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1.	Berggren Kleja, Dan, et al. (author) Metallers mobilitet i mark 2006 Reports (peer-reviewed)abstract I rapporten beskrivs nuvarande kunskapsläge när det gäller metallers uppträdande imark. Riskbedömningar för metaller i förorenad mark diskuteras.De flesta metaller binds i viss utsträckning i marken, oftast genom olika ytreaktioner med markens organiska material eller med järn- och aluminiumoxider, ochibland även genom utfällningsreaktioner. I vilken omfattning detta sker beror avfaktorer som t.ex. pH, redoxförhållanden, löst organiskt material (DOC) i markvattnet, samt förekomst av konkurrerande joner. Det är också viktigt att beaktavilka former metallerna förekommer som i markvattnet. Komplexbildning medt.ex. DOC minskar i regel toxiciteten. För att bättre ta hänsyn till markkemiskaförhållanden i riskbedömningen bör geokemiska modeller komma till ökad användning.Metaller lösta i vattnet följer med när vattnet strömmar och kan transporterastill grund- och ytvatten eller tas upp av växter. Hur snabbt detta går beror, förutomkemiska och biologiska processer, även på en rad olika jordegenskaper. Till exempel innehåller vissa jordar s.k. makroporer vilka ger upphov till preferentiellt flöde.Detta innebär att en del av metallerna snabbare kan transporteras genom marken,förbi jordpartiklar där metallerna annars skulle bindas.De olika modeller som används för att beskriva påverkan av markförorening pågrundvatten kan delas in i två grupper: stationära modeller antar att källtermen ärkonstant och tar enbart hänsyn till den utspädning som sker i grundvattnet. Exempel på sådana modeller är den svenska riktvärdesmodellen, JAGG och RBCA. I detvå senare modellerna finns möjlighet att ta hänsyn till nedbrytning av organiskaämnen. Tidsberoende modeller antar en avklingande källterm och en tidsberoendetransport i grundvattnet, exempelvis RISC och TAC-modellen. För beräkning avtransport i grundvattnet tas hänsyn till flödes- och fastläggningsmekanismer somadvektion, dispersion och linjär sorption.Med hjälp av laktester kan man uppskatta den andel av metallföroreningen somär löslig i vatten. Denna information kan sedan användas för att beräkna adsorptionsparametrar (Kd-värden, m.m.) för spridningsmodeller. Laktester kan ibland gemissvisande resultat eftersom de orsakar utspädning av provet, bl.a. blir DOCkoncentrationerna alltför låga. Dessutom bör de inte användas för sulfidjordar.Geokemiska modeller kan användas för att förbättra tolkningen av laktester för attfå till stånd realistiska uppskattningar av Kd-värden.Det finns ett antal spridningsmodeller som kan användas för att bedöma riskenför spridning till grundvatten och ytvatten. De är kraftfulla verktyg som dock ännuinte använts i någon större utsträckning i Sverige. Detta beror på flera orsaker, bl.a.de hydrogeologiska förhållandena i Sverige, behovet av anpassningen av de modeller som är allmänt tillgängliga, svårigheter att ta fram bra dataunderlag samt ensvag tradition i att använda modeller och förstå modellresultat.Ett par angelägna forsknings- och utvecklingsinsatser är att ta fram bättre uppskattningar av metalladsorption i svensk mark, och att anpassa existerande spridningsmodeller för användning i riskbedömningar.
2.	Loth, Daan W, et al. (author) Genome-wide association analysis identifies six new loci associated with forced vital capacity 2014 In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 46, s. 669-677 Journal article (peer-reviewed)abstract Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P < 5 × 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispanic individuals. We detected transcripts for all six newly implicated genes in human lung tissue. The new loci may inform mechanisms involved in lung development and the pathogenesis of restrictive lung disease.
3.	Ahmad, Muhammad Arslan, et al. (author) Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X-Ray 2018 In: Water Resources Research. - 0043-1397 .- 1944-7973. ; 54, s. 9255-9263 Journal article (peer-reviewed)abstract The saturated hydraulic conductivity of soil, K-s, is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability of a model based on percolation theory and critical path analysis to estimate K-s measured on 95 undisturbed soil cores collected from contrasting soil types. One parameter (the pore geometry factor) was derived by model fitting, while the remaining two parameters (the critical pore diameter, d(c), and the effective porosity) were derived from X-ray computed tomography measurements. The model gave a highly significant fit to the K-s measurements (p<0.0001) although only 47% of the variation was explained and the fitted pore geometry factor was approximately 1 to 2 orders of magnitude larger than various theoretical values obtained for idealized porous media and pore network models. Apart from assumptions in the model that might not hold in reality, this could also be attributed to experimental error induced by, for example, air entrapment and changes in the soil pore structure occurring during sample presaturation and the measurement of K-s. Variation in the critical pore diameter, d(c), was the dominant source of variation in K-s, which suggests that d(c) is a suitable length scale for predicting soil permeability. Thus, from the point of view of pedotransfer functions, it could be worthwhile to direct future research toward exploring the correlations of d(c) with basic soil properties and site attributes.
4.	Artigas Soler, María, et al. (author) Genome-wide association and large-scale follow up identifies 16 new loci influencing lung function. 2011 In: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 43:11, s. 1082-90 Journal article (peer-reviewed)abstract Pulmonary function measures reflect respiratory health and are used in the diagnosis of chronic obstructive pulmonary disease. We tested genome-wide association with forced expiratory volume in 1 second and the ratio of forced expiratory volume in 1 second to forced vital capacity in 48,201 individuals of European ancestry with follow up of the top associations in up to an additional 46,411 individuals. We identified new regions showing association (combined P < 5 × 10(-8)) with pulmonary function in or near MFAP2, TGFB2, HDAC4, RARB, MECOM (also known as EVI1), SPATA9, ARMC2, NCR3, ZKSCAN3, CDC123, C10orf11, LRP1, CCDC38, MMP15, CFDP1 and KCNE2. Identification of these 16 new loci may provide insight into the molecular mechanisms regulating pulmonary function and into molecular targets for future therapy to alleviate reduced lung function.
5.	Boström, Gustaf, et al. (author) Riskkartering av bekämpningsmedel i Skånes grundvatten : simuleringar med MACRO-SE 2015 Reports (other academic/artistic)abstract Syftet med detta projekt har varit att göra en kartering av riskerna med bekämpningsmedelsläckage till grundvatten i Skåne. Karteringen utfördes genom simuleringar med riskbedömningsverktyget MACRO-SE som har utvecklats inom Kompetenscentrum för kemiska bekämpningsmedel (CKB) vid Sveriges lantbruksuniversitet (SLU) i Uppsala. Bearbetning och analys av simuleringsresultaten har gjorts av CKB i samarbete med Länsstyrelsen Skåne. Riskkarteringen har utförts för bekämpningsmedlen bentazon, isoproturon, kvinmerak, MCPA, metazaklor och metribuzin vilka tidigare har påvisats i grundvatten. Dessa substanser är också representativa för en stor del av jordbruket i Skåne då de används i stor mängd och tillsammans täcker in en stor del av alla grödor som odlas i länet. Tidigare kunskapssammanställningar pekar på att det framförallt är äldre, idag förbjudna ämnen som hittas i djupare grundvatten. Men eftersom det finns en, ofta lång, tidsfördröjning mellan att ett ämne sprutas på markytan tills det att det kan infiltrera ner till grundvattnet är det intressant att närmare studera om även dagens användning av bekämpningsmedel framöver kan leda till förekomst av olika substanser i grundvattnet. Inför simuleringarna definierades scenarier som motsvarar den typiska användningen av idag för respektive substans. Utifrån dessa scenarier och data för bekämpningsmedlens fysiska och kemiska egenskaper, kartor över arealen åkermark, odlade grödor, klimatdata och jordarternas egenskaper simulerar modellen koncentrationer av bekämpningsmedlet i markvattnet på ca 2 meters djup, som kan ses som det vatten som infiltrerar genom den omättade zonen för att bli grundvatten. Resultaten visar inte koncentrationer i det djupare grundvattnet, för detta skulle det krävas en avancerad och högupplöst modell för grundvattenflöden för hela Skåne. De simulerade koncentrationerna i markvattnet på 2 meters djup kan därför ses som ett slags värsta-falls-antagande av möjliga halter av bekämpningsmedel som den simulerade användningen kan ge upphov till i grundvattnet. Modellresultaten pekar på att samtliga undersökta substanser skulle kunna uppnå detekterbara koncentrationer i grundvattnet på något ställe i länet. För substanserna bentazon och metazaklor visar resultaten att halter över gränsvärdet för dricksvatten (0,1 µg/l) även skulle kunna förekomma på vissa platser i länet. En summering av koncentrationerna för de simulerade substanserna visar att dricksvattengränsvärdet för summahalt bekämpningsmedel (0,5 µg/l) skulle kunna överskridas inom några mycket små områden i nordvästra och sydöstra Skåne. Generellt sett är riskerna för bekämpningsmedelsläckage till grundvattnet betydligt större i södra och västra delarna av länet, mycket beroende på den betydligt högre andelen åkermark där men också på grund av vädret i klimatzonen i detta område. Som ett beslutsunderlag för vattenförvaltningen på Länsstyrelsen har även de simulerade koncentrationerna aggregerats utifrån de grundvattenförekomster som definierats för vattenförvaltningen och som därmed ska status- och riskklassas. Beräkningar av medelvärden per grundvattenförekomst för de utvalda substanserna visar att i nästan alla fall ligger de simulerade halerna under dricksvattengränsvärdet. Simuleringar har också gjorts för historisk användning av bentazon och MCPA. Utifrån användningsdata som var typisk 1986 kan man se att det är stora skillnader i riskerna för grundvattenläckage jämfört med dagens användning. Simuleringarna med den historiska användningen resulterade i avsevärt högre koncentrationer, vilket framförallt förklaras med de betydligt högre doserna som då tilläts. En jämförelse har även genomförts mellan av modellen simulerade koncentrationer och uppmätta koncentrationer på samma plats. Dessa jämförelser tyder på att MACRO-SE i stor utsträckning kan prediktera ifall ett ämne innebär en risk för detekterbara koncentrationer i grundvattnet. Simuleringsresultaten kan dock inte visa risker av transport av bekämpningsmedel i grundvatten eller lateral transport av bekämpningsmedel från intilliggande inströmningsområden och denna faktor måste tas hänsyn till med hjälp av andra informationskällor vid riskbedömning av specifika grundvattenförekomster. Vad gäller uppskattningar av faktiska koncentrationer i grundvattnet är predikterade och uppmätta koncentrationer ofta i samma storleksordning, för de få data som finns för jämförelse, men korrelationen mellan koncentrationerna är svag. Ett bättre dataunderlag av koordinatsatta provtagningar i grundvatten på 2 meters djup skulle bidra till ett bättre test av modellen som skulle vara värdefullt för fortsatt utveckling. Resultaten från denna rapport kan användas för att peka ut de substanser som kan utgöra en risk för läckage till grundvattnet samt i vilka områden denna risk är störst. Resultaten kan även användas i Länsstyrelsens vattenförvaltningsarbete som ett underlag i påverkansbedömningen samt för att ta fram nya stationer för kontrollerande och operativa övervakning av grundvattnet och på så sätt effektivisera de regionala miljöövervakningsprogrammen. Riskkartorna kan ge information om var arbetet med grundvattenskydd behöver intensifieras, samt utgöra underlag för upprättande av nya eller revidering av äldre vattenskyddsområden.
6.	Boye, Kristin, et al. (author) Pesticide run-off to Swedish surface waters and appropriate mitigation strategies : a review of the knowledge focusing on vegetated buffer strips 2012 Reports (other academic/artistic)abstract Environmental monitoring has revealed that pesticides regularly enter surface waters in Sweden. Mitigation measures to control point sources and spray drift have successfully reduced pesticide concentrations in natural waters, but concentrations still sometimes exceed ecotoxicological guideline values. In addition, the EU directives on water (2000/60/EC) and sustainable use of pesticides (2009/128/EC), and the regulations regarding placing plant protection products on the market (EC 1107/2009) stipulate that mitigation strategies should be developed against diffuse sources, such as surface run-off and drainage. This report presents a compilation of existing knowledge as data support for the relevant authorities in the implementation of run-off mitigation strategies in regulatory and subsidy systems. The report describes a number of measures (vegetated buffer strips in particular, but also wetlands, ditch management, integrated pest management and other management strategies) to reduce the risk of surface run-off of pesticides. The report also evaluates the validity under Swedish conditions of the R1 scenario in the PRZM-in-FOCUS model for assessing the risk of pesticide concentrations exceeding the ecotoxicological guideline values due to pesticide transport through run-off. In Sweden, the majority of surface run-off occurs during snowmelt, when pesticide losses are unlikely. The temporal and spatial incidence of run-off events during the growing season and the amount of pesticides transported in this way are currently unknown. Phosphorus models estimate that up to 33% of total annual water flow enters water courses as surface run-off in the worst case scenario, and around 10% on average, but lack of model calibration data renders these estimates highly uncertain. Field data from a drained silt loam (considered to represent the 95th percentile worst case for run-off under Swedish conditions) suggest that 35- 50% of total monthly water flow during summer (May-September) occurs as surface run-off. Thus, surface run-off may contribute considerably to pesticide transport locally, but is still considered unlikely to be of major importance on a national level, although data are lacking to confirm this assumption. Therefore, local adaptation of mitigation measures is deemed a more efficient strategy for Sweden than general solutions, such as mandatory vegetated buffer strips along all water courses. This would also simplify coupling to other environmental mitigation measures, e.g. concerning nutrients and biodiversity, and increase acceptance among farmers. The R1 scenario in PRZM-in-FOCUS greatly overestimates the risks of run-off and erosion for Sweden, since the assumptions on soil and weather conditions are more extreme than is realistic for Sweden. Thus, alternative solutions suggested in this report for assessing pesticide run-off risks in Sweden are: 1) developing a Swedish scenario for the PRZM model; 2) expanding the Swedish groundwater scenario for the MACRO-in-FOCUS model to include run-off estimation; and 3) establishing a system for local run-off mitigation that is sufficiently reliable to justify the assumption that pesticides will rarely enter surface waters through runoff. It is strongly suggested that research and monitoring projects be supported to provide a better database on which to build risk assessment scenarios and risk management strategies.
7.	Boye, Kristin, et al. (author) Ytavrinning av växtskyddsmedel i Sverige och lämpliga motåtgärder : en kunskapssammanställning med focus på skyddszoner 2012 Reports (other academic/artistic)abstract Ytavrinning är en av flera möjliga diffusa spridningsvägar för växtskyddsmedel till ytvatten. Motåtgärder mot ytavrinning av växtskyddsmedel, med speciellt fokus på skyddszoner, har aktualiserats genom EU:s antagande av ett nytt ramdirektiv (2009/128/EG)1 för hållbar användning av bekämpningsmedel och genom riskbedömningsrutiner vid produktregistrering av växtskyddsmedel enligt växtskyddsmedelsförordningen (EG 1107/2009)2 . Med anledning av detta har problemets omfattning i Sverige och olika motåtgärders relevans och effektivitet under svenska mark- och väderförhållanden undersökts genom en litteraturgenomgång och intervjuer med svenska och internationella aktörer och experter. Rimligheten i riskbedömningsmodelleringar med R1 scenariot i PRZM-in-FOCUS har också utvärderats för svenska förhållanden. Bedömningen är att ytavrinning lokalt kan vara av stor betydelse för transport av växtskyddsmedel till ytvatten i Sverige, men att fenomenet troligtvis är begränsat i tid och rum till tillfällen (t ex extrem nederbörd) och/eller platser (t ex erosionsbenägna jordar, traktorspår, området runt dräneringsbrunnar) där särskild risk för ytavrinning föreligger. R1- scenariots mark- och väderförhållanden är inte representativa för svensk åkermark och modelleringarna överskattar troligtvis risken för transport genom ytavrinning. Skyddszoner och andra motåtgärder bedöms effektivt kunna reducera mängden växtskyddsmedel i ytavrinning om placeringen i landskapet och utformningen är rätt. De lokala förutsättningarna i form av t ex topografi (på landskaps- och fältnivå), markegenskaper, brukningsmetoder och grödor är avgörande för vilken typ av åtgärd(er) som lämpar sig bäst och var den/de ska placeras. Att införa obligatoriska skyddszoner längs med alla vattendrag bedöms därför inte motiverat, då den förväntade effekten är låg i förhållande till de stora arealer jordbruksmark som skulle behöva tas ur produktion. Istället förespråkas lokalt anpassade åtgärder, som kan föreskrivas eller ingå i rådgivning och miljöstödssystem. Eventuellt bör ett alternativ till dagens riskbedömningsmodelleringar övervägas för att nå en rimligare försiktighetsnivå i bedömningarna.
8.	Casali, Emilien, et al. (author) Macropore flow in relation to the geometry and topology of soil macropore networks: Re-visiting the kinematic wave equation 2024 In: Journal of Hydrology. - 0022-1694 .- 1879-2707. ; 630 Journal article (peer-reviewed)abstract The rapid flow of water through soil macropores significantly affects the partitioning of precipitation between surface runoff and infiltration and also the rate of solute transport in soil, both of which have an impact on the risk of contamination of surface water and groundwater. The kinematic wave equation is often employed as a model of gravity-driven water flow through soil macropores. The exponent in this simple model influences the pore water velocity attained in the macropores at any given input rate and is usually estimated by inverse modelling against measured flow rates or water contents. In theory, the exponent in the kinematic wave equation should depend on the geometry and topology of the conducting macropore networks, although these relationships have not so far been investigated. In this study, we related metrics of soil structure derived from X-ray images to values of the kinematic exponent estimated from drainage experiments on twenty-two columns sampled at three different field sites under two contrasting land uses and at three different depths. We found that smaller values of the exponent in the kinematic wave equation, which would equate to more rapid flow of water through soil macropores, were found in plough pan and subsoil columns of smaller macroporosity, for which biopores comprised a significant fraction. The macroporosity in these columns was more vertically oriented and poorly inter-connected, though still continuous across the sample. In contrast, topsoil columns from both arable land and grassland had better connected, denser and more isotropically-distributed macropore networks and larger values of the kinematic exponent. Our results suggest that for predictive modelling at large scales, it may be feasible to estimate the kinematic exponent using class pedotransfer functions based on pedological information such as land use and horizon type.
9.	Etana, Ararso, et al. (author) Effect of subsoil compaction on hydraulic parameters 2010 Conference paper (other academic/artistic)
10.	Etana, Ararso, et al. (author) Persistent subsoil compaction and its effects on preferential flow patterns in a loamy till soil 2013 In: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 192, s. 430-436 Journal article (peer-reviewed)abstract Persistence of subsoil compaction was investigated in a field experiment in southern Sweden. The investigation compared two treatments (control and compaction by four passes track-by-track), 14 years after the experimental traffic. The compaction experiment was carried out in 1995 with a 6-row sugar beet harvester with a wheel load of c. 10.4 Mg. Investigations included penetration resistance, bulk density, water retention, saturated hydraulic conductivity, in situ near-saturated hydraulic conductivity, and dye tracing experiments. The measurements of penetration resistance and bulk density clearly showed the persistence of subsoil compaction. In addition, both macroporosity and saturated and near-saturated hydraulic conductivity were smaller in the compacted plots, although these differences were not statistically significant. Dye tracing allowed us to visualize flow patterns in the soil and to quantitatively distinguish compacted and non-compacted subsoil profiles. Despite significant soil textural heterogeneity across the experimental field, the dye tracing data showed that persistent compaction may enhance preferential flow. (C) 2012 Elsevier B.V. All rights reserved.
11.	Etana, Ararso, et al. (author) Visualization of subsoil compaction 2010 In: DJF Report. ; , s. 87-90 Conference paper (other academic/artistic)
12.	Feng, Shaohong, et al. (author) Dense sampling of bird diversity increases power of comparative genomics 2020 In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 587:7833 Journal article (peer-reviewed)abstract Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity(1-4). Sparse taxon sampling has previously been proposed to confound phylogenetic inference(5), and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species. A dataset of the genomes of 363 species from the Bird 10,000 Genomes Project shows increased power to detect shared and lineage-specific variation, demonstrating the importance of phylogenetically diverse taxon sampling in whole-genome sequencing.
13.	Forouzanfar, Mohammad H, et al. (author) Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013 : a systematic analysis for the Global Burden of Disease Study 2013. 2015 In: The Lancet. - 0140-6736 .- 1474-547X. ; 386:10010, s. 2287-2323 Journal article (peer-reviewed)abstract BACKGROUND: The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.METHODS: Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol.FINDINGS: All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8-58·5) of deaths and 41·6% (40·1-43·0) of DALYs. Risks quantified account for 87·9% (86·5-89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa.INTERPRETATION: Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.FUNDING: Bill & Melinda Gates Foundation.
14.	Fukumasu, Jumpei, et al. (author) Oxalate-extractable aluminum alongside carbon inputs may be a major determinant for organic carbon content in agricultural topsoils in humid continental climate 2021 In: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 402 Journal article (peer-reviewed)abstract The relative importance of various soil mineral constituents (e.g. clay-sized particles, aluminum- and iron-bearing mineral reactive phases) in protecting soil organic carbon (SOC) from decomposition is not yet fully understood in arable soils formed from quaternary deposits in humid continental climates. In this study, we investigated the relationships between soil physico-chemical properties (i.e. contents of oxalate-extractable aluminum (Alox) and iron (Feox) and clay size particle < 2 mu m), grain yield (as a proxy for carbon input) and total SOC as well as SOC in different soil fractions for samples taken from the topsoil of an arable field at Bjertorp in south-west Sweden. We found a positive correlation between Alox and total SOC content, where Alox explained ca. 48% of the spatial variation in SOC. We also found that ca. 80% of SOC was stored in silt- and claysized (SC) fractions, where Al-bearing reactive mineral phases (estimated by Alox) may be important for organicmineral associations and clay aggregation. Our results were supported by data collated from the literature for arable topsoil in similar climates, which also showed positive correlations between SOC and Alox contents (R-2 = 23.1 - 74.5%). Multiple linear regression showed that including spatially-variable crop yields as a proxy for carbon inputs improved the prediction of SOC variation across the Bjertorp field. Other unquantified soil properties such as exchangeable calcium may account for the remaining unexplained variation in topsoil SOC. We conclude that Al-bearing reactive mineral phases are more important than clay content and Fe-bearing reactive mineral phases for SOC stabilization in arable topsoil in humid continental climates.
15.	Fukumasu, Jumpei, et al. (author) Relations between soil organic carbon content and the pore size distribution for an arable topsoil with large variations in soil properties 2022 In: European Journal of Soil Science. - : Wiley. - 1351-0754 .- 1365-2389. ; 73 Journal article (peer-reviewed)abstract Soil organic carbon (SOC) in arable topsoil is known to have beneficial effects on soil physical properties that are important for soil fertility. The effects of SOC content on soil aggregate stability have been well documented; however, few studies have investigated its relationship with the soil pore structure, which has a strong influence on water dynamics and biogeochemical cycling. In the present study, we examined the relationships between SOC and clay contents and pore size distributions (PSDs) across an arable field with large spatial variations in topsoil SOC and clay contents by combining X-ray tomography and measurements of soil water retention. Additionally, we investigated the relationships between fractionated SOC, reactive Fe and Al oxide contents and soil pore structure. We found that porosities in the 0.2-720 mu m diameter class were positively correlated with SOC content. A unit increase of SOC content was associated with a relatively large increase in porosity in the 0.2-5 and 480-720 mu m diameter classes, which indicates that enhanced SOC content would increase plant available water content and unsaturated hydraulic conductivity. On the other hand, macroporosities (1200-3120 mu m diameter classes) and bioporosity were positively correlated with clay content but not with SOC content. Due to strong correlations between soil texture, carbon-to-nitrogen ratios and reactive iron contents, we could not separate the relative importance of these soil properties for PSDs. Reactive aluminium and particulate organic carbon contents were poorer predictors for PSDs compared with clay and SOC contents. This study provides new insights on the relations between SOC and soil pore structure in an arable soil and may lead to improved estimations of the effects of enhanced SOC sequestration on soil water dynamics and soil water supply to crops. Highlights Relations between soil organic carbon (SOC) and pore size distribution (PSD) in an arable soil were explored. We used X-ray tomography and soil water retention to quantify a wide range of PSD. There were positive correlations between SOC and porosities in 0.2-720 mu m diameter classes. Porosities in 0.2-5 and 480-720 mu m diameter classes were more strongly correlated with SOC than clay. Our results have implications for improved estimates of effects of SOC sequestration on soil water dynamics.
16.	Ghafoor, Abdul, et al. (author) Improved methodologies to relate degradation kinetics to site or environmental variables 2014 In: Abstracts Of Papers Of The American Chemical Society. - 0065-7727. ; 248 Conference paper (other academic/artistic)
17.	Ghafoor, Abdul, et al. (author) Measurements and modeling of pesticide persistence in soil at the catchment scale 2011 In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 409, s. 1900-1908 Journal article (peer-reviewed)abstract Degradation of pesticides in soils is both spatially variable and also one of the most sensitive factors determining losses to surface water and groundwater. To date, no general guidance is available on suitable approaches for dealing with spatial variation in pesticide degradation in catchment or regional scale modeling applications. The purpose of the study was therefore to study the influence of various soil physical, chemical and microbiological characteristics on pesticide persistence in the contrasting cultivated soils found in a small (13 km(2)) agricultural catchment in Sweden and to develop and test a simple model approach that could support catchment scale modeling. Persistence of bentazone, glyphosate and isoproturon was investigated in laboratory incubation experiments. Degradation rate constants were highly variable with coefficients of variation ranging between 42 and 64% for the three herbicides. Multiple linear regression analysis and Mallows Cp statistic were employed to select the best set of independent parameters accounting for the variation in degradation. Soil pH and the proportion of active microorganisms (r) together explained 69% of the variation in the bentazone degradation rate constant; the Freundlich sorption co-efficient (K-f) and soil laccase activity together explained 88% of the variation in degradation rate of glyphosate, while soil pH was a significant predictor (p < 0.05) for isoproturon persistence. However, correlations between many potential predictor variables made clear interpretations of the statistical analysis difficult. Multiplicative models based on two predictors chosen 'a priori', one accounting for microbial activity (e.g. microbial respiration, laccase activity or the surrogate variable soil organic carbon, SOC) and one accounting for the effects of sorption on bioavailability, showed promise to support predictions of degradation for large-scale modeling applications, explaining up to 50% of the variation in herbicide persistence. (C) 2011 Elsevier B.V. All rights reserved.
18.	Ghafoor, Abdul, et al. (author) Measurements and modelling of pesticide persistence in soil at the catchment scale 2011 Conference paper (other academic/artistic)
19.	Ghafoor, Abdul, et al. (author) Modeling Spatial Variation in Microbial Degradation of Pesticides in Soil 2011 In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 45, s. 6411-6419 Journal article (peer-reviewed)abstract Currently, no general guidance is available on suitable approaches for dealing with spatial variation in the first-order pesticide degradation rate constant k even though it is a very sensitive parameter and often highly variable at the field, catchment, and regional scales. Supported by some mechanistic reasoning, we propose a simple general modeling approach to predict k from the sorption constant, which reflects bioavailability, and easily measurable surrogate variables for microbial biomass/activity (organic carbon and clay contents). The soil depth was also explicitly included as an additional predictor variable. This approach was tested in a meta-analysis of available literature data using bootstrapped partial least-squares regression. It explained 73% of the variation in k for the 19 pesticide-study combinations (n = 212) in the database. When 4 of the 19 pesticide-study combinations were excluded (n = 169), the approach explained 80% of the variation in the degradation rate constant. We conclude that the approach shows promise as an effective way to account for the effects of bioavailability and microbial activity on microbial pesticide degradation in large-scale model applications.
20.	Ghafoor, Abdul, et al. (author) Modelling pesticide sorption in the surface and subsurface soils of an agricultural catchment 2013 In: Pest Management Science. - : Wiley. - 1526-498X .- 1526-4998. ; 69, s. 919-929 Journal article (peer-reviewed)abstract CONCLUSIONInformation on clay, iron and aluminium oxides and soil pH, in addition to organic carbon, is needed for accurate prediction of pesticide leaching. The variables f(oc), f(clay) and pH are generally available, whereas measurements of oxides of Al and Fe are rarely reported. The authors therefore emphasise the need to measure and report contents of oxides of Al and Fe in soil survey databases, because small variations in their concentrations may contribute significantly to large variations in sorption, especially of ionisable pesticides. (c) 2012 Society of Chemical Industry
21.	Ghafoor, Abdul, et al. (author) Soil properties and susceptibility to preferential solute transport in tilled topsoil at the catchment scale 2013 In: Journal of Hydrology. - : Elsevier BV. - 0022-1694 .- 1879-2707. ; 492, s. 190-199 Journal article (peer-reviewed)abstract Preferential water flow and solute transport can have dramatic effects on the leaching of contaminants to groundwater and surface waters (via subsurface drainage) and is therefore of major concern to policy and decision-makers in the realm of water resources management. Unfortunately, we cannot measure these processes at the landscape scales that are relevant for management (farms, catchments, regions), which implies that an approach based on pedotransfer functions is needed to support model predictions. However, the extent to which susceptibility to preferential solute transport can be predicted from proxy site and soil attributes that can be observed and mapped at the landscape scale is still largely unknown. We therefore carried out non-reactive solute breakthrough experiments on 45 topsoil columns sampled from the contrasting soil types found in a 13 km(2) agricultural catchment in Sweden. Non-parametric indicators of preferential solute transport were derived from the shapes of the solute breakthrough curves and related to soil physical and hydraulic properties measured in the same columns. The results showed that preferential transport was weakly (and negatively) correlated with the saturated macropore hydraulic conductivity. In contrast, it was much more strongly controlled by the size of the largest water-filled pore, which in turn was significantly correlated to the saturated hydraulic conductivity of the soil matrix and soil textural classes. Preferential transport was also weakly expressed in three fine-textured soils of large organic carbon content. We conclude that the spatial pattern of preferential transport across the studied catchment should show a clear deterministic component since it depended on soil properties (e.g. clay content) that are expressed relatively uniformly across larger areas of land. (C) 2013 Elsevier B.V. All rights reserved.
22.	Gustafsson, Jon Petter, et al. (author) Modeller för spridning av metaller från mark till vatten 2007 Reports (other academic/artistic)abstract Att förstå och kvantifiera metallers spridning i mark och grundvatten är en central del av riskbedömningen för förorenad mark. För att göra detta krävs kunskap om hur stor utlakningen av den aktuella metallen är från föroreningskällan samt hur den lokala hydrologin, geologin och geokemin påverkar spridningen till en näraliggande recipient genom bl.a. utspädning och fördröjning. Olika typer av spridningsmodeller kan användas beroende på föroreningens typ, förorenat media (mark, grundvatten, ytvatten, sediment), hydrogeologiska förhållanden samt inte minst beroende på vilken typ av frågor som man vill besvara. De allra enklaste spridningsmodeller som används idag för förorenade områden (t.ex. för beräkning av riktvärden för mark) tar inte hänsyn till någon bindning till den fasta fasen - sorption - i marken och därmed ingen fördröjning under grundvattentransporten. Istället uppskattas endast den utspädning som sker när förorenat vatten blandas upp med annat grundvatten. Nästa typ av modeller, som i framtiden bör föredras framför de enklaste modellerna, använder sig av advektionsdispersionsekvationen med antagande om linjär sorption (Kd-värden). Dessamodeller kan beräkna halter och utsläpp som funktion av tid och rum. Två näraliggande områden där utvecklingen av spridningsmodeller kommit relativt långt, och där det finns erfarenheter av intresse att hämta i samband med riskbedömning av förorenad mark, är säkerhetsanalyser av kärnavfallsförvar i berg, samt simulering av pesticidutlakning från åkermark. Fördelningskoefficienten mellan jord och lösning, det s.k. Kd-värdet, är avcentral betydelse i riskbedömningen för att korrekt kunna förutsäga spridningen av en förorening genom markvatten- och grundvattenzonen. Man bör dock skilja denna fördelningskoefficient från den som beskriver utlakningen från en föroreningskälla grundad på totalhalten av föroreningen; denna koefficient bör kallas Ktot. Den senare kan användas för att bestämma den lösta koncentrationen för en förorening vid föroreningskällan (Cw i riktvärdesmodellen), men bör inte användas för bedömning av spridningsrisk till grund- och ytvatten. Då ”egna” Kd-värden för spridning uppskattas i samband med platsspecifika riskbedömningar, bör dessa utgå antingen från den geokemiskt aktiva mängden bestämd från en extraktion / tillgänglighetstest eller från ett sorptionstest. Utvidgade Freundlichuttryck kan, rätt använda, vara ett enkelt men ändå betydligt förbättrat redskap för att uppskatta Kd-värden för spridning av vissa metaller i ytliga jordlager. I rapporten har flera publicerade modeller byggda på utvidgade Freundlichuttryck utvärderats. Av de undersökta modellerna framgår det att Sauvés modell är den som ligger närmast till hands att rekommenderas för uppskattningar av Kd-värden i ytliga jordlager för Cd, Cu, Ni, Pb och Zn. För att använda Sauvés modell behövs uppskattningar av pH, halt organiskt kol, och av antingen koncentrationen löst metall i vattenfas eller halt fastlagd (potentiellt lakbar) metall. På sikt kan mer termodynamiskt grundande så kallade multiytmodeller vara ett intressant alternativ för många oorganiska föroreningar; dessa har dock i dagens läge alltför låg användarvänlighet. I djupare jordlager i t.ex. grundvattenzonen kan inte Sauvés modell användas. Inte heller är det lämpligt att använda t.ex. Naturvårdsverkets onservativa antaganden om Kd-värden för den generella riktvärdesmodellen, eftersom dessa endast är konservativa för ytliga jordhorisonter och riskerar att överskatta Kd-värden för grundvattenzonen. Det är angeläget med mer forskning för att belysa djupare jordlagers sorptionsegenskaper. Vid beräkningar av transport i jordar är det viktigt att ta hänsyn till att endast en del av den totala mängden jord är tillgänglig för sorption. Vid simuleringar med advektions-dispersionsmodellen kan fördröjningsfaktorn justeras för att kompensera för den begränsade sorptionskapaciteten, men även andra mer komplicerat uppbyggda modeller finns som även beräknar utbytet mellan delar av jorden med mobilt respektive immobilt vatten. En bra spridningsmodell omfattar: (i) en tidsberoende beskrivning av utlakningsförloppet från en föroreningskälla; (ii) en transportmodell som tar hänsyn till heterogeniteter och till att endast vissa delar av jorden är tillgänglig för sorption; (iii) hänsynstagande till halt löst organiskt material vilket kan forcera utlakningen för vissa metaller (t.ex. Cu, Hg), (iv) beskrivning av sorption av föroreningar med hjälp av utvidgade Freundlichuttryck.
23.	Hancock, Dana B, et al. (author) Genome-Wide Joint Meta-Analysis of SNP and SNP-by-Smoking Interaction Identifies Novel Loci for Pulmonary Function 2012 In: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 8:12, s. e1003098- Journal article (peer-reviewed)abstract Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV1), and its ratio to forced vital capacity (FEV1/FVC). Given that cigarette smoking adversely affects pulmonary function, we conducted genome-wide joint meta-analyses (JMA) of single nucleotide polymorphism (SNP) and SNP-by-smoking (ever-smoking or pack-years) associations on FEV1 and FEV1/FVC across 19 studies (total N = 50,047). We identified three novel loci not previously associated with pulmonary function. SNPs in or near DNER (smallest PJMA = 5.00×10−11), HLA-DQB1 and HLA-DQA2 (smallest PJMA = 4.35×10−9), and KCNJ2 and SOX9 (smallest PJMA = 1.28×10−8) were associated with FEV1/FVC or FEV1 in meta-analysis models including SNP main effects, smoking main effects, and SNP-by-smoking (ever-smoking or pack-years) interaction. The HLA region has been widely implicated for autoimmune and lung phenotypes, unlike the other novel loci, which have not been widely implicated. We evaluated DNER, KCNJ2, and SOX9 and found them to be expressed in human lung tissue. DNER and SOX9 further showed evidence of differential expression in human airway epithelium in smokers compared to non-smokers. Our findings demonstrated that joint testing of SNP and SNP-by-environment interaction identified novel loci associated with complex traits that are missed when considering only the genetic main effects.
24.	Jarvis, Nicholas, et al. (author) A Conceptual Model of Soil Susceptibility to Macropore Flow 2009 In: Vadose Zone Journal. - : Wiley. - 1539-1663. ; 8, s. 902-910 Journal article (peer-reviewed)abstract The extent to which a fast, nonequilibrium, and highly transient pore-scale process such as macropore flow can be predicted is very often debated, although little research has been conducted to investigate this issue. The validity of approaches to "upscaling" transport predictions from pore through Darcy to landscape scales critically depends on the answer to this question. We developed a simple conceptual model of soil susceptibility to macropore flow, based on a synthesis of existing experimental information. The conceptual model takes the form of a decision tree, which classifies soil horizons into one of four susceptibility classes on the basis of easily available site and soil factors. The model was tested against an independent database of tracer breakthrough experiments on undisturbed soil columns collated from the literature (n = 52), using the pore volumes drained at peak solute concentration, t(p), as a measure of the strength of macropore flow. Analysis of variance for t(p) as a function of susceptibility class showed that the overall model was significant. A significant proportion of the residual variation in t(p) could be attributed to variation in clay content within one of the susceptibility classes. Some important sources of experimental error were also Identified that may account for much of the remaining unexplained variation. We concluded that macropore flow is predictable to a sufficient degree from easily available soil properties and site factors. The simple classification tree developed in this study could be used to support hydropedological approaches to quantifying the spatial distribution of contaminant leaching at the landscape scale by providing the basis for class pedotransfer functions to estimate model parameters related to macropore flow. Such an approach has been implemented in the European project FOOTPRINT.
25.	Jarvis, Nicholas (author) A review of non-equilibrium water flow and solute transport in soil macropores: principles, controlling factors and consequences for water quality 2020 In: European Journal of Soil Science. - : Wiley. - 1351-0754 .- 1365-2389. ; 71, s. 279-302 Research review (peer-reviewed)abstract This review discusses the causes and consequences of 'non-equilibrium' water flow and solute transport in large structural pores or macropores (root and earthworm channels, fissures and interaggregate voids). The experimental evidence suggests that pores larger than c. 0.3 mm in equivalent cylindrical diameter allow rapid non-equilibrium flow. Apart from their large size and continuity, this is also due to the presence of impermeable linings and coatings that restrict lateral mass exchange. Macropores also represent microsites in soil that are more biologically active, and often more chemically reactive than the bulk soil. However, sorption retardation during transport through such pores is weaker than in the bulk soil, due to their small surface areas and significant kinetic effects, especially in larger macropores. The potential for non-equilibrium water flow and solute transport at any site depends on the nature of the macropore network, which is determined by the factors of structure formation and degradation, including the abundance and activity of soil biota such as earthworms, soil properties (e.g. clay content), site factors (e.g. slope position, drying intensity, vegetation) and management (e.g. cropping, tillage, traffic). A conceptual model is proposed that summarizes these effects of site factors on the inherent potential for non-equilibrium water flow and solute transport in macropores. Initial and boundary conditions determine the extent to which this potential is realized. High rain intensities clearly increase the strength of non-equilibrium flow in macropores, but the effects of initial water content seem complex, due to the confounding effects of soil shrinkage and water repellency. The impacts of macropore flow on water quality are most significant for relatively immobile solutes that are foreign to the soil and whose effects on ecosystem and human health are pronounced even at small leached fractions (e.g. pesticides). The review concludes with a discussion of topics where process understanding is still lacking, and also suggests some potential applications of the considerable knowledge that has accumulated in recent decades.
26.	Jarvis, Nicholas (author) Comment on “Macroscopic root water uptake distribution using a matric flux potential approach” 2010 In: Vadose Zone Journal. - : Wiley. - 1539-1663. ; 9, s. 499-502 Other publication (peer-reviewed)
27.	Jarvis, Nicholas, et al. (author) Connectivity and percolation of structural pore networks in a cultivated silt loam soil quantified by X-ray tomography 2017 In: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 287, s. 71-79 Journal article (peer-reviewed)abstract The connectivity of macropore networks is thought to exert an important control on preferential flow in soil, although little progress has been made towards incorporating an understanding of these effects into management oriented flow and transport models. In principle, concepts from percolation theory should be well suited to quantify the connectivity of preferred flow pathways, but so far its relevance for natural soils in the field has not been tested. To investigate this question, X-ray tomography was used to measure soil pore space architecture at an image resolution of 65 pm for 64 samples taken in two consecutive years in the harrowed and ploughed layers of a silt loam soil a few weeks after spring cultivation. The results showed that the pore networks displayed key features predicted by classical percolation theory: a strong relationship was found between the percolating fraction and the imaged porosity, with a percolation threshold of ca. 0.04 to 0.06 m(3) m(-3) in the harrowed layer. A percolation threshold was less clearly identifiable in topsoil that had not been recently tilled, although this may probably be attributed to finite size sampling effects in this layer, which showed a more heterogeneous and structured distribution of the pore space. Although further work on more strongly structured soil horizons, especially subsoils, would be desirable, it is tentatively suggested that percolation concepts could prove useful to estimate the conducting macroporosity in management models of preferential flow and transport. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
28.	Jarvis, Nicholas, et al. (author) Coupled modelling of hydrological processes and grassland production in two contrasting climates 2022 In: Hydrology and Earth System Sciences. - : Copernicus GmbH. - 1027-5606 .- 1607-7938. ; 26, s. 2277-2299 Journal article (peer-reviewed)abstract Projections of global climate models suggest that ongoing human-induced climate change will lead to an increase in the frequency of severe droughts in many important agricultural regions of the world. Eco-hydrological models that integrate current understanding of the interacting processes governing soil water balance and plant growth may be useful tools to predict the impacts of climate change on crop production. However, the validation status of these models for making predictions under climate change is still unclear, since few suitable datasets are available for model testing. One promising approach is to test models using data obtained in "space-for-time" substitution experiments, in which samples are transferred among locations with contrasting current climates in order to mimic future climatic conditions. An important advantage of this approach is that the soil type is the same, so that differences in soil properties are not confounded with the influence of climate on water balance and crop growth. In this study, we evaluate the capability of a relatively simple eco-hydrological model to reproduce 6 years (2013-2018) of measurements of soil water contents, water balance components and grass production made in weighing lysimeters located at two sites within the TERENO-SoilCan network in Germany. Three lysimeters are located at an upland site at Rollesbroich with a cool, wet climate, while three others had been moved from Rollesbroich to a warmer and drier climate on the lower Rhine valley floodplain at Selhausen. Four of the most sensitive parameters in the model were treated as uncertain within the framework of the GLUE (generalized likelihood uncertainty estimation) methodology, while the remaining parameters in the model were set according to site measurements or data in the literature. The model satisfactorily reproduced the measurements at both sites, and some significant differences in the posterior ranges of the four uncertain parameters were found. In particular, the results indicated greater stomatal conductance as well an increase in dry-matter allocation below ground and a significantly larger maximum root depth for the three lysimeters that had been moved to Selhausen. As a consequence, the apparent water use efficiency (above-ground harvest divided by evapotranspiration) was significantly smaller at Selhausen than Rollesbroich. Data on species abundance on the lysimeters provide one possible explanation for the differences in the plant traits at the two sites derived from model calibration. These observations showed that the plant community at Selhausen had changed significantly in response to the drier climate, with a significant decrease in the abundance of herbs and an increase in the proportion of grass species. The differences in root depth and leaf conductance may also be a consequence of plasticity or acclimation at the species level. Regardless of the reason, we may conclude that such adaptations introduce significant additional uncertainties into model predictions of water balance and plant growth in response to climate change.
29.	Jarvis, Nicholas (author) Extended sorption partitioning models for pesticide leaching risk assessments: Can we improve upon the k(oc) concept? 2016 In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 539, s. 294-303 Journal article (peer-reviewed)
30.	Jarvis, Nicholas (author) Global environmental changes impact soil hydraulic functions through biophysical feedbacks 2019 In: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 25, s. 1895-1904 Journal article (peer-reviewed)abstract Although only representing 0.05% of global freshwater, or 0.001% of all global water, soil water supports all terrestrial biological life. Soil moisture behaviour in most models is constrained by hydraulic parameters that do not change. Here we argue that biological feedbacks from plants, macro-fauna and the microbiome influence soil structure, and thus the soil hydraulic parameters and the soil water content signals we observe. Incorporating biological feedbacks into soil hydrological models is therefore important for understanding environmental change and its impacts on ecosystems. We anticipate that environmental change will accelerate and modify soil hydraulic function. Increasingly, we understand the vital role that soil moisture exerts on the carbon cycle and other environmental threats such as heatwaves, droughts and floods, wildfires, regional precipitation patterns, disease regulation and infrastructure stability, in addition to agricultural production. Biological feedbacks may result in changes to soil hydraulic function that could be irreversible, resulting in alternative stable states (ASS) of soil moisture. To explore this, we need models that consider all the major feedbacks between soil properties and soil-plant-faunal-microbial-atmospheric processes, which is something we currently do not have. Therefore, a new direction is required to incorporate a dynamic description of soil structure and hydraulic property evolution into soil-plant-atmosphere, or land surface, models that consider feedbacks from land use and climate drivers of change, so as to better model ecosystem dynamics.
31.	Jarvis, Nicholas, et al. (author) Identifiering av vattenskyddsområden med låg risk för påverkan av växtskyddsmedel 2018 Reports (other academic/artistic)
32.	Jarvis, Nicholas, et al. (author) Identifiering av vattenskyddsområden med låg risk för påverkan av växtskyddsmedel 2018 Reports (other academic/artistic)abstract I 7 kap. 21 och 22 §§ miljöbalken finns bestämmelser om inrättande av vattenskyddsområde. Vattenskyddsområdet inklusive meddelade bestämmelser ska säkerställa att råvattnet efter ett normalt reningsförfarande ska kunna beredas till ett hälsosamt livsmedel. Enligt 7 kap. 25 § MB måste den myndighet som beslutar om att inrätta vattenskyddsområdet också ta hänsyn till det enskilda intresset och föreskrifterna får därför inte gå längre än vad som behövs för att uppnå syftet med områdesskyddet.Vad avser växtskyddsmedel så finns sedan 1997 i Sverige ett generellt förbud mot att yrkesmässigt sprida kemiska växtskyddsmedel inom vattenskyddsområde utan särskilt tillstånd från den kommunala nämnden för miljöfrågor. Den generella tillståndsplikten gäller inte i vattenskyddsområden som inrättas eller ändras efter 1 januari 2018. De förändrade reglerna kommer innebära en successiv utfasning av den generella tillståndsplikten allteftersom vattenskyddsområdena ses över. Utfasningen av den generella tillståndsplikten innebär att behovet av särreglering av användningen av växtskyddsmedel måste utredas individuellt för varje vattenskyddsområde och att ställning måste tas till lämplig restriktionsnivå i vattenskyddsföreskrifterna.Risker för oavsiktlig spridning av växtskyddsmedel i miljön styrs av många olika faktorer. Klimat- och markförhållanden på den aktuella platsen är av stor betydelse liksom egenskaperna hos den verksamma substansen samt i vilken dos och med vilken frekvens växtskyddsmedel används. En mycket betydelsefull faktor för vilken koncentration av växtskyddsmedelsrester som slutgiltigt kan tänkas uppkomma i en sjö, ett vattendrag eller en grundvattenresurs är emellertid hur stor andel av tillrinningsområdet som behandlas. Denna rapport beskriver ett angreppssätt för att utifrån andelen jordbruksmark i tillrinningsområdet identifiera de vattenskyddsområden där risken för påverkan av växtskyddsmedel är låg. Den totala användningen av växtskyddsmedel i samhället domineras idag av jordbruks- och trädgårdssektorn. Därför är andelen jordbruksmark i tillrinningsområdet är en mycket betydelsefull faktor i bedömningen av den aggregerade riskbilden för vattentäkten. Syftet med rapporten är att stötta de myndigheter som beslutar om inrättande av vattenskyddsområden i bedömningen om lämplig restriktionsnivå för användning av växtskyddsmedel i vattenskyddsföreskrifter.
33.	Jarvis, Nicholas, et al. (author) Impacts of soil management and climate on saturated and near-saturated hydraulic conductivity: analyses of the Open Tension-disk Infiltrometer Meta-database (OTIM) 2023 In: Hydrology and Earth System Sciences. - 1027-5606 .- 1607-7938. ; 27, s. 2703-2724 Journal article (peer-reviewed)abstract Saturated and near-saturated soil hydraulic conductivities K-h (mmh(-1)) determine the partitioning of precipitation into surface runoff and infiltration and are fundamental to soils' susceptibility to preferential flow. Recent studies found indications that climate factors influence K-h, which is highly relevant in the face of climate change. In this study, we investigated relationships between pedoclimatic factors and K-h and also evaluated effects of land use and soil management. To this end, we collated the Open Tension-disk Infiltrometer Meta-database (OTIM), which contains 1297 individual data entries from 172 different publication sources. We analysed a spectrum of saturated and near-saturated hydraulic conductivities at matric potentials between 0 and 100 mm. We found that methodological details like the direction of the wetting sequence or the choice of method for calculating infiltration rates to hydraulic conductivities had a large impact on the results. We therefore restricted ourselves to a subset of 466 of the 1297 data entries with similar methodological approaches. Correlations between K-s and K-h at higher supply tensions decreased especially close to saturation, indicating a different flow mechanism at and very close to saturation than towards the dry end of the investigated tension range. Climate factors were better correlated with topsoil near-saturated hydraulic conductivities at supply tensions >= 30mm than soil texture, bulk density and organic carbon content. We find it most likely that the climate variables are proxies for soil macropore networks created by the respective biological activity, pedogenesis and climate-specific land use and management choices. Due to incomplete documentation in the source publications of OTIM, we were able to investigate only a few land use types and agricultural management practices. Land use, tillage system and soil compaction significantly influenced K-h, with effect sizes appearing comparable to the ones of soil texture and soil organic carbon. The data in OTIM show that experimental bias is present, introduced by the choice of measurement time relative to soil tillage, experimental design or data evaluation procedures. The establishment of best-practice rules for tension-disk infiltrometer measurements would therefore be helpful. Future studies are needed to investigate how climate shapes soil macropore networks and how land use and management can be adapted to improve soil hydraulic properties. Both tasks require large numbers of new measurement data with improved documentation on soil biology and land use and management history.
34.	Jarvis, Nicholas, et al. (author) Improved descriptions of soil hydrology in crop models: The elephant in the room? 2022 In: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 202 Journal article (peer-reviewed)abstract Soil-crop simulation models are widely used to assess the impacts of soil management and climate change on soil water balance, solute transport and crop production. In this context, it is important that hydrological processes in the soil-crop system are accurately modelled. We suggest here that empirical treatments of soil water flow, water uptake by plant mots and transpiration limit the applicability of crop models and increase prediction errors. We further argue that this empiricism is to a large extent unnecessary, as parsimonious physics-based descriptions of these water flow processes in the soil-crop system are now available. Recent reviews and opinion articles, whilst strongly advocating the need for improvements to crop models, fail to mention the significant role played by accurate treatments of soil hydrology. It seems to us that empirical models of soil water flow have become the elephant in the room.
35.	Jarvis, Nicholas, et al. (author) Interactions between soil structure dynamics, hydrological processes, and organic matter cycling: A new soil-crop model 2024 In: European Journal of Soil Science. - 1351-0754 .- 1365-2389. ; 75 Journal article (peer-reviewed)abstract The structure of soil is critical for the ecosystem services it provides since it regulates many key soil processes, including water, air and solute movement, root growth and the activity of soil biota. Soil structure is dynamic, driven by external factors such as land management and climate and mediated by a wide range of biological agents and physical processes operating at strongly contrasting time-scales, from seconds (e.g., tillage) to many decades (e.g., faunal activity and soil aggregation). In this respect, positive feedbacks in the soil-plant system may lead in the longer term to soil physical degradation or to the recovery of structurally poor soils. As far as we are aware, no existing soil-crop model can account for such processes. In this paper, we describe a new soil-crop model (USSF, Uppsala model of Soil Structure and Function) that accounts for the effects of soil structure dynamics on water and organic matter cycling at the soil profile scale. Soil structure dynamics are expressed as time-varying physical (bulk density, porosity) and hydraulic properties (water retention, hydraulic conductivity) responding to the activity of biological agents (i.e., earthworms, plant roots) and physical processes (i.e., tillage, soil swell-shrink) at seasonal to decadal time-scales. In this first application of the model, we present the results of 30-year scenario simulations that illustrate the potential role and importance of soil structure dynamics for the soil water balance, carbon storage in soil, root growth, and winter wheat yields on two soils (loam and clay) in the climate of central Sweden. A sensitivity analysis was also performed for these two scenarios using the Morris method of elementary effects, which revealed that the most sensitive parameters controlling soil structure dynamics in the USSF model are those determining aggregation induced by organic matter turnover and swell/shrink. We suggest that the USSF model is a promising new tool to investigate a wide range of processes and phenomena triggered by land use and climate change. Results from this study show that feedback in the soil-crop system mediated by the dynamics of soil physical and hydraulic properties are potentially of central importance for long-term predictions of soil water balance, crop production, and carbon sequestration under global change.
36.	Jarvis, Nicholas, et al. (author) Long-term effects of grass-clover leys on the structure of a silt loam soil in a cold climate 2017 In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 247, s. 319-328 Journal article (peer-reviewed)abstract Grass/legume leys are commonly included in the crop rotation in mixed farming systems in cold or humid regions in order to sustain the supply of nutrients and maintain soil fertility. Leys are also known to sequester soil organic carbon and also improve the structural stability and mechanical properties of soil. However, few studies have investigated the long-term effects of ley rotations on the architectural properties of the structural pore space in soil. We investigated the effects of grass/clover leys on soil structure in the topsoil and upper subsoil of a silt loam in a long-term field trial established in 1956 at Offer in northern Sweden. This experiment includes four treatments with varying proportions of ley (1, 2, 3 or 5 years) in 6-year rotations. We used X-ray tomography to quantify topsoil structural pore space at a resolution of 65 mu m in the first year of arable cropping following the ley break, a few weeks after sowing in spring. Earthworm populations were quantified by both hand-sorting and chemical extraction, while near-saturated infiltration was measured as a proxy for soil structure in the upper subsoil. In the topsoil, the treatments with a greater proportion of ley had larger organic carbon contents, smaller bulk densities and larger porosities. However, effects of crop rotation on the pore space were limited to pores smaller than 65 pm, as no treatment effects were found for the volume, size distribution, connectivity or complexity of the X-ray imaged pore space, even though the grass-clover leys promoted larger numbers and biomass of topsoil-dwelling earthworm species. Furthermore, no positive effects of grass/clover leys on organic carbon content and soil structure were found in the subsoil. The macropore infiltration capacity in upper subsoil was generally very small (overall median value of 3 mm h(-1)) indicating a lack of functional macroporosity below plough depth. Consistent with these results, no individuals of deep-burrowing earthworm species were found at the site, while previous observations showed only shallow rooting, both of which are attributed to the cold climate and poor subsoil drainage.
37.	Jarvis, Nicholas, et al. (author) MACRO (v5.2): Model Use, Calibration, and Validation 2012 In: Transactions of the Asabe. - : American Society of Agricultural and Biological Engineers (ASABE). - 2151-0032 .- 2151-0040. ; 55, s. 1413-1423 Journal article (peer-reviewed)abstract MACRO is a one-dimensional dual-permeability model of variably saturated water flow and reactive solute transport in soil that has been used since the early 1990s as a research tool to investigate the effects of macropore flow on soil hydrology and contaminant transport under transient field conditions. It is also widely used in the form of bespoke versions in pesticide exposure and risk assessments for groundwater and surface waters, e.g., in registration procedures in the European Union (EU). Macropore flow is a highly episodic, fast, non-equilibrium process that can dominate the leaching of reactive solutes in structured soils. This has important consequences for model calibration and validation procedures. Firstly, it means that in addition to water contents and resident solute concentrations, water flows and flux concentrations measured at high time resolution are required. Secondly, it implies that more weight must be placed on flux data obtained during these important but short-lived episodic flow events if parameters controlling macropore flow are to be reliably estimated. Although the choice of approach will vary with the purpose, automatic or hybrid automatic/manual calibration procedures are generally recommended for MACRO, especially global methods that account for uncertainty within a multi-objective framework. Despite the complexity of the processes it attempts to represent, MICRO is a parsimonious model, requiring only five additional parameters to simulate water flow and reactive solute transport, compared to the use of the Richards equation and the advection-dispers ion equation. Nevertheless, for practical reasons, the size of the parameter space that can be explored by calibration is often quite limited. This emphasizes the importance of measuring those parameters that can be measured and the role of sensitivity analyses in supporting the choice of parameters to calibrate. This will vary between applications, but at least for structured soils, all five parameters regulating the generation and strength of non-equilibrium flow and transport are usually rather influential.
38.	Jarvis, Nicholas (author) Meta-analysis of pesticide sorption in subsoil 2018 In: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 37, s. 755-761 Journal article (peer-reviewed)abstract Models used to assess leaching risks generally use organic carbon partition coefficient (k(OC)) values derived from batch experiments on topsoil samples to estimate pesticide sorption in subsoils of much smaller organic carbon contents. This can introduce significant errors in leaching risk calculations, because inorganic sorbents can play an important role for sorption in subsoil. The objectives of the present study were therefore to summarize the available literature data on pesticide sorption in subsoils and to test whether a simple alternative model could improve on the standard k(OC) approach used in risk assessment models for pesticide leaching. This model describes the sorption constant as a power law function of the organic carbon content. A database with the results of batch sorption experiments was collated from published studies that emphasized measurements in subsoils. This database contains 1029 data entries from 36 published studies with data for 29 active substances (11 nonionic compounds, 10 weak acids, 6 weak bases, one cation, and one zwitterion). The results show that whereas the constant k(OC) model proved to be an adequate model for 17 of the 63 individual datasets, the power law model gave acceptable fits (p<0.05) for 60 of these cases. The exponent in the power law model varied over a wide range, from slightly negative to near unity. It also differed significantly (p=0.015) for ionized and nonionized compounds, with median values of 0.25 and 0.55, respectively. It is concluded that the power law model could be used to parameterize subsoil sorption in regulatory leaching models, because it has widespread applicability and is simple enough for this purpose. Suitable ways of incorporating this approach in risk assessment procedures are discussed. Environ Toxicol Chem 2018;37:755-761. (c) 2017 SETAC
39.	Jarvis, Nicholas, et al. (author) Modelling the effects of bioturbation on the re-distribution of 137Cs in an undisturbed grassland soil 2010 In: European Journal of Soil Science. - : Wiley. - 1351-0754 .- 1365-2389. ; 61, s. 24-34 Journal article (peer-reviewed)abstract Summary Under favourable conditions, soil ingestion by earthworm populations can be equivalent to approximately 5–10% of the topsoil mass per year. This suggests that for contaminants that are strongly bound to soil, earthworm ‘bioturbation’ may be a more important transport mechanism than water-borne advection dispersion. It is therefore quite surprising that few modelling studies to date have explicitly considered the effects of biological processes on contaminant transport in soil. In this study, we present a general model that incorporates the effects of both ‘local’ and ‘non-local’ biological mixing into the framework of the standard physical (advective-dispersive) transport model. The model is tested against measurements of the redistribution of caesium-137 (137Cs) derived from the Chernobyl accident, in a grassland soil during 21 years after fallout. Three model parameters related to biological transport were calibrated within ranges defined by measured data and literature information on earthworm biomasses and feeding rates. Other parameters such as decay half-life and sorption constant were set to known or measured values. A physical advective-dispersive transport model based on measured sorption strongly underestimated the downward displacement of 137Cs. A dye-tracing experiment suggested the occurrence of physical non-equilibrium transport in soil macropores, but this was inadequate to explain the extent of the deep penetration of 137Cs observed at the site. A simple bio-diffusion model representing ‘local’ mixing worked reasonably well, but failed to reproduce the deep penetration of Cs as well as a dilution observed close to the soil surface. A comprehensive model including physical advectivedispersive transport, and both ‘local’ and ‘non-local’ mixing caused by the activities of both endogeic and anecic earthworms, gave an excellent match to the measured depth profiles of 137Cs, with predictions mostly lying within confidence intervals for the means of measured data and model efficiencies exceeding 0.9 on all sampling occasions but the first
40.	Jarvis, Nicholas, et al. (author) Preferential flow in a pedological perspective 2012 In: Hydropedology: Synergistic Integration of Soil Science and Hydrology. - 9780123869418 ; , s. 75-120 Book chapter (peer-reviewed)
41.	Jarvis, Nicholas (author) Reflection on Jarvis (2007), "Review of non-equilibrium water flow and solute transport in soil macropores: Principles, controlling factors and consequences for water quality". European Journal of Soil Science, 58, 523-546 2020 In: European Journal of Soil Science. - : Wiley. - 1351-0754 .- 1365-2389. ; 71, s. 303-307 Journal article (peer-reviewed)
42.	Jarvis, Nicholas, et al. (author) Reply to ‘Comment on “Understanding preferential flow in the vadose zone: Recent advances and future prospects” by N. Jarvis et al.’ 2017 In: Vadose Zone Journal. - : Wiley. - 1539-1663. ; 16 Journal article (peer-reviewed)
43.	Jarvis, Nicholas (author) Simple physics-based models of compensatory plant water uptake: concepts and eco-hydrological consequences 2011 In: Hydrology and Earth System Sciences. - : Copernicus GmbH. - 1027-5606 .- 1607-7938. ; 15, s. 3431-3446 Journal article (peer-reviewed)abstract Many land surface schemes and simulation models of plant growth designed for practical use employ simple empirical sub-models of root water uptake that cannot adequately reflect the critical role water uptake from sparsely rooted deep subsoil plays in meeting atmospheric transpiration demand in water-limited environments, especially in the presence of shallow groundwater. A failure to account for this so-called "compensatory" water uptake may have serious consequences for both local and global modeling of water and energy fluxes, carbon balances and climate. Some purely empirical compensatory root water uptake models have been proposed, but they are of limited use in global modeling exercises since their parameters cannot be related to measurable soil and vegetation properties. A parsimonious physics-based model of uptake compensation has been developed that requires no more parameters than empirical approaches. This model is described and some aspects of its behavior are illustrated with the help of example simulations. These analyses demonstrate that hydraulic lift can be considered as an extreme form of compensation and that the degree of compensation is principally a function of soil capillarity and the ratio of total effective root length to potential transpiration. Thus, uptake compensation increases as root to leaf area ratios increase, since potential transpiration depends on leaf area. Results of "scenario" simulations for two case studies, one at the local scale (riparian vegetation growing above shallow water tables in seasonally dry or arid climates) and one at a global scale (water balances across an aridity gradient in the continental USA), are presented to illustrate biases in model predictions that arise when water uptake compensation is neglected. In the first case, it is shown that only a compensated model can match the strong relationships between water table depth and leaf area and transpiration observed in riparian forest ecosystems, where sparse roots in the capillary fringe contribute a significant proportion of the water uptake during extended dry periods. The results of the second case study suggest that uncompensated models may give biased estimates of long-term evapotranspiration at the continental scale. In the example presented here, the uncompensated model underestimated total evapotranspiration by 5-7% in climates of intermediate aridity, while the ratio of transpiration to evaporation was also smaller than for the compensated model, especially in arid climates. It is concluded that the parsimonious physics-based model concepts described here may be useful in the context of eco-hydrological modeling at local, regional and global scales.
44.	Jarvis, Nicholas, et al. (author) Soil and crop management practices and the water regulation functions of soils: a qualitative synthesis of meta-analyses relevant to European agriculture 2023 In: Soil. - : Copernicus GmbH. - 2199-3971 .- 2199-398X. ; 9, s. 1-20 Research review (peer-reviewed)abstract Adopting soil and crop management practices that conserve or enhance soil structure is critical for supporting the sustainable adaptation of agriculture to climate change, as it should help maintain agricultural production in the face of increasing drought or water excess without impairing environmental quality. In this paper, we evaluate the evidence for this assertion by synthesizing the results of 34 published meta-analyses of the effects of such practices on soil physical and hydraulic properties relevant for climate change adaptation in European agriculture. We also review an additional 127 meta-analyses that investigated synergies and trade-offs or help to explain the effects of soil and crop management in terms of the underlying processes and mechanisms. Finally, we identify how responses to alternative soil–crop management systems vary under contrasting agro-environmental conditions across Europe. This information may help practitioners and policymakers to draw context-specific conclusions concerning the efficacy of management practices as climate adaptation tools.Our synthesis demonstrates that organic soil amendments and the adoption of practices that maintain “continuous living cover” result in significant benefits for the water regulation function of soils, mostly arising from the additional carbon inputs to soil and the stimulation of biological processes. These effects are clearly related to improved soil aggregation and enhanced bio-porosity, both of which reduce surface runoff and increase infiltration. One potentially negative consequence of these systems is a reduction in soil water storage and groundwater recharge, which may be problematic in dry climates. Some important synergies are reductions in nitrate leaching to groundwater and greenhouse gas emissions for nonleguminous cover crop systems. The benefits of reducing tillage intensity appear much less clear-cut. Increases in soil bulk density due to traffic compaction are commonly reported. However, biological activity is enhanced under reduced tillage intensity, which should improve soil structure and infiltration capacity and reduce surface runoff and the losses of agro-chemicals to surface water. However, the evidence for these beneficial effects is inconclusive, while significant trade-offs include yield penalties and increases in greenhouse gas emissions and the risks of leaching of pesticides and nitrate.Our synthesis also highlights important knowledge gaps on the effects of management practices on root growth and transpiration. Thus, conclusions related to the impacts of management on the crop water supply and other water regulation functions are necessarily based on inferences derived from proxy variables. Based on these knowledge gaps, we outlined several key avenues for future research on this topic.
45.	Jarvis, Nicholas, et al. (author) Soil compaction and preferential solute transport 2012 In: NJF Report. - 1653-2015. ; 8, s. 47- Conference paper (other academic/artistic)
46.	Jarvis, Nicholas, et al. (author) Understanding Preferential Flow in the Vadose Zone: Recent Advances and Future Prospects 2016 In: Vadose Zone Journal. - : Wiley. - 1539-1663. ; 15 Journal article (peer-reviewed)abstract In this update, we review some of the more significant advances that have been made in the last decade in the study of preferential flow through the vadose zone as well as suggest some research needs in the coming years. We focus mostly on work that aims to improve understanding of the processes themselves and less on more applied aspects concerning the various consequences of preferential flow (e.g., for surface water and groundwater quality). In recent years, the research emphasis has shifted somewhat toward the two extremes of the scale continuum, the pore scale and the scale of management ( field, catchments, and landscapes). This trend has been facilitated by significant advances in both measurement technologies (e.g., noninvasive imaging techniques and high frequency-high spatial resolution monitoring of soil moisture at field and catchment scales) and application of novel methods of analysis to large datasets (e.g., machine learning). This work has led to a better understanding of how pore network properties control preferential flow at the pore to core scales as well as some new insights into the influence of site attributes (climate, land uses, soil types) at field to landscape scales. We conclude that models do not at present fully reflect the current state of process understanding and empirical knowledge of preferential flow. However, we expect that significant advances in computational techniques, computer hardware, and measurement technologies will lead to increasingly reliable model predictions of the impacts of preferential flow, even at the larger scales relevant for management.
47.	Jarvis, Nicholas (author) Upscaling soil saturated hydraulic conductivity from pore throat characteristics 2017 In: Advances in Water Resources. - : Elsevier BV. - 0309-1708. ; 104, s. 105-113 Journal article (peer-reviewed)abstract Upscaling and/or estimating saturated hydraulic conductivity K sat at the core scale from microscopic/macroscopic soil characteristics has been actively under investigation in the hydrology and soil physics communities for several decades. Numerous models have been developed based on different approaches, such as the bundle of capillary tubes model, pedotransfer functions, etc. In this study, we apply concepts from critical path analysis, an upscaling technique first developed in the physics literature, to estimate saturated hydraulic conductivity at the core scale from microscopic pore throat characteristics reflected in capillary pressure data. With this new model, we find K sat estimations to be within a factor of 3 of the average measured saturated hydraulic conductivities reported by Rawls et al. (1982) for the eleven USDA soil texture classes. (C) 2017 Elsevier Ltd. All rights reserved.
48.	Jordá Guerra, Helena, et al. (author) Using boosted regression trees to explore key factors controlling saturated and near-saturated hydraulic conductivity 2015 In: European Journal of Soil Science. - : Wiley. - 1351-0754 .- 1365-2389. ; 66, s. 744-756 Journal article (peer-reviewed)abstract Hydraulic conductivity at and near saturation is difficult to predict. We investigated, for the first time, the potential of boosted regression trees to identify the key factors that determine saturated and near-saturated hydraulic conductivities in undisturbed soils with a global meta-database of tension infiltrometer measurements. Our results demonstrate that pedotransfer functions developed from meta-databases may strongly over-estimate prediction performance unless they are validated against each individual data source separately. For such a source-wise cross-validation, we estimated the hydraulic conductivity at a tension of 10 cm (K-10) and the saturated hydraulic conductivity (K-s) with coefficients of determination of 0.36 and 0.15, respectively. The most important predictors for K-10 were the average annual precipitation and temperature at the measurement location, which are key variables for pedogenesis and constrain soil management. More research is required for the in-depth interpretation of their influence on hydraulic conductivity. The soil clay and organic carbon contents were also important predictors of K-10, with hydraulic conductivity decreasing as organic carbon contents increased up to 1.5% and as clay contents increased between about 10 and 40%. The direction of the tension-sequence with which the infiltrometer data were collected was also a significant predictor. Land use and bulk density were the most important predictors for K-s. The direction of the tension-sequence and the soil texture class were also important, with both coarse and fine-textured soils generally having larger K-s values than medium-textured soils.
49.	Keller, Thomas, et al. (author) Risk assessment and effects of soil compaction: research chains at work 2012 In: NJF Report. - 1653-2015. ; 8, s. 13-16 Conference paper (other academic/artistic)
50.	Keller, Thomas, et al. (author) Subsoil pore characteristics and functions are negatively affected 14 years after compaction in a Swedish sandy clay loam 2011 Conference paper (other academic/artistic)

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