1,060 research outputs found
Studies in the population dynamics of some Teesdale plants
The study was essentially a demographic one. Few studies of this kind have been carried out on rare plant populations. Permanent quadrats (selected subjectively for the presence of some Teesdale plants, including Gentlana verna and Polygala amarelle) were established on Widdybank and Cronkley Fells in the Northern Pennines. The quadrats were all established on the grazed or eroding areas of sugar limestone grassland. For each quadrat the grid positions of all the individuals of the species being recorded were plotted on a chart. The fate of the initially recorded mixed-age population and that of all subsequent additions was noted at each visit. Larger permanently marked sample sites, usually adjacent to a permanent quadrat, were recorded once a year for the number of flowering and non-flowering individuals. Individuals which flowered were then recorded for the number of flowers, fruits and seeds they produced. From these data the population flux, mortality, survival and age-distribution of the individuals in the quadrats were obtained. The relative importance of sexual reproduction was ascertained by closely following the appearance of seedlings and vegetative shoots in each of the quadrats where a species produced both
Assessing the risk of phosphorus transfer to high ecological status rivers: Integration of nutrient management with soil geochemical and hydrological conditions
Reducing MCPA herbicide pollution at catchment scale using an agri-environmental scheme
Publication history: Accepted - 16 May 2022; Published online - 20 May 2022.In river catchments used as drinking water sources, high pesticide concentrations in abstracted waters require an expensive
treatment step prior to supply. The acid herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) is particularly
problematic as it is highly mobile in the soil-water environment following application. Here, an agri-environmental
scheme (AES) was introduced to a large-scale catchment (384 km2) to potentially reduce the burden of pesticides in
the water treatment process. The main measure offered was contractor application of glyphosate by weed wiping as
a substitute for boom spraying of MCPA, supported by educational and advisory activities. A combined innovation applied
in the assessment was, i) a full before-after-control-impact (BACI) framework over four peak application seasons
(April to October 2018 to 2021) where a neighbouring catchment (386 km2) did not have an AES and, ii) an enhanced
monitoring approach where river discharge and MCPA concentrations were measured synchronously in each catchment.
During peak application periods the sample resolution was every 7 h, and daily during quiescent winter periods.
This sampling approach enabled flow- and time-weighted concentrations to be established, and a detailed record of
export loads. These loads were up to 0.242 kg kmā2 yrā1, and over an order of magnitude higher than previously reported
in the literature. Despite this, and accounting for inter-annual and seasonal variations in river discharges, the
AES catchment indicated a reduction in both flow- and time-weighted MCPA concentration of up to 21% and 24%, respectively,
compared to the control catchment. No pollution swapping was detected. Nevertheless, the percentage of
MCPA occurrences above a 0.1 Ī¼g Lā1 threshold did not reduce and so the need for treatment was not fully resolved.
Although the work highlights the advantages of catchment management approaches for pollution reduction in source
water catchments, it also indicates that maximising participation will be essential for future AES.This work was carried out as part of Source to Tap (IVA5018), a project supported by the European Union's INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB)
Impact of slurry application method on phosphorus loss in runoff from grassland soils during periods of high soil moisture content
Abstract
Previous studies have reported that the trailing shoe application technique reduces phosphorus (P) in the runoff postslurry application when compared to the traditional splash-plate application technique. However, the effectiveness of the trailing-shoe technique as a means of reducing P losses has not been evaluated when slurry is applied during periods of high soil moisture levels and lower herbage covers. To address this issue, three treatments were examined in a 3 Ć 4 factorial design split-plot experiment, with treatments comprising three slurry treatments: control (no slurry), splashplate and trailing-shoe, and four slurry application dates: 7 December, 18 January, 1 March and 10 April. Dairy cow slurry was applied at a rate of 20 m3/ha, while simulated runoff was generated 2, 9 and 16 days later and analysed for a range of P fractions. Dissolved reactive P concentrations in runoff at day two was 41% lower when slurry was applied using the trailing-shoe technique, compared to the splash-plate technique (P < 0.05). In addition, P concentrations in runoff were higher (P < 0.05) from slurry applied in December and March compared to slurry applied in January or April, coinciding with periods of higher soil moisture contents. While the latter highlights that ācalendarā-based non-spreading periods might not always achieve the desired consequences, the study demonstrated that further field-scale investigations into the trailing shoe as a mitigation measure to reduced P loss from agricultural soils is warranted.</jats:p
Impact of slurry application method on phosphorus loss in runoff from grassland soils during periods of high soil moisture content
Previous studies have reported that the trailing shoe application technique reduces phosphorus (P) in the runoff postslurry application when compared to the traditional splash-plate application technique. However, the effectiveness of the trailing-shoe technique as a means of reducing P losses has not been evaluated when slurry is applied during periods of high soil moisture levels and lower herbage covers. To address this issue, three treatments were examined in a 3 Ć 4 factorial design split-plot experiment, with treatments comprising three slurry treatments: control (no slurry), splashplate and trailing-shoe, and four slurry application dates: 7 December, 18 January, 1 March and 10 April. Dairy cow slurry was applied at a rate of 20 m3/ha, while simulated runoff was generated 2, 9 and 16 days later and analysed for a range of P fractions. Dissolved reactive P concentrations in runoff at day two was 41% lower when slurry was applied using the trailing-shoe technique, compared to the splash-plate technique (P < 0.05). In addition, P concentrations in runoff were higher (P < 0.05) from slurry applied in December and March compared to slurry applied in January or April, coinciding with periods of higher soil moisture contents. While the latter highlights that ācalendarā-based non-spreading periods might not always achieve the desired consequences, the study demonstrated that further field-scale investigations into the trailing shoe as a mitigation measure to reduced P loss from agricultural soils is warranted.</p
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Visualizing Chinaās Belt and Road Initiative on RT (Russia Today): from infrastructural project to human development
This paper comprises original research on Chinaās use of bilateral media cooperation to mediate its Belt and Road Initiative (BRI). Building upon the literature on strategic narratives, aesthetic power and the Silk Road as a foreign policy concept, we present a detailed case study of the visual imagery of the āSilk Roadā documentary collaboration between Chinaās and Russiaās state-owned international broadcasters, China Radio International and RT (formerly Russia Today). We employ a visual methodology to interrogate the formation and projection of multimodal (visual, textual and oral) narratives about Chinaās infrastructural activities along this metaphorical new āSilk Roadā. We examine how the Silk Road series gives sense to Chinaās BRI, the relative weighting of Chinese and Russian strategic narratives about the BRI, and how power is distributed in this Chinese-Russian media partnership. Our analysis reveals that in re-packaging visual imagery that applies nostalgia to the history of core places and technologizes their future, the series projects a pre-curated Chinese visual narrative that emplots the BRI as human and cultural development. Russian regional strategic narratives are marginalized. China is applying its aesthetic power to Russian journalists and politicians; RT obtains some commercial benefits, but the Russian stateās aesthetic power is ceded to China
THE USE OF ARTIFICIAL NEURAL NETWORKS IN THE ESTIMATION OF THE PERCEPTION OF SOUND BY THE HUMAN AUDITORY SYSTEM
Are agriāenvironment schemes successful in delivering conservation grazing management on saltmarsh?
1.Grasslands occur around the globe and, in temperate regions, their natural management by fire, drought and wild herbivores has largely been replaced by grazing with domestic livestock. Successful management for agriculture is not always suitable for conservation and can have a detrimental effect on biodiversity. Conservation grazing of saltmarshes, delivered through agriāenvironment schemes, may provide a solution to counteract biodiversity loss by providing farmers with financial incentives to graze these internationally important coastal wetlands more sensitively. 2.To assess whether conservation grazing is being achieved, and whether agriāenvironment schemes are effective in delivering this management, we conducted a national survey on English saltmarshes, scoring the management on each site as optimal, suboptimal or detrimental in terms of suitability for achieving conservation aims for five aspects of grazing: presence, stock type, intensity, timing and habitat impact. 3.Although most saltmarshes suitable for grazing in England were grazed, conservation grazing was not being achieved. Sites under agriāenvironment management for longer did score higher and approached optimal levels in terms of grazing intensity in one region, but sites with agriāenvironment agreements were no more likely to be grazed at optimal conservation levels than sites without them overall, indicating that agriāenvironment schemes, in their current form, are an ineffective delivery mechanism for conservation grazing on saltmarsh. 4.The low specificity of agriāenvironment prescription wording may contribute to this failure, with prescriptions either being vague or specifying suboptimal or detrimental management objectives, particularly for grazing intensity, timing and stock type. These objectives are often set too high or too low, during unsuitable periods, or using stock types inappropriate for achieving conservation aims. 5.Synthesis and applications. Our national survey indicates that agriāenvironment schemes are not currently delivering conservation grazing on English saltmarshes. Agriāenvironment schemes are the only mechanism through which such grazing can be implemented on a national scale, so improving their effectiveness is a priority. Policymakers, researchers and managers need to work together to ensure better translation of conservation guidelines into schemes, increasing the specificity of management prescriptions and improving understanding of the need for management measures. A more detailed and reliable system of auditing to ensure that management activities are taking place would be beneficial, or alternatively moving to a resultsābased scheme where payments are made on desirable outcomes rather than on evidence of management
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