Publications

An experiment was conducted during March, 1999 to study ways in which to improve techniques for measuring low amounts of total-column precipitable water vapor (PWV). The experiment was conducted at the DOE's ARM program's North Slope of Alaska/Adjacent Arctic Ocean Cloud and Radiation Testbed site (DoE ARM NSA/AAO CaRT) located just outside Barrow, Alaska. NASA and NOAA deployed a suite of radiometers covering 25 channels in the frequency range of 20 GHz up to 340 GHz including 8 channels around the 183 GHz water vapor absorption line. In addition to the usual CaRT site instrumentation the NOAA Depolarization and Backscatter Unattended Lidar (DABUL), the SUNY Rotating Shadowband Spectroradiometer (RSS) and other surface based meteorological instrumentation were deployed during the intensive observation period. Vaisala RS80 radiosondes were launched daily as well as nearby National Weather Service VIZ sondes. Atmospheric conditions ranged from clear calm skies to blowing snow and heavy multi-layer cloud coverage. Measurements made by the radiosondes indicate the PWV varied from approx. 1 to approx. 5 mm during the experiment. The near-surface temperature varied between about -40 C to - 15 C. In this presentation, an overview of the experiment with examples of data collected will be presented. Application of the data for assessing the potential and limitations of millimeter-wave radiometry for retrieving very low amounts of PWV will be discussed.

This chapter discusses the current approaches to measuring rehabilitation success and considers how rehabilitation practices can impact on soil health using two industrial-scale case studies: (1) jarrah (Eucalyptus marginata) forest rehabilitation following bauxite...

No abstract is provided for this article.

To predict how biodiversity will respond to global change, it is crucial to understand the relative roles of abiotic drivers and biotic interactions in driving associations between the biodiversity of disparate taxa. It is particularly challenging to understand diversity–diversity links across domains and habitats, because data are rarely available for multiple above‐ and below‐ground taxa across multiple sites. Here, we analyse data from a unique biodiversity data set gathered across a variety of oceanic temperate terrestrial habitats in Wales, comprising 300 sites with co‐located soil microbial, plant, bird and pollinator surveys along with climate and soil physicochemical information. Soil groups are analysed using metabarcoding of the 16S, ITS1 and 18S DNA regions, allowing in‐depth characterisation of microbial and soil animal biodiversity. We explore biodiversity relationships along three aspects of community composition: First, we assess correlation between the alpha diversity of different groups. Second, we assess whether biotic turnover between sites is correlated across different groups. Finally, we investigate the co‐occurrence of individual taxa across sites. In each analysis, we assess the contribution of linear or nonlinear environmental effects. We find that a positive correlation between alpha diversity of plants, soil bacteria, soil fungi, soil heterotrophic protists, bees and butterflies is in fact driven by complex nonlinear responses to abiotic drivers. In contrast, environmental variation did not account for positive associations between the diversity of plants and both birds and AM fungi, suggesting a role for biotic interactions. Both the diversity and taxon‐level associations between the differing soil groups remained even after accounting for nonlinear environmental gradients. Above‐ground, spatial factors played larger roles in driving biotic communities, while linear environmental gradients were sufficient to explain many group‐ and taxon‐level relationships. Synthesis . Our results show how nonlinear responses to environmental gradients drive many of the relationships between plant biodiversity and the biodiversity of above‐ and below‐ground biological communities. Our work shows how different aspects of biodiversity might respond nonlinearly to changing environments and identifies cases where management‐induced changes in one community could either influence other taxa or lead to loss of apparent biological associations.

Oligopeptides constitute an important yet understudied component of soil’s dissolved organic nitrogen (DON) pool, representing a primary breakdown product of proteins. However, the mechanisms of oligopeptide uptake and utilisation by crop roots remain poorly understood in a plant nutrition context. We investigated the rate and spatial uptake pattern of ¹⁴C-labelled alanine and di- to pentapeptides of alanine in wheat and rice under sterile hydroponic conditions. Both species demonstrated the capacity to absorb N through amino acids and oligopeptides, with rice roots showing higher peptide uptake than wheat. Specifically, alanine absorption exceeded peptide uptake by 3–7-fold in rice and 6–9-fold in wheat. Using phosphor imaging, we demonstrated that alanine and oligopeptide uptake occurred throughout the root system, with the highest accumulation in the root tip and root hair regions. Further, spatial analysis revealed that peptide absorption rates in rice were 2–5 times higher in the 0–1 cm root section and 1.5–4 times higher in the 1–2 cm section compared to corresponding wheat root segments. We conclude that plants can directly take up amino acids and oligopeptides to acquire exogenous N, with marked differences occurring among species in both uptake efficiency and spatial uptake patterns.

Evidence suggests that climate change is increasing the frequency of extreme weather events (e.g. excessive rainfall, heat, wind). The winter of 2013-14 saw exceptional levels of rainfall across the UK leading to extreme and prolonged flooding (up to 3 months with floodwater depths up to 3 m) in several low-lying agricultural areas (e.g. Somerset Levels, Thames Valley). The impact of extreme flooding and the speed of ecosystem recovery at the field-scale, however, remain poorly understood. The main objectives of this study were therefore to: (1) assess the effect of this extreme winter flooding event on a range of soil physical, chemical and biological quality indicators at 15 flood-affected sites (arable and grassland), (2) determine if these changes in soil health were reversible in the short term (< 1 year), and (3) to evaluate the effectiveness of different mechanical interventions (sward-lifting, subsoiling, slot-seeding and aerating) to accelerate the amelioration of the damage caused by winter flooding at 2 of the 15 sites. Once the floodwater had receded (April 2014), we found that several of the measured soil quality indicators were negatively affected in the flooded areas in comparison with non-flooded areas. This included a decrease in soil bulk density (by 19%), soil pH (by 0.4 units), and available P (by up to 42%). Flooding increased soil microbial biomass (60%), induced a shift in soil microbial community structure and reduced earthworm numbers. After 8 months of recovery, only soil pH remained significantly reduced (by 0.3 units) in the flooded areas in comparison to the unflooded areas. Flooding had a negative impact on the overlying vegetation at the arable sites (biomass production was reduced by between 19 and 34%) but had no major impact at the grassland sites in the long-term. In the flood amelioration experiment, the subsoiled plots produced grass with a higher nutrient content (e.g. N - up to 35%, Ca - up to 19% and Mg - up to 58%). However, the four different interventions appeared to have little positive impact on most of the soil quality indicators measured. In conclusion, extreme winter flooding was found to induce short-term alterations in key soil quality indicators and to destroy winter crops, although these effects did not persist in the longer term. Our results therefore indicate that the temperate agroecosystems evaluated here were highly resilient to winter flood stress and that recovery to a pre-flood state could be achieved within 1 year. Improved management strategies are still needed to speed up the rate of recovery after flood events to facilitate a faster return to agricultural production.

This book brings together cutting-edge studies and reviews on the water-related health aspects of SARS-CoV-2, contributed by our research community. The contributions are related to the potential risk of waterborne COVID-19 transmission, household water uses, and hygiene during the pandemic, and surveillance of SARS-CoV-2 RNA in wastewater.In Focus–a book series that showcases the latest accomplishments in water research. Each book focuses on a specialist area with papers from top experts in the field. It aims to be a vehicle for in-depth understanding and inspire further conversations in the sector.

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.

The microbial entombing effect refers to the accumulation and stabilisation of microbially derived carbon (C) in soils following the sustained production of microbial biomass and necromass. Fertilisation practices modify soil microbial activity and C cycling and consequently influence the microbial entombing effect, which has implications for global C sequestration. We conducted a global meta-analysis to evaluate the impact of fertilisation practices on the microbial entombing effect, focusing on microbial necromass C (MNC), microbial biomass C (MBC) and the microbial necromass accumulation coefficient (NAC = MNC/MBC) across 319, 1665 and 199 paired datasets, respectively. Overall, fertilisation increased MNC by 16.6%, primarily because of an overall increase in MBC (31.9%) rather than an increase in NAC. Inorganic fertiliser application resulted in a higher accumulation of MNC (14.7%) and MBC (24.9%) in croplands than in forests and grasslands. Combining nitrogen (N) and phosphorus (P) fertilisers with straw (NPS) exhibited the highest potential for global MNC accumulation (14,900 Tg), exceeding the global average by 10.6% under fertilisation. Combining N and P fertilisers with manure (NPM) resulted in the highest global MBC (660 Tg) and NAC (35.3). These findings highlight the necessity of combined organic-inorganic fertilisation strategies to enhance soil C sequestration by increasing the contribution of the microbial entombing effect. While mean annual temperature (MAT) played a key role in determining MBC, the initial pH (ipH) and initial soil organic C (iSOC) were the dominant factors influencing the microbial entombing effect. In alkaline soils, particularly those in Central and Western Asia, NPS and NPM fertilisation exhibited the greatest potential for enhancing MNC and NAC, respectively. This study provides mechanistic insights into the impacts of fertilisation on the microbial entombing effect and highlights the critical need for site-specific management to optimise soil C sequestration.

Polycyclic aromatic hydrocarbons ( PAH s) in the environment originate mainly from incomplete combustion of fossil fuels, and pose a significant human health risk. Soils act as environmental sinks for PAH s, as they become strongly absorbed onto soil particles; degradation is mainly driven by microbial catabolism, although it is dependent on PAH bioavailability. There is current interest in burying biochar in soil as a long‐term soil carbon store; however, biochar inherently contains varying levels of PAH s and its application could contaminate soil, and its high sorptive capacity may facilitate the persistence of PAH s in the environment. The aim of this study was to determine the effect of adding biochar to soil on microbial mineralization of PAH s, and to quantify whether or not soils amended with biochar were less likely to leach PAH s. We used contrasting agricultural soils ( E utric C ambisol and C ambic P odzol) spiked with the labelled PAH compound 14 C ‐phenanthrene and amended with either wood biochar or rice husk biochar. Mineralization was quantified by measuring the release of 14 CO 2 and simulated rain used to quantify leaching of PAH through biochar‐amended soil. Rice husk biochar had higher concentrations of PAH s (64.65 mg kg −1 ) than wood biochar (9.56 mg kg −1 ), and both soil types contained quantifiable levels of PAH s. However, soil that had contained biochar for 3 years had significantly higher levels of PAH (1.95 mg kg −1 ) compared to unamended soil (1.13 mg kg −1 ). PAH catabolism in soil was reduced when amended with biochar, although biochar amendment did not consistently decrease PAH leaching. Biochar‐mediated inhibition of PAH mineralization is a consequence of increased sorption and reduced bioavailability. Before large scale biochar addition to soils is adopted, future work is needed to address the dynamic between sorbent saturation and microbial activity and how this relates to the concentration of PAH s in soil solution and their persistence in the environment.

Microplastics (MPs) pollution is becoming one of the most pressing environmental issues globally. MPs in the marine, freshwater and terrestrial environments have been fairly well investigated. However, knowledge of the atmospheric-mediated deposition of MPs within rural environments is limited. Here, we present the results of bulk (dry and wet) atmospheric MPs deposition in a rural region of Quzhou County in the North China Plain (NCP). Samples of MPs in the atmospheric bulk deposition were collected for individual rainfall events over a 12-month period from August 2020 to August 2021. The number and size of MPs from 35 rainfall samples were measured by fluorescence microscopy, while the chemical composition of MPs was identified using micro-Fourier transform infrared spectroscopy (μ-FTIR). The results showed that the atmospheric MPs deposition rate in summer (892–75,421 particles/m2/day) was highest compared to 735–9428, 280–4244 and 86–1347 particles/m2/day in spring, autumn, and winter, respectively. Furthermore, the MPs deposition rates in our study were 1–2 orders of magnitude higher than those in other regions, indicating a higher rate of MPs deposition in the rural region of the NCP. MPs with a diameter of 3–50 μm accounted for 75.6 %, 78.4 %, 73.4 % and 66.1 % of total MPs deposition in spring, summer, autumn, and winter, respectively, showing that the majority of MPs in the current study were small in size. Rayon fibers accounted for the largest proportion (32 %) of all MPs, followed by polyethylene terephthalate (12 %) and polyethylene (8 %). This study also found that a significant positive correlation between rainfall volume and MPs deposition rate. In addition, HYSPLIT back-trajectory modelling showed that the farthest source of deposition MPs may have come from Russia.

No abstract is provided for this article.