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Benchmark of European Lobster (Homarus gammarus) in Swedish areas of Skagerrak, Kattegat and Öresund
Get PDFThis report summarizes the process of conducting a benchmark for the assessment of European lobster in the Swedish coastal areas of the Skagerrak, Kattegat and Öresund. Catch data, survey indices, commercial catch per unit of effort and life history data, on which the assessment is based on, are described in summary in the report and in detailed form in the attached appendices. Furthermore, the report summarizes the model structure and the sensitivity analyses done to generate an ensemble model that can be used to estimate the stock status of the lobster stock and provide advice. The current assessment is considered an improvement compared to previous modelling. This is due to advances in the modelling tools used, as well as improved data and knowledge on spatial distribution and size composition. The lobster stock on the Swedish west coast is currently assessed as being around sustainable biological levels. After a period of excessive fishing and low biomass, recent management measures have likely succeeded in limiting fishing and improving the status of the stock. Under the current fishing pressure, the stock may develop positively, but what future fishing pressure may look like under current management, without a limitation in total catch, is not possible to predict
Filtermaterial i markbaserade avloppsanläggningar
Get PDFDet filtermaterial som används i markbaserade avloppsanläggningar, avsedda för rening av hushållsspillvatten, utgörs traditionellt av naturgrus. Kring hälften av de små avloppsanläggningarna i Sverige bedöms vara markbaserade anläggningar. Samtidigt finns en målsättning om att minska det nationella naturgrusuttaget, och det är inte tillåtet att etablera en naturgrustäkt om det är tekniskt möjligt och ekonomiskt rimligt att använda ett alternativt material. Detta med anledning av att naturgrus betraktas som en ändlig resurs av stor betydelse för Sveriges dricksvattenförsörjning, med tanke på naturgrusförekomsters förmåga att lagra vatten och potential att därmed utgöra vattentäkter. Detta projekt har syftat till att identifiera material som skulle kunna ersätta naturgrus som filtermaterial i markbaserade avloppsanläggningar, samt att bedöma teknisk funktionalitet och hållbarhet hos dessa alternativa material. Bedömningen av hållbarhet har delats in i miljömässiga, ekonomiska och sociala aspekter. Projektets huvudsakliga frågeställningar var:1. Vilka material har högst potential som hållbara filtermaterial i markbaserade avloppsanläggningar? 2. Vilka ytterligare studier behövs för att bättre kunna utvärdera respektive materials potential samt optimera användningen av dessa material som filtermaterial?Inledningsvis identifierades 35 potentiella filtermaterial, baserat på erfarenhet hos projektgruppen men också genom inhämtning av förslag från externa parter och litteratursökningar. För att avgränsa studiens omfång beslutades att sju filtermaterial skulle väljas ut för vidare undersökningar, här benämnda djupstudie. Urvalet av material till djupstudien gjordes baserat på hur mycket litteraturdata som fanns tillgänglig rörande respektive material. Bedömning av mängden tillgängliga litteraturdata baserades på litteratursökning via den vetenskapliga databasen Scopus, där artiklar som inkluderade tema avloppsrening samt filtrering söktes ut (1 529 artiklar identifierades). Urvalet av de sju filtermaterialen baserades också på om det gick att hitta en expert som kunde ställa upp och svara på frågor gällande respektive material. Experterna var viktiga för projektet då det bedömdes vara svårt att få fram heltäckande information om respektive material och hållbarhetsaspekt enbart via litteraturkällor. Den litteratur som sökts fram användes som databas för att undersöka filtermaterialens tekniska funktionalitet med avseende på reningseffektivitet (för organiskt material, fosfor, kväve, metaller, bakterier och virus samt organiska mikroföroreningar). För att bedöma materialens potential med avseende på övriga kriterier utfördes ytterligare riktade informationssökningar via vetenskapliga databaser samt bredare sökmotorer (för att finna ”grå” litteratur och andra rapporterade erfarenheter). Dessutom hölls workshops och intervjuer med de experter som identifierats.De sju material som valdes ut för djupstudien var: • Ballast från tvättade schaktmassor • Bark • Bergkross • Biokol • Däckklipp • Krossad betong • Grov moränBedömningen av materialen skedde genom multikriterieanalys (MKA). MKA är en väletablerad beslutsstödsmetod som används då olika beslutsalternativ, i detta fall val av filtermaterial, utvärderas med avseende på ett flertal aspekter och syftet är att kunna ge en sammanfattande helhetsbild över alternativens för- och nackdelar. Då de alternativ som ska jämföras i MKA:n har identifierats följer beslut om vilka aspekter, det vill säga kriterier, som ska ingå i analysen. Sedan görs en bedömning av respektive material utifrån respektive kriterium. I detta fall definierades totalt 19 olika kriterier, vilket betyder att totalt 133 individuella bedömningar gjordes (=19 kriterier × 7 material). Varje bedömning länkades även till en osäkerhetsbedömning för att belysa vilka aspekter som bedöms vara i störst behov av ytterligare utredning. För att räkna fram en totalbedömning av respektive materialräknades poängen för de 19 kriterierna samman till ett slutresultat. Innan dess genomförde dock projektgruppen, med bidrag från projektets referensgrupp, en viktning av de individuella kriterierna, där vissa kriterier bedömdes ha större betydelse än andra för materialens sammantagna hållbarhet.Sammantaget resulterade bedömningarna i att alla material förutom biokol bedöms kunna ha likvärdig eller högre hållbarhet än naturgrus. Att biokol fick ett sämre poäng är framför allt förknippat med att detta material i dagsläget bedöms kosta betydligt mer än naturgrus. Samtliga material har både för- och nackdelar jämfört med naturgrus – ur olika aspekter beroende på material. Det gör att det högsta totalpoäng som tilldelats ett material (0,35 poäng för bark) är betydligt lägre än det teoretiskt möjliga maxpoänget (3 poäng). Att flera material förefaller ha högre potential än naturgrus tycks lovande för framtiden. En viktig sak att påpeka är dock att denna studie inte har haft till syfte att fastställa vilka material som bör godkännas för faktisk tillämpning i markbaserade anläggningar. För verklig til - lämpning bedöms de flesta materialen behöva genomgå ytterligare granskning, bland annat med avseende på:• Modifieringar för att anpassa materialen för aktuell tillämpning. • Efterföljande utvärdering av materialens långsiktiga reningsförmåga. • Hur sammansättning (t.ex. kornstorleksfördelning) och riskminimering (läckage av t.ex. organiska mikroföroreningar) inför användning/försäljning av materialen ska fastställas.Dessutom finns behov av att utreda den regionala tillgången på material inom olika landsdelar
How does forest fertilization influence tree productivity of boreal forests? An analysis of data from commercial forestry across Sweden
Get PDFForest fertilization is a forest management practice that is often claimed to increase productivity in boreal forests. Although regarded as an efficient way to increase profitability, it is also costly, and associated with risks such as biodiversity loss and nitrogen leaching from the soil. To be both cost-efficient and sustainable, potential enhanced productivity due to fertilization should be balanced against the adverse environmental impact. One effective strategy is to limit fertilization to sites where it can most significantly increase tree productivity, while avoiding application in less suitable areas. However, the current understanding of the specific conditions under which forest fertilization optimally stimulates tree growth is limited. To clarify this, we analysed standing tree volume from 32,498 recently harvested fertilized and unfertilized stands from Sweden's largest forest owner. We applied generalized additive models to quantify the effect of fertilization on standing tree volume at harvest and how the fertilization effect depended on dominant tree species, stand characteristics (site index, stem density), climatic conditions (temperature sum), and management (thinning, stand age at harvest). We found that the effect of operational fertilization was highly context-dependent. In pine-dominated stands, fertilization failed to increase tree volumes in cold climates and low-productive stands. In spruce-dominated stands, fertilization did not result in increased tree volumes in low-productive and high-productive stands. For a more sustainable and cost-efficient application of this practice we suggest that the context dependency of the efficiency of fertilization is given more attention. Hence, we recommend to refrain from fertilizing pine-dominated stands situated on lowproductive land or in regions with cold climates, such as those found in northern Sweden
X-marked trees: carriers of Indigenous Sami traditions
Get PDFCultural landscapes affiliated with the Indigenous Sámi of the northern boreal forests are laden with cognitive elements of social and religious significance. Here, the authors focus on trees bearing incised markings and use an archaeological and ethnohistoric interpretive framework to explore the significance of such trees in S & aacute;mi landscapes. Intensive forestry is destroying culturally modified trees at an alarming rate, and their significance as the bearers of culture and history is being stripped from forest landscapes. As a step towards understanding their importance, this work makes a plea for the documentation, interpretation and protection of the remaining trees
Progress towards sustainable agriculture hampered by siloed scientific discourses
Get PDFThere is no consensus in society on how to achieve sustainability. Scientists' limited experience in reflecting on their guiding assumptions, combined with a tendency to inflate their own research findings, hinders interdisciplinary dialogue and limits the usefulness of science. Through bibliometrics and discourse analysis, we analysed highly cited articles on agroecology and sustainable intensification. In broad terms, agroecology prioritizes diversity while sidelining productivity and adheres to relational epistemology, while sustainable intensification emphasizes boosting crop production while reducing environmental impact within a reductionist epistemology. Both discourses claim to have the solution to agricultural sustainability but are largely inexplicit about their guiding assumptions and their own limitations, and rarely engage with research in the other discourse. Interdisciplinary dialogue based on transparent and self-critical reflection on the assumptions and limitations of research could increase the relevance of science in societal dialogues about alternative pathways towards sustainable agriculture.Two major discourses for agricultural sustainability, agroecology and sustainable intensification, have produced extensive research bases, but do not engage or overlap with each other. This analysis examines how these 'silos' may hamper further research
Synergistic effects of glutathione and zinc seed priming in alleviating salt stress on maize seed germination, metabolite levels, seedling vigor, and nutrient acquisition
Get PDFThe comparative effects of reduced glutathione (GSH) and 0.5 % Zn (applied separately or in combination) were assessed on maize in relation to seed metabolite levels, seedling growth, antioxidative defense mechanism, levels of biochemicals and nutrient acquisition under NaCl stress. The level of applied salinity was 120 mM in Hoagland's nutrient solution. Salinity negatively affected seed germination and the emergence of seedlings; associated with altered seed metabolic activities. The high salinity also elevated the levels of malondialdehyde (MDA), increased reactive oxygen species (ROS) levels, altered metabolite levels, reduced uptake of mineral nutrients and increased the uptake of Na+ in maize seedlings. Interestingly, the GSH seed priming protocol, when applied alone or with Zn, ameliorated the physiological negativities associated with high salinity upon maize germination, emergence and seedling development. The three millimolar GSH concentration in combination with Zn (0.5 %) improved the germination attributes and emergence of seedlings. The GSH level of 3 mM with Zn was also effective in mitigating the negative impacts of NaCl salinity on seedling growth, associated with better maintenance of physio-biochemical activities, reduced uptake or translocation of Na2+, and better maintenance of the increased K+/Na+ and Ca2+/Na+. The improvement in maize salt stress tolerance, attributed to 3 mM GSH with 0.5 % Zn as seed treatment, was associated with reduced Na+ uptake that decreased its toxicity. Based on this study, it is plausible to use a combination of GSH and Zn as seed priming agentsto enhance the physiological resilience of maize growing in areas with high salinity
Liquid Fragmentation Induced by Particle Aggregation During Two-Phase Flow in 3D Porous Media
Get PDFNatural or engineered microparticles are often encountered in subsurface multiphase flow systems. This introduces a complex flow scenario with a variety of applications. However, the influence of particles on multiphase flow dynamics and the underlying mechanism remain elusive. Here, we investigate particle transport behavior and fluid phase distribution within 3D porous media through direct visualization utilizing laser scanning confocal microscopy. The mechanisms and factors governing particle aggregation during two-phase flow are elucidated. We identify a previously overlooked pore-scale phenomenon: fragmentation of wetting liquid induced by spontaneous particle aggregation in localized regions. This process dramatically increases the number of wetting clusters while reducing the fluid connectivity, resulting in a change in the relative permeability of fluids. These findings reveal the dynamic coupling mechanism between pore-scale particle aggregation and fluid flow and transport properties at larger scales, providing critical insights for predicting and controlling particle mediated geophysical flow processes
An eco-physiological model of forest photosynthesis and transpiration under combined nitrogen and water limitation
Get PDFAlthough the separate effects of water and nitrogen (N) limitations on forest growth are well known, the question of how to predict their combined effects remains a challenge for modeling of climate change impacts on forests. Here, we address this challenge by developing a new eco-physiological model that accounts for plasticity in stomatal conductance and leaf N concentration. Based on optimality principle, our model determines stomatal conductance and leaf N concentration by balancing carbon uptake maximization, hydraulic risk and cost of maintaining photosynthetic capacity. We demonstrate the accuracy of the model predictions by comparing them against gross primary production estimates from eddy covariance flux measurements and sap-flow measurement scaled canopy transpiration in a long-term fertilized and an unfertilized Scots pine (Pinus sylvestris L.) forest in northern Sweden. The model also explains the response to N fertilization as a consequence of (i) reduced carbon cost of N uptake and (ii) increased leaf area per hydraulic conductance. The results suggest that leaves optimally coordinate N concentration and stomatal conductance both on short (weekly) time scales in response to weather conditions and on longer time scales in response to soil water and N availabilities
Long-term transfer of 137 Cs in sensitive agricultural environments after the Chornobyl fallout in Sweden
Get PDFIn this study, the long-term transfer of 137 Cs from soil to grass on Swedish farms and fields, heavily contaminated after the 1986 radioactive fallout, was investigated. The study spans over 8-14 years, beginning in June 1986, and covers various soil types and agricultural practices. The transfer of 137 Cs from soil to grass was highly variable, with transfer factors ranging from 1.0 x 10-5 to 0.357 m2 kg-1 . Higher values were observed on fields with sandy loam, loamy sand, and organic soils, and lower values on fields with a high clay content. The transfer of 137 Cs to grass generally exhibited an exponential decline across the majority of fields over the years. The rate of decrease was most pronounced in clay loam and silty loam soils, while it was least evident in sandy loam, sandy soils, and peat soils. The soil properties and farming practices were more important for 137 Cs uptake than the initial deposition density. The transfer factor had a negative correlation with soil pH, clay, and fine silt content. No significant relationships were found with other soil variables, such as soil organic matter content and plant available potassium concentration. The median effective half-life of 137 Cs in the grass was 4.5 years, with a range of 2-18 years. The uptake of 137 Cs by plants did not correlate with the potassium concentration in grass tissues; however, the activity concentration of 137 Cs in grass correlated negatively with the potassium content in the plants grown on fields with high deposition levels
Microclimate temperature effects propagate across scales in forest ecosystems
Get PDFContextForest canopies shape subcanopy environments, affecting biodiversity and ecosystem processes. Empirical forest microclimate studies are often restricted to local scales and short-term effects, but forest dynamics unfold at landscape scales and over long time periods.ObjectivesWe developed the first explicit and dynamic implementation of microclimate temperature buffering in a forest landscape model and investigated effects on simulated forest dynamics and outcomes.MethodsWe adapted the individual-based forest landscape and disturbance model iLand to use microclimate temperature for three processes [decomposition, bark beetle (Ips typographus L.) development, and tree seedling establishment]. We simulated forest dynamics with or without microclimate temperature buffering in a temperate European mountain landscape under historical climate and disturbance conditions.ResultsTemperature buffering effects propagated from local to landscape scales. After 1,000 simulation years, average total carbon and cumulative net ecosystem productivity were 2% and 21% higher, respectively, and tree species composition differed in simulations including versus excluding microclimate buffering. When microclimate buffering was included, Norway spruce (Picea abies (L.) Karst.) increased by 9% and European beech (Fagus sylvatica L.) decreased by 12% in mean basal area share. Some effects were amplified across scales, such as a mean 16% decrease in local-scale bark beetle development rates resulting in a mean 45% decrease in landscape-scale bark beetle-caused mortality.ConclusionsMicroclimate effects on forests scaled nonlinearly from stand to landscape and days to millennia, underlining the utility of complex simulation models for dynamic upscaling in space and time. Microclimate temperature buffering can alter forest dynamics at landscape scales