the total amount of N applied was held constant (1 g of N), the amount of N2O released was similar when urine was applied as a high N concentration small patch (800 kg N/ha) compared with a low N concentration large patch (200 kg N/ha). Urine N2O emission factors in this study were, on average, 10 times lower than the IPCC default of 1% for sheep excreta. This research clearly demonstrates that the chemical and physical nature of the urine patch influences N2O emissions, yet further research is required to gather more data on typical sheep urine volumes (in idual and daily), urination frequency, urine N concentrations and the typical volumes of soil influenced by urine deposition, to provide more accurate estimates of emissions from sheep grazed pastures.
Publisher: Elsevier BV
Date: 07-2022
Publisher: FapUNIFESP (SciELO)
Date: 2021
Publisher: Elsevier BV
Date: 05-2014
Publisher: MDPI AG
Date: 23-11-2022
DOI: 10.3390/S22239100
Abstract: Crop productivity is highly dependent on the availability of soluble nitrogen (N), e.g. nitrate, in soil. When N levels are low, fertilisers are applied to replenish the soil’s reserves. Typically the timing of these applications is based on paper-based guidance and sensor-based measurements of canopy greenness, which provides an indirect measure of soil N status. However this approach often means that N fertiliser is applied inappropriately or too late, resulting in excess N being lost to the environment, or too little N to meet crop demand. To promote greater N use efficiency and improve agricultural sustainability, we developed an Internet of Things (IoT) approach for the real-time measurement of soil nitrate levels using ion-selective membrane sensors in combination with digital soil moisture probes. The node incorporates state-of-the-art IoT connectivity using a LoRaWAN transceiver. The sensing platform can transfer real-time data via a cloud-connected gateway for processing and storage. In summary, we present a validated soil sensor system for real-time monitoring of soil nitrate concentrations, which can support fertiliser management decisions, improve N use efficiency and reduce N losses to the environment.
Publisher: Elsevier BV
Date: 03-2013
Publisher: Wiley
Date: 16-12-2014
Publisher: Springer Science and Business Media LLC
Date: 25-07-2018
DOI: 10.1038/S41598-018-29559-4
Abstract: Proteins play a crucial role in many soil processes, however, standardised methods to extract soluble protein from soil are lacking. The aim of this study was to compare the ability of different extractants to quantify the recovery of soluble proteins from three soil types (Cambisol, Ferralsol and Histosol) with contrasting clay and organic matter contents. Known amounts of plant-derived 14 C-labelled soluble proteins were incubated with soil and then extracted with solutions of contrasting pH, concentration and polarity. Protein recovery proved highly solvent and soil dependent (Histosol Cambisol Ferralsol) and no single extractant was capable of complete protein recovery. In comparison to deionised water (10–60% of the total protein recovered), maximal recovery was observed with NaOH (0.1 M 61–80%) and Na-pyrophosphate (0.05 M, pH 7.0 45–75% recovery). We conclude that the dependence of protein recovery on both extractant and soil type prevents direct comparison of studies using different recovery methods, particularly if no extraction controls are used. We present recommendations for a standard protein extraction protocol.
Publisher: Elsevier BV
Date: 12-2015
Publisher: IWA Publishing
Date: 02-2022
DOI: 10.2166/WH.2022.185
Abstract: The COVID-19 pandemic has resulted in over 340 million infection cases (as of 21 January 2022) and more than 5.57 million deaths globally. In reaction, science, technology and innovation communities across the globe have organised themselves to contribute to national responses to COVID-19 disease. A significant contribution has been from the establishment of wastewater-based epidemiological (WBE) surveillance interventions and programmes for monitoring the spread of COVID-19 in at least 55 countries. Here, we examine and share experiences and lessons learnt in establishing such surveillance programmes. We use case studies to highlight testing methods and logistics considerations associated in scaling the implementing of such programmes in South Africa, the Netherlands, Turkey and England. The four countries were selected to represent different regions of the world and the perspective based on the considerable progress made in establishing and implementing their national WBE programmes. The selected countries also represent different climatic zones, economies, and development stages, which influence the implementation of national programmes of this nature and magnitude. In addition, the four countries' programmes offer good experiences and lessons learnt since they are systematic, and cover extensive areas, disseminate knowledge locally and internationally and partnered with authorities (government). The programmes also strengthened working relations and partnerships between and among local and global organisations. This paper shares these experiences and lessons to encourage others in the water and public health sectors on the benefits and value of WBE in tackling SARS-CoV-2 and related future circumstances.
Publisher: Springer Science and Business Media LLC
Date: 14-10-2012
Publisher: Springer Science and Business Media LLC
Date: 13-03-2015
Publisher: Elsevier BV
Date: 04-2018
Publisher: Elsevier BV
Date: 11-2015
Publisher: Springer Science and Business Media LLC
Date: 11-12-2015
Publisher: Elsevier BV
Date: 10-2014
Publisher: National Shellfisheries Association
Date: 08-2013
DOI: 10.2983/035.032.0233
Publisher: Springer Science and Business Media LLC
Date: 21-02-2014
DOI: 10.1007/S11538-013-9932-4
Abstract: At a time of increasing global demand for food, dwindling land and resources, and escalating pressures from climate change, the farming industry is undergoing financial strain, with a need to improve efficiency and crop yields. In order to improve efficiencies in farming, and in fertiliser usage in particular, understanding must be gained of the fertiliser-to-crop-yield pathway. We model one aspect of this pathway the transport of nutrients within the vascular tissues of a crop plant from roots to leaves. We present a mathematical model of the transport of nutrients within the xylem vessels in response to the evapotranspiration of water. We determine seven different classes of flow, including positive unidirectional flow, which is optimal for nutrient transport from the roots to the leaves and root multidirectional flow, which is similar to the hydraulic lift process observed in plants. We also investigate the effect of diffusion on nutrient transport and find that diffusion can be significant at the vessel termini especially if there is an axial efflux of nutrient, and at night when transpiration is minimal. Models such as these can then be coupled to whole-plant models to be used for optimisation of nutrient delivery scenarios.
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.SCITOTENV.2016.03.076
Abstract: To safeguard human health, legislative measures require the monitoring of faecal indicator bacteria (FIB) concentrations in recreational and shellfish waters. Consequently, numerous studies have focussed on FIB survival in the water column and more recently in estuarine sediments. However, there is a paucity of information regarding the influence of contrasting suspended particulate matter (SPM) concentrations on the survival of FIB in the water column of estuaries. Here, microcosms containing freshwater or brackish water with low, high and extreme SPM concentrations were inoculated with sewage and ovine faeces and the decay rate of Escherichia coli, coliforms and enterococci were determined by enumeration over five consecutive days. E. coli derived from ovine faeces proliferated and persisted at high levels in both freshwater and brackish microcosms (no decay), whereas ovine enterococci demonstrated a net decay over the duration of the experiment. Furthermore, SPM concentration had a significant effect on the decay rates of both E. coli and enterococci from ovine faeces in brackish microcosms, but decay rate was greater at low SPM concentrations for E. coli, whereas the opposite was observed for enterococci, whose decay rates increased as SPM concentration increased. E. coli, enterococci and coliforms derived from wastewater demonstrated a net decay in both freshwater and brackish microcosms, with contrasting effects of SPM concentration on decay rate. In addition, some FIB groups demonstrated contrasting responses (decay or proliferation) in the first 24h following inoculation into freshwater versus brackish microcosms. Overall, SPM concentrations influenced the proliferation and decay rates of FIB in brackish waters, but had minimal influence in freshwater. These results demonstrate that the survival rates of FIB in aquatic environments are system specific, species and source dependent, and influenced by SPM concentration. This study has important implications for catchment-based risk assessments and source apportionment of FIB pollution in aquatic environments.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 05-2014
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.SCITOTENV.2017.04.049
Abstract: Dissolved organic matter (DOM) plays a central role in regulating productivity and nutrient cycling in freshwaters. It is therefore vital that we can representatively s le and preserve DOM in freshwaters for subsequent analysis. Here we investigated the effect of filtration, temperature (5 and 25°C) and acidification (HCl) on the persistence of low molecular weight (MW) dissolved organic carbon (DOC), nitrogen (DON) and orthophosphate in oligotrophic and eutrophic freshwater environments. Our results showed the rapid loss of isotopically-labelled glucose and amino acids from both filtered (0.22 and 0.45μm) and unfiltered waters. We ascribe this substrate depletion in filtered s les to the activity of ultra-small (<0.45μm) microorganisms (bacteria and archaea) present in the water. As expected, the rate of C, N and P loss was much greater at higher temperatures and was repressed by the addition of HCl. Based on our results and an evaluation of the protocols used in recently published studies, we conclude that current techniques used to s le water for low MW DOM characterisation are frequently inadequate and lack proper validation. In contrast to the high degree of analytical precision and rigorous statistical analysis of most studies, we argue that insufficient consideration is still given to the presence of ultra-small microorganisms and potential changes that can occur in the low MW fraction of DOM prior to analysis.
Publisher: Wiley
Date: 09-2014
Publisher: Elsevier BV
Date: 09-2021
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-1139
Abstract: Trace gases of nitrogen (N), such as NOx (nitric oxide, NO + nitrogen dioxide, NO2) have a negative impact on human health and the environment. Although NOx are naturally produced in volcanic eruptions, forest fires and biotic nitrification and denitrification in soils, human activity is a major source of these contaminants via e.g. the combustion of fossil fuels. Additionally, N fertilization in agricultural soils is also an important source of NOx emissions. These emissions involve a loss of soil N to the atmosphere and have a negative impact in air quality. The abiotic part of the N cycle in terrestrial ecosystems has not received as much attention as the biotic part and certain abiotic reactions could play a key role in regulating NOx emissions. Photocatalysis is an ex le as this is used to abate NOx gases in urban and industrial areas. This reaction requires the presence of a catalyst (e.g. titanium oxide), oxygen, water, and energy from the sun (UV-visible light) to transform NO from the atmosphere into innocuous inorganic N forms (mainly nitrate, NO3-). There is a continuous investment in the production of catalysts by the industry. However, a variety of soil minerals such as anatase or rutile (titanium oxides), hematite and goethite (iron oxides), are found in soils and they could act as catalysts however, the occurrence of photocatalysis in soils has not been evaluated so far. In this study, we assess (i) the potential of a selection of soils with different mineralogy and a wide variety of soil properties to fix or emit NOx through photocatalysis, and (ii) the possible alterations in the fixation or emission of other N gases from the soil, i.e., nitrous oxide (N2O) and ammonia (NH3), when photocatalysis is induced. Around thirty agricultural soils were selected to meet the first objective and irradiated for 1 hour with UV-visible light under a constant flux of air and NO (100 ppm). Similar experiments were carried out with a selection of soils, whose potential to fix NO was different and tested in the previous experiment, to satisfy the second objective. However, only air (without NO) was pumped within the soil chamber in this case and the soils were previously fertilized with different N fertilisers (urea or KNO3-) and rates (0 to 250 mg N kg-1 soil). Our experiments show that weathered soils (with a high content in titanium and iron oxides) were able to fix more atmospheric NO through photocatalysis (objective i), and that NO and NH3 fixation and emissions after N fertilization depended not only on the N fertilizer and rate but also on soil properties, mainly soil pH and N content (objective ii). Soil mineralogy and properties play a key role in soil photocatalysis, and this abiotic reaction should be considered in order to design more sustainable strategies for agriculture.
Publisher: Elsevier BV
Date: 02-2019
Publisher: Wiley
Date: 11-2021
DOI: 10.1111/EJSS.13184
Abstract: Here we describe and evaluate the success of a multi‐institutional Centre for Doctoral Training (CDT), which was established to address a UK skills shortage in Soil Science. The government‐funded ‘STARS’ (Soils Training And Research Studentships) CDT was established in 2015 across a range of universities and research institutes in the UK. It recruited 41 PhD students equitably split across the institutions under four core research themes identified as being central to the national need, namely, (1) Understanding the soil–root interface, (2) Soils and the delivery of ecosystem services, (3) Resilience and response of functions in soil systems and (4) Modelling the soil ecosystem at different spatial and temporal scales. In addition, the STARS CDT provided a erse skills programme, including: Holistic training in soils, the promotion of collegiality and joint working, strategies to promote science and generate impact, internships with end users (e.g., policymakers, industry), personal wellbeing, and ways to generate a lasting soils training legacy. Overall, both supervisors and students have reported a positive experience of the CDT in comparison to the conventional doctoral training programmes, which have less discipline focus and little chance for students to scientifically interact with their cohorts or to undertake joint training activities. The STARS CDT also allowed students to freely access research infrastructure across the partner institutions (e.g., long‐term field trials, specialised analytical facilities, high‐performance computing), breaking down traditional institutional barriers and thus maximising the students' potential to undertake high‐quality research. The success and legacy of the STARS CDT can be evidenced in many ways however, it is exemplified by the large number and ersity of journal papers produced, the lasting collaborations, final career destinations, and creation of a web‐based legacy portal including new and reflective video material. Soil science was identified as having a scientific skills shortage in the UK. A dedicated soil science Centre for Doctoral Training (CDT) was established to address this skills gap. The multi‐institutional, discipline‐focused CDT proved more successful than conventional generic PhD training programmes. The CDT model provides critical mass to provide more effective training of soil scientists.
Publisher: Wiley
Date: 04-09-2013
DOI: 10.1111/IJFS.12331
Publisher: Informa UK Limited
Date: 28-08-2014
Publisher: Elsevier BV
Date: 09-2013
Publisher: Elsevier BV
Date: 2017
Publisher: Cambridge University Press (CUP)
Date: 23-05-2013
DOI: 10.1017/S0021859613000245
Abstract: Livestock production is a significant source of methane (CH 4 ) and nitrous oxide (N 2 O) emissions globally. In any sheep-producing nation, an effective agricultural greenhouse gas (GHG) mitigation strategy must include sheep-targeted interventions. The most prominent interventions suited to sheep systems are reviewed in the current paper, with a focus on farm-level enteric CH 4 and soil N 2 O emissions. A small number of currently available interventions emerge which have broad consensus on their mitigation potential. These include breeding to increase lambing percentages and diet formulation to minimize nitrogen excretion. The majority of interventions still require significant research and development before deployment. Research into the efficacy of interventions such as incorporation of biochar is in its infancy, while for others such as dietary supplements, successes in isolated studies now need to be replicated in long-term field trials under a range of conditions. Enhancing understanding of underlying biological processes will allow capitalization of interventions such as vaccination against rumen methanogenesis and pasture drainage. Many interventions cannot be recommended at a regional or national scale because, either, their mitigation potential is inextricably linked to soil and weather conditions in the locality of use, or their use is restricted to more intensive, closely managed systems. Distilling the long list of interventions to produce an effective farm-level mitigation strategy must involve: accounting for all GHG fluxes and interactions, identifying complimentary sets of additive interventions, and accounting for baseline emissions and current practice. Tools such as whole farm GHG models and marginal abatement cost curves are crucial in the development of tailored, practical sheep farm GHG mitigation strategies.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.SCITOTENV.2018.04.038
Abstract: Enteric viruses represent a global public health threat and are implicated in numerous foodborne and waterborne disease outbreaks. Nonetheless, relatively little is known of their fate and stability in the environment. In this study we used carefully validated methods to monitor enteric viruses, namely adenovirus (AdV), JC polyomavirus (JCV), noroviruses (NoVs), sapovirus (SaV) and hepatitis A and E viruses (HAV and HEV) from wastewater source to beaches and shellfish beds. Wastewater influent and effluent, surface water, sediment and shellfish s les were collected in the Conwy catchment (North Wales, UK) once a month for one year. High concentrations of AdV and JCV were found in the majority of s les, and no seasonal patterns were observed. No HAV and HEV were detected and no related illnesses were reported in the area during the period of s ling. Noroviruses and SaV were also detected at high concentrations in wastewater and surface water, and their presence correlated with local gastroenteritis outbreaks during the spring and autumn seasons. Noroviruses were also found in estuarine sediment and in shellfish harvested for human consumption. As PCR-based methods were used for quantification, viral infectivity and degradation was estimated using a NoV capsid integrity assay. The assay revealed low-levels of viral decay in wastewater effluent compared to influent, and more significant decay in environmental waters and sediment. Results suggest that AdV and JCV may be suitable markers for the assessment of the spatial distribution of wastewater contamination in the environment and pathogenic viruses can be directly monitored during and after reported outbreaks to prevent further environment-derived illnesses.
Publisher: Elsevier BV
Date: 07-2017
Publisher: Elsevier BV
Date: 02-2023
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-19705
Abstract: & & Afforestation with pure and mixed-species is an important strategy to improve soil organic carbon (SOC) stocks and restore degraded lands. However, what remains unclear is the stability of SOC to microbial degradation after afforestation and the effect of tree species composition. Moreover, it is important to reveal how sensitive the SOC in afforestation lands is to environmental changes, such as warming. To study the combined effects of warming and the tree species composition on decomposition of SOC by microorganisms and enzyme activities, soils were collected from the monocultural and mixtures of Silver birch (Betula Pendula) and European beech (Fagus Silvatica) (BangorDiversity, UK, 12 years since afforestation) and were incubated for 169 days at 0, 10, 20, 30 & #176 C at 60 % of WHC. The field experiment is arranged into a completely randomized design with n=4. The CO& sub& & /sub& efflux was measured constantly, whereas activities of & #946 -glucosidase, chitinase and acid phosphatase, and content of microbial biomass C (MBC) were obtained at the end of the incubation.& Results showed that soil cumulative CO& sub& & /sub& efflux increased by 34.7& #8211 % with the temperature. Potential enzyme activities were dependent on tree species composition. Warming, but not tree species exhibited a significant impact on the temperature sensitivity (Q10) of soil cumulative CO& sub& & /sub& efflux and enzyme activities. The greatest temperature sensitivity (Q& sub& & /sub& ) of total CO& sub& & /sub& efflux was found at 10& #8211 & #176 C and was 2.0& #8211 .1, but that of enzyme activities were found as 0.9& #8211 .1 at 0& #8211 & #176 C. These results suggest that warming has an asynchronous effect on the SOC decomposition and enzyme activity, and enzymes cannot account for the temperature sensitivity of soil respiration. Thus, thermal adaptations of SOC mineralization is independent of the adaptation of the enzyme pool.& &
Publisher: Journal of Research Publication House LLC
Date: 04-04-2017
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.ENVRES.2022.114142
Abstract: Increasing tropospheric ozone poses a potential threat to both above- and belowground components of the terrestrial biosphere. Microorganisms are the main drivers of soil ecological processes, however, the link between soil microbial communities and ecological functions under elevated ozone remains poorly understood. In this study, we assessed the responses of three crop seedlings (i.e., soybean, maize, and wheat) growth and soil microbial communities to elevated ozone (40 ppb O
Publisher: Elsevier BV
Date: 08-2016
Publisher: Wiley
Date: 12-07-2013
DOI: 10.1111/NPH.12405
Abstract: The ability of plants to compete effectively for nitrogen (N) resources is critical to plant survival. However, controversy surrounds the importance of organic and inorganic sources of N in plant nutrition because of our poor ability to visualize and understand processes happening at the root–microbial–soil interface. Using high‐resolution nano‐scale secondary ion mass spectrometry stable isotope imaging (Nano SIMS ‐ SII ), we quantified the fate of 15 N over both space and time within the rhizosphere. We pulse‐labelled the soil surrounding wheat ( Triticum aestivum ) roots with either or 15 N‐glutamate and traced the movement of 15 N over 24 h. Imaging revealed that glutamate was rapidly depleted from the rhizosphere and that most 15 N was captured by rhizobacteria, leading to very high 15 N microbial enrichment. After microbial capture, approximately half of the 15 N‐glutamate was rapidly mineralized, leading to the excretion of , which became available for plant capture. Roots proved to be poor competitors for 15 N‐glutamate and took up N mainly as . Spatial mapping of 15 N revealed differential patterns of 15 N uptake within bacteria and the rapid uptake and redistribution of 15 N within roots. In conclusion, we demonstrate the rapid cycling and transformation of N at the soil–root interface and that wheat capture of organic N is low in comparison to inorganic N under the conditions tested.
Publisher: Springer Science and Business Media LLC
Date: 18-08-2016
DOI: 10.1007/S00248-016-0832-7
Abstract: Our study used a ∼360-year fire chronosequence in northern Sweden to investigate post-fire microbial community dynamics in the boreal bryosphere (the living and dead parts of the feather moss layer on the forest floor, along with the associated biota). We anticipated systematic changes in microbial community structure and growth strategy with increasing time since fire (TSF) and used licon pyrosequencing to establish microbial community structure. We also recorded edaphic factors (relating to pH, C and N accumulation) and the physical characteristics of the feather moss layer. The molecular analyses revealed an unexpectedly erse microbial community. The structure of the community could be largely explained by just two factors, TSF and pH, although the importance of TSF diminished as the forest recovered from disturbance. The microbial communities on the youngest site (TSF = 14 years) were clearly different from older locations (>100 years), suggesting relatively rapid post-fire recovery. A shift towards Proteobacterial taxa on older sites, coupled with a decline in the relative abundance of Acidobacteria, suggested an increase in resource availability with TSF. Saprotrophs dominated the fungal community. Mycorrhizal fungi appeared to decline in abundance with TSF, possibly due to changing N status. Our study provided evidence for the decadal-scale legacy of burning, with implications for boreal forests that are expected to experience more frequent burns over the course of the next century.
Publisher: Springer Science and Business Media LLC
Date: 03-2017
Publisher: Elsevier BV
Date: 08-2017
Publisher: American Chemical Society (ACS)
Date: 03-06-2014
DOI: 10.1021/ES501670J
Abstract: Society relies heavily on inorganic phosphorus (P) compounds throughout its food chain. This dependency is not only very inefficient and increasingly costly but is depleting finite global reserves of rock phosphate. It has also left a legacy of P accumulation in soils, sediments and wastes that is leaking into our surface waters and contributing to widespread eutrophication. We argue for a new, more precise but more challenging paradigm in P fertilizer management that seeks to develop more sustainable food chains that maintain P availability to crops and livestock but with reduced amounts of imported mineral P and improved soil function. This new strategy requires greater public awareness of the environmental consequences of dietary choice, better understanding of soil-plant-animal P dynamics, increased recovery of both used P and unutilized legacy soil P, and new innovative technologies to improve fertilizer P recovery. In combination, they are expected to deliver significant economic, environmental, and resource-protection gains, and contribute to future global P stewardship.
Publisher: Elsevier BV
Date: 11-2014
Publisher: Wiley
Date: 04-04-2012
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.JENVMAN.2015.01.046
Abstract: Eutrophication is a major water pollution issue and can lead to excessive growth of aquatic plant biomass (APB). However, the assimilation of nutrients into APB provides a significant target for their recovery and reuse, and harvesting problematic APB in impacted freshwater bodies offers a complementary approach to aquatic restoration, which could potentially deliver multiple wider ecosystem benefits. This critical review provides an assessment of opportunities and risks linked to nutrient recovery from agriculturally impacted water-bodies through the harvesting of APB for recycling and reuse as fertilisers and soil amendments. By evaluating the economic, social, environmental and health-related dimensions of this resource recovery from 'waste' process we propose a research agenda for closing the loop on nutrient transfer from land to water. We identify that environmental benefits are rarely, if ever, prioritised as essential criteria for the exploitation of resources from waste and yet this is key for addressing the current imbalance that sees environmental managers routinely undervaluing the wider environmental benefits that may accrue beyond resource recovery. The approach we advocate for the recycling of 'waste' APB nutrients is to couple the remediation of eutrophic waters with the sustainable production of feed and fertiliser, whilst providing multiple downstream benefits and minimising environmental trade-offs. This integrated 'ecosystem services approach' has the potential to holistically close the loop on agricultural nutrient loss, and thus sustainably recover finite resources such as phosphorus from waste.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Elsevier BV
Date: 11-2023
Publisher: Elsevier BV
Date: 10-2021
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-19732
Abstract: & & Viruses play a crucial and underexplored role in soil microbial ecosystems, but soil viral ecology has focused exclusively on DNA viruses. The role of RNA viruses in soil ecosystems has therefore been largely overlooked, despite their significant impact on public health and food security. Here, we report the first ever study to apply viromics to survey soil RNA viral communities from five sites along an altitudinal primary productivity gradient in the UK. We identified over 3,000 viral sequences, of which over half were unclassified, and newly identified viruses were placed in a global context by the phylogenetic comparison of their RNA-dependent RNA polymerase genes. Unlike DNA viral communities, the RNA viromes were heavily dominated by viruses of eukaryotes, including pathogens of plants, fungi, vertebrates and invertebrates. S ling sites showed minimal similarity in viral community composition, suggesting that we have just scratched the surface of soil RNA viral ersity. Wider sequencing efforts and method development are required to further explore soil RNA viromes and understand their ecological function however, this study represents an important step towards the characterisation of soil viral communities and interactions with their microbial hosts, which will provide a more holistic view of the biology of economically and ecologically important soils.& &
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 07-2018
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-16477
Abstract: & & Soils Training and Research Studentships (STARS) is a NERC and BBSRC funded Centre for Doctoral Training (CDT).& The consortium comprises of four universities and four research institutes from around England, Scotland and Wales who are collaborating to offer training to PhD students in soil science. The program offered forty PhD studentships over four cohorts, which started in 2016 and due to complete in 2022. The ambitious program aimed to address the under representation of soil science and graduates in UK higher education institutes.& & & & The comprehensive CDT supports cross-institute participation which allows a sharing of resources both human and physical promoting a cross-disciplinary research environment. Students have received group training from experts across the respective establishments encouraging inter-institute collaboration and support. Centralised funding has supported a range of outside training from motion graphic skills to clowning in public to genomics and statistics and the production of video media products by students and staff communicating their research and knowledge. In addition, the managerial structure at STARS has allowed for easy access to professional and industry placements for students. By building upon the traditional PhD experience, STARS has been able to facilitate not only quality doctoral research but also graduates with the skill set and networks required by the next generation of soils scientists to help achieve the 2030 Sustainable Development Goals.& & & & Collectively, the STARS consortium has amassed& a vast range of soils research, knowledge, skills and training resources. To remain ambitious and forward focused our legacy project will bring together these resources and continue to work to build on the relationships forged under STARS and into the broader soil community.& & These resources will be accessible to those outside of STARS and outside of the research community because resources that offer the tools to support healthy soils, clean water, access to healthy food is not our legacy, it is everyone& #8217 s.& The legacy we are left with will not only be comprised of our journal publications but our success in sharing our knowledge, translating our findings and being active participants in global dialogues.& &
Publisher: Wiley
Date: 22-04-2013
DOI: 10.1111/NPH.12294
Abstract: Root hairs are known to be highly important for uptake of sparingly soluble nutrients, particularly in nutrient deficient soils. Development of increasingly sophisticated mathematical models has allowed uptake characteristics to be quantified. However, modelling has been constrained by a lack of methods for imaging live root hairs growing in real soils. We developed a plant growth protocol and used Synchrotron Radiation X ‐ray T omographic M icroscopy ( SRXTM ) to uncover the three‐dimensional (3 D) interactions of root hairs in real soil. We developed a model of phosphate uptake by root hairs based directly on the geometry of hairs and associated soil pores as revealed by imaging. Previous modelling studies found that root hairs dominate phosphate uptake. By contrast, our study suggests that hairs and roots contribute equally. We show that uptake by hairs is more localized than by roots and strongly dependent on root hair and aggregate orientation. The ability to image hair–soil interactions enables a step change in modelling approaches, allowing a more realistic treatment of processes at the scale of in idual root hairs in soil pores.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Springer Science and Business Media LLC
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 12-06-2015
Publisher: Springer Science and Business Media LLC
Date: 24-10-2016
Publisher: Wiley
Date: 06-04-2017
DOI: 10.1111/GBI.12237
Abstract: Ammonium- and Fe(II)-rich fluid flows, known from deep-sea hydrothermal systems, have been extensively studied in the last decades and are considered as sites with high microbial ersity and activity. Their shallow-submarine counterparts, despite their easier accessibility, have so far been under-investigated, and as a consequence, much less is known about microbial communities inhabiting these ecosystems. A field of shallow expulsion of hydrothermal fluids has been discovered at depths of 170-400 meters off the base of the Basiluzzo Islet (Aeolian Volcanic Archipelago, Southern Tyrrhenian Sea). This area consists predominantly of both actively diffusing and inactive 1-3 meters-high structures in the form of vertical pinnacles, steeples and mounds covered by a thick orange to brown crust deposits hosting rich benthic fauna. Integrated morphological, mineralogical, and geochemical analyses revealed that, above all, these crusts are formed by ferrihydrite-type Fe
Publisher: Wiley
Date: 02-03-2019
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 10-2014
Publisher: Springer Science and Business Media LLC
Date: 07-02-2017
Publisher: Elsevier BV
Date: 07-2014
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 10-2018
Publisher: FapUNIFESP (SciELO)
Date: 2020
Publisher: Elsevier BV
Date: 06-2020
DOI: 10.1016/J.SCITOTENV.2019.135130
Abstract: Drainage and cultivation have turned peatlands from carbon (C) sinks into hotspots for greenhouse gas (GHG) emissions. Raising the water table and planting of winter cover crops are potential strategies to help reduce peat oxidation and re-initiate net C accumulation during the non-cropping period. However, the effects of these practices as well as their interactions on GHG emissions remain unclear. Here, we carried out an outdoor mesocosm experiment to elucidate the effect of water table levels (-30 cm and -50 cm) and winter cover crop cultivation (vetch, rye, no plant) on carbon dioxide (CO
Publisher: Wiley
Date: 03-10-2016
DOI: 10.1111/GCBB.12402
Publisher: Frontiers Media SA
Date: 24-01-2017
Publisher: Elsevier BV
Date: 07-2023
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United States of America
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Davey Jones.