scholarly journals Sulphate reduction determines the long-term effect of iron amendments on phosphorus retention in lake sediments

2021 ◽  
Author(s):  
Lena Heinrich ◽  
Jan Dietel ◽  
Michael Hupfer
Keyword(s):  
Management Plan ◽  
Sulphate Reduction ◽  
Phosphorus Retention ◽  
Sulphur Deposition ◽  
Excess Iron ◽  
Sediment Stratigraphy ◽  
Management Interventions ◽  
Contrasting Effect ◽  
Geochemical Analyses

Abstract Purpose This field study aimed to guide the planning of iron amendments for phosphorus retention by investigating the long-term fate of iron added to two urban lakes (Plötzensee and Groß Glienicker See) in Berlin, Germany. The contributions of iron dosing to improve lake status as well as the relevance of competing processes for management success were evaluated. Methods Sediment stratigraphy, as well as occurrence of iron minerals, and fluxes between water and sediment were examined using geochemical analyses (i.e. element composition, sequential extraction, X-ray diffraction, and pore water analyses). A one-box lake model was used to relate these fluxes to monitoring data from the water column and to sediment inventories. Results In both lakes, the added iron was preserved in the sediment. Whereas phosphorus retention increased following the addition of iron to Groß Glienicker See, sulphur was retained by the excess iron in Plötzensee. This contrasting effect is attributed to significantly different sulphate reduction rates in two lakes (Wilcoxon rank sum test: W = 25, p = 0.008). According to the one-box model, sulphate reduction explained both the decrease in measured sulphate concentrations after iron application as well as the observed increase in sulphur deposition in the sediments. Conclusion Management interventions involving iron amendments to enhance phosphorus retention must consider the competing process of iron sulphide formation during the entire management plan period, and additional iron may need to be applied to account for this effect.

scholarly journals Pseudogymnoascus destructans growth in wood, soil and guano substrates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jenny Urbina ◽  
Tara Chestnut ◽  
Jennifer M. Allen ◽  
Taal Levi
Keyword(s):  
Dna Extraction ◽  
Emerging Infectious Diseases ◽  
Transmission Risk ◽  
Pseudogymnoascus Destructans ◽  
White Nose Syndrome ◽  
Management Interventions ◽  
Pathogen Persistence ◽  
Tenfold Increase ◽  
And Control

AbstractUnderstanding how a pathogen can grow on different substrates and how this growth impacts its dispersal are critical to understanding the risks and control of emerging infectious diseases. Pseudogymnoascus destructans (Pd) causes white-nose syndrome (WNS) in many bat species and can persist in, and transmit from, the environment. We experimentally evaluated Pd growth on common substrates to better understand mechanisms of pathogen persistence, transmission and viability. We inoculated autoclaved guano, fresh guano, soil, and wood with live Pd fungus and evaluated (1) whether Pd grows or persists on each (2) if spores of the fungus remain viable 4 months after inoculation on each substrate, and (3) whether detection and quantitation of Pd on swabs is sensitive to the choice to two commonly used DNA extraction kits. After inoculating each substrate with 460,000 Pd spores, we collected ~ 0.20 g of guano and soil, and swabs from wood every 16 days for 64 days to quantify pathogen load through time using real-time qPCR. We detected Pd on all substrates over the course of the experiment. We observed a tenfold increase in pathogen loads on autoclaved guano and persistence but not growth in fresh guano. Pathogen loads increased marginally on wood but declined ~ 60-fold in soil. After four months, apparently viable spores were harvested from all substrates but germination did not occur from fresh guano. We additionally found that detection and quantitation of Pd from swabs of wood surfaces is sensitive to the DNA extraction method. The commonly used PrepMan Ultra Reagent protocol yielded substantially less DNA than did the QIAGEN DNeasy Blood and Tissue Kit. Notably the PrepMan Ultra Reagent failed to detect Pd in many wood swabs that were detected by QIAGEN and were subsequently found to contain substantial live conidia. Our results indicate that Pd can persist or even grow on common environmental substrates with results dependent on whether microbial competitors have been eliminated. Although we observed clear rapid declines in Pd on soil, viable spores were harvested four months after inoculation. These results suggest that environmental substrates and guano can in general serve as infectious environmental reservoirs due to long-term persistence, and even growth, of live Pd. This should inform management interventions to sanitize or modify structures to reduce transmission risk as well early detection rapid response (EDRR) planning.

scholarly journals Minor Treatments Can Play a Significant Role in Preserving Natural Habitats and Protected Species on the Shore of a Central European Lake

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1540
Author(s):  
Bence Fülöp ◽  
Bálint Pacsai ◽  
Judit Bódis
Keyword(s):  
Plant Species ◽  
Conservation Status ◽  
Active Management ◽  
Lake Balaton ◽  
Protected Species ◽  
Natural Habitats ◽  
Management Interventions ◽  
Natural Grasslands ◽  
Tourism Potential

Semi-natural grasslands were previously established through traditional land use and maintained by active management, but their extension nowadays is declining rapidly, particularly in areas that also have tourism potential. In parallel, the conservation value of the remaining areas is increasing. The shore of Lake Balaton is a particularly good example, as Lake Balaton is an area highly affected by tourism, yet there have been valuable habitats able to survive and provide refuge for many vulnerable, protected species. Fortunately, we have reliable information about the vegetation of the area from two decades ago. Comparing these data with our recent surveys we investigated the changes in habitats and the distribution of protected plant species in connection with the active conservation treatments such as grazing or cutting. Our results show that in areas where treatments are still ongoing, protected plant species are more likely to survive, or even other species can appear, which is in clear contrast with conditions experienced in abandoned areas, where at least seven protected species have disappeared. According to our results, minor, but appropriately chosen and well-executed management interventions, can help in the long-term maintenance of species-rich habitats and improving the conservation status of threatened species.

Geochemistry and Sr–Nd isotopic composition of Eocene lamphrophyre dykes, southeastern British Columbia

2003 ◽  
Vol 40 (6) ◽  
pp. 853-864 ◽  
Author(s):  
J H Sevigny ◽  
R J Thériault
Keyword(s):  
British Columbia ◽  
Limited Range ◽  
Calc Alkaline ◽  
Lithospheric Thinning ◽  
Enriched Mantle ◽  
Mantle Enrichment ◽  
Mantle Reservoir ◽  
Geochemical Analyses ◽  
Alkaline Lamprophyres

Mineral compositions, geochemical analyses, and Sr–Nd isotopic compositions are reported for alkaline and calc-alkaline lamprophyres collected along the southern margin of the Valhalla Complex, southeastern British Columbia. The lamprophyres were emplaced during Eocene extension and lithospheric thinning associated with tectonic denudation of the Valhalla Complex. SiO2 contents range from 44.4–51.6 wt.%, K2O from 1.3–3.7 wt.%, and volatile contents (H2O + CO2 + SO3) from 0.8–4.6 wt.%. MgO and Cr contents are 9.5–7.6 wt.% and 540–130 ppm, respectively, for samples with Mg#s between 0.69 and 0.65. Chrondrite-normalized rare-earth element patterns are strongly fractionated with Cen = 120–375 and Ybn = 8.4–12.7. Alkaline lamprophyres contain biotite ± kaersutite ± calcic plagioclase and exhibit a limited range in initial 87Sr/86Sr (0.7051–0.7057), initial εNd (–3.7 to –4.3), and TDM (766–796 Ma). Calc-alkaline lamprophyres contain F-rich phlogopite and sodic plagioclase, and exhibit a wider range in initial 87Sr/86Sr (0.7064–0.7090), initial εNd (–6.3 to –11.9), and TDM (917–1,614 Ma). Alkaline lamprophyres are interpreted as uncontaminated melts derived from a long-term, volatile, and incompatible element-enriched mantle reservoir. Mantle enrichment coincided with continental rifting of western North America (ca. 760 Ma). The enriched mantle reservoir remained isolated for ~700 Ma. Lamprophyres were generated by partial melting of the mantle reservoir in response to adiabatic decompression and lithospheric thinning during Eocene extension.

scholarly journals Vegetation change (1988–2010) in Camdeboo National Park (South Africa), using fixed-point photo monitoring: The role of herbivory and climate

Koedoe ◽  
2013 ◽  
Vol 55 (1) ◽  
Author(s):  
Mmoto L. Masubelele ◽  
Michael T. Hoffman ◽  
William Bond ◽  
Peter Burdett
Keyword(s):  
South Africa ◽  
Fixed Point ◽  
National Parks ◽  
Vegetation Cover ◽  
National Park ◽  
Vegetation Change ◽  
Growth Form ◽  
Annual Rainfall ◽  
Management Interventions

Fixed-point photo monitoring supplemented by animal census data and climate monitoring potential has never been explored as a long-term monitoring tool for studying vegetation change in the arid and semi-arid national parks of South Africa. The long-term (1988–2010), fixed-point monitoring dataset developed for the Camdeboo National Park, therefore, provides an important opportunity to do this. Using a quantitative estimate of the change in vegetation and growth form cover in 1152 fixed-point photographs, as well as series of step-point vegetation surveys at each photo monitoring site, this study documented the extent of vegetation change in the park in response to key climate drivers, such as rainfall, as well as land use drivers such as herbivory by indigenous ungulates. We demonstrated the varied response of vegetation cover within three main growth forms (grasses, dwarf shrubs [< 1 m] and tall shrubs [> 1 m]) in three different vegetation units and landforms (slopes, plains, rivers) within the Camdeboo National Park since 1988. Sites within Albany Thicket and Dwarf Shrublands showed the least change in vegetation cover, whilst Azonal vegetation and Grassy Dwarf Shrublands were more dynamic. Abiotic factors such as drought and flooding, total annual rainfall and rainfall seasonality appeared to have the greatest influence on growth form cover as assessed from the fixed-point photographs. Herbivory appeared not to have had a noticeable impact on the vegetation of the Camdeboo National Park as far as could be determined from the rather coarse approach used in this analysis and herbivore densities remained relatively low over the study duration.Conservation implications: We provided an historical assessment of the pattern of vegetation and climatic trends that can help evaluate many of South African National Parks’ biodiversity monitoring programmes, especially relating to habitat change. It will help arid parks in assessing the trajectories of vegetation in response to herbivory, climate and management interventions.

scholarly journals Vegetation and seed bank dynamics highlight the importance of post-restoration management in sown grasslands

2020 ◽  
Author(s):  
Orsolya Valkó ◽  
Balázs Deák ◽  
Péter Török ◽  
Katalin Tóth ◽  
Réka Kiss ◽  
...  
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Rapid Development ◽  
Management Plan ◽  
Landscape Scale ◽  
List Type ◽  
Restoration Management ◽  
Seed Bank Dynamics ◽  
Term Management

AbstractSowing grass seeds generally supports the rapid development of a closed perennial vegetation, which makes the method universally suitable for fast and effective landscape-scale restoration of grasslands. However, sustaining the recovered grasslands, and increasing their diversity is a challenging task. Understanding the role of seed bank compositional changes and vegetation dynamics contributes to designating management regimes that support the establishment of target species and suppress weeds. Our aim was to reveal the effect of post-restoration management on the vegetation and seed bank dynamics in grasslands restored in one of the largest European landscape-scale restoration projects. Eight years after restoration we sampled the vegetation and seed bank in a total of 96 plots located in 12 recovered grasslands in the Great Hungarian Plain. In each recovered grassland stand we designated a mown (mown from Year 1 to Year 8) and an abandoned sample site (mown from Year 1 to Year 3 then abandoned from Year 4 to Year 8). Mown and abandoned sites showed divergent vegetation and seed bank development. Abandonment led to the decline of sown grasses and higher cover of weeds, especially in the alkaline grasslands. Our study confirmed that seed bank has a limited contribution to the maintenance of biodiversity in both grassland types. We found that five years of abandonment had a larger effect on the seed bank than on the vegetation. We stress that long-term management is crucial for controlling the emergence of the weeds from their dense seed bank in restored grasslands.Implications for practiceSeed sowing of grass mixtures can be a feasible tool for restoring grasslands at large scales. However, the developed vegetation usually has low biodiversity and a high seed density of weeds is typical in the soil seed bank even several years after the restoration. Therefore, post-restoration management is necessary for suppressing weeds both aboveground and belowground.We recommend to design the long-term management of the sites subjected to grassland restoration already in the planning phase of the restoration projects and ensure that the management plan is ecologically and economically feasible.We recommend to complement the monitoring of vegetation with the analysis of soil seed bank for evaluating restoration success.

scholarly journals Corporate Financial Risk Management Interventions in the Organic Agri-Food Chains

2021 ◽  
Vol 2 (2) ◽  
pp. p22
Author(s):  
Licia Scarciofalo
Keyword(s):  
Financial Risk ◽  
Raw Materials ◽  
Investment Banks ◽  
Over The Counter ◽  
Food Supply Chains ◽  
Management Interventions ◽  
Regulated Markets ◽  
Inherent Nature ◽  
Constituent Elements

This study arises from the need to propose an alternative solution to existing hedging methods to all companies interested in hedging the price risk of raw materials. The research focuses mainly on the actors of the agri-food supply chains, in particular the organic sector, given the growing trend of the cultivation methodology and the need to protect entrepreneurs involved in short-chain spinneret who have less possibility of relieve higher costs incurred to ensure the sustainability of the product. However, our analysis envisages a customizable hedging method for any company that intends to protect itself from the price fluctuations of the commodity that represents the inherent nature of its business. The technique consists in the construction of specific contracts (in particular, derivative financial instruments) by investment banks or commercial banks oriented to the corporate segment that offer this service. Personalization is achieved by calibrating the constituent elements of the derivative on the basis of hedging needs. The parameterization is carried out by replicating the contractual specifications of the main futures on commodities listed on regulated markets. This will allow the creation of a combination of option contracts listed on the over-the-counter market in an overall strategy aimed at medium-long term hedging.

Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

2017 ◽  
Keyword(s):  
Size Structure ◽  
Population Decline ◽  
Round Goby ◽  
Management Plan ◽  
Neogobius Melanostomus ◽  
Before And After ◽  
Catch Rates ◽  
Survival Studies ◽  
St Lawrence River

<em>Abstract</em>.— Long-term research indicates a significant and ongoing decline within the upper St. Lawrence River Muskellunge <em>Esox masquinongy </em>population. Index surveys show a sharp reduction in catch of both spawning adults and age-0 Muskellunge, and catch rates by anglers have similarly declined while harvest remains low. Other changes associated with population decline include presence of fewer female adult Muskellunge and a change in adult Muskellunge size structure (increase in proportion of fish <1,016 mm) in addition to more large individuals greater than 1,372 mm. A significant adult die-off occurred from 2005 to 2008 (103 adults recovered in U.S. and Canadian waters) concomitant with an outbreak of viral hemorrhagic septicemia (VHS). These population changes were also temporally correlated with detection and proliferation of invasive Round Goby <em>Neogobius melanostomus</em>, a known VHS virus (VHSV) reservoir, egg predator, and competitor with native fishes. Comparisons of index netting before and after VHSV and Round Goby invasions suggest a direct link to the decline, but because these are correlations, we can only explore these effects. To examine the viability of Muskellunge nursery sites, we repeated survival studies conducted in the early 1990s with experimental releases of advanced fry at four locations during 2013–2015. Findings indicate contribution to age-0 populations, but catches poststocking (wild and stocked) were lower compared to the 1990s. We review information regarding potential stressors, including VHSV and Round Goby invasion, and conclude that their combined effects have created significant uncertainty and challenges to sustainable management of the Muskellunge population. In response, the St. Lawrence River Muskellunge management plan should be updated with a focus on restoration of the declining Muskellunge stock. Recommended actions target advancing conservation and restoration of critical habitat, restoring lost subpopulations, and reducing mortality associated with angling (e.g., from handling and harvest).

Spinal development and spinal dysraphism

2019 ◽  
pp. 983-992
Author(s):  
Dominic Thompson
Keyword(s):  
Spinal Cord ◽  
Spinal Dysraphism ◽  
Radical Resection ◽  
Management Plan ◽  
Congenital Disorders ◽  
Spinal Cord Development ◽  
Precise Diagnosis ◽  
Over Time ◽  
Spinal Cord Tethering

The term spinal dysraphism encompasses a group of congenital disorders of spinal cord development. This potentially confusing array of conditions is best understood from an embryological perspective, and a unifying method of classification is presented. Spinal dysraphism is associated with neurological, urological, and orthopaedic deficits, these may be present at birth or may evolve over time due to the effects of spinal cord tethering. Precise diagnosis is essential to formulating an appropriate surgical management plan in order to optimize long-term neurological outcome. Contemporary and controversial surgical advances in the field are discussed including electrophysiology directed radical resection for spinal lipomas and antenatal surgery for myelomeningocele.

scholarly journals Land use influences on acidification and recovery of freshwaters in Galloway, south-west Scotland

2001 ◽  
Vol 5 (3) ◽  
pp. 451-458 ◽  
Author(s):  
R. C. Helliwell ◽  
R. C. Ferrier ◽  
L. Johnston ◽  
J. Goodwin ◽  
R. Doughty
Keyword(s):  
Surface Waters ◽  
Chemical Recovery ◽  
Dry Period ◽  
Sulphur Deposition ◽  
South West ◽  
Recovery From Acidification ◽  
Long Term Trends ◽  
Acid Status ◽  
Annual Discharge

Abstract. The long term response of surface waters to changes in sulphur deposition and afforestation is investigated for three upland river systems in the Galloway region of south-west Scotland. From 1984-1999, these rivers exhibited a statistically significant decline in non-marine sulphate concentrations in response to reduced acid deposition. This reduction in non-marine sulphate was, however, insufficient to induce a pH recovery over the period. A statistically significant increase in river pH was observed between 1956-1970 (0.05 yr-1) when subsidised agricultural lime payments were at a maximum. In 1976, this subsidy ceased and surface waters have progressively acidified. In addition, climatic change is found to influence long-term trends in pH. Mean annual pH was greatest during a dry period between 1969-1973 when total annual discharge was low. Thereafter, pH declined gradually in response to higher rainfall and increased total annual discharge. Overall, surface waters draining the afforested catchments of the Rivers Cree and Bladnoch are more acid than those draining the moorland catchment of the Luce. These results indicate that in afforested catchments, current reductions in sulphur emissions have not led to an observed improvement in the acid status of surface waters. Forestry, therefore, represents a confounding factor with regard to chemical recovery from acidification in this region. Keywords: acidification, afforestation, deposition, rivers, lochs, non-marine sulphate, pH

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