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  • 51. Bartsch, Annett
    et al.
    Widhalm, Barbara
    Kuhry, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Palmtag, Juri
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Siewert, Matthias Benjamin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Can C-band synthetic aperture radar be used to estimate soil organic carbon storage in tundra?2016In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 13, no 19, p. 5453-5470Article in journal (Refereed)
    Abstract [en]

    A new approach for the estimation of soil organic carbon (SOC) pools north of the tree line has been developed based on synthetic aperture radar (SAR; ENVISAT Advanced SAR Global Monitoring mode) data. SOC values are directly determined from backscatter values instead of upscaling using land cover or soil classes. The multi-mode capability of SAR allows application across scales. It can be shown that measurements in C band under frozen conditions represent vegetation and surface structure properties which relate to soil properties, specifically SOC. It is estimated that at least 29 Pg C is stored in the upper 30 cm of soils north of the tree line. This is approximately 25% less than stocks derived from the soil-map-based Northern Circumpolar Soil Carbon Database (NCSCD). The total stored carbon is underestimated since the established empirical relationship is not valid for peatlands or strongly cryoturbated soils. The approach does, however, provide the first spatially consistent account of soil organic carbon across the Arctic. Furthermore, it could be shown that values obtained from 1 km resolution SAR correspond to accounts based on a high spatial resolution (2 m) land cover map over a study area of about 7 x 7 km in NE Siberia. The approach can be also potentially transferred to medium-resolution C-band SAR data such as ENVISAT ASAR Wide Swath with similar to 120m resolution but it is in general limited to regions without woody vegetation. Global Monitoring-mode-derived SOC increases with unfrozen period length. This indicates the importance of this parameter for modelling of the spatial distribution of soil organic carbon storage.

  • 52. Baskaran, Preetisri
    et al.
    Hyvönen, Riitta
    Berglund, S. Linnea
    Clemmensen, Karina E.
    Ågren, Göran I.
    Lindahl, Björn D.
    Manzoni, Stefano
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Modelling the influence of ectomycorrhizal decomposition on plant nutrition and soil carbon sequestration in boreal forest ecosystems2017In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 213, no 3, p. 1452-1465Article in journal (Refereed)
    Abstract [en]

    Tree growth in boreal forests is limited by nitrogen (N) availability. Most boreal forest trees form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve the uptake of inorganic N and also have the capacity to decompose soil organic matter (SOM) and to mobilize organic N (ECM decomposition'). To study the effects of ECM decomposition' on ecosystem carbon (C) and N balances, we performed a sensitivity analysis on a model of C and N flows between plants, SOM, saprotrophs, ECM fungi, and inorganic N stores. The analysis indicates that C and N balances were sensitive to model parameters regulating ECM biomass and decomposition. Under low N availability, the optimal C allocation to ECM fungi, above which the symbiosis switches from mutualism to parasitism, increases with increasing relative involvement of ECM fungi in SOM decomposition. Under low N conditions, increased ECM organic N mining promotes tree growth but decreases soil C storage, leading to a negative correlation between C stores above- and below-ground. The interplay between plant production and soil C storage is sensitive to the partitioning of decomposition between ECM fungi and saprotrophs. Better understanding of interactions between functional guilds of soil fungi may significantly improve predictions of ecosystem responses to environmental change.

  • 53.
    Belin, Klas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Exkursioners bidrag till elevers kunskapsutveckling: En klassificering av exkursionsguider med hjälp av Blooms reviderade taxonomi2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna studie syftar till att ta reda på vilka kunskaper och kognitiva processer elever kan få underexkursioner i ämnet geografi. Utöver detta undersöktes hur exkursioner bedrivs i Stockholms län.Undersökningen genomfördes genom en insamling av exkursionsguider som sedan analyserades medhjälp av Blooms reviderade taxonomi. För att få ett bredare underlag kring hur exkursioner utövasskickades webbenkäter ut till ett flertal lärare.Överlag är begreppskunskapen den mest framträdande kunskapen under de undersökta exkursionernavilket stämmer överens med den tidigare forskningen inom detta område. Exkursionsguiderna visaräven att majoriteten av exkursionsuppgifterna vill få eleven till den lägre nivån av kognitivt tänkande ioch med att uppgifterna syftar till att eleven ska förstå begrepp. Resultatet visar dock att det finns entendens att elever ges en möjlighet till en högre nivå av tänkande under de exkursioner där eleven äraktiv och försöker hitta svar på uppgifterna de fått av läraren.

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  • 54.
    Belyazid, Salim
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Giuliana, Zanchi
    Water limitation can negate the effect of higher temperatures on forest carbon sequestration2019In: European Journal of Forest Research, ISSN 1612-4669, E-ISSN 1612-4677, Vol. 138, no 2, p. 287-297Article in journal (Refereed)
    Abstract [en]

    Climate change will bring about a consistent increase in temperatures. Annual precipitation rates are also expected to increase in boreal countries, but the seasonal distribution will be uneven, and several areas in the boreal zone will experience wetter winters and drier summers. This study uses the dynamic forest ecosystem model ForSAFE to estimate the combined effect of changes in temperature and precipitation on forest carbon stocks in Sweden. The model is used to simulate carbon stock changes in 544 productive forest sites from the Swedish National Forest Inventory. Forest carbon stocks under two alternative climate scenarios are compared to stocks under a hypothetical scenario of no climate change (baseline). Results show that lower water availability in the future can cause a significant reduction in tree carbon compared to a baseline scenario, particularly expressed in the southern and eastern parts of Sweden. In contrast, the north-western parts will experience an increase in tree carbon stocks. Results show also that summer precipitation is a better predictor of tree carbon reduction than annual precipitation. Finally, the change in soil carbon stock is less conspicuous than in tree carbon stock, showing no significant change in the north and a relatively small but consistent decline in the south. The study indicates that the prospect of higher water deficit caused by climate change cannot be ignored in future forest management planning.

  • 55.
    Belyazid, Salim
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Phelan, Jennifer
    Nihlgård, Bengt
    Sverdrup, Harald
    Driscoll, Charles
    Fernandez, Ivan
    Aherne, Julian
    Teeling-Adams, Leslie M.
    Bailey, Scott
    Arsenault, Matt
    Cleavitt, Natalie
    Engstrom, Brett
    Dennis, Robin
    Sperduto, Dan
    Werier, David
    Clark, Christopher
    Assessing the Effects of Climate Change and Air Pollution on Soil Properties and Plant Diversity in Northeastern US Hardwood Forests: Model Setup and Evaluation2019In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 230, no 5, article id 106Article in journal (Refereed)
    Abstract [en]

    The integrated forest ecosystem model ForSAFE-Veg was used to simulate soil processes and understory vegetation composition at threesugar maple, beech, yellow birchhardwood forest sites in the Northeastern United States (one at Hubbard Brook, NH, and two at Bear Brook, ME). Input data were pooled from a variety of sources and proved coherent and consistent. While the biogeochemical component ForSAFE was used with limited calibration, the ground vegetation composition module Veg was calibrated to field releves. Evaluating different simulated ecosystem indicators (soil solution chemistry, tree biomass, ground vegetation composition) showed that the model performed comparably well regardless of the site's soil condition, climate, and amounts of nitrogen (N) and sulfur (S) deposition, with the exception of failing to capture tree biomass decline at Hubbard Brook. The model performed better when compared with annual observation than monthly data. The results support the assumption that the biogeochemical model ForSAFE can be used with limited calibration and provide reasonable confidence, while the vegetation community composition module Veg requires calibration if the individual plant species are of interest. The study welcomes recent advances in empirically explaining the responses of hardwood forests to nutrient imbalances and points to the need for more research.

  • 56. Bengtsson, J.
    et al.
    Bullock, J. M.
    Egoh, B.
    Everson, C.
    Everson, T.
    O'Connor, T.
    O'Farrell, P. J.
    Smith, H. G.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography. Stellenbosch University, South Africa.
    Grasslands-more important for ecosystem services than you might think2019In: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 10, no 2, article id e02582Article in journal (Refereed)
    Abstract [en]

    Extensively managed grasslands are recognized globally for their high biodiversity and their social and cultural values. However, their capacity to deliver multiple ecosystem services (ES) as parts of agricultural systems is surprisingly understudied compared to other production systems. We undertook a comprehensive overview of ES provided by natural and semi-natural grasslands, using southern Africa (SA) and northwest Europe as case studies, respectively. We show that these grasslands can supply additional non-agricultural services, such as water supply and flow regulation, carbon storage, erosion control, climate mitigation, pollination, and cultural ES. While demand for ecosystems services seems to balance supply in natural grasslands of SA, the smaller areas of semi-natural grasslands in Europe appear to not meet the demand for many services. We identified three bundles of related ES from grasslands: water ES including fodder production, cultural ES connected to livestock production, and population-based regulating services (e.g., pollination and biological control), which also linked to biodiversity. Greenhouse gas emission mitigation seemed unrelated to the three bundles. The similarities among the bundles in SA and northwestern Europe suggest that there are generalities in ES relations among natural and semi-natural grassland areas. We assessed trade-offs and synergies among services in relation to management practices and found that although some trade-offs are inevitable, appropriate management may create synergies and avoid trade-offs among many services. We argue that ecosystem service and food security research and policy should give higher priority to how grasslands can be managed for fodder and meat production alongside other ES. By integrating grass-lands into agricultural production systems and land-use decisions locally and regionally, their potential to contribute to functional landscapes and to food security and sustainable livelihoods can be greatly enhanced.

  • 57.
    Bennich, Therese
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    The Route to Sustainability-Prospects and Challenges of the Bio-Based Economy2017In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 9, no 6, article id 887Article, review/survey (Refereed)
    Abstract [en]

    The bio-based economy has been increasingly recognized in the sustainability debate over the last two decades, presented as a solution to a number of ecological and social challenges. Its premises include climate change mitigation, cleaner production processes, economic growth, and new employment opportunities. Yet, a transition to a bio-based economy is hampered by risk factors and uncertainties. In this paper, we explore the concept of a bio-based economy, focusing on opportunities of achieving sustainability, as well as challenges of a transition. Departing from an understanding of sustainability provided by the weak and strong sustainability paradigms, we first outline the definition and development of the bio-based economy from a theoretical perspective. Second, we use Sweden as an example of how a transition towards a bio-based economy has been evolving in practice. The review indicates that the proposed direction and strategies of the bio-based economy are promising, but sometimes contradictory, resulting in different views on the actions needed for its premises to be realized. Additionally, current developments adhere largely to the principles of the weak sustainability paradigm. In order for the bio-based economy to develop in accordance with the notion of strong sustainability, important steps to facilitate a transition would include acknowledging and addressing the trade-offs caused by biophysical and social limits to growth.

  • 58.
    Bennich, Therese
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kopainsky, Birgit
    Diemer, Arnaud
    The Bio-Based Economy: Dynamics Governing Transition Pathways in the Swedish Forestry Sector2018In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 10, no 4, article id 976Article in journal (Refereed)
    Abstract [en]

    A transition to a bio-based economy would entail change in coupled social-ecological systems. These systems are characterised by complexity, giving rise to potential unintended consequences and trade-offs caused by actions aiming to facilitate a transition process. Yet, many of the analyses to date have been focusing on single and predominantly technological aspects of the bio-based economy. The main contribution of our work is to the development of an integrated understanding of potential future transition pathways, with the present paper focusing specifically on terrestrial biological resources derived from the forestry sector in Sweden. Desired change processes identified include a transition to diversified forest management, a structural change in the forestry industry to enable high-value added production, and increased political support for the bio-based economy concept. Hindrances identified include the ability to demonstrate added values for end consumers of novel biomass applications, and uncertainty linked to a perceived high level of polarisation in the forestry debate. The results outline how these different processes are interrelated, allowing for the identification of high order leverage points and interventions to facilitate a transition to a bio-based economy.

  • 59.
    Bennich, Therese
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kopainsky, Birgit
    Diemer, Arnaud
    Understanding the Transition to a Bio-Based Economy: Exploring Dynamics Linked to the Agricultural Sector in Sweden2018In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 10, no 5, article id 1504Article in journal (Refereed)
    Abstract [en]

    There is a growing interest in the bio-based economy, evident in the policy domain as well as in the academic literature. Its proponents consider it an opportunity to address multiple societal challenges, and the concept has broad reach across different sectors of society. However, a potential transition process is also linked to areas of risk and uncertainty, and the need for interdisciplinary research and for the identification of potential trade-offs and synergies between parallel visions of the bio-based economy have been emphasized. The aim of this paper is to contribute to addressing this gap by using an approach combining tools for systems analysis with expert interviews. Focusing specifically on dynamics in the agricultural sector in Sweden, an integrated understanding of the social and ecological processes contributing to or hindering a transition in this area is developed, high order leverage points are identified, and potential impacts of proposed interventions explored. The paper also considers cross-sectoral linkages between the forestry and agricultural sectors.

  • 60.
    Berg, Håkan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Maneas, Giorgos
    Stockholm University, Faculty of Science, Department of Physical Geography. Navarino Environmental Observatory, Greece.
    Salguero Engström, Amanda
    Stockholm University, Faculty of Science, Department of Physical Geography.
    A Comparison between Organic and Conventional Olive Farming in Messenia, Greece2018In: Horticulturae, E-ISSN 2311-7524, Vol. 4, no 3, article id 15Article in journal (Refereed)
    Abstract [en]

    Olive farming is one of the most important occupations in Messenia, Greece. The region is considered the largest olive producer in the country and it is recognized as a Protected Designation of Origin (PDO) for Kalamata olive oil, which is considered extra fine. In response to the declining trend of organic olive farming in Greece, this study assesses to what extent organic olive farming in Messenia provides a financially and environmentally competitive alternative to conventional olive farming. In this study, 39 olive farmers (23 conventional and 16 organic) participated in interviews based on questionnaires. The results showed that organic olive farming is significantly more profitable than conventional farming, primarily because of a higher price for organic olive oil. Despite this, the majority of the conventional farmers perceived a low profit from organic farming as the main constraint to organic olive farming. All farmers agreed that organic olive farming contributed to a better environment, health and quality of olive oil. Organic farmers used fewer synthetic pesticides and fertilizers and applied more environmentally-friendly ground vegetation management techniques than conventional farmers. Overall, organic farming was found to provide a competitive and sustainable alternative to conventional olive farming in Messenia.

  • 61.
    Berg, Håkan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Nguyen, Thanh Tam
    Stockholm University, Faculty of Science, Department of Physical Geography. Nong Lam University, Vietnam.
    Use of pesticides and attitude to pest management strategies among rice and rice-fish farmers in the Mekong Delta, Vietnam2012In: International Journal of Pest Management, ISSN 0967-0874, E-ISSN 1366-5863, Vol. 58, no 2, p. 153-164Article in journal (Refereed)
    Abstract [en]

    This study assesses the use of pesticides and attitude to pest management strategies among rice and rice-fish farmersin Can Tho’ and Tien Giang provinces of the Mekong Delta, Vietnam, in 2007. A comparison is made to a similarstudy in 1999, in order to identify changes in patterns of pesticide use and possible influences of integrated pestmanagement (IPM) programmes and brown planthopper (a major pest) outbreaks. One hundred and twenty farmersused 66 different pesticides, similar to the 64 pesticides recorded as being used in the 1999 survey. Nine of the 10 mostpopular pesticides in 2007 were the same as those found to be popular in 1999. Insecticides are used by 73–95% ofthe farmers, which is the most commonly employed type of pesticide. The number of applications of both herbicidesand fungicides has more than halved since 1999 for all farmers, while insecticide applications has doubled for IPMfarmers (those with prior training in IPM methodology). Similarly, the average dose of active ingredient (a.i.) ofinsecticides per crop has decreased slightly for non-IPM rice farmers, while it has more than doubled among IPMfarmers, resulting in almost the same amount of a.i. per crop for all groups of farmers (insecticides 0.6, fungicides 0.5,and herbicides 0.3 kg a.i. ha71 crop71). Overall, the results indicate a temporal trend for more selective use ofpesticides and an increased awareness among non-IPM farmers of the negative side effects of pesticide use.

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  • 62.
    Berg, Håkan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Söderholm, Agnes Ekman
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Söderström, Anna-Sara
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Tam, Nguyen Thanh
    Stockholm University, Faculty of Science, Department of Physical Geography. Nong Lam University, Vietnam.
    Recognizing wetland ecosystem services for sustainable rice farming in the Mekong Delta, Vietnam2017In: Sustainability Science, ISSN 1862-4065, E-ISSN 1862-4057, Vol. 12, no 1, p. 137-154Article in journal (Refereed)
    Abstract [en]

    The increased rice production in the Mekong Delta during the last two decades has improved agricultural income and reduced poverty, but it has also had negative impacts on the environment and human health. This study shows that integrated rice-fish farming and integrated pest management strategies provide sustainable options to intensive rice farming, because of a more balanced use of multiple ecosystem services that benefit the farmers' health, economy and the environment. The study investigates and compares farming strategies among 40 rice and 20 rice-fish farmers in two locations in the Mekong Delta. Production costs and income are used to compare the systems' financial sustainability. The farmers' perception on how their farming practices influence on ecosystem services and their livelihoods are used as an indication of the systems' ecological and social sustainability. Although rice-fish farmers used lower amount of pesticides and fertilisers than rice farmers, there were no statistical differences in their rice yields or net income. Rice was seen as the most important ecosystem service from rice fields and related wetlands, but also several other ecosystem services, such as water quality, aquatic animals, plants, habitats, and natural enemies to pests, were seen as important to the farmers' livelihoods and wellbeing. All farmers perceived that there had been a general reduction in all these other ecosystem services, due to intensive rice farming during the last 15 years, and that they will continue to decline. The majority of the farmers were willing to reduce their rice yields slightly for an improved quality of the other ecosystem services.

  • 63.
    Berg, Håkan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Tam, Nguyen Thanh
    Decreased use of pesticides for increased yields of rice and fish-options for sustainable food production in the Mekong Delta2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 619-620, p. 319-327Article in journal (Refereed)
    Abstract [en]

    This study assesses the use of pesticides and the attitude to pest management strategies among rice and rice-fish farmers in the Can Tho and Tien Giang provinces in Vietnam. Interviews were made with 80 farmers. The farmers were divided in to farmers cultivating only rice with a high use (RHP) and low use (RLP) of pesticides, and farmers cultivating rice and fish with a high use (RFHP) and low use (RFLP) of pesticides. 80% of the HP farmers relied mainly on pesticides to control pests, while >80% of the LP farmers also applied IPM strategies. Insecticides were the most commonly used pesticides. 85% of all farmers experienced health effects from using pesticides. 80% of the farmers felt that the yield of fish had decreased over the last three years, and that this mainly was caused by pesticides. The RFHP farmers had lower fish survival and fish yields as compared to the RFLP farmers. The RFHP farmers also had significant lower rice yields than the RFLP farmers, and there were significant correlations between both decreased fish yields and rice yields with increased use of pesticides among rice-fish farmers. Increased rice yields were positively correlated with increased fish survival, indicating the synergistic effects between rice and fish production. Overall, the RFLP farmers had the highest income of the four farmers´ groups, while RFHP farmers had the lowest income. This shows that rice-fish farming provides a competitive and sustainable alternative to intensive rice-farming, but only if the farmer restricts the use of pesticides. This would not only help to reduce the production costs, but also to decrease environmental and health effects, and it is proposed that rice-fish farming with a low use of pesticides provides an attractive alternative to rice-monocropping for a sustainable and diversified food production in the Mekong Delta.

  • 64.
    Berggren, Anna
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Inledande försökt till mätning med Europas navigeringssystem Galileo2016Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Europe is presently building up a satellite navigation system of their own, Galileo. Unlike the American system, GPS, and the Russian system, Glonass, Galileo will be a civilian system. It will be independent from, but interoperable with both GPS and Glonass. After many delays have enough satellites been launched and placed in orbit to make it possible to start up Galileo’s initial services during December 2016.

    This study gives an account of the construction and development of the Galileo system. During two weeks in the spring 2016 experimental RTK measurements were made with Galileo combined with GPS where the satellite corrections were distributed from Lantmäteriet’s (the Swedish mapping, cadastral and land registration authority’s) supportsystem for satellite positioning, SWEPOS. The measurements were carried out with singlestation RTK towards a SWEPOS reference station at Mosebacke on Södermalm in Stockholm. The rover was placed over a fixed point about 1.2 km from the reference station.The purpose of the study was to determine if it was possible in the spring 2016 to make any measurements with Galileo and to see what Galileo can add to RTK measurements combined with GPS in SWEPOS.

    During the spring 2016 it was not possible to make any measurements with only Galileo satellites due to the fact that there were too few satellites in orbit. The results from the measurements indicate that combining Galileo and GPS could be positive for network RTK in SWEPOS. The part of achieved fixed solutions increases, the average time until fixed solution is achieved shortens and the space vehicle geometry (PDOP) gets a better value when combining GPS and Galileo. It is however too soon to say anything certain about the influence of Galileo on the position uncertainty.

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  • 65.
    Bergström, Catrin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hälsorisker med avsaltat dricksvatten från Östersjön2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Brist på dricksvatten är ett hot som finns på många platser runtomkring i världen, även iflera områden i Sverige. En effekt av detta är att avsaltningstekniken har blivit en alltvanligare metod för att trygga dricksvattenförsörjningen och en växande gruppmänniskor konsumerar nu avsaltat dricksvatten. Avsaltat dricksvatten är dock en ganskany lösning på dricksvattenproblematiken i Sverige och det finns relativt lite forskningom vilka hälsorisker det kan finnas med att använda Östersjön som råvattenkälla. Syftetmed denna rapport är att öka kunskapen om potentiella hälsorisker med avsaltatdricksvatten från Östersjön. Den centrala frågeställningen handlar om vilka erfarenheteroch forskning om hälsorisker med avsaltat dricksvatten det finns och vilka hälsoriskersom kan finnas när Östersjön används som råvattenkälla i avsaltningsverk. Denlitteratur och information som ligger till grund för resultatet i denna rapport inhämtadesgenom litteratursökningar och genom att sakkunniga experter och tjänstemänkonsulterades. Resultaten i denna rapport visar bland annat att avsaltningsteknikenöverlag är en effektiv metod för att avskilja många typer av olika oönskade ochohälsosamma ämnen i dricksvatten. Avskiljningsgraden för alger och algtoxin iavsaltningsverk är hög, men det kan förekomma låga halter av alger och algtoxin idricksvatten från anläggningar med bristande underhåll. Vidare visar resultaten att detfinns indikationer på att konsumtion av avsaltat dricksvatten istället för vanligtdricksvatten kan vara ofördelaktigt för vissa individer eftersom avsaltat dricksvattenofta är mineralfattigt. De slutsatser som kan dras är bland annat att avsaltningsteknikenavskiljer många miljöföroreningar och andra ohälsosamma ämnen som finns iÖstersjöns havsvatten. Vidare bör försiktighet tillämpas eftersom låg avskiljningsgradav ännu okända föroreningar i Östersjön och potentiella hälsoeffekter av dessa inte kanuteslutas. Dessutom går det i nuläget inte att avgöra vilka hälsorisker låga halter avalger och algtoxin i dricksvatten från avsaltningsverk i dåligt skick skulle kunna föramed sig. Till sist kan slutsatsen dras att dricksvatten kan vara en viktig källa tillmineraler för individer som inte får i sig tillräckligt med mineraler via kosten. Det gårdock i nuläget inte att fastställa betydelsen av dricksvatten som en mineralkälla förindivider som äter en mineralrik kost.

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  • 66.
    Bergström, Erik
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Den prerecenta lokalglaciationens utbredningshistoria inom Skanderna: The history of the pre-recent local glaciation in the Scandinavian mountains1973Doctoral thesis, monograph (Other academic)
  • 67. Bernes, Claes
    et al.
    Bullock, James M.
    Jakobsson, Simon
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rundlof, Maj
    Verheyen, Kris
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    How are biodiversity and dispersal of species affected by the management of roadsides? A systematic map2017In: Environmental Evidence, ISSN 2047-2382, E-ISSN 2047-2382, Vol. 6, no 1, article id 24Article in journal (Refereed)
    Abstract [en]

    Background: In many parts of the world, roadsides are regularly managed for traffic-safety reasons. Hence, there are similarities between roadsides and certain other managed habitats, such as wooded pastures and mown or grazed grasslands. These habitats have declined rapidly in Europe during the last century. For many species historically associated with them, roadsides may function as new primary habitats or as dispersal corridors in fragmented landscapes. Current recommendations for roadside management to promote conservation values are largely based on studies of plants in semi-natural grasslands, although such areas often differ from roadsides in terms of environmental conditions and disturbance regimes. Moreover, roadsides provide habitat not only for plants but also for many insects. For these reasons, stakeholders in Sweden have emphasised the need for more targeted management recommendations, based on actual studies of roadside biodiversity. Methods: This systematic map provides an overview of the available evidence on how biodiversity is affected by various forms of roadside management, and how such management influences the dispersal of species along roads or roadsides. We searched for literature using 13 online publication databases, 4 search engines, 36 specialist websites and 5 literature reviews. Search terms were developed in English, Danish, Dutch, French, German, Norwegian, Spanish and Swedish. Identified articles were screened for relevance using criteria set out in a protocol. No geographical restrictions were applied, and all species and groups of organisms were considered. Descriptions of included studies are available in an Excel file, and also in an interactive GIS application that can be accessed at an external website. Results: Our searches identified more than 7000 articles. The 207 articles included after screening described 301 individual studies considered to be relevant. More than two-thirds of these studies were conducted in North America, with most of the rest performed in Europe. More than half of the studies were published in grey literature such as reports from agencies or consultants. The interventions most commonly studied were herbicide use, sowing and mowing, followed by soil amendments such as mulching and fertiliser additions. The outcomes most frequently reported were effects of interventions on the abundance or species richness of herbs/forbs, graminoids and woody plants. Effects on insects and birds were reported in 6 and 3% of the studies, respectively. Conclusions: This systematic map is based on a comprehensive and systematic screening of all available literature on the effects of roadside management on biodiversity and dispersal of species. As such it should be of value to a range of actors, including managers and policymakers. The map provides a key to finding concrete guidance for conservation- and restoration-oriented roadside management from published research. However, the map also highlights important knowledge gaps: little data was found for some geographical regions, research is heavily biased taxonomically towards plants, and no study was found on how species dispersal was affected by roadside management. The map could therefore be a source of inspiration for new research.

  • 68. Bernes, Claes
    et al.
    Bullock, James M.
    Jakobsson, Simon
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Verheyen, Kris
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    How does roadside vegetation management affect the diversity of vascular plants and invertebrates? A systematic review protocol2017In: Environmental Evidence, ISSN 2047-2382, E-ISSN 2047-2382, Vol. 6, no 1, article id 16Article, review/survey (Refereed)
    Abstract [en]

    Background: Roadsides have been acknowledged as potential substitutes for semi-natural grasslands and other open habitats with high biodiversity, many of which are now declining. Current recommendations for roadside management to promote conservation of biodiversity are largely based on studies of plants in meadows or pastures, although such areas often differ from roadsides in terms of environmental conditions and disturbance regimes. Stakeholders in Sweden have emphasised the need for more targeted guidelines for roadside management, based on actual roadside studies. We recently performed a systematic mapping of the evidence on how roadside management affects biodiversity and the dispersal of species. Through this process, we found 98 studies on how the richness or abundance of species on roadsides is affected by management such as regular mowing, burning, grazing or selective mechanical removal of plants. Since all of these interventions entail removal of plant biomass, they are comparable. Most of the studies recorded management effects on vascular plants, but there were 14 investigations of insects and other invertebrates. We now intend to proceed with a full systematic review of how maintenance or restoration of roadsides based on non-chemical vegetation removal affects the diversity of vascular plants and invertebrates. Methods: Most of the evidence on which the proposed systematic review is to be based will be selected from the systematic map. To identify more recently published literature on the topic of the review, we will perform a search update using a subset of the search terms applied for the systematic map. The criteria for inclusion of studies will be the same as for the map, except that interventions and outcomes will be restricted to those relevant to the review. Relevant studies will be subject to critical appraisal and categorised as having high or low validity for the review. Studies with low validity will be excluded from the review. Utilisable data on outcomes, interventions and other potential effect modifiers will be extracted from included articles. A narrative synthesis will describe the validity and findings of all studies in the review. Where a sufficient number of studies report similar outcome types, meta-analysis will be conducted.

  • 69.
    Berntell, Ellen
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Zhang, Qiong
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Chafik, Léon
    Körnich, Heiner
    Representation of Multidecadal Sahel Rainfall Variability in 20th Century Reanalyses2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 10937Article in journal (Refereed)
    Abstract [en]

    Summer rainfall in the Sahel region has exhibited strong multidecadal variability during the 20th century causing dramatic human and socio-economic impacts. Studies have suggested that the variability is linked to the Atlantic multidecadal variability; a spatially persistent pattern of warm/cold sea surface temperatures in the North Atlantic. In the last few years, several promising century-long reanalysis datasets have been made available, opening up for further studies into the dynamics inducing the observed low-frequency rainfall variability in Sahel. We find that although three of the 20th century ECMWF reanalyses show clear multidecadal rainfall variability with extended wet and dry periods, the timing of the multidecadal variability in two of these reanalyses is found to exhibit almost anti-phase features for a large part of the 20th century when compared to observations. The best representation of the multidecadal rainfall variability is found in the ECMWF reanalysis that, unlike the other reanalyses (including NOAA's 20th century), do not assimilate any observations and may well be a critical reason for this mismatch, as discussed herein. This reanalysis, namely ERA-20CM, is thus recommended for future studies on the dynamics driving the multidecadal rainfall variability in Sahel and its linkages to the low-frequency North Atlantic oceanic temperatures.

  • 70.
    Berntsson, Annika
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jansson, Krister N.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kylander, Malin E.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    De Vleeschouwer, Francois
    Bertrand, Sebastien
    Late Holocene high precipitation events recorded in lake sediments and catchment geomorphology, Lake Vuoksjavratje, NW Sweden2015In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 44, no 4, p. 676-692Article in journal (Refereed)
    Abstract [en]

    In this paper, we show the potential of combining multi-proxy analysis of lake sediments with catchment geomorphology to better understand palaeoenvironmental changes. Previous studies have suggested that alpine lakes in N Sweden may be highly sensitive to variations in catchment erosion and precipitation, and that this sensitivity may influence ecologically based reconstructions of past temperature changes. We analysed lake sediments covering the last 5100 years from the alpine Lake Vuoksjavratje in NW Sweden in order to identify different erosional regimes in the lake catchment, sediment sources and lake sedimentary processes, which ultimately affect the palaeoecological record. The measured proxies include elemental geochemistry from XRF core scanning, grain size, sediment accumulation rates, fraction of terrestrial organic carbon and geomorphological mapping, supported by previously published chironomid and total organic carbon data. From the integrated results we identified time intervals when increased intensity of precipitation altered sedimentation and lake catchment erosional processes. The most prominent event occurred c. 2900 cal. a BP and is interpreted to be the result of excessive precipitation, possibly related to the climatic shift towards cooler and wetter conditions referred to as the 2.8 ka event.

  • 71. Berry, Z. Carter
    et al.
    Evaristo, Jaivime
    Moore, Georgianne
    Poca, María
    Steppe, Kathy
    Verrot, Lucile
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Aberdeen, UK.
    Asbjornsen, Heidi
    Borma, Laura S.
    Bretfeld, Mario
    Herve-Fernandez, Pedro
    Seyfried, Mark
    Schwendenmann, Luitgard
    Sinacore, Katherine
    De Wispelaere, Lien
    McDonnell, Jeffrey
    The two water worlds hypothesis: Addressing multiple working hypotheses and proposing a way forward2018In: Ecohydrology, ISSN 1936-0584, E-ISSN 1936-0592, Vol. 11, no 3, article id e1843Article in journal (Refereed)
    Abstract [en]

    Recent studies using water isotopes have shown that trees and streams appear to return distinct water pools to the hydrosphere. Cryogenically extracted plant and soil water isotopic signatures diverge from the meteoric water lines, suggesting that plants would preferentially use bound soil water, while mobile soil water that infiltrates the soil recharges groundwater and feeds streamflow all plots on meteoric water lines. These findings have been described under the two water worlds (TWW) hypothesis. In spite of growing evidence for the TWW hypothesis, several questions remain unsolved within the scope of this framework. Here, we address the TWW as a null hypothesis and further assess the following: (a) the theoretical biophysical feasibility for two distinct water pools to exist, (b) plant and soil processes that could explain the different isotopic composition between the two water pools, and (c) methodological issues that could explain the divergent isotopic signatures. Moreover, we propose a way forward under the framework of the TWW hypothesis, proposing alternative perspectives and explanations, experiments to further test them, and methodological advances that could help illuminate this quest. We further highlight the need to improve our sampling resolution of plants and soils across time and space. We ultimately propose a set of key priorities for future research to improve our understanding of the ecohydrological processes controlling water flows through the soil-plant-atmosphere continuum.

  • 72. Beyer, Friderike
    et al.
    Jäck, Ortrud
    Manzoni, Stefano
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Weih, Martin
    Relationship between foliar δ13C and sapwood area indicates different water use patterns across 236 Salix genotypes2018In: Trees, ISSN 0931-1890, E-ISSN 1432-2285, Vol. 32, no 6, p. 1737-1750Article in journal (Refereed)
    Abstract [en]

    The relationship between leaf δ13C and plant size (represented by e.g. total leaf area) has been used to analyze different water use patterns of plants. However, the total leaf area (TLA) is difficult to assess in trees. Our aims were to (i) identify a feasible predictor for TLA; (ii) estimate the effects of TLA on leaf-level δ13C and δ18O values; and (iii) evaluate whether the relationship between leaf-level δ13C and a TLA proxy can be used to discriminate between different water use patterns. Various leaf and shoot traits of up to 236 Salix genotypes field-grown in Sweden and Italy were assessed and analyzed. Accumulated shoot diameter and sapwood area (SA) calculated from it were the best predictors for TLA. The SA was significantly correlated with foliar δ13C, but not δ18O values in some genotypes. The effects of SA on foliar δ13C values varied significantly among genotypes, and the foliar δ13C–SA relationship could be used to discriminate between different water use patterns across 236 Salix genotypes. Our results demonstrate a great variability of water use patterns across taxonomically closely related plants, and may also have implications for Salix pre-breeding and selection for different drought conditions.

  • 73.
    Beygi, Heydar
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Impact of irrigation development and climate change on the water level of Lake Urmia, Iran2015Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Lake Urmia, located in the north-west of Iran, is one of the largest hypersaline lakes in the world. In recent years, there has been a significant decrease in the lake’s area and volume by 88% and 80% respectively. An integrated water balance model of the Lake Urmia Drainage Basin (LUDB) and Lake Urmia was developed to identify these main drivers of the significant changes, and to investigate the possible future evolution of the lake under effects of projected climate change and land use change. We used an energy balance method to estimate the evaporation from the lake and the Turc-Langbein method to estimate the evapotranspiration from the drainage basin of the lake. Agricultural irrigation water was introduced to the model as an extra precipitation over the irrigated fields, after being subtracted from the surplus runoff (precipitation−evapotranspiration). The agricultural land development was assumed to be linear that changed from 300000 ha at 1979 to 500000 at 2010, which is consistent with the best available data on the actual irrigation development in the basin. We estimated the annual evaporation over the Lake Urmia and the evapotranspiration over its drainage basin as 932 mm and 287 mm respectively. Our results showed that decreased precipitation and increased temperature over the basin since 1995 could explain 68% of the observed lake level decrease. Irrigation developments during the last four decades were found to be responsible for 32% of the observed lake level decrease. Thus the future lake level of the Lake Urmia is very likely to continue to decrease unless the current climate condition will be followed by a period of increased precipitation. If the current climate conditions will prevail also in the future, even a 20% decrease in the irrigated land area, which is actually quite ambitious, will not make the lake recover to its ecological level at the end of 2020.

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  • 74. Bini, Monica
    et al.
    Zanchetta, Giovanni
    Persoiu, Aurel
    Cartier, Rosine
    Catala, Albert
    Cacho, Isabel
    Dean, Jonathan R.
    Di Rita, Federico
    Drysdale, Russell N.
    Finnè, Martin
    Stockholm University, Faculty of Science, Department of Physical Geography. Uppsala University, Sweden.
    Isola, Ilaria
    Jalali, Bassem
    Lirer, Fabrizio
    Magri, Donatella
    Masi, Alessia
    Marks, Leszek
    Mercuri, Anna Maria
    Peyron, Odile
    Sadori, Laura
    Sicre, Marie-Alexandrine
    Welc, Fabian
    Zielhofer, Christoph
    Brisset, Elodie
    The 4.2 ka BP Event in the Mediterranean region: an overview2019In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 15, no 2, p. 555-577Article in journal (Refereed)
    Abstract [en]

    The Mediterranean region and the Levant have returned some of the clearest evidence of a climatically dry period occurring around 4200 years ago. However, some regional evidence is controversial and contradictory, and issues remain regarding timing, progression, and regional articulation of this event. In this paper, we review the evidence from selected proxies (sea-surface temperature, precipitation, and temperature reconstructed from pollen, delta O-18 on speleothems, and delta O-18 on lacustrine carbonate) over the Mediterranean Basin to infer possible regional climate patterns during the interval between 4.3 and 3.8 ka. The values and limitations of these proxies are discussed, and their potential for furnishing information on seasonality is also explored. Despite the chronological uncertainties, which are the main limitations for disentangling details of the climatic conditions, the data suggest that winter over the Mediterranean involved drier conditions, in addition to already dry summers. However, some exceptions to this prevail - where wetter conditions seem to have persisted - suggesting regional heterogeneity in climate patterns. Temperature data, even if sparse, also suggest a cooling anomaly, even if this is not uniform. The most common paradigm to interpret the precipitation regime in the Mediterranean - a North Atlantic Oscillation-like pattern - is not completely satisfactory to interpret the selected data.

  • 75. Birkhofer, Klaus
    et al.
    Andersson, Georg K. S.
    Bengtsson, Janne
    Bommarco, Riccardo
    Dänhardt, Juliana
    Ekbom, Barbara
    Ekroos, Johan
    Hahn, Thomas
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hedlund, Katarina
    Jönsson, Annelie M.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Olsson, Ola
    Rader, Romina
    Rusch, Adrien
    Stjernman, Martin
    Williams, Alwyn
    Smith, Henrik G.
    Relationships between multiple biodiversity components and ecosystem services along a landscape complexity gradient2018In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 218, p. 247-253Article in journal (Refereed)
    Abstract [en]

    The assessment of effects of anthropogenic disturbance on biodiversity (BD) and ecosystem services (ES) and their relationships are key priorities of the Intergovernmental Panel for Biodiversity and Ecosystem Services. Agricultural landscapes and their associated BD provide multiple ES and it is crucial to understand how relationships between ES and BD components change along gradients of landscape complexity. In this study, we related eight ES potentials to the species richness of five invertebrate, vertebrate and plant taxonomic groups in cereal farming systems. The landscape complexity gradient ranged from areas dominated by annually tilled arable land to areas with high proportions of unfertilized, non-rotational pastures and uncultivated field borders. We show that after accounting for landscape complexity relationships between yield and bird richness or biological control became more positive, but relationships between bird richness and biological control became less positive. The relationship between bird and plant richness turned from positive to negative. Multidiversity (overall biodiversity), was positively related to landscape complexity, whereas multifunctionality (overall ES provision), was not significantly related to either one of these. Our results suggest that multidiversity can be promoted by increasing landscape complexity; however; we found no support for a simultaneous increase of several individual ES, BD components or multifunctionality. These results challenge the assumption that bio-diversity-friendly landscape management will always simultaneously promote multiple ES in agricultural landscapes. Future studies need to verify this pattern by using multi-year data, larger sets of ES and BD components and a study design that is appropriate to address larger spatial scales and relationships in several regions.

  • 76. Birkhofer, Klaus
    et al.
    Busch, Adrien
    Andersson, Georg K. S.
    Bommarco, Riccardo
    Danhardt, Juliana
    Ekbom, Barbara
    Jonsson, Annelie
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Olsson, Ola
    Rader, Romina
    Stjernman, Martin
    Williams, Alwyn
    Hedlund, Katarina
    Smith, Henrik G.
    A framework to identify indicator species for ecosystem services in agricultural landscapes2018In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 91, p. 278-286Article in journal (Refereed)
    Abstract [en]

    Improving our understanding of the relationships between biodiversity and the delivery of ecosystem services is crucial for the development of sustainable agriculture. We introduce a novel framework that is based on the identification of indicator species for single or multiple ecosystem services across taxonomic groups based on indicator species analyses. We utilize multi-species community data (unlike previous single species approaches) without giving up information about the identity of species in our framework (unlike previous species richness approaches). We compiled a comprehensive community dataset including abundances of 683 invertebrate, vertebrate and plant species to identify indicator species that were either positively or negatively related to biological control, diversity of red-listed species or crop yield in agricultural landscapes in southern Sweden. Our results demonstrate that some taxonomic groups include significantly higher percentages of indicator species for these ecosystem services. Spider communities for example included a higher percentage of significant positive indicator species for biological control than ground or rove beetle communities. Bundles of indicator species for the analysed ecosystem service potentials usually included species that could be linked to the respective ecosystem service based on their functional role in local communities. Several of these species are conspicuous enough to be monitored by trained amateurs and could be used in bundles that are either crucial for the provision of individual ecosystem services or indicate agricultural landscapes with high value for red-listed species or crop yields. The use of bundles of characteristic indicator species for the simultaneous assessment of ecosystem services may reduce the amount of labour, time and cost in future assessments. In addition, future analysis using our framework in other ecosystems or with other subsets of ecosystem services and taxonomic groups will improve our understanding of service-providing species in local communities. In any case, expert knowledge is needed to select species from the identified subsets of significant indicator species and these species should be validated by existing data or additional sampling prior to being used for ecosystem service monitoring.

  • 77. Biskaborn, Boris K.
    et al.
    Smith, Sharon L.
    Noetzli, Jeannette
    Matthes, Heidrun
    Vieira, Goncalo
    Streletskiy, Dmitry A.
    Schoeneich, Philippe
    Romanovsky, Vladimir E.
    Lewkowicz, Antoni G.
    Abramov, Andrey
    Allard, Michel
    Boike, Julia
    Cable, William L.
    Christiansen, Hanne H.
    Delaloye, Reynald
    Diekmann, Bernhard
    Drozdov, Dmitry
    Etzelmüller, Bernd
    Grosse, Guido
    Guglielmin, Mauro
    Ingeman-Nielsen, Thomas
    Isaksen, Ketil
    Ishikawa, Mamoru
    Johansson, Margareta
    Johannsson, Halldor
    Joo, Anseok
    Kaverin, Dmitry
    Kholodov, Alexander
    Konstantinov, Pavel
    Kröger, Tim
    Lambiel, Christophe
    Lanckman, Jean-Pierre
    Luo, Dongliang
    Malkova, Galina
    Meiklejohn, Ian
    Moskalenko, Natalia
    Oliva, Marc
    Phillips, Marcia
    Ramos, Miguel
    Sannel, A. Britta K.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Sergeev, Dmitrii
    Seybold, Cathy
    Skryabin, Pavel
    Vasiliev, Alexander
    Wu, Qingbai
    Yoshikawa, Kenji
    Zheleznyak, Mikhail
    Lantuit, Hugues
    Permafrost is warming at a global scale2019In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, article id 264Article in journal (Refereed)
    Abstract [en]

    Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007-2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 +/- 0.15 degrees C. Over the same period, discontinuous permafrost warmed by 0.20 +/- 0.10 degrees C. Permafrost in mountains warmed by 0.19 +/- 0.05 degrees C and in Antarctica by 0.37 +/- 0.10 degrees C. Globally, permafrost temperature increased by 0.29 +/- 0.12 degrees C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.

  • 78. Björk, Alexandra
    et al.
    Skånes, Helle
    Stockholm University, Faculty of Science, Department of Physical Geography.
    The Need for Awareness of Semantic Plasticity in International Harmonization of Geographical Information: Seen from a Nordic Forest Classification Perspective2015In: Land Use and Land Cover Semantics: Principles, Best Practices and Prospects / [ed] Ola Ahlqvist, Dalia Varanka, Steffen Fritz, Krzysztof Janowicz, Boka Raton: CRC Press, 2015, p. 41-58Chapter in book (Refereed)
    Abstract [en]

    The aim of this chapter is to address and clarify the important issues and challenges of semantic plasticity when it comes to forest classification and geographical information. Necessary improvements for international data harmonization and implementation are highlighted along with the need for increased awareness of the consequences for ecological modeling. We envisage a combination of thoroughly described metadata and controlled vocabularies as a means to ensure the future use of a wide range of regional and national classification systems in an ontological framework that enables crosswalks between classification systems and spatial comparisons between existing data sets. This would allow for a wide range of old, contemporary, and future data sets to be used together in landscape-related analyses.

  • 79. Björk, Alexandra
    et al.
    Skånes, Helle
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Ahlqvist, Ola
    Ser vi skogen för alla träd? Vikten av semantisk plasticitet vid harmonisering av geodata2015In: Sinus, no 4, p. 2Article in journal (Other (popular science, discussion, etc.))
  • 80. Björklund, J.
    et al.
    von Arx, G.
    Nievergelt, D.
    Wilson, R.
    Van den Bulcke, J.
    Günther, B.
    Loader, N. J.
    Rydval, M.
    Fonti, P.
    Scharnweber, T.
    Andreu-Hayles, L.
    Büntgen, U.
    D'Arrigo, R.
    Davi, N.
    De Mil, T.
    Esper, J.
    Gärtner, H.
    Geary, J.
    Gunnarson, Björn E.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hartl, C.
    Hevia, A.
    Song, H.
    Janecka, K.
    Kaczka, R. J.
    Kirdyanov, A. V.
    Kochbeck, M.
    Liu, Y.
    Meko, M.
    Mundo, I.
    Nicolussi, K.
    Oelkers, R.
    Pichler, T.
    Sánchez-Salguero, R.
    Schneider, L.
    Schweingruber, F.
    Timonen, M.
    Trouet, V.
    Van Acker, J.
    Verstege, A.
    Villalba, R.
    Wilmking, M.
    Frank, D.
    Scientific Merits and Analytical Challenges of Tree-Ring Densitometry2019In: Reviews of geophysics, ISSN 8755-1209, E-ISSN 1944-9208, Vol. 57, no 4, p. 1224-1264Article, review/survey (Refereed)
    Abstract [en]

    X-ray microdensitometry on annually resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density (MXD) parameter, but also increasingly through other density parameters. For 50 years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular, and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resolution. Here we review the current understanding and merits of wood density for tree-ring research, associated microdensitometric techniques, and analytical measurement challenges. The review is further complemented with a careful comparison of new measurements derived at 17 laboratories, using several different techniques. The new experiment allowed us to corroborate and refresh long-standing wisdom but also provide new insights. Key outcomes include (i) a demonstration of the need for mass/volume-based recalibration to accurately estimate average ring density; (ii) a substantiation of systematic differences in MXD measurements that cautions for great care when combining density data sets for climate reconstructions; and (iii) insights into the relevance of analytical measurement resolution in signals derived from tree-ring density data. Finally, we provide recommendations expected to facilitate futureinter-comparability and interpretations for global change research.

  • 81. Björklund, Johanna
    et al.
    Eksvärd, Karin
    Schaffer, Christina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Exploring the potential of edible forest gardens: experiences from a participatory action research project in Sweden2019In: Agroforestry Systems, ISSN 0167-4366, E-ISSN 1572-9680, Vol. 93, no 3, p. 1107-1118Article in journal (Refereed)
    Abstract [en]

    To meet the environmental challenges that are presently confronting society, the narrow focus on agricultural production needs to be altered to one that places equal value on the generation of crucial ecosystem services. Current research shows that perennial intercropping systems such as agroforestry may be a feasible alternative. Based on studies during the establishment of edible forest gardens in 12 participating farms in Sweden, this paper explores the potential of utilizing multi-strata designs for food production in temperate, high-income countries. Design and species composition of such gardens, types of food they provide, and how they would best fit into the present landscape are discussed. Factors for success and major problems related to the establishment are shared. Potential benefits were found to be closely related to a thorough analysis of the social and ecological contexts before establishment. Characteristics of the site and goals of the garden need to guide species and design choices. If forest garden approaches to food production should contribute to more than local self-sufficiency, the gardens need to increase in scale. Marginal lands and transitions areas between different land uses may be appropriate. Large knowledge gaps concerning potential production, social and economic benefits, and agronomic issues were identified.

  • 82.
    Blomberg, Freddy
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Inläckage i dagbrott: En jämförelse mellan beräknade och uppmätta värden i dagbrott i norra Sverige2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Before the construction of an open pit mine is initialized it is common practice to perform hydrogeological surveys, in order to quantify the inflow of groundwater from surrounding soil and bedrock layers. As expansion of the pits progress, continuous pumping will need to be done, as groundwater will otherwise fill the pits, preventing further mining. Several quantification methods are available for these analyses, which can be either analytical or numerical in their structure. In this study, a review of established methods is performed. Then the inflow to five active mines in northern Sweden are estimated, using four analytical methods. The results from using these methods are then compared to the measured pumping rates in the mines, to evaluate the methods efficiency in estimating the correct withdrawal. One of the mines is also evaluated using a numerical model. All methods approximate the inflow rates to the same order of magnitude as the measured values. However, the same method can in some mines overestimate the inflow while in other mines make an underestimation of it. As they in most cases make an adequate approximation of the inflow, further use of the methods are recommended. Smaller adjustments might be needed based on local knowledge of the modeled area. The sensitivity analysis that was performed show a significant predisposition toward changes in hydraulic conductivity, emphasizing the importance of thorough surveys before parameterization of the models.

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  • 83.
    Blomdin, Robin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Paleoglaciology of the Tian Shan and Altai Mountains, Central Asia2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The mountain-systems of Central Asia, act as barriers to atmospheric circulation patterns, which in turn impose striking climate gradients across the region. Glaciers are sensitive indicators of climate change and respond to changes in climate gradients over time by advancing during cold and wet periods and receding during warm and dry periods. The aim of this thesis is to investigate whether there are large-scale patterns in how past glaciers in the Tian Shan and the Altai Mountains of Central Asia responded to climate change. Multiple methods have been used, including: remote sensing, terrain analysis, field investigations, and cosmogenic nuclide (CN) dating. The glacial landform records indicate that the region experienced mainly alpine-style glaciations in the past. Large complexes of ice-marginal moraines in high elevation basins are evidence of outlet glaciers sourced from large valley glaciers, ice caps and ice-fields, and these moraine sequences, record the maximum extent of paleoglaciation. In the Ikh-Turgen Mountains, located in the continental, eastern Altai Mountains, deglaciation of these moraines occurred during marine oxygen isotope stage (MIS) 3 at ~45 ka. This is consistent with a colder and wetter climate during this time, inferred from ice core and lake level proxies. Another deglacial phase occurred during MIS 2 at ~23 ka, synchronous with the global Last Glacial Maximum. In the Russian Altai Mountains, lobate moraines in the Chuya Basin indicate deglaciation at ~19 ka, by a highly dynamic paleoglacier in the Chagan-Uzun catchment, which experienced surge-like behaviour. Furthermore, across the Tian Shan, an evaluation of new and existing CN glacial chronologies (25 dated moraines) indicates that only one regional glacial stage, between 15 and 28 ka (MIS 2), can be defined and spatially correlated across the region. These paleoglaciers were mainly restricted to valleys as a result of arid conditions during this time and variation in their extents is interpreted to reflect topographic modulation on regional climate. The ages of the oldest evidence for robust local glacial stages in the Tian Shan are not yet well constrained, however, moraines in the central Kyrgyz Tian Shan and the eastern Chinese Tian Shan have apparent minimum ages overlapping with MIS 5 and MIS 3 (with missing MIS 4 and 6 stages). However, different geological processes, such as inheritance and post-depositional shielding (e.g. deposition by surging glaciers or hummocky terrain deposition), have influenced the dating resolution, making several moraine ages inappropriate for regional comparison. Finally, to quantify regional patterns of paleoglaciation, the hypsometry (area-elevation distribution) of glacial landforms is used to estimate average paleo equilibrium line altitudes for the region. This analysis shows that while present-day ELAs mirror strong climate gradients, paleoglaciation patterns were characterised by more gentle ELA gradients. The paleo-ELA depressions across Central Asia were most prominent in the continental southern and eastern regions (500–700 m). Finally, the results from this thesis, show that Central Asia was repeatedly glaciated in the past, but underscore the importance of considering 1) catchment characteristics and styles of glaciation and 2) other non-climatic factors controlling glacier dynamics when interpreting CN chronologies to make paleoclimate inference.

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  • 84.
    Blomdin, Robin
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University.
    The Late Glacial History of the Magellan Strait in southern Patagonia, Chile: Testing the Applicability of KF-IRSL Dating2012Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    The timing of the ice margin retreat of the Late Glacial Patagonian ice sheet (PIS) in southern Patagonia has been the object of discussion for many years. In order to resolve questions about the complex response of the PIS to past climate change; geological interpretation and modelling data needs evaluation against absolute chronology. The aim of this project is to re-map the landforms and sediment of the Magellan Strait, to reconstruct the late glacial ice retreat during the deglaciation and to investigate the applicability of OSL dating to glaciofluvial sediment from this region. Unfortunately previous studies have shown that the quartz OSL luminescence characteristics, of this region, are unsuitable for dating. Therefore the potential of K-feldspar IRSL signals are reviewed and examined. Samples were collected from landforms interpreted as being deposited during the deglaciation of the Magellan ice lobe, with an expected age range between 17.5 and 23 ka, and from recently deposited sediments (<1 ka). Small aliquots and single grain distributions were studied by applying a IR50 SAR protocol with IRSL stimulation at 50°C for 100 s and a preheat of 250 °C (held at 60 s) are measured.  Appropriate uncertainties were assigned to the dose distribution data, by quantifying the laboratory over-dispersion (σOD) parameter (22.2% for small aliquots and 17.7 % for single grains) in laboratory bleached and γ-irradiated samples.  Thereafter the possible effects of incomplete bleaching and anomalous fading were examined. For the natural samples environmental over-dispersions between 30–130 % and mean interpreted residual doses between ~30 and 80 Gy were observed. Statistical models were further applied to identify the part of the dose population that was most likely to have been completely bleached. The models are consistent with each other which imply that they successfully identified the fully-bleached grains in the distributions; however observed discrepancies between the small aliquot and single grain data were also discussed. Large g2day values (on average 7.92±0.6%/decade for large aliquots) were observed but nevertheless, comparing our fading corrected ages to the expected age range result in 2 out of 3 ages consistent with geological interpretation and an established radiocarbon and cosmogenic nuclide chronology suggesting that this correction was done successfully. The results of these investigations suggest that small aliquot/single grain fading can be corrected for using an average value and that KF-IRSL dating is applicable in this part of Southern Patagonia. The third age is supported by an alternative geological interpretation while the two consistent ages imply that in the Magellan Strait the hills of the Brunswick peninsula (70-100 m.a.s.l) were deglaciated at around ~21 ka. Finally some recommendations for future research are considered.

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  • 85.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. Purdue University, USA.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jon M.
    Stockholm University, Faculty of Science, Department of Physical Geography. Purdue University, USA.
    Lifton, N. A.
    Heyman, J.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Petrakov, D. A.
    Caffee, M. W.
    Ivanov, M. N.
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rogozhina, I.
    Usubaliev, R.
    Evaluating the timing of former glacier expansions in the Tian Shan: A key step towards robust spatial correlations2016In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 153, p. 78-96Article in journal (Refereed)
    Abstract [en]

    The timing of past glaciation across the Tian Shan provides a proxy for past climate change in this critical area. Correlating glacial stages across the region is difficult but cosmogenic exposure ages have considerable potential. A drawback is the large observed scatter in Be-10 surface exposure data. To quantify the robustness of the dating, we compile, recalculate, and perform statistical analyses on sets of 10Be surface exposure ages from 25 moraines, consisting of 114 new and previously published ages. We assess boulder age scatter by dividing boulder groups into quality classes and rejecting boulder groups of poor quality. This allows us to distinguish and correlate robustly dated glacier limits, resulting in a more conservative chronology than advanced in previous publications. Our analysis shows that only one regional glacial stage can be reliably correlated across the Tian Shan, with glacier expansions occurring between 15 and 281 a during marine oxygen isotope stage (MIS) 2. However, there are examples of older more extensive indicators of glacial stages between MIS 3 and MIS 6. Paleoglacier extent during MIS 2 was mainly restricted to valley glaciation. Local deviations occur: in the central Kyrgyz Tian Shan paleoglaciers were more extensive and we propose that the topographic context explains this pattern. Correlation between glacial stages prior to late MIS 2 is less reliable, because of the low number of samples and/or the poor resolution of the dating. With the current resolution and spatial coverage of robustly-dated glacier limits we advise that paleoclimatic implications for the Tian Shan glacial chronology beyond MIS 2 are speculative and that continued work toward robust glacial chronologies is needed to resolve questions regarding drivers of past glaciation in the Tian Shan and Central Asia.

  • 86.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Caffee, Marc W.
    Heyman, Jakob
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rogozhina, Irina
    Ivanov, Mikhail N.
    Petrakov, Dmitry A.
    Walther, Michael
    Rudoy, Alexei N.
    Zhang, Wei
    Orkhonselenge, Alexander
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lifton, Nathaniel A.
    Jansson, Krister N.
    Paleoglaciation on opposite flanks of the Ikh-Turgen Mountains, Central Asia: Importance of style of moraine deposition for 10-Be surface exposure datingManuscript (preprint) (Other academic)
    Abstract [en]

    The ages of marginal moraines that record extensive glacier expansions across the Altai Mountains of Central Asia are poorly documented. We present 18 10Be exposure ages from moraines in valleys on opposite flanks of the Ikh-Turgen Mountains. On the eastern side, exposure ages from a latero-frontal moraine indicate deglaciation during MIS 3 (45.3±2.7 ka) and MIS 2 (22.8±3.5 ka). Corresponding exposure ages, from the western side, indicate a more complex story with large scatter (~14-53 ka). Owing to their close proximity, the paleoglaciers should have responded similarly to climate forcing, yet they exhibited a distinctly different behavior. We propose that differences in glacier dynamics caused differences in ice-marginal depositional environments, explaining the scatter in exposure ages on the western side. This study shows the importance of style of deposition in chronological studies of glacial landforms and demonstrates that certain moraine types can be difficult to use as paleoclimate proxies.

  • 87.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography. Purdue University, USA.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Bern, Switzerland.
    Caffee, Marc W.
    Heyman, Jakob
    Rogozhina, Irina
    Ivanov, Mikhail N.
    Petrakov, Dmitry A.
    Walther, Michael
    Rudoy, Alexei N.
    Zhang, Wei
    Orkhonselenge, Alexander
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lifton, Nathaniel A.
    Jansson, Krister N.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Timing and dynamics of glaciation in the Ikh Turgen Mountains, Altai region, High Asia2018In: Quaternary Geochronology, ISSN 1871-1014, E-ISSN 1878-0350, Vol. 47, p. 54-71Article in journal (Refereed)
    Abstract [en]

    Spanning the northern sector of High Asia, the Altai region contains a rich landform record of glaciation. We report the extent, chronologies, and dynamics of two paleoglaciers on opposite flanks of the Ikh Turgen mountains (In Russian: Chikhacheva Range), straddling the border between Russia and Mongolia, using a combination of remote sensing-based glacial geomorphological mapping, Be-10 surface exposure dating, and geomorphometric analysis. On the eastern side (Mongolia), the Turgen-Asgat paleoglacier, with its potential for developing a large accumulation area (similar to 257 km(2)), expanded 40 km down valley, and mean ages from a latero-frontal moraine indicate deglaciation during marine oxygen isotope stage (MIS) 3 (45.1 +/- 1.8 ka, n = 4) and MIS 2 (22.8 +/- 3.3 ka, n = 5). These minimum age constraints are consistent with other Be-10 glacial chronologies and paleoclimate records from the region, which indicates glacier culmination during cold and wet conditions coinciding with MIS 3 (piedmont-style glaciation; inferred for a few sites across the region) and glacier culmination during cold and dry conditions coinciding with MIS 2 (mainly valley-style glaciation; inferred from several sites across the region). On the western side (Russia), the Boguty paleoglacier had a smaller accumulation area (similar to 222 km(2)), and advanced 30 km down valley across a low gradient forefield. Surface exposure ages from two moraine complexes on this side of the mountains exhibit wide scatter (similar to 14-53 ka, n = 8), making paleoclimate inferences and comparison to other proxies difficult. Ice surface profile reconstructions imply that the two paleoglaciers likely shared an ice divide.

  • 88.
    Blomdin, Robin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hättestrand, Clas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Heyman, Jakob
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Gribenski, Natacha
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Topographic and climatic controls on paleoglaciation patterns across the Tian Shan and Altai Mountains, Central AsiaManuscript (preprint) (Other academic)
    Abstract [en]

    Reconstructing spatial patterns of the extents and dynamics of paleoglaciers across Central Asia is key in understanding the mechanisms of global environmental change. The Tian Shan and Altai Mountains are located in the continental interior of Eurasia, at the confluence of several major climate systems. In order to test hypothesized patterns in paleoglacier extent, and to test the role of paleoclimate and mountain topography in modulating the evolution of these glacial systems, we perform a domain-wide terrain analysis. We first divide the Tian Shan and the Altai Mountains into six physiographic regions delineated by major drainage divides and outlining generalised climate zones. Thereafter we mine published datasets on the distribution of glaciers and glacial landforms, calculate their area-elevation distributions (hypsometry), and extract present-day regional equilibrium line altitudes (ELAs) and long-term average ELAs (paleo-ELAs). We show that the use of glacial landform hypsometry is an effective tool to quantify broad-scale paleoglaciation patterns and find that there is a regional variability in glacier extents across the Tian Shan and Altai Mountains. Reconstructed ELAs show pronounced spatial gradients; increasing ELAs from northern to southern Tian Shan, and increasing ELAs from the northern to both the southeastern and southwestern Altai Mountains. In contrast, maximum paleoglaciation patterns and paleo-ELAs were more uniform across the two mountain systems, with inter-regional topographic variability influencing moraine distributions and thus complicating regional paleo-ELA determinations. Because estimated paleo-ELAs were relatively uniform across the Tian Shan and Altai Mountains, the paleo-ELA lowering were most pronounced in the more continental southern and eastern regions. Our current data is insufficient to explain whether this observation is the result of a different regional paleoclimatic regime than today, or if paleoglaciers responded dynamically different to a paleoclimate forcing of the same magnitude. Our ELA reconstructions also lack temporal constraints, so we furthermore propose that future studies systematically compare hypsometry-derived ELA reconstructions with those stemming from surface energy mass balance models, other proxy records (i.e. lake- and ice core records), and from chronologically constrained ice-marginal moraines.  

  • 89. Blonder, Benjamin
    et al.
    Graae, Bente J.
    Greer, Burke
    Haagsma, Marja
    Helsen, Kenny
    Kapás, Rozália E.
    Stockholm University, Faculty of Science, Department of Physical Geography. Norwegian University of Science and Technology (NTNU), Norway; Rocky Mountain Biological Laboratory, USA.
    Pai, Henry
    Rieksta, Jolanta
    Sapena, Dillon
    Still, Christopher J.
    Strimbeck, Richard
    Remote sensing of ploidy level in quaking aspen (Populus tremuloides Michx.)2020In: Journal of Ecology, ISSN 0022-0477, E-ISSN 1365-2745, Vol. 108, no 1, p. 175-188Article in journal (Refereed)
    Abstract [en]

    Ploidy level in plants may influence ecological functioning, demography and response to climate change. However, measuring ploidy level typically requires intensive cell or molecular methods. We map ploidy level variation in quaking aspen, a dominant North American tree species that can be diploid or triploid and that grows in spatially extensive clones. We identify the predictors and spatial scale of ploidy level variation using a combination of genetic and ground-based and airborne remote sensing methods. We show that ground-based leaf spectra and airborne canopy spectra can both classify aspen by ploidy level with a precision-recall harmonic mean of 0.75-0.95 and Cohen's kappa of c. 0.6-0.9. Ground-based bark spectra cannot classify ploidy level better than chance. We also found that diploids are more common on higher elevation and steeper sites in a network of forest plots in Colorado, and that ploidy level distribution varies at subkilometer spatial scales. Synthesis. Our proof-of-concept study shows that remote sensing of ploidy level could become feasible in this tree species. Mapping ploidy level across landscapes could provide insights into the genetic basis of species' responses to climate change.

  • 90. Blösch, Günter
    et al.
    Bierkens, Marc F. P.
    Chambel, Antonio
    Cudennec, Christophe
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Fiori, Aldo
    Kirchner, James W.
    McDonnell, Jeffrey J.
    Savenije, Hubert H. G.
    Sivapalan, Murugesu
    Stumpp, Christine
    Toth, Elena
    Volpi, Elena
    Carr, Gemma
    Lupton, Claire
    Salinas, Jose
    Szeles, Borbala
    Viglione, Alberto
    Aksoy, Hafzullah
    Allen, Scott T.
    Amin, Anam
    Andreassian, Vazken
    Arheimer, Berit
    Aryal, Santosh K.
    Baker, Victor
    Bardsley, Earl
    Barendrecht, Marlies H.
    Bartosova, Alena
    Batelaan, Okke
    Berghuijs, Wouter R.
    Beven, Keith
    Blume, Theresa
    Bogaard, Thom
    de Amorim, Pablo Borges
    Boettcher, Michael E.
    Boulet, Gilles
    Breinl, Korbinian
    Brilly, Mitja
    Brocca, Luca
    Buytaert, Wouter
    Castellarin, Attilio
    Castelletti, Andrea
    Chen, Xiaohong
    Chen, Yangbo
    Chen, Yuanfang
    Chifflard, Peter
    Claps, Pierluigi
    Clark, Martyn P.
    Collins, Adrian L.
    Croke, Barry
    Dathe, Annette
    David, Paula C.
    de Barros, Felipe P. J.
    de Rooij, Gerrit
    Di Baldassarre, Giuliano
    Driscoll, Jessica M.
    Duethmann, Doris
    Dwivedi, Ravindra
    Eris, Ebru
    Farmer, William H.
    Feiccabrino, James
    Ferguson, Grant
    Ferrari, Ennio
    Ferraris, Stefano
    Fersch, Benjamin
    Finger, David
    Foglia, Laura
    Fowler, Keirnan
    Gartsman, Boris
    Gascoin, Simon
    Gaume, Eric
    Gelfan, Alexander
    Geris, Josie
    Gharari, Shervan
    Gleeson, Tom
    Glendell, Miriam
    Bevacqua, Alena Gonzalez
    Gonzalez-Dugo, Maria P.
    Grimaldi, Salvatore
    Gupta, A. B.
    Guse, Bjoern
    Han, Dawei
    Hannah, David
    Harpold, Adrian
    Haun, Stefan
    Heal, Kate
    Helfricht, Kay
    Herrnegger, Mathew
    Hipsey, Matthew
    Hlavacikova, Hana
    Hohmann, Clara
    Holko, Ladislav
    Hopkinson, Christopher
    Hrachowitz, Markus
    Illangasekare, Tissa H.
    Inam, Azhar
    Innocente, Camyla
    Istanbulluoglu, Erkan
    Jarihani, Ben
    Kalantari, Zahra
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kalvans, Andis
    Khanal, Sonu
    Khatami, Sina
    Kiesel, Jens
    Kirkby, Mike
    Knoben, Wouter
    Kochanek, Krzysztof
    Kohnova, Silvia
    Kolechkina, Alla
    Krause, Stefan
    Kreamer, David
    Kreibich, Heidi
    Kunstmann, Harald
    Lange, Holger
    Liberato, Margarida L. R.
    Lindquist, Eric
    Link, Timothy
    Liu, Junguo
    Loucks, Daniel Peter
    Luce, Charles
    Mahe, Gil
    Makarieva, Olga
    Malard, Julien
    Mashtayeva, Shamshagul
    Maskey, Shreedhar
    Mas-Pla, Josep
    Mavrova-Guirguinova, Maria
    Mazzoleni, Maurizio
    Mernild, Sebastian
    Misstear, Bruce Dudley
    Montanari, Alberto
    Mueller-Thomy, Hannes
    Nabizadeh, Alireza
    Nardi, Fernando
    Neale, Christopher
    Nesterova, Nataliia
    Nurtaev, Bakhram
    Odongo, Vincent O.
    Panda, Subhabrata
    Pande, Saket
    Pang, Zhonghe
    Papacharalampous, Georgia
    Perrin, Charles
    Pfister, Laurent
    Pimentel, Rafael
    Polo, Maria J.
    Post, David
    Sierra, Cristina Prieto
    Ramos, Maria-Helena
    Renner, Maik
    Reynolds, Jose Eduardo
    Ridolfi, Elena
    Rigon, Riccardo
    Riva, Monica
    Robertson, David E.
    Rosso, Renzo
    Roy, Tirthankar
    Sa, Joao H. M.
    Salvadori, Gianfausto
    Sandells, Mel
    Schaefli, Bettina
    Schumann, Andreas
    Scolobig, Anna
    Seibert, Jan
    Servat, Eric
    Shafiei, Mojtaba
    Sharma, Ashish
    Sidibe, Moussa
    Sidle, Roy C.
    Skaugen, Thomas
    Smith, Hugh
    Spiessl, Sabine M.
    Stein, Lina
    Steinsland, Ingelin
    Strasser, Ulrich
    Su, Bob
    Szolgay, Jan
    Tarboton, David
    Tauro, Flavia
    Thirel, Guillaume
    Tian, Fuqiang
    Tong, Rui
    Tussupova, Kamshat
    Tyralis, Hristos
    Uijlenhoet, Remko
    van Beek, Rens
    van der Ent, Ruud J.
    van der Ploeg, Martine
    Van Loon, Anne F.
    van Meerveld, Ilja
    van Nooijen, Ronald
    van Oel, Pieter R.
    Vidal, Jean-Philippe
    von Freyberg, Jana
    Vorogushyn, Sergiy
    Wachniew, Przemyslaw
    Wade, Andrew J.
    Ward, Philip
    Westerberg, Ida K.
    White, Christopher
    Wood, Eric F.
    Woods, Ross
    Xu, Zongxue
    Yilmaz, Koray K.
    Zhang, Yongqiang
    Twenty-three unsolved problems in hydrology (UPH) - a community perspective2019In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 64, no 10, p. 1141-1158Article in journal (Refereed)
    Abstract [en]

    This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.

  • 91.
    Bogren, Fredrik
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Evidence for birch forests and a highly productive environment near the margin of the Fennoscandian ice sheet in the Värriötunturit area, northeastern Finland2019Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    High-resolution records of early Holocene deposits are rare, and as a consequence reconstruction of terrestrial environments very soon after the deglaciation has often been difficult. In this study the palaeoenvironmental conditions of early Holocene (c. 10600-7500 cal. yr BP) are reconstructed in the Värriötunturit area of northeastern Finland, using evidence from plant macrofossils and pollen preserved in a lake sediment sequence retrieved from the small lake Kuutsjärvi. Special emphasis is put on the environment immediately following the deglaciation as the base of the sediment sequence is rich in minerogenic material interpreted to have been deposited by meltwater pulses from the retreating ice sheet. The abundance and variety of fossil remains in these early meltwater deposits provide evidence for a very productive ice-marginal environment in the area between the lake and the ice sheet, and the presence of tree-type Betula macro remains as well as high percentage values of tree-type Betula pollen suggests that a subarctic birch forest established just a few years after the deglaciation. In the following centuries the birch forest around the lake became rich in an under growth of ferns, and at c. 9400 cal. yr BP a transition into a mixed pine and birch forest took place. Due to absence of indicator plant taxa in the sediment it was not possible to reconstruct temperature conditions for any parts of the sequence in this study. However, the rapid colonisation of birch forests suggests that the climate was warm already during deglaciation, which is also in accordance with climatic conditions reconstructed for the early Holocene in the nearby Sokli area just 10 km away, as well as in other parts of Fennoscandia and Russia.

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  • 92.
    Bohman, Ida
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Den arktiska permafrostens minskning och dess positiva feedback till den globala uppvärmningen2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    24 % of the Northern Hemisphere’s landmass is underlain by permafrost. 1 700 billion tonnes of organic carbon (C) is stored in the permafrost, and the ongoing climate change lead to permafrost thawing and carbon release.

    This study examines the extent of thawing permafrost and the estimated carbon emissions as a consequence of permafrost thawing. The results show an estimated decrease of near-surface permafrost up to 81% before 2100 due to an increase of the average global temperature. Thawing permafrost releases CO2 and CH4 to the atmosphere, which amplifies the greenhouse effect and creates a positive feedback to global warming.

    The magnitude of the positive feedback is uncertain but an average of 178 Pg C is expected to release to the atmosphere by 2100 if the anthropogenic emissions continues. A potential increase in biomass due to favorable growing conditions is not expected to offset the carbon emissions.

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  • 93.
    Bohman, Ida
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Synergier och målkonflikter mellan klimatmålet om noll nettoutsläpp av växthusgaser år 2045 och Sveriges nationella miljökvalitetsmål2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In January 2018, Sweden’s new Climate Act and long-term climate goal entered into force. The goal states that, by 2045, Sweden will reach net-zero emissions of greenhouse gases. The goal is ambitious and requires powerful climate change mitigations in a variety of sectors, which can lead to both positive synergies and negative tradeoffs with the 16 existing Environmental Quality Objectives. Examining and analyzing such interactions can accelerate the achievement of the goals and reduce the risk of unwanted complications. 

    The purpose of this study is to assess the central measures of achieving the climate goal, and to evaluate and clarify possible synergies and tradeoffs between the climate goal and Sweden’s Environmental Objectives. The applied methods include literature studies, expert assessments, Causal Loop Diagrams and a comparative analysis method, and a total of 160 interactions between the climate goal and the Environmental Objectives have been examined. 

    37% of the interactions show positive synergies, and 47% show no significant impact between the climate goal and the Environmental Objectives. Only 16% of the interactions are estimated to lead to possible negative tradeoffs. In many cases, type of used technology and the location of the measures play a decisive role; with careful planning and precautionary principles, synergies can be supported and tradeoffs avoided.

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  • 94. Bokhorst, Stef
    et al.
    Pedersen, Stine Hojlund
    Brucker, Ludovic
    Anisimov, Oleg
    Bjerke, Jarle W.
    Brown, Ross D.
    Ehrich, Dorothee
    Essery, Richard L. H.
    Heilig, Achim
    Ingvander, Susanne
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Johansson, Cecilia
    Johansson, Margareta
    Jonsdottir, Ingibjorg Svala
    Inga, Niila
    Luojus, Kari
    Macelloni, Giovanni
    Mariash, Heather
    McLennan, Donald
    Rosqvist, Gunhild Ninis
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Bergen, Norway.
    Sato, Atsushi
    Savela, Hannele
    Schneebeli, Martin
    Sokolov, Aleksandr
    Sokratov, Sergey A.
    Terzago, Silvia
    Vikhamar-Schuler, Dagrun
    Williamson, Scott
    Qiu, Yubao
    Callaghan, Terry V.
    Changing Arctic snow cover: A review of recent developments and assessment of future needs for observations, modelling, and impacts2016In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 45, no 5, p. 516-537Article, review/survey (Refereed)
    Abstract [en]

    Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for impact assessments and adaptation strategies. Although much progress has been made in understanding and predicting snow-cover changes and their multiple consequences, many uncertainties remain. In this paper, we review advances in snow monitoring and modelling, and the impact of snow changes on ecosystems and society in Arctic regions. Interdisciplinary activities are required to resolve the current limitations on measuring and modelling snow characteristics through the cold season and at different spatial scales to assure human well-being, economic stability, and improve the ability to predict manage and adapt to natural hazards in the Arctic region.

  • 95.
    Borja, Sonia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kalantari, Zahra
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Global Wetting by Seasonal Surface Water Over the Last Decades2020In: Earth's future, E-ISSN 2328-4277, Vol. 8, no 3, article id UNSP e2019EF001449Article in journal (Refereed)
    Abstract [en]

    Surface water bodies and their changes in the landscape are critical for societies and ecosystems. However, the global change in surface water area over the last decades remains unclear, as recent studies using the same satellite data disagree on its direction. Here, we reanalyze reported maps of global water classification based on that data in order to estimate the changes in long-term average surface water area from the first (1985-2000) to the second (2001-2015) half of the recent 30-year period (1985-2015). We find a net gain in global surface water area by 100,454 km(2), primarily due to seasonal water gains (83,329 km(2)). Over the world, we identify net wetting in 187 and net drying in 57 regional hydrological catchments, with the greatest water gain in Sabarmati (India) and loss in Amu Darya (Uzbekistan). We provide an interactive map to further explore the highly heterogeneous local changes around the world.

  • 96. Bothe, Oliver
    et al.
    Hind, Alistair
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, Department of Mathematics.
    Moberg, Anders
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Zorita, Eduardo
    Continental-scale temperature variability in PMIP3 simulations and PAGES 2k regional temperature reconstructions over the past millennium2015In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 11, no 12, p. 1673-1699Article in journal (Refereed)
    Abstract [en]

    Estimated external radiative forcings, model results, and proxy-based climate reconstructions have been used over the past several decades to improve our understanding of the mechanisms underlying observed climate variability and change over the past millennium. Here, the recent set of temperature reconstructions at the continental-scale generated by the PAGES 2k project and a collection of state-of-the-art model simulations driven by realistic external forcings are jointly analysed. The first aim is to estimate the consistency between model results and reconstructions for each continental-scale region over the time and frequency domains. Secondly, the links between regions are investigated to determine whether reconstructed global-scale covariability patterns are similar to those identified in model simulations. The third aim is to assess the role of external forcings in the observed temperature variations. From a large set of analyses, we conclude that models are in relatively good agreement with temperature reconstructions for Northern Hemisphere regions, particularly in the Arctic. This is likely due to the relatively large amplitude of the externally forced response across northern and high-latitude regions, which results in a clearly detectable signature in both reconstructions and simulations. Conversely, models disagree strongly with the reconstructions in the Southern Hemisphere. Furthermore, the simulations are more regionally coherent than the reconstructions, perhaps due to an underestimation of the magnitude of internal variability in models or to an overestimation of the response to the external forcing in the Southern Hemisphere. Part of the disagreement might also reflect large uncertainties in the reconstructions, specifically in some Southern Hemisphere regions, which are based on fewer palaeoclimate records than in the Northern Hemisphere.

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  • 97. Bouchard, Frédéric
    et al.
    Sansoulet, Julie
    Fritz, Michael
    Malenfant-Lepage, Julie
    Nieuwendam, Alexandre
    Paquette, Michel
    Rudy, Ashley C. A.
    Siewert, Matthias B.
    Sjöberg, Ylva
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Tanski, George
    Habeck, J. Otto
    Harbor, Jon
    Frozen-Ground Cartoons: Permafrost comics as an innovative tool for polar outreach, education, and engagement2019In: Polar Record, ISSN 0032-2474, E-ISSN 1475-3057, Vol. 54, no 5-6, p. 366-372Article in journal (Refereed)
    Abstract [en]

    Permafrost occupies 20 million square kilometres of Earth's high-latitude and high-altitude landscapes. These regions are sensitive to climate change and human activities; hence, permafrost research is of considerable scientific and societal importance. However, the results of this research are generally not known by the general public. Communicating scientific concepts is an increasingly important task in the research world. Different ways to engage learners and incorporate narratives in teaching materials exist, yet they are generally underused. Here we report on an international scientific outreach project called Frozen-Ground Cartoons, which aims at making permafrost science accessible and fun for students, teachers, and parents through the creation of comic strips. We present the context in which the project was initiated, as well as recent education and outreach activities. The future phases of the project primarily involve a series of augmented reality materials, such as maps, photos, videos, and 3D drawings. With this project we aim to foster understanding of permafrost research among broader audiences, inspire future permafrost researchers, and raise public and science community awareness of polar science, education, outreach, and engagement.

  • 98. Boy, Michael
    et al.
    Thomson, Erik S.
    Acosta Navarro, Juan-C.
    Arnalds, Olafur
    Batchvarova, Ekaterina
    Back, Jaana
    Berninger, Frank
    Bilde, Merete
    Brasseur, Zoe
    Dagsson-Waldhauserova, Pavla
    Castarede, Dimitri
    Dalirian, Maryam
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Leeuw, Gerrit
    Dragosics, Monika
    Duplissy, Ella-Maria
    Duplissy, Jonathan
    Ekman, Annica M. L.
    Stockholm University, Faculty of Science, Department of Meteorology .
    Fang, Keyan
    Gallet, Jean-Charles
    Glasius, Marianne
    Gryning, Sven-Erik
    Grythe, Henrik
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. NILU–Norwegian Institute for Air Research, Norway.
    Hansson, Hans-Christen
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Hansson, Margareta
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Isaksson, Elisabeth
    Iversen, Trond
    Jonsdottir, Ingibjorg
    Kasurinen, Ville
    Kirkevag, Alf
    Korhola, Atte
    Krejci, Radovan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Kristjansson, Jon Egill
    Lappalainen, Hanna K.
    Lauri, Antti
    Lepparanta, Matti
    Lihavainen, Heikki
    Makkonen, Risto
    Massling, Andreas
    Meinander, Outi
    Nilsson, E. Douglas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Olafsson, Haraldur
    Pettersson, Jan B. C.
    Prisle, Nonne L.
    Riipinen, Ilona
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Roldin, Pontus
    Ruppel, Meri
    Salter, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Sand, Maria
    Seland, Oyvind
    Seppa, Heikki
    Skov, Henrik
    Soares, Joana
    Stohl, Andreas
    Ström, Johan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Svensson, Jonas
    Swietlicki, Erik
    Tabakova, Ksenia
    Thorsteinsson, Throstur
    Virkkula, Aki
    Weyhenmeyer, Gesa A.
    Wu, Yusheng
    Zieger, Paul
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Kulmala, Markku
    Interactions between the atmosphere, cryosphere, and ecosystems at northern high latitudes2019In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 19, no 3, p. 2015-2061Article in journal (Refereed)
    Abstract [en]

    The Nordic Centre of Excellence CRAICC (Cryosphere-Atmosphere Interactions in a Changing Arctic Climate), funded by NordForsk in the years 2011-2016, is the largest joint Nordic research and innovation initiative to date, aiming to strengthen research and innovation regarding climate change issues in the Nordic region. CRAICC gathered more than 100 scientists from all Nordic countries in a virtual centre with the objectives of identifying and quantifying the major processes controlling Arctic warming and related feedback mechanisms, outlining strategies to mitigate Arctic warming, and developing Nordic Earth system modelling with a focus on short-lived climate forcers (SLCFs), including natural and anthropogenic aerosols. The outcome of CRAICC is reflected in more than 150 peer-reviewed scientific publications, most of which are in the CRAICC special issue of the journal Atmospheric Chemistry and Physics. This paper presents an overview of the main scientific topics investigated in the centre and provides the reader with a state-of-the-art comprehensive summary of what has been achieved in CRAICC with links to the particular publications for further detail. Faced with a vast amount of scientific discovery, we do not claim to completely summarize the results from CRAICC within this paper, but rather concentrate here on the main results which are related to feedback loops in climate change-cryosphere interactions that affect Arctic amplification.

  • 99.
    Boyd, Meighan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Speleothems from Warm Climates: Holocene Records from the Caribbean and Mediterranean Regions2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis contributes to increased knowledge on Holocene climate and environmental variability from two complex and sparsely studied areas. Using a speleothem from Gasparee Cave, Trinidad, as a paleoclimate archive, the local expression of the 8.2 ka (thousand years before 1950) climate event and associated patterns of the inter-tropical convergence zone (ITCZ) and rainfall is provided. Subsequent speleothem studies using multi-proxy analysis of stalagmites from Kapsia Cave and Alepotrypa Cave, Greece, provide records of climate, vegetation and human induced changes in the cave environment during parts of the Holocene.

    The speleothems from the well-studied Neolithic habitation site, Alepotrypa Cave, have produced a climate and habitation record which covers the period of 6.3-1.0 ka. The cave was inhabited between 8.0-5.2 ka and was closed by a tectonic event, which has preserved the settlement. The stable oxygen record shows the first well-dated and robust expression of the 4.2 ka dry event in the Peloponnese, places the timing of the 3.2 ka dry event within an ongoing dry period, and shows a final dry event at 1.6 ka. The North Atlantic as well as more regional drivers, such as the North Sea Caspian Pattern Index is proposed to, in a complex interplay, govern many of the climate trends and events observed.

    Trace element variation after the site is abandoned indicate what is interpreted as two volcanic eruptions, the Minoan eruption of Thera (Santorini) around 3.6 ka and the 2.7 ka eruption of Somma (Vesuvius). Variations in trace elements during the habitation period show clear human influence, indicating an association with specific cave activities. One of the most interesting prospects for continued work on Alepotrypa Cave is this successful marriage of speleothem studies and archeology. A framework of dates which constrain some behavior of people living in the cave is only the beginning, and there is great potential to continue finding new clues in the speleothem data.

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  • 100.
    Boyd, Meighan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hoffmann, Dirk
    Max Planck Institute for Evolutionary Anthropology, Germany.
    Jochum, Klaus Peter
    Max Planck Institute for Chemistry, Germany.
    Karkanas, Panagiotis
    American School of Classical Studies at Athens, Greece.
    Krusic, Paul J.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Papathanasiou, Anastasia
    Greek Ministry of Culture, Greece.
    Scholz, Denis
    Johannes Gutenberg-University Mainz, Germany.
    Stoll, Brigitte
    Max Planck Institute for Chemistry, Germany.
    Holmgren, Karin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Trace elements as recorders of human activity and environmental indicators at Alepotrypa Cave, GreeceManuscript (preprint) (Other academic)
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