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Does peatland rewetting mitigate flooding from extreme rainfall events?
Get PDFPristine peatlands are believed to play an important role in regulating hydrological extremes because they can act as reservoirs for rainwater and release it gradually during dry periods. Rewetting of drained peatlands has therefore been considered an important strategy to reduce the catastrophic effects of flooding. With the anticipation of more frequent extreme rainfall events in the future due to a changing global climate, the importance of peatland rewetting in flood mitigation becomes even more important. To date, however, empirical data showing that rewetting of drained peatlands actually restores their hydrological function similar to pristine peatlands are largely lacking, particularly for boreal fens. To assess whether peatland rewetting can mitigate flooding from extreme rainfall events and ensure water security in a future climate, we measured event-based runoff responses before and after rewetting using a BACI approach (before-after and control-impact) within a replicated, catchment-scale study at the Trollberget Experimental Area in northern Sweden. High-resolution hydrological field observations, including groundwater level (GWL), discharge, and rainfall data, were collected over 4 years, allowing us to detect and analyze 17 rainfall-runoff events before and 30 events after rewetting. We found that the rewetted sites experienced an increase in the GWL following rewetting and that this was consistently observed across all distances from the blocked ditch within the peatland. Our rainfall-runoff analysis revealed that rewetting significantly decreased peak flow and the runoff coefficient and reduced the overall flashiness of hydrographs, making the rewetted sites function more like the pristine control peatland. However, "lag time", which was already similar to pristine conditions, was pushed farther away from pristine conditions following rewetting. Yet, our results showed that the effectiveness of ditch blocking in flood moderation was strongly influenced by the initial condition and the catchment percentage of restoration, as one of our two rewetted peatlands did not show significant change, attributed to it being already similar to the pristine site, suggesting less treatment effect, and the other catchment, with higher restoration percentage, had a better response to treatment. In summary, our findings suggest that peatland rewetting has the potential to mitigate flood responses; however, further research over a longer time period is needed, as peat properties and the peatland vegetation will develop and change over time
Physiological response to weight carrying and associations with conformation traits in Icelandic horses used for tour riding
Get PDFBackground Weight carrying capacity is an important trait in riding horses and it may be associated with conformation. This study examined the physiological response to a ridden incremental weight carrying test in 16 adult Icelandic horses used for tour riding. Horses carried 20% (BWR20%), 25% (BWR25%), 30% (BWR30%) and 35% (BWR35%) of their body weight (BW) in tolt (similar to 5.7 m/seconds, 640 m/step), and associations with body measurements and back conformation (score) were examined. Horses were divided into two groups (narrow or broad back) and body measurements were collected. Plasma lactate was analysed in blood samples collected after each step in the exercise test, an exponential equation was fitted, and BW-ratio was calculated for 2, 3 and 4 mmol/L (BWRLa2, BWRLa3 and BWRLa4). Plasma creatine kinase (CK) and aspartate amino transferase (AST) were analysed at rest and 24 h post exercise.Results Four out of 15 horses did not reach a plasma lactate concentration of 4 mmol/L, even at BWR35%. A positive correlation was found between chest width and BWRLa4 and between the difference between height at withers and croup and BWRLa2 (P < 0.05). Hock circumference and the difference between height at croup and back were negatively correlated with BWRLa2 (P < 0.05). The change in CK from rest to 24 h post exercise was negatively correlated with the difference between height at withers and height at back and croup (P < 0.05).Conclusions The physiological response to weight carrying was relatively low. A wider chest, "uphill" conformation, straight backline and smaller hock circumference were associated with weight carrying capacity, but group (narrow or broad back) was not
A Comprehensive and Ultrasensitive Isotope Calibration Method for Soil Amino Compounds Using Orbitrap Mass Spectrometry
Get PDFBound amino compounds (amino acid and amino sugar polymers) comprise a significant proportion (similar to 40%) of soil organic nitrogen and therefore represent an essential source of nitrogen for plant and microbial nutrition. The analysis of their content and isotope enrichment still represents a significant challenge due to the low isotope enrichment levels reached under near-native soil conditions and the lack of isotopically labeled standards for some key amino compounds. In this study, we used both a C-13-labeled and an unlabeled amino acid mixture to establish isotope calibration curves for 16 amino compounds, using the 6-aminoquinolyl-N-hydroxysccinimidyl carbamate (AQC) derivatization method and ultrahigh-performance liquid chromatography with high-resolution Orbitrap mass spectrometry (UPLC-Orbitrap MS). Molecular ions of AQC-derivatives for all standard amino compounds were identified at the expected m/z values of the respective isotopologues. The isotope calibration curves exhibited excellent linear fits across the whole C-13 enrichment range and polynomial fits in the low C-13 enrichment range (R-2 > 0.990). However, the polynomial fitting terms differed between individual amino acids. Subsequently, we developed equations to relate the calibrated regression terms to the physicochemical properties of the respective amino acids, here mainly the ratio of amino compound-C atoms to total C atoms in AQC-amino compound derivatives. Based on these regressions, we could ultimately predict isotope calibration curves for those amino compounds unavailable as C-13 labeled standards, for example, muramic acid, hydroxyproline, and diaminopimelic acid. To test the model accuracy, we compared the outcomes of measured calibrations with predicted calibrations for amino acids where we had isotopically enriched standards. The results of linear regression between measured and predicted data were excellent, where R-2 was >0.97, and mean absolute (percentage) deviations, MAD and MAPD, were 0.334 and 15.8%. Finally, we applied both standard and predicted calibration curves to low C-13 amended soil samples and unlabeled controls to test the applicability of our model. The limit of detection (LOD) as the minimum detectable atom % C-13 incorporation of amino compounds ranged from 0.0003 to 0.14 atom % among different amino compounds. This general predictive model can be used to comprehensively quantify isotope enrichments across the entire soil amino compound profile, including amino sugars and proteinogenic and nonproteinogenic amino acids, providing valuable insights for a better understanding of the overall fate of different amino compounds in soils and other complex environmental systems
State servants, cash, and credit market modernizations in early modern Stockholm
Get PDFThis study examines the credit market in seventeenth-century Stockholm, a rapidly growing city whose credit market is an early example of a market with both private and institutional actors. Using a sample of 1,500 probate inventories from 1679 to 1708, we focus on the practices and experiences of municipal and state servants, and we examine in detail the probate inventories of employees of the royal court. The latter group had their wages paid by the king in a world where being in arrears was the norm, and their spatial and social proximity to the Bank of the Estates made them potential pioneers in the movement towards an institutionalized and formalized capital market. The credit market has a mixed character, both in terms of the opportunities available to investors and in terms of their behavior. For people with a surplus of cash and good connections, money lending could be a way to increase their income. The court servants and many others moved seamlessly between institutional and private, as well as formal and informal, credit. The article shows that wage earners and state servants were central to the transformation of the early modern credit market. For them, the credit market and the bank offered investment opportunities that matched their skills and circumstances
Interaction of Perfluorooctanoate and Perfluorohexanoate with Moringa oleifera Seed Protein
Get PDFPer- and polyfluoroalkyl substances (PFAS) are persistent and potentially toxic pollutants found widely in the environment; however, there is a lack of understanding how these materials interact with many interfaces that are important for remediation. The association of perfluorooctanoate (PFOA) and perfluorohexanoate (PFHxA) with Moringa oleifera seed protein was investigated using neutron reflectometry. The seed protein is known to associate with many materials and adsorbs irreversibly to silica surfaces, and it was shown that it was not removed by rinsing with water. PFHxA and PFOA were found to adsorb to the previously bound protein, forming mixed layers of protein, surfactant, and water that expanded to incorporate the extra material. On rinsing with water, PFOA was removed from the layer, leaving the protein bound to the silica surface. An almost three-times larger volume fraction of PFOA than PFHxA was observed in the protein layer. At the critical micelle concentration, the layer consisted of 1.8 mg m-2 PFOA and 1.3 mg m-2 of protein. Comparison of the relative amounts of each surfactant and protein suggests that hydrophobic interactions play a significant role in the coadsorption. The results indicate that the seed protein could be used to adsorb PFAS reversibly as a step toward remediation of contamination. This quantification of association with an albumin-like protein is important for understanding of transport both in human bodies and in the environment
Bioconversion of aquaculture waste blended with vegetable by-products using Hermetia illucens larvae: Process parameters and larval quality
Get PDFThe constantly increasing aquaculture production generates high amounts of biowaste worldwide, which must be properly treated in order to keep aquaculture’s footprint low. This study aimed at evaluating the bioconversion of aquaculture waste streams (RAS sludge, fish trimmings, and harvest macroalgae waste) using black soldier fly (Hermetia illucens, BSF) larvae and the quality of the resulting larval biomass. The study was conducted in a modified shipping container simulating a large-scale setting and the diets were formulated using brewery spent grains and cabbage as base, mixing in aquaculture waste, aiming to treat the highest inclusion rate possible. A bioconversion efficiency of above 20 %DM and a material reduction generally above 55 %DM were observed, while generating a larval biomass that was rich in protein (> 35 %DM), essential amino acids and fatty acids. The larvae reared on fish trimmings (from an anchovy processing plant) had the highest crude fat content (29.0 ± 1.1 %DM) in relation to other treatments, while the macroalgae waste dietary inclusion generated larvae with low fat content (14.7 ± 1.5 %DM on average). Interestingly, it was observed that the addition of aquaculture wastes, even in small inclusion levels (between 15 % and 25 % on wet basis), reduced the concentration of saturated fatty acids in the larvae (especially lauric acid and pentadecanoic acid). It was concluded that BSF larvae are able to bioconvert varied aquaculture waste streams and it is possible to produce tailored larval biomass by adding such waste streams in their diets, enabling the production of a protein ingredient with specific traits to be used in aquafeeds
Cropping system redesign for allelopathy: A vision for the 'post-herbicide era'
Get PDFArable weed management faces an uncertain future. A climate of tightening regulations and widespread herbicide resistance has led to suggestions that we are entering the 'post herbicide era', but successful weed management with no, or fewer, herbicides will require a diversification and de-intensification of management strategies. One underappreciated strategy is to utilise the natural chemical interactions between plants, both antagonistic (allelopathy), and benign (allelobiosis). The prevailing, reductionist approach to allelopathy is as a substitution for synthetic herbicides, which has had the effect of limiting our ecological understanding of these plant-plant interactions. I posit here that allelopathy and allelobiosis will only be effective in regulating arable weeds through ecological redesign, inspired by the ecosystems outside of agricultural land in which these interactions affect plant growth. Increased integration of concepts from studies of these ecosystems should therefore be prioritised in allelopathic weed management. Research should, for instance, consider recognition interactions, the stimuli which can induce allelopathic responses, and the effects of plant community diversity on these interactions. In short, researchers should consider the desired outcome of allelopathic weed management and the context in which it would be required to operate. As such, management of agricultural land should prioritise reductions in disturbance and especially tillage, to foster the development of a benign, self-regulatory weed community based on low-level competition and allelopathic inhibition, which does not require intensive management efforts
Belowground Interactions in a Barley Cultivar Mixture: Root Distribution and Arbuscular Mycorrhizal Contributions to Uptake of Heterogeneous Phosphorus
Get PDFCultivar mixtures have the potential to mitigate abiotic stress and stabilize crop yields, but their belowground dynamics remain poorly understood. We evaluated phosphorus (P) uptake by two contrasting spring barley (Hordeum vulgare L.) cultivars ("Anneli" and "Feedway"), grown either in 50:50 mixture or as pure stand. The cultivars were grown in mesocosms under four P fertilization treatments: low-P, homogeneous high-P (90 mg P/kg), and localized P hotspots (100 mg P) placed either in the topsoil (5 cm) or subsoil (35 cm). To trace P uptake pathways, the hotspots were labeled with 33P and enclosed in mesh bags allowing only mycorrhizal hyphae (25 mu m) or both roots and hyphae (2 mm) to access the hotspot. After 35 days, we measured aboveground biomass, total P content, P-33 specific activity, and root biomass, length, diameter, and arbuscular mycorrhiza fungi (AMF) root colonization. In the mixture, reduced P uptake by "Feedway" led to lower overall performance compared to pure stand. Root modifications in the mixture did not enhance biomass or P acquisition, potentially due to decreased AMF colonization. Although different P placements altered P uptake patterns, they did not increase total P uptake. Roots accessed the P hotspots and acquired P-33 without notable proliferation in the enriched zones. Our findings underscore the complexity of belowground interactions involving root distribution, competition for P, and AMF, and highlight the need for future research to optimize nutrient acquisition and performance in cultivar mixtures
Sensory screening of pea (Pisum sativum L.) seeds and correlations to seed quality
Get PDFGrowing demand for environmentally sustainable protein sources is shifting dietary preferences toward plantderived alternatives such as legumes. Pea (Pisum sativum L.) seeds offer great potential for expanded human consumption, but sensory quality is key for consumer acceptance and cultivar development. In this study, a diversity panel of 15 pea accessions was evaluated for nutrients and phytochemicals (protein, resistant and nonresistant starch, fatty acids, choline, phytate, saponins, and sucrose) and their sensory attributes (taste, aroma, mouthfeel, and aftertaste). Among the sensory attributes, mouthfeel and aroma contributed most to the variation. Principal component analysis revealed two large, distinct clusters, primarily separated by seed coat (testa) colour. Accessions with a dark-coloured testa were generally perceived more odour intense and with more texture, while accessions with light-coloured testa were sweeter and juicier. Accessions with wrinkled seeds stood out in their content of non-resistant starch, sucrose, total choline, and phytate, when compared to smooth and dimpled seeds. Shorter cooking times were positively correlated to the perception of higher bitterness. This study highlights the potential in combining seed compositional analysis and sensory evaluations for screening pea accessions suitable for the development of future food products
Human excreta recycling in Sweden: a PESTEL-SWOT framework analysis-Review
Get PDFSource-separating sanitation systems can maximise resource recovery from wastewater and mitigate the environmental impacts of conventional wastewater treatment plants, including eutrophication and climate change. This study conducts a comprehensive review of the literature on source-separating sanitation systems in Sweden, aiming to identify the challenges hindering their diffusion and potential expansion opportunities. Employing a rapid evidence synthesis approach, we extracted data from the Web of Science and supplemented findings through hand-searches in additional electronic databases. Of the 713 studies initially identified, 24 met our stringent inclusion criteria. The analysis was structured around a combined PESTEL (Political, Economic, Technical, Social, Environmental, Legal) and SWOT (Strengths, Weaknesses, Opportunities, Threats) framework to synthesise the existing body of work and discern main patterns. The findings underscore the untapped strengths in these technologies' potential in enhancing nutrient recovery and food security, in addition to reducing eutrophication and greenhouse gas emissions. The studies analysed reported Sweden's strengths in source separation, highlighting organisational diversity, market benefits, social acceptance, technological readiness, and nutrient recovery, all contributing to the SDGs and addressing challenges such as eutrophication and limited sanitation access. The primary challenges were identified as social and cultural taboos towards the recycling of human excreta, disbelief in its quality as a fertiliser, concerns about hazardous substances like pharmaceuticals, and a preference for using it to grow non-food crops. Our article main contribution lies in proposing 12 structured upscaling strategies addressing these barriers and leveraging the opportunities identified including policy measures to incentivise circular practices, building support through stakeholder engagement, updating building codes to require double piping, and enhancing municipal-utility cooperation. While grounded in Sweden, our study contributes to research on the broader shift towards sustainable food systems by leveraging internal strengths and external opportunities in circular wastewater systems