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  • 1. Abbott, Benjamin W.
    et al.
    Brown, Michael
    Carey, Joanna C.
    Ernakovich, Jessica
    Frederick, Jennifer M.
    Guo, Laodong
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lee, Raymond M.
    Loranty, Michael M.
    Macdonald, Robie
    Mann, Paul J.
    Natali, Susan M.
    Olefeldt, David
    Pearson, Pam
    Rec, Abigail
    Robards, Martin
    Salmon, Verity G.
    Sayedi, Sayedeh Sara
    Schädel, Christina
    Schuur, Edward A. G.
    Shakil, Sarah
    Shogren, Arial J.
    Strauss, Jens
    Tank, Suzanne E.
    Thornton, Brett
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Treharne, Rachael
    Turetsky, Merritt
    Voigt, Carolina
    Wright, Nancy
    Yang, Yuanhe
    Zarnetske, Jay P.
    Zhang, Qiwen
    Zolkos, Scott
    We Must Stop Fossil Fuel Emissions to Protect Permafrost Ecosystems2022In: Frontiers in Environmental Science, E-ISSN 2296-665X, Vol. 10, article id 889428Article, review/survey (Refereed)
    Abstract [en]

    Climate change is an existential threat to the vast global permafrost domain. The diverse human cultures, ecological communities, and biogeochemical cycles of this tenth of the planet depend on the persistence of frozen conditions. The complexity, immensity, and remoteness of permafrost ecosystems make it difficult to grasp how quickly things are changing and what can be done about it. Here, we summarize terrestrial and marine changes in the permafrost domain with an eye toward global policy. While many questions remain, we know that continued fossil fuel burning is incompatible with the continued existence of the permafrost domain as we know it. If we fail to protect permafrost ecosystems, the consequences for human rights, biosphere integrity, and global climate will be severe. The policy implications are clear: the faster we reduce human emissions and draw down atmospheric CO2, the more of the permafrost domain we can save. Emissions reduction targets must be strengthened and accompanied by support for local peoples to protect intact ecological communities and natural carbon sinks within the permafrost domain. Some proposed geoengineering interventions such as solar shading, surface albedo modification, and vegetation manipulations are unproven and may exacerbate environmental injustice without providing lasting protection. Conversely, astounding advances in renewable energy have reopened viable pathways to halve human greenhouse gas emissions by 2030 and effectively stop them well before 2050. We call on leaders, corporations, researchers, and citizens everywhere to acknowledge the global importance of the permafrost domain and work towards climate restoration and empowerment of Indigenous and immigrant communities in these regions.

  • 2. Abbott, Benjamin W.
    et al.
    Jones, Jeremy B.
    Schuur, Edward A. G.
    Chapin, F. Stuart
    Bowden, William B.
    Bret-Harte, M. Syndonia
    Epstein, Howard E.
    Flannigan, Michael D.
    Harms, Tamara K.
    Hollingsworth, Teresa N.
    Mack, Michelle C.
    McGuire, A. David
    Natali, Susan M.
    Rocha, Adrian V.
    Tank, Suzanne E.
    Turetsky, Merritt R.
    Vonk, Jorien E.
    Wickland, Kimberly P.
    Aiken, George R.
    Alexander, Heather D.
    Amon, Rainer M. W.
    Benscoter, Brian W.
    Bergeron, Yves
    Bishop, Kevin
    Blarquez, Olivier
    Bond-Lamberty, Ben
    Breen, Amy L.
    Buffam, Ishi
    Cai, Yihua
    Carcaillet, Christopher
    Carey, Sean K.
    Chen, Jing M.
    Chen, Han Y. H.
    Christensen, Torben R.
    Cooper, Lee W.
    Cornelissen, J. Hans C.
    de Groot, William J.
    DeLuca, Thomas H.
    Dorrepaal, Ellen
    Fetcher, Ned
    Finlay, Jacques C.
    Forbes, Bruce C.
    French, Nancy H. F.
    Gauthier, Sylvie
    Girardin, Martin P.
    Goetz, Scott J.
    Goldammer, Johann G.
    Gough, Laura
    Grogan, Paul
    Guo, Laodong
    Higuera, Philip E.
    Hinzman, Larry
    Hu, Feng Sheng
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jafarov, Elchin E.
    Jandt, Randi
    Johnstone, Jill F.
    Karlsson, Jan
    Kasischke, Eric S.
    Kattner, Gerhard
    Kelly, Ryan
    Keuper, Frida
    Kling, George W.
    Kortelainen, Pirkko
    Kouki, Jari
    Kuhry, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Laudon, Hjalmar
    Laurion, Isabelle
    Macdonald, Robie W.
    Mann, Paul J.
    Martikainen, Pertti J.
    McClelland, James W.
    Molau, Ulf
    Oberbauer, Steven F.
    Olefeldt, David
    Pare, David
    Parisien, Marc-Andre
    Payette, Serge
    Peng, Changhui
    Pokrovsky, Oleg S.
    Rastetter, Edward B.
    Raymond, Peter A.
    Raynolds, Martha K.
    Rein, Guillermo
    Reynolds, James F.
    Robards, Martin
    Rogers, Brendan M.
    Schaedel, Christina
    Schaefer, Kevin
    Schmidt, Inger K.
    Shvidenko, Anatoly
    Sky, Jasper
    Spencer, Robert G. M.
    Starr, Gregory
    Striegl, Robert G.
    Teisserenc, Roman
    Tranvik, Lars J.
    Virtanen, Tarmo
    Welker, Jeffrey M.
    Zimov, Sergei
    Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment2016In: Environmental Research Letters, E-ISSN 1748-9326, Vol. 11, no 3, article id 034014Article in journal (Refereed)
    Abstract [en]

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

  • 3. Abihudi, Siri A.
    et al.
    de Boer, Hugo J.
    Treydte, Anna C.
    Stockholm University, Faculty of Science, Department of Physical Geography. Nelson Mandela African Institution for Science and Technology (NM-AIST), Tanzania.
    Conservation status revision and communities' perceptions of 22 Aloe species in Tanzania2021In: Plant Ecology and Evolution, ISSN 2032-3913, E-ISSN 2032-3921, Vol. 154, no 3, p. 391-404Article in journal (Refereed)
    Abstract [en]

    Background and aims – Many Aloe species are globally threatened due to overharvesting for trade and habitat destruction. CITES regulates their international trade. In Tanzania, 50% of all existing Aloe species had previously been assessed, though some of these assessments were Data Deficient. For those with sufficient data, an update is required as the rate of decline has rapidly increased over the last years.

    Material and methods – We estimated Area of Occupancy (AOO), Extent of Occurrence (EOO), and number of locations for 22 Tanzanian Aloe species using the Geospatial Conservation Assessment software (GeoCAT). We assessed the reasons leading to their decline based on direct field observations and community perceptions.

    Key results – We revised the conservation status of 22 Aloe species; two were assessed as Critically Endangered, ten as Endangered, five as Vulnerable, and five as Least Concern. We re-discovered the Critically Endangered Aloe boscawenii, which had not been seen in Tanzania for more than six decades. We propose to downgrade the endemic Aloe dorotheaeAloe leptosiphon, and Aloe flexilifolia from Critically Endangered to a lower threat level. The community perception on Aloe species availability did not accurately reflect their categorisation based on the IUCN criteria B. We identified agricultural activities and climate change effects as the two main threats to Tanzanian Aloe species.

    Conclusion – We conclude that overall numbers are declining for 22 Aloe species in Tanzania, mainly due to human activities. We recommend the implementation of laws and policies to protect their natural habitats.

  • 4. Abraham, Vojtech
    et al.
    Hicks, Sheila
    Svobodova-Svitavska, Helena
    Bozilova, Elissaveta
    Panajiotidis, Sampson
    Filipova-Marinova, Mariana
    Jensen, Christin Eldegard
    Tonkov, Spassimir
    Pidek, Irena Agnieszka
    Swieta-Musznicka, Joanna
    Zimny, Marcelina
    Kvavadze, Eliso
    Filbrandt-Czaja, Anna
    Hättestrand, Martina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Karlioglu Kilic, Nurgül
    Kosenko, Jana
    Nosova, Maria
    Severova, Elena
    Volkova, Olga
    Hallsdottir, Margret
    Kalnina, Laimdota
    Noryskiewicz, Agnieszka M.
    Noryskiewicz, Bozena
    Pardoe, Heather
    Christodoulou, Areti
    Koff, Tiiu
    Fontana, Sonia L.
    Alenius, Teija
    Isaksson, Elisabeth
    Seppä, Heikki
    Veski, Siim
    Pedziszewska, Anna
    Weiser, Martin
    Giesecke, Thomas
    Patterns in recent and Holocene pollen accumulation rates across Europe - the Pollen Monitoring Programme Database as a tool for vegetation reconstruction2021In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 18, no 15, p. 4511-4534Article in journal (Refereed)
    Abstract [en]

    The collection of modern, spatially extensive pollen data is important for the interpretation of fossil pollen assemblages and the reconstruction of past vegetation communities in space and time. Modern datasets are readily available for percentage data but lacking for pollen accumulation rates (PARs). Filling this gap has been the motivation of the pollen monitoring network, whose contributors monitored pollen deposition in modified Tauber traps for several years or decades across Europe. Here we present this monitoring dataset consisting of 351 trap locations with a total of 2742 annual samples covering the period from 1981 to 2017. This dataset shows that total PAR is influenced by forest cover and climate parameters, which determine pollen productivity and correlate with latitude. Treeless vegetation produced PAR values of at least 140 grains cm(-2) yr(-1). Tree PAR increased by at least 400 grains cm(-2) yr(-1) with each 10% increase in forest cover. Pollen traps situated beyond 200 km of the distribution of a given tree species still collect occasional pollen grains of that species. The threshold of this long-distance transport differs for individual species and is generally below 60 grains cm(-2) yr(-1). Comparisons between modern and fossil PAR from the same regions show similar values. For temperate taxa, modern analogues for fossil PARs are generally found downslope or southward of the fossil sites. While we do not find modern situations comparable to fossil PAR values of some taxa (e.g. Corylus), CO2 fertilization and land use may cause high modern PARs that are not documented in the fossil record. The modern data are now publicly available in the Neotoma Paleoecology Database and aid interpretations of fossil PAR data.

  • 5.
    A'Campo, Willeke
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Bartsch, Annett
    Roth, Achim
    Wendleder, Anna
    Martin, Victoria S.
    Durstewitz, Luca
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lodi, Rachele
    Wagner, Julia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Arctic Tundra Land Cover Classification on the Beaufort Coast Using the Kennaugh Element Framework on Dual-Polarimetric TerraSAR-X Imagery2021In: Remote Sensing, E-ISSN 2072-4292, Vol. 13, no 23, article id 4780Article in journal (Refereed)
    Abstract [en]

    Arctic tundra landscapes are highly complex and are rapidly changing due to the warming climate. Datasets that document the spatial and temporal variability of the landscape are needed to monitor the rapid changes. Synthetic Aperture Radar (SAR) imagery is specifically suitable for monitoring the Arctic, as SAR, unlike optical remote sensing, can provide time series regardless of weather and illumination conditions. This study examines the potential of seasonal backscatter mechanisms in Arctic tundra environments for improving land cover classification purposes by using a time series of HH/HV TerraSAR-X (TSX) imagery. A Random Forest (RF) classification was applied on multi-temporal Sigma Nought intensity and multi-temporal Kennaugh matrix element data. The backscatter analysis revealed clear differences in the polarimetric response of water, soil, and vegetation, while backscatter signal variations within different vegetation classes were more nuanced. The RF models showed that land cover classes could be distinguished with 92.4% accuracy for the Kennaugh element data, compared to 57.7% accuracy for the Sigma Nought intensity data. Texture predictors, while improving the classification accuracy on the one hand, degraded the spatial resolution of the land cover product. The Kennaugh elements derived from TSX winter acquisitions were most important for the RF model, followed by the Kennaugh elements derived from summer and autumn acquisitions. The results of this study demonstrate that multi-temporal Kennaugh elements derived from dual-polarized X-band imagery are a powerful tool for Arctic tundra land cover mapping.

  • 6. Acharya, Kamal Prasad
    et al.
    De Frenne, Pieter
    Brunet, Jörg
    Chabrerie, Olivier
    Cousins, Sara A. O.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Diekmann, Martin
    Hermy, Martin
    Kolb, Annette
    Lemke, Isgard
    Plue, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Verheyen, Kris
    Graae, Bente Jessen
    Latitudinal variation of life-history traits of an exotic and a native impatiens species in Europe2017In: Acta Oecologica, ISSN 1146-609X, E-ISSN 1873-6238, Vol. 81, p. 40-47Article in journal (Refereed)
    Abstract [en]

    Understanding the responses of invasive and native populations to environmental change is crucial for reliable predictions of invasions in the face of global change. While comparisons of responses across invasive species with different life histories have been performed before, comparing functional traits of congeneric native and invasive species may help to reveal driving factors associated with invasion. Here we compared morphological functional trait patterns of an invasive species (Impatiens parviflora) with its congeneric native species (I. noli-tangere) along an approximately 1600 km European latitudinal gradient from France (49 degrees 34'N) to Norway (63 degrees 40'N). Soil nitrogen was recorded during six weeks of the growing season, and light, soil moisture, and nutrient availability were estimated for each sampled population using community weighted means of indicator values for co-occurring species. Temperature data were gathered from nearby weather stations. Both the native and invasive species are taller at higher latitudes and this response is strongest in the invasive species. Seed mass and number of seeds per capsule increase in I. noli-tangere but decrease in I. parviflora towards higher latitudes. Surprisingly, plant height in the invasive I. parviflora decreases with increasing soil nitrogen availability. The latitudinal pattern in seed mass is positively related to temperature in I. noli-tangere and negatively in I. parviflora. Leaf area of both species decreases with increasing Ellenberg indicator values for nitrogen and light but increases with increasing soil moisture. Soil nitrogen concentrations and Ellenberg indicator values for nitrogen have significant positive (I. nolitangere) and negative (I. parviflora) effects on the number of seeds per capsule. Our results show that the native I. noli-tangere has efficient reproduction at its range edge while the invasive I. parviflora shows a marked decrease in seed size and seed number per capsule. These patterns are unrelated to the growth and obtained size of the plants: even low soil nitrogen availability in the north seemed not to limit plant growth and size. Our results suggest that the invasive I. parviflora tends to become more invasive at lower latitudes by producing heavier seeds and more seeds per capsule.

  • 7.
    Adriansson, Linus
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stockholm i färger: En kritisk diskursanalys av kulturarvets produktion och legitimering i stadens bebyggelsemiljö2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Avsikten med denna uppsats är att med en kritisk diskursanalys undersöka hur kunskap om kulturarvet och kulturhistoriska värden konstrueras i Stockholms byggda miljö. Akademisk litteratur inom kulturarvsforskningen beskriver en situation där det uppstått ett glapp mellan teori och praktik inom kulturarvssektorn som vidgats sedan postmodernismens och konstruktionismens framväxt i början på 1970-talet. Den utövande kulturarvsvården och värderingsprocessen är i stor utsträckning styrd av värdeorienterade klassificeringssystem där utgångspunkten är att finna och tolka olika värdetyper i ett objekt. Detta traditionella förhållningssätt är en del av ”den auktoriserade kulturarvsdiskursen”; ett begrepp inom kulturarvsforskningen som menar att kulturarvssektorn premierar traditionella värden genom expertutpekanden vilket leder till en reproduktion av kanoniserade objekt med vissa ideologiska förtecken. Sedan år 1974 finns det i Sverige nationella kulturpolitiska mål fastslagna och sedan år 2012 finns det fyra nationella kulturmiljömål som landets kulturmiljövårdande institutioner ska sträva. Målens tankegods förmedlar en ambition om att göra kulturmiljöer och kunskap tillgängligt för att främja demokratisering av kulturarvet. I Stockholms kommun är det Stadsmuseet som ansvarar för utpekandet och klassificeringen av kulturhistoriskt värdefulla byggnader och miljöer. Syftet med undersökningen är att bidra med en djupare förståelse för hur kunskapen om kulturhistoriska värden i Stockholms byggda kulturmiljö produceras och legitimeras. Resultat och analys visar att diskurserna i Stadsmuseets översiktsdokument sedan klassificeringens introduktion under tidigt 1980-tal har förändrats av ideologiska, politiska och ekonomiska element. Museets och kommunens samtida översiktsdokument har en anknytning till kunskapsläget inom kulturarvsforskningen genom att argumentera för relativa, pluralistiska värden. Men den traditionella värdesynen och expertdiskursen i värderingsprocessen har lett till en värdering och klassificering som reproducerar en traditionell förståelse av det byggda kulturarvet. En universell metod i kombination med intern praxis används för att identifiera vilka kulturhistoriska värden som finns, utan att precisera vilka egenskaper som upprätthåller dessa värden. Det ger klassificeringen en svag anknytning till kulturarvsforskning, regeringens kulturpolitiska mål och den egna institutionens värdesyn i samtida översiktsdokument.

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  • 8.
    Aggemyr, Elsa
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Auffret, Alistair G.
    Stockholm University, Faculty of Science, Department of Physical Geography. Swedish University of Agricultural Sciences, Sweden.
    Jädergård, Love
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Cousins, Sara A. O.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Species richness and composition differ in response to landscape and biogeography2018In: Landscape Ecology, ISSN 0921-2973, E-ISSN 1572-9761, Vol. 33, no 12, p. 2273-2284Article in journal (Refereed)
    Abstract [en]

    Context Understanding how landscape patterns affect species diversity is of great importance in the fields of biogeography, landscape ecology and conservation planning, but despite the rapid advance in biodiversity analysis, investigations of spatial effects on biodiversity are still largely focused on species richness.

    Objectives We wanted to know if and how species richness and species composition are differentially driven by the spatial measures dominating studies in landscape ecology and biogeography. As both measures require the same limited presence/absence information, it is important to choose an appropriate diversity measure, as differing results could have important consequences for interpreting ecological processes.

    Methods We recorded plant occurrences on 112 islands in the Baltic archipelago. Species richness and composition were calculated for each island, and the explanatory power of island area and habitat heterogeneity, distance to mainland and structural connectivity at three different landscape sizes were examined.

    Results A total of 354 different plant species were recorded. The influence of landscape variables differed depending on which diversity measure was used. Island area and structural connectivity determined plant species richness, while species composition revealed a more complex pattern, being influenced by island area, habitat heterogeneity and structural connectivity.

    Conclusions Although both measures require the same basic input data, species composition can reveal more about the ecological processes affecting plant communities in fragmented landscapes than species richness alone. Therefore, we recommend that species community composition should be used as an additional standard measure of diversity for biogeography, landscape ecology and conservation planning.

  • 9. AghaKouchak, Amir
    et al.
    Mirchi, Ali
    Madani, Kaveh
    Stockholm University, Faculty of Science, Department of Physical Geography. Yale University, USA.
    Di Baldassarre, Giuliano
    Nazemi, Ali
    Alborzi, Aneseh
    Anjileli, Hassan
    Azarderakhsh, Marzi
    Chiang, Felicia
    Hassanzadeh, Elmira
    Huning, Laurie S.
    Mallakpour, Iman
    Martinez, Alexandre
    Mazdiyasni, Omid
    Moftakhari, Hamed
    Norouzi, Hamid
    Sadegh, Mojtaba
    Sadeqi, Dalal
    Van Loon, Anne F.
    Wanders, Niko
    Anthropogenic Drought: Definition, Challenges, and Opportunities2021In: Reviews of geophysics, ISSN 8755-1209, E-ISSN 1944-9208, Vol. 59, no 2, article id e2019RG000683Article, review/survey (Refereed)
    Abstract [en]

    Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions and activities, and altered micro-climate conditions due to changes in land and water management. This definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems that drive the development of anthropogenic drought. This process magnifies the water supply demand gap and can lead to water bankruptcy, which will become more rampant around the globe in the coming decades due to continuously growing water demands under compounding effects of climate change and global environmental degradation. This challenge has de facto implications for both short-term and long-term water resources planning and management, water governance, and policymaking. Herein, after a brief overview of the anthropogenic drought concept and its examples, we discuss existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon.

  • 10. Ahlkrona, Josefin
    et al.
    Lötstedt, Per
    Kirchner, Nina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Zwinger, Thomas
    Dynamically coupling the non-linear Stokes equations with the shallow ice approximation in glaciology: Description and first applications of the ISCAL method2016In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 308, p. 1-19Article in journal (Refereed)
    Abstract [en]

    We propose and implement a new method, called the Ice Sheet Coupled Approximation Levels (ISCAL) method, for simulation of ice sheet flow in large domains during long time-intervals. The method couples the full Stokes (FS) equations with the Shallow Ice Approximation (SIA). The part of the domain where SIA is applied is determined automatically and dynamically based on estimates of the modeling error. For a three dimensional model problem, ISCAL computes the solution substantially faster with a low reduction in accuracy compared to a monolithic FS. Furthermore, ISCAL is shown to be able to detect rapid dynamic changes in the flow. Three different error estimations are applied and compared. Finally, ISCAL is applied to the Greenland Ice Sheet on a quasi-uniform grid, proving ISCAL to be a potential valuable tool for the ice sheet modeling community.

  • 11. Ahlmer, Anna-Klara
    et al.
    Cavalli, Marco
    Hansson, Klas
    Koutsouris, Alexander J.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Crema, Stefano
    Kalantari, Zahra
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Soil moisture remote-sensing applications for identification of flood-prone areas along transport infrastructure2018In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 77, no 14, article id 533Article in journal (Refereed)
    Abstract [en]

    The expected increase in precipitation and temperature in Scandinavia, and especially short-time heavy precipitation, will increase the frequency of flooding. Urban areas are the most vulnerable, and specifically, the road infrastructure. The accumulation of large volumes of water and sediments on road-stream intersections gets severe consequences for the road drainage structures. This study integrates the spatial and temporal soil moisture properties into the research about flood prediction methods by a case study of two areas in Sweden, Vastra Gotaland and Varmland, which was affected by severe flooding in August 2014. Soil moisture data are derived from remote-sensing techniques, with a focus on the soil moisture-specific satellites ASCAT and SMOS. Furthermore, several physical catchments descriptors (PCDs) are analyzed and the result shows that larger slopes and drainage density, in general, mean a higher risk of flooding. The precipitation is the same; however, it can be concluded that more precipitation in most cases gives higher soil moisture values. The lack, or the dimensioning, of road drainage structures seems to have a large impact on the flood risk as more sediment and water can be accumulated at the road-stream intersection. The results show that the method implementing soil moisture satellite data is promising for improving the reliability of flooding.

  • 12. Ahlström, A. P.
    et al.
    Anderson, B.
    Arenillas, M.
    Bajracharya, S.
    Baroni, C.
    Bidlake, W. R.
    Braun, L. N.
    Caceres, B.
    Casassa, G.
    Ceballos, J. L.
    Cobos, G.
    Davila, L. R.
    Delgado Granados, H.
    Demberel, O.
    Demuth, M. N.
    Espizua, L.
    Fischer, A.
    Fujita, K.
    Gadek, B.
    Ghazanfar, A.
    Hagen, J. O.
    Hoelzle, M.
    Holmlund, Per
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Karimi, N.
    Li, Z.
    Martinez De Pison, E.
    Pelto, M.
    Pitte, P.
    Popovnin, V. V.
    Portocarrero, C. A.
    Prinz, R.
    Ramirez, J.
    Rudell, A.
    Sangewar, C.
    Severskiy, I
    Sigurdsson, O.
    Soruco, A.
    Tielidze, L.
    Usubaliev, R.
    Van Ommen, T.
    Vincent, C.
    Yakovlev, A.
    Historically unprecedented global glacier decline in the early 21st century2015In: Journal of Glaciology, ISSN 0022-1430, E-ISSN 1727-5652, Vol. 61, no 228, p. 745-+Article in journal (Refereed)
    Abstract [en]

    Observations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (similar to 42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (similar to 5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable.

  • 13. Ahlström, Hanna
    et al.
    Hileman, Jacob
    Wang-Erlandsson, Lan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Mancilla Garcia, Maria
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Université Libre de Bruxelles (ULB), Belgium.
    Moore, Michele-Lee
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. University of Victoria, Canada.
    Jonas, Krisztina
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Pranindita, Agnes
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Kuiper, Jan J.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Fetzer, Ingo
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Svedin, Uno
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    An Earth system law perspective on governing social-hydrological systems in the Anthropocene2021In: Earth System Governance, ISSN 2589-8116, Vol. 10, article id 100120Article in journal (Refereed)
    Abstract [en]

    The global hydrological cycle is characterized by complex interdependencies and self-regulating feedbacks that keep water in an ever-evolving state of flux at local, regional, and global levels. Increasingly, the scale of human impacts in the Anthropocene is altering the dynamics of this cycle, which presents additional challenges for water governance. Earth system law provides an important approach for addressing gaps in governance that arise from the mismatch between the global hydrological cycle and dispersed regulatory architecture across institutions and geographic regions. In this article, we articulate the potential for Earth system law to account for core hydrological problems that complicate water governance, including delay, redistribution, intertwinements, permanence, and scale. Through merging concepts from Earth system law with existing policy and legal principles, we frame an approach for addressing hydrological problems in the Anthropocene and strengthening institutional fit between established governance systems and the global hydrological cycle. We discuss how such an approach can be applied, and the challenges and implications for governing water as a cycle and complex social-hydrological system, both in research and practice.

  • 14. Aichner, Bernhard
    et al.
    Makhmudov, Zafar
    Rajabov, Iljomjon
    Zhang, Qiong
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Pausata, Francesco S. R.
    Werner, Martin
    Heinecke, Liv
    Kuessner, Marie L.
    Feakins, Sarah J.
    Sachse, Dirk
    Mischke, Steffen
    Hydroclimate in the Pamirs Was Driven by Changes in Precipitation-Evaporation Seasonality Since the Last Glacial Period2019In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 46, no 23, p. 13972-13983Article in journal (Refereed)
    Abstract [en]

    The Central Asian Pamir Mountains (Pamirs) are a high-altitude region sensitive to climatic change, with only few paleoclimatic records available. To examine the glacial-interglacial hydrological changes in the region, we analyzed the geochemical parameters of a 31-kyr record from Lake Karakul and performed a set of experiments with climate models to interpret the results. delta D values of terrestrial biomarkers showed insolation-driven trends reflecting major shifts of water vapor sources. For aquatic biomarkers, positive delta D shifts driven by changes in precipitation seasonality were observed at ca. 31-30, 28-26, and 17-14 kyr BP. Multiproxy paleoecological data and modelling results suggest that increased water availability, induced by decreased summer evaporation, triggered higher lake levels during those episodes, possibly synchronous to northern hemispheric rapid climate events. We conclude that seasonal changes in precipitation-evaporation balance significantly influenced the hydrological state of a large waterbody such as Lake Karakul, while annual precipitation amount and inflows remained fairly constant.

  • 15. Akselsson, Cecilia
    et al.
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Critical biomass harvesting - Applying a new concept for Swedish forest soils2018In: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 409, p. 67-73Article in journal (Refereed)
    Abstract [en]

    The contribution of forest harvesting to base cation losses and soil acidification has increased in recent years in Sweden, as the demand for bioenergy has increased and the sulphur deposition has decreased. Thus, new policy tools are required to evaluate the progress of the recovery from acidification, and as a basis for forest management recommendations. In this study we introduce and test a concept, Critical biomass harvesting. The concept builds on the concept Critical loads, which has been used world-wide for several decades as a bridge between science and policies related to transboundary air pollution and acidification. The basis for the concept is an acidity mass balance, with sources and sinks of acidity. A critical limit defines the highest acceptable acidification status of the water leaving the root zone. Based on the critical limit, the highest allowed biomass harvesting can be calculated, keeping the other parameters constant. In this study the critical limit was set to ANC (Acid Neutralizing Capacity) = 0. Nitrogen was assumed to be affecting acidity only if it leaches from the root zone. The critical biomass harvesting was calculated for almost 12000 National Forest Inventory sites with spruce and pine forest, using the best available data on deposition, weathering and nitrogen leaching. The exceedance of critical biomass harvesting was calculated as the difference between the estimated harvest losses and the critical biomass harvesting. The results were presented as median values in merged catchments in a catchment database, with totally 2079 merged catchments in Sweden. According to the calculations, critical biomass harvesting was exceeded in the southern half of Sweden already at stem harvesting in spruce forests. Whole-tree harvesting expanded the exceedance area, and increased the exceedance levels in southern Sweden. The exceedance in pine forest was lower and affected smaller areas. It was concluded that the concept of critical biomass harvesting can be successfully applied on the same database that has been used for critical load calculations in Sweden, using basically the same approach as has been extensively applied, evaluated and discussed in a critical load context. The results from the calculations in Sweden indicate that whole-tree harvesting, without wood ash recycling, can be expected to further slow down recovery, especially in the most acidified parts of the country, in the southwest.

  • 16. Akselsson, Cecilia
    et al.
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Stendahl, Johan
    Finlay, Roger
    Olsson, Bengt A.
    Erlandsson Lampa, Martin
    Wallander, Håkan
    Gustafsson, Jon Petter
    Bishop, Kevin
    Weathering rates in Swedish forest soils2019In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, no 22, p. 4429-4450Article in journal (Refereed)
    Abstract [en]

    Soil and water acidification was internationally recognised as a severe environmental problem in the late 1960s. The interest in establishing critical loads led to a peak in weathering research in the 1980s and 1990s, since base cation weathering is the long-term counterbalance to acidification pressure. Assessments of weathering rates and associated uncertainties have recently become an area of renewed research interest, this time due to demand for forest residues to provide renewable bioenergy. Increased demand for forest fuels increases the risk of depleting the soils of base cations produced in situ by weathering. This is the background to the research programme Quantifying Weathering Rates for Sustainable Forestry (QWARTS), which ran from 2012 to 2019. The programme involved research groups working at different scales, from laboratory experiments to modelling. The aims of this study were to (1) investigate the variation in published weathering rates of base cations from different approaches in Sweden, with consideration of the key uncertainties for each method; (2) assess the robustness of the results in relation to sustainable forestry; and (3) discuss the results in relation to new insights from the QWARTS programme and propose ways to further reduce uncertainties. In the study we found that the variation in estimated weathering rates at single-site level was large, but still most sites could be placed reliably in broader classes of weathering rates. At the regional level, the results from the different approaches were in general agreement. Comparisons with base cation losses after stem-only and whole-tree harvesting showed sites where whole-tree harvesting was clearly not sustainable and other sites where variation in weathering rates from different approaches obscured the overall balance. Clear imbalances appeared mainly after whole-tree harvesting in spruce forests in southern and central Sweden. Based on the research findings in the QWARTS programme, it was concluded that the PROFILE/ForSAFE family of models provides the most important fundamental understanding of the contribution of weathering to long-term availability of base cations to support forest growth. However, these approaches should be continually assessed against other approaches. Uncertainties in the model approaches can be further reduced, mainly by finding ways to reduce uncertainties in input data on soil texture and associated hydrological parameters but also by developing the models, e.g. to better represent biological feedbacks under the influence of climate change.

  • 17. Akselsson, Cecilia
    et al.
    Kronnäs, Veronika
    Stadlinger, Nadja
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Zanchi, Giuliana
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Karlsson, Per Erik
    Hellsten, Sofie
    Pihl Karlsson, Gunilla
    A Combined Measurement and Modelling Approach to Assess the Sustainability of Whole-Tree Harvesting—A Swedish Case Study2021In: Sustainability, E-ISSN 2071-1050, Vol. 13, no 4, article id 2395Article in journal (Refereed)
    Abstract [en]

    The demand of renewable energy has increased the interest in whole-tree harvesting. The sustainability of whole-tree harvesting after clear-cutting, from an acidification point of view, depends on two factors: the present acidification status and the further loss of buffering capacity at harvesting. The aims of this study were to investigate the relationship between these two factors at 26 sites along an acidification gradient in Sweden, to divide the sites into risk classes, and to examine the geographical distribution of them in order to provide policy-relevant insights. The present status was represented by the acid neutralizing capacity (ANC) in soil solution, and the loss of buffering capacity was represented by the estimated exceedance of critical biomass harvesting (CBH). The sites were divided into three risk classes combining ANC and exceedance of CBH. ANC and exceedance of CBH were negatively correlated, and most sites had either ANC < 0 and exceedance (high risk) or ANC > 0 and no exceedance (low risk). There was a geographical pattern, with the high risk class concentrated to southern Sweden, which was mainly explained by higher historical sulfur deposition and site productivity in the south. The risk classes can be used in the formulation of policies on whole-tree harvesting and wood ash recycling.

  • 18. Akselsson, Cecilia
    et al.
    Olsson, Jonas
    Belyazid, Salim
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Capell, René
    Can increased weathering rates due to future warming compensate for base cation losses following whole-tree harvesting in spruce forests?2016In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 128, no 1-2, p. 89-105Article in journal (Refereed)
    Abstract [en]

    Whole-tree harvesting, i.e. harvesting of stems, branches and tops, has become increasingly common during recent decades due to the increased demand for renewable energy. Whole-tree harvesting leads to an increase in base cation losses from the ecosystem, which can counteract recovery from acidification. An increase in weathering rates due to higher temperatures is sometimes suggested as a process that may counteract the acidifying effect of whole-tree harvesting. In this study the potential effect of increasing temperature on weathering rates was compared with the increase in base cation losses following whole-tree harvesting in spruce forests, along a temperature gradient in Sweden. The mechanistic model PROFILE was used to estimate weathering rates at National Forest Inventory sites at today's temperature and the temperature in 2050, as estimated by two different climate projections. The same dataset was used to calculate base cation losses following stem-only and whole-tree harvesting. The calculations showed that the increase in temperature until 2050 would result in an increase in the base cation weathering rate of 20-33 %, and that whole-tree harvesting would lead to an increase in base cation losses of 66 % on average, compared to stem-only harvesting. A sensitivity analysis showed that moisture changes are important for future weathering rates, but the effect of the temperature change was dominating even when the most extreme moisture changes were applied. It was concluded that an increase in weathering rates resulting from higher temperatures would not compensate for the increase in base cation losses following whole-tree harvesting, except in the northernmost part of Sweden.

  • 19. Alaoui, Abdallah
    et al.
    Barão, Lúcia
    Ferreira, Carla S. S.
    Stockholm University, Faculty of Science, Department of Physical Geography. Coimbra Agrarian Technical School, Portugal.
    Hessel, Rudi
    An Overview of Sustainability Assessment Frameworks in Agriculture2022In: Land, E-ISSN 2073-445X, Vol. 11, no 4, article id 537Article in journal (Refereed)
    Abstract [en]

    Recent research established a link between environmental alterations due to agriculture intensification, social damage and the loss of economic growth. Thus, the integration of environmental and social dimensions is key for economic development. In recent years, several frameworks have been proposed to assess the overall sustainability of farms. Nevertheless, the myriad of existing frameworks and the variety of indicators result in difficulties in selecting the most appropriate framework for study site application. This manuscript aims to: (i) understand the criteria to select appropriate frameworks and summarize the range of those being used to assess sustainability; (ii) identify the available frameworks to assess agricultural sustainability; and (iii) analyze the strengths, weaknesses and applicability of each framework. Six frameworks, namely SAFA, RISE, MASC, LADA, SMART and public goods (PG), were identified. Results show that SMART is the framework that considers, in a balanced way, the environmental, sociocultural and economic dimensions of sustainability, whereas others focused on the environmental (RISE), environmental and economic (PG) and sociocultural (SAFA) dimension. However, depending on the scale assessment, sector of application and the sustainability completeness intended, all frameworks are suitable for the assessment. We present a decision tree to help future users understand the best option for their objective. 

  • 20.
    Alavaisha, Edmond
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Agricultural expansion impacts on wetland ecosystem services from Kilombero Valley, Tanzania2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Land use change has major impact on the world’s wetland ecosystems and biodiversity. The motivation behind this change has been to increase agricultural production, often resulting in negative effects on water quality and soil fertility. Tanzania has carried out a large expansion and intensification of agriculture under the Kilimo kwanza (First agriculture) initiative which has triggered the need for better knowledge on land use change effects and associated ecosystem functioning. This thesis considers small-scale irrigation schemes to understand the effects of agriculture expansion and farming practices on nutrients, water quality and ecosystem services (ES) in Kilombero Valley, Tanzania. The study approach is multidisciplinary involving interviews, remote sensing, geographical information system techniques, and in-field soil and water ecological sampling. The major land use change in the valley during the last three decades was transformation from forest, bushland and grassland into cultivated land. The rate of change was faster adjacent to irrigation schemes and most changes occurred downstream irrigation canals, close to the floodplain. Irrigation and fertilization contributed to soil carbon and nitrogen accumulation in crop fields, which both declined in concentration with depth into the soil. However, such management practices and agricultural land expansion had impacts on several ES – especially water quality in streams. Streams surrounded mainly by cultivated land, as well as downstream areas, had lower water quality compared to streams with less settlement, more natural vegetation and upstream areas. Furthermore, when evaluated, macroinvertebrates indices were found to be a good indicator of water quality and a complement to chemical and physical water analysis. Irrigation farming produced more food compared to rainfed farming, and also other ES such as flood regulation, erosion control and several cultural services, depending on the river discharge. The thesis shows the importance to use irrigation/fertilization management to enhance soil fertility and preserve soil structure, but also the need for proper irrigation management to prevent flooding and erosion, conserve natural vegetation, and protect water quality. To enhance nature conservation, preserve biodiversity and secure future supply of ES in the valley, investment in irrigation infrastructures should be done at small-scale to mitigate the large-scale exploitation of Kilombero wetland.

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  • 21.
    Alavaisha, Edmond
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Dar es Salaam, Tanzania.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Smallholder perceptions on ecosystem services generation in irrigated and rainfed farming- Kilombero, TanzaniaManuscript (preprint) (Other academic)
  • 22.
    Alavaisha, Edmond
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI). University of Dar es Salaam, Tanzania.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    Supply and demand of ecosystem services among smallholder farmers in irrigated and rainfed farming, Kilombero, Tanzania2022In: Ecosystems and People, ISSN 2639-5908, E-ISSN 2639-5916, Vol. 18, no 1, p. 661-671Article in journal (Refereed)
    Abstract [en]

    A sufficient supply of ecosystem services (ESs) in agriculture provides the basis for human sustainable development. Intensified large-scale farming has changed wetland ecosystems extensively by reducing both the resilience and capacity to support production of many ESs. Small-scale farming may also affect the generation of ESs where the impact often reflects the differences in farming practices. This paper explores the supply and demand of the ESs between management practices, irrigated and rainfed, of smallholder farmers in Kilombero wetland, Tanzania. We conducted interviews involving 30 households and two focus groups with five discussants for each practice, rainfed and irrigation. Generally, we found that the need for ES, especially food, water and flood control, in both farming practices, were exceeding the capacity to supply. In general, irrigation farming compared to rainfed farming was associated with higher levels of food production, increasing flood regulation and erosion control. However, the ES delivery and need were not uniform depending on the river discharge. The differences in supply and demand of ESs between farming practices suggest that society would benefit from investing in irrigation and regulatory infrastructures to minimize flooding risk and to build up the ecosystem’s natural capacity to produce services. Such practical policy-relevant measures could balance the gap between supply and demand of ESs in smallholder farming systems in Tanzanian wetland. 

  • 23.
    Alavaisha, Edmond
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Dar es Salaam, Tanzania.
    Lyon, Steve W.
    Stockholm University, Faculty of Science, Department of Physical Geography. The Nature Conservancy, USA.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Assessment of Water Quality Across Irrigation Schemes: A Case Study of Wetland Agriculture Impacts in Kilombero Valley, Tanzania2019In: Water, E-ISSN 2073-4441, Vol. 11, no 4, article id 671Article in journal (Refereed)
    Abstract [en]

    Coupled change in land and water use due to increased farming intensity is a main factor affecting water quality and quantity, ecological functions and biodiversity globally. Prolonging growing seasons and increasing productivity in wetlands through irrigation have been targeted for increasing food security, particularly in developing countries. Nevertheless, irrigation and drainage have often been associated with degradation of water quality through increased agrochemical and fertiliser runoff and leaching at local scales. In this study, we investigated water quality in streams used for irrigation in a wetland area in Kilombero Valley, Tanzania. We measured physical-chemical water parameters and collected macroinvertebrates with different sensitivity to water quality across several small irrigation schemes covering various conditions. Turbidity, temperature, nitrate-N, and ammonium-N were significantly higher at sampling sites downstream of irrigation compared to upstream. Macroinvertebrate diversity, richness and average score per taxa (ASPT) were higher in general in sampling sites upstream of irrigation, with more sensitive macroinvertebrates decreasing in abundance downstream. There was a positive correlation between physical-chemical parameters and macroinvertebrate indices across the sites. We demonstrate that macroinvertebrate indices can be used as a quick assessment of water quality in response to irrigation schemes in small-scale farming systems of Tanzania. This in turn can allow us to track changes affecting wetland ecosystem function and biodiversity at higher trophic levels and across larger scales, thereby providing useful early warnings to help avoid widespread degradation under widespread agricultural intensification.

  • 24.
    Alavaisha, Edmond
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Dar es Salaam, Tanzania.
    Manzoni, Stefano
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Different agricultural practices affect soil carbon, nitrogen and phosphorous in Kilombero -Tanzania2019In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 234, p. 159-166Article in journal (Refereed)
    Abstract [en]

    Converting natural and semi-natural vegetation to agriculture is currently the most significant land use change at global scale. This conversion leads to changes in soil nutrients and increased CO2 emissions. However, knowledge of how soil organic carbon and nutrients change under various farming management is still limited, especially for small scale farming systems. This study evaluated the effects of different farming systems on soil organic carbon (SOC), total nitrogen (TN) and total phosphorous (TP) in subsistence farming at Kilombero, Tanzania. We applied an in-situ experimental setup, comparing maize and rice farming with and without irrigation and difference in fertilizers, with replicated soil sampling at five soil depths to a depth of 60 cm. The results show that irrigation had a positive effect on profile-averaged concentrations of SOC and TN, while fertilization had a positive effect on TN. Higher concentrations and stocks of TN were found in maize field soils compered to rice fields. In the vertical profile, irrigation and fertilization had positive effects on concentrations of SOC and TN of top soil layers, and the interaction between irrigation and fertilization extended the effect to deeper soil layers. Our results indicate that moderate irrigation and fertilization can help to improve carbon storage and nutrient availability (TN) in small-scale farming soils in Africa.

  • 25.
    Alavaisha, Edmond
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Dar es Salaam, Tanzania.
    Mbande, Victor
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Börjeson, Lowe
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Effects of land use change related to small-scale irrigation schemes in Kilombero wetland, TanzaniaManuscript (preprint) (Other academic)
  • 26.
    Alavaisha, Edmond
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. University of Dar es Salaam, Tanzania.
    Mbande, Victor
    Stockholm University, Faculty of Social Sciences, Department of Human Geography. Mwalimu Nyerere Memorial Academy, Tanzania.
    Börjeson, Lowe
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Lindborg, Regina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Effects of Land Use Change Related to Small-Scale Irrigation Schemes in Kilombero Wetland, Tanzania2021In: Frontiers in Environmental Science, E-ISSN 2296-665X, Vol. 9, article id 611686Article in journal (Refereed)
    Abstract [en]

    Increasing agricultural land use intensity is one of the major land use/land cover (LULC) changes in wetland ecosystems. LULC changes have major impacts on the environment, livelihoods and nature conservation. In this study, we evaluate the impacts of investments in small-scale irrigation schemes on LULC in relation to regional development in Kilombero Valley, Tanzania. We used Remote Sensing (RS) and Geographical Information System (GIS) techniques together with interviews with Key Informants (KI) and Focus Group Discussion (FGD) with different stakeholders to assess the historical development of irrigation schemes and LULC change at local and regional scales over 3 decades. Overall, LULC differed over time and with spatial scale. The main transformation along irrigation schemes was from grassland and bushland into cultivated land. A similar pattern was also found at the regional valley scale, but here transformations from forest were more common. The rate of expansion of cultivated land was also higher where investments in irrigation infrastructure were made than in the wider valley landscape. While discussing the effects of irrigation and intensification on LULC in the valley, the KI and FGD participants expressed that local investments in intensification and smallholder irrigation may reduce pressure on natural land cover such as forest being transformed into cultivation. Such a pattern of spatially concentrated intensification of land use may provide an opportunity for nature conservation in the valley and likewise contribute positively to increased production and improve livelihoods of smallholder farmers.

  • 27.
    Alavimoghaddam, Mohammadreza
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Assessing the ability of HEC-HMS rainfall-runoff model to simulate stream flow across Sweden2017Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Computer modeling is the powerful tool for simulating nature’s behavior; however, still more efforts are need for reaching perfect simulation with computer models (especially in the hydrological field of study). In this Master’s thesis, the accuracy of the HEC-HMS computer model for long term rainfall-runoff simulation was evaluated across Sweden. Five different catchments from north to south of Sweden were selected and then simulation have done for 34 years of available data. Simulation was conducted using daily, monthly and yearly time scale resolutions. Results from the north to the south of Sweden were completely different. Simulated runoff and observed runoff in northern catchments followed the same pattern over different time scales but in the southern part of Sweden the results had different patterns in space and time. The best results with HEC-HMS were found in the northern catchments with steep main river slopes. In the southern catchments the model could not predict runoff in any realistic manner at any time and space scale. In total the HEC-HMS model cannot simulate the rainfall runoff for long periods of simulation across Sweden. This is especially true in southern parts of the country dominate with low elevation catchments. However, with regards to its ability for event-based simulation HEC-HMS could be a suitable tool to simulate flood event discharges that are needed for road or other hydraulic structures designs. But, this would require significant amounts of calibration and model development.

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  • 28. Albert, Aurélie
    et al.
    Auffret, Alistair G.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Cosyns, Eric
    Cousins, Sara A. O.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    D'hondt, Bram
    Eichberg, Carsten
    Eycott, Amy E.
    Heinken, Thilo
    Hoffmann, Maurice
    Jaroszewicz, Bogdan
    Malo, Juan E.
    Mårell, Anders
    Mouissie, Maarten
    Pakeman, Robin J.
    Picard, Mélanie
    Plue, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Poschlod, Peter
    Provoost, Sam
    Schulze, Kiowa Alraune
    Baltzinger, Christophe
    Seed dispersal by ungulates as an ecological filter: a trait-based meta-analysis2015In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 124, no 9, p. 1109-1120Article in journal (Refereed)
    Abstract [en]

    Plant communities are often dispersal-limited and zoochory can be an efficient mechanism for plants to colonize new patches of potentially suitable habitat. We predicted that seed dispersal by ungulates acts as an ecological filter - which differentially affects individuals according to their characteristics and shapes species assemblages - and that the filter varies according to the dispersal mechanism (endozoochory, fur-epizoochory and hoof-epizoochory). We conducted two-step individual participant data meta-analyses of 52 studies on plant dispersal by ungulates in fragmented landscapes, comparing eight plant traits and two habitat indicators between dispersed and non-dispersed plants. We found that ungulates dispersed at least 44% of the available plant species. Moreover, some plant traits and habitat indicators increased the likelihood for plant of being dispersed. Persistent or nitrophilous plant species from open habitats or bearing dry or elongated diaspores were more likely to be dispersed by ungulates, whatever the dispersal mechanism. In addition, endozoochory was more likely for diaspores bearing elongated appendages whereas epizoochory was more likely for diaspores released relatively high in vegetation. Hoof-epizoochory was more likely for light diaspores without hooked appendages. Fur-epizoochory was more likely for diaspores with appendages, particularly elongated or hooked ones. We thus observed a gradient of filtering effect among the three dispersal mechanisms. Endozoochory had an effect of rather weak intensity (impacting six plant characteristics with variations between ungulate-dispersed and non-dispersed plant species mostly below 25%), whereas hoof-epizoochory had a stronger effect (eight characteristics included five ones with above 75% variation), and fur-epizoochory an even stronger one (nine characteristics included six ones with above 75% variation). Our results demonstrate that seed dispersal by ungulates is an ecological filter whose intensity varies according to the dispersal mechanism considered. Ungulates can thus play a key role in plant community dynamics and have implications for plant spatial distribution patterns at multiple scales.

  • 29. Albert, James S.
    et al.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Duke-Sylvester, Scott M.
    Magurran, Anne E.
    Oberdorff, Thierry
    Reis, Roberto E.
    Winemiller, Kirk O.
    Ripple, William J.
    Scientists' warning to humanity on the freshwater biodiversity crisis2021In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 50, p. 85-94Article in journal (Refereed)
    Abstract [en]

    Freshwater ecosystems provide irreplaceable services for both nature and society. The quality and quantity of freshwater affect biogeochemical processes and ecological dynamics that determine biodiversity, ecosystem productivity, and human health and welfare at local, regional and global scales. Freshwater ecosystems and their associated riparian habitats are amongst the most biologically diverse on Earth, and have inestimable economic, health, cultural, scientific and educational values. Yet human impacts to lakes, rivers, streams, wetlands and groundwater are dramatically reducing biodiversity and robbing critical natural resources and services from current and future generations. Freshwater biodiversity is declining rapidly on every continent and in every major river basin on Earth, and this degradation is occurring more rapidly than in terrestrial ecosystems. Currently, about one third of all global freshwater discharges pass through human agricultural, industrial or urban infrastructure. About one fifth of the Earth's arable land is now already equipped for irrigation, including all the most productive lands, and this proportion is projected to surpass one third by midcentury to feed the rapidly expanding populations of humans and commensal species, especially poultry and ruminant livestock. Less than one fifth of the world's preindustrial freshwater wetlands remain, and this proportion is projected to decline to under one tenth by midcentury, with imminent threats from water transfer megaprojects in Brazil and India, and coastal wetland drainage megaprojects in China. The Living Planet Index for freshwater vertebrate populations has declined to just one third that of 1970, and is projected to sink below one fifth by midcentury. A linear model of global economic expansion yields the chilling prediction that human utilization of critical freshwater resources will approach one half of the Earth's total capacity by midcentury. Although the magnitude and growth of the human freshwater footprint are greater than is generally understood by policy makers, the news media, or the general public, slowing and reversing dramatic losses of freshwater species and ecosystems is still possible. We recommend a set of urgent policy actions that promote clean water, conserve watershed services, and restore freshwater ecosystems and their vital services. Effective management of freshwater resources and ecosystems must be ranked amongst humanity's highest priorities.

  • 30. Alborzi, Aneseh
    et al.
    Mirchi, Ali
    Moftakhari, Hamed
    Mallakpour, Iman
    Alian, Sara
    Nazemi, Ali
    Hassanzadeh, Elmira
    Mazdiyasni, Omid
    Ashraf, Samaneh
    Madani, Kaveh
    Stockholm University, Faculty of Science, Department of Physical Geography. Imperial College London, United Kingdom.
    Norouzi, Hamid
    Azarderakhsh, Marzi
    Mehran, Ali
    Sadegh, Mojtaba
    Castelletti, Andrea
    AghaKouchak, Amir
    Climate-informed environmental inflows to revive a drying lake facing meteorological and anthropogenic droughts2018In: Environmental Research Letters, E-ISSN 1748-9326, Vol. 13, no 8, article id 084010Article in journal (Refereed)
    Abstract [en]

    The rapid shrinkage of Lake Urmia, one of the world's largest saline lakes located in northwestern Iran, is a tragic wake-up call to revisit the principles of water resources management based on the socio-economic and environmental dimensions of sustainable development. The overarching goal of this paper is to set a framework for deriving dynamic, climate-informed environmental inflows for drying lakes considering both meteorological/climatic and anthropogenic conditions. We report on the compounding effects of meteorological drought and unsustainable water resource management that contributed to Lake Urmia's contemporary environmental catastrophe. Using rich datasets of hydrologic attributes, water demands and withdrawals, as well as water management infrastructure (i.e. reservoir capacity and operating policies), we provide a quantitative assessment of the basin's water resources, demonstrating that Lake Urmia reached a tipping point in the early 2000s. The lake level failed to rebound to its designated ecological threshold (1274 m above sea level) during a relatively normal hydro-period immediately after the drought of record (1998-2002). The collapse was caused by a marked overshoot of the basin's hydrologic capacity due to growing anthropogenic drought in the face of extreme climatological stressors. We offer a dynamic environmental inflow plan for different climate conditions (dry, wet and near normal), combined with three representative water withdrawal scenarios. Assuming effective implementation of the proposed 40% reduction in the current water withdrawals, the required environmental inflows range from 2900 million cubic meters per year (mcm yr(-1)) during dry conditions to 5400 mcm yr(-1) during wet periods with the average being 4100 mcm yr(-1). Finally, for different environmental inflow scenarios, we estimate the expected recovery time for re-establishing the ecological level of Lake Urmia.

  • 31.
    Aldén, Nina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Potential for mitigating GHG emissions at a Swedish wastewater treatment plant – a life cycle approach2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To meet the national and international climate goals every potential GHG mitigating effort needs to be addressed. The aim of this thesis is to investigate if the wastewater treatment plant (WWTP), Ekebyhov, can reduce its GHG emissions by making changes inthe treatmentprocess. The main GHGs emitted from WWT areN2O, CH4and CO2. To begin with, Ekebyhov’scurrent carbon footprintwas calculated in a base line scenario, using a calculation tool (ECT). The results showed that the total footprintamounted to 522 tons CO2eqper year, with the majority of the emissions (83 %) from the activated sludge process. Five GHG-mitigating measures were identified and potential GHG emission reduction (PGER) was calculated from 1) optimized WWT, 2) urea treated sludge, 3) change of chemicals, 4) green transports and 5) added anaerobic digestion (AD) process. The largest PGER came from added AD, followed by optimized WWT. Finally, the PGER for all measures was calculated and resulted in net negative emissions of -95 tons CO2eq per year. The thesis shows that it is possible to reduce the carbon footprint of Ekebyhov WWTP, even to a net negative result. It is, however important to address other impact categories in a full LCA to be able to make fully informed decisions.

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  • 32. Alexanderson, Helena
    et al.
    Hättestrand, Martina
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Lindqvist, Mimmi A.
    Sigfúsdóttir, Thorbjörg
    MIS 3 age of the Veiki moraine in N Sweden – Dating the landform record of an intermediate-sized ice sheet in Scandinavia2022In: Arctic, Antarctic and Alpine research, ISSN 1523-0430, E-ISSN 1938-4246, Vol. 54, no 1, p. 239-261Article in journal (Refereed)
    Abstract [en]

    The Veiki moraine in northern Sweden, a geomorphologically distinct landscape of ice-walled lake plains, has been interpreted to represent the former margin of an intermediate-sized pre–Last Glacial Maximum (LGM) Fennoscandian ice sheet, but its age is debated as either marine isotope stage (MIS) 5c or MIS 3. We have applied optically stimulated luminescence (OSL) and radiocarbon dating to four sites within the northern part of the Veiki moraine to establish its chronology. The radiocarbon ages provide only minimum ages and most OSL ages have low precision due to poor luminescence characteristics and problems with incomplete bleaching, leading to two alternative ages. In either case, the OSL dating places the Veiki moraine formation in MIS 3 (best estimate 56–39 ka). Sedimentation continued in the low-lying centers of some plateaus (ice-walled lake plains) during MIS 3 and during the Holocene, with a break during the Last Glacial Maximum when the area was ice covered. We speculatively constrain the broad timing further by relating the sequence of events to other climate records. We suggest that ice margin retreat to the west of the Veiki area took place during Greenland Interstadial (GI) 16.1 (58.0–56.5 ka) and that limited ice advances, which led to debris-covered ice margins in the Veiki zone, occurred during the following stadials GS-16.1 to 15.1 (56.5–54.2 ka). The GI-14 interstadial, which began 54.2 ka and lasted ~5.9 ka, could then be the period when the ice within the dead-ice landscape melted, first leading to ice-walled lakes and later to the inversed topography characteristic of the Veiki landscape. 

  • 33. Alfredsson, H.
    et al.
    Clymans, W.
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kuhry, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Conley, D. J.
    Estimated storage of amorphous silica in soils of the circum-Arctic tundra region2016In: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 30, no 3, p. 479-500Article in journal (Refereed)
    Abstract [en]

    We investigated the vertical distribution, storage, landscape partitioning, and spatial variability of soil amorphous silica (ASi) at four different sites underlain by continuous permafrost and representative of mountainous and lowland tundra, in the circum-Arctic region. Based on a larger set of data, we present the first estimate of the ASi soil reservoir (0-1m depth) in circum-Arctic tundra terrain. At all sites, the vertical distribution of ASi concentrations followed the pattern of either (1) declining concentrations with depth (most common) or (2) increasing/maximum concentrations with depth. Our results suggest that a set of processes, including biological control, solifluction and other slope processes, cryoturbation, and formation of inorganic precipitates influence vertical distributions of ASi in permafrost terrain, with the capacity to retain stored ASi on millennial timescales. At the four study sites, areal ASi storage (0-1m) is generally higher in graminoid tundra compared to wetlands. Our circum-Arctic upscaling estimates, based on both vegetation and soil classification separately, suggest a storage amounting to 219 +/- 28 and 274 +/- 33 Tmol Si, respectively, of which at least 30% is stored in permafrost. This estimate would account for about 3% of the global soil ASi storage while occupying an equal portion of the global land area. This result does not support the hypothesis that the circum-Arctic tundra soil ASi reservoir contains relatively higher amounts of ASi than other biomes globally as demonstrated for carbon. Nevertheless, climate warming has the potential to significantly alter ASi storage and terrestrial Si cycling in the Arctic.

  • 34. Alfredsson, Hanna
    et al.
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Clymans, Wim
    Stadmark, Johanna
    Kuhry, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Conley, Daniel J.
    Amorphous silica pools in permafrost soils of the Central Canadian Arctic and the potential impact of climate change2015In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 124, no 1-3, p. 441-459Article in journal (Refereed)
    Abstract [en]

    We investigated the distribution, storage and landscape partitioning of soil amorphous silica (ASi) in a central Canadian region dominated by tundra and peatlands to provide a first estimate of the amount of ASi stored in Arctic permafrost ecosystems. We hypothesize that, similar to soil organic matter, Arctic soils store large amounts of ASi which may be affected by projected climate changes and associated changes in permafrost regimes. Average soil ASi storage (top 1 m) ranged between 9600 and 83,500 kg SiO2 ha(-1) among different land-cover types. Lichen tundra contained the lowest amounts of ASi while no significant differences were found in ASi storage among other land-cover types. Clear differences were observed between ASi storage allocated into the top organic versus the mineral horizon of soils. Bog peatlands, fen peatlands and wet shrub tundra stored between 7090 and 45,400 kg SiO2 ha(-1) in the top organic horizon, while the corresponding storage in lichen tundra, moist shrub- and dry shrub tundra only amounted to 1500-1760 kg SiO2 ha(-1). Diatoms and phytoliths are important components of ASi storage in the top organic horizon of peatlands and shrub tundra systems, while it appears to be a negligible component of ASi storage in the mineral horizon of shrub tundra classes. ASi concentrations decrease with depth in the soil profile for fen peatlands and all shrub tundra classes, suggesting recycling of ASi, whereas bog peatlands appeared to act as sinks retaining stored ASi on millennial time scales. Our results provide a conceptual framework to assess the potential effects of climate change impacts on terrestrial Si cycling in the Arctic. We believe that ASi stored in peatlands are particularly sensitive to climate change, because a larger fraction of the ASi pool is stored in perennially frozen ground compared to shrub tundra systems. A likely outcome of climate warming and permafrost thaw could be mobilization of previously frozen ASi, altered soil storage of biogenically derived ASi and an increased Si flux to the Arctic Ocean.

  • 35. Aliabad, Fahime Arabi
    et al.
    Malamiri, Hamid Reza Ghafarian
    Shojaei, Saeed
    Sarsangi, Alireza
    Santos Ferreira, Carla Sofia
    Stockholm University, Faculty of Science, Department of Physical Geography. Agrarian School of Coimbra, Portugal.
    Kalantari, Zahra
    Stockholm University, Faculty of Science, Department of Physical Geography. KTH Royal Institute of Technology, Sweden.
    Investigating the Ability to Identify New Constructions in Urban Areas Using Images from Unmanned Aerial Vehicles, Google Earth, and Sentinel-22022In: Remote Sensing, E-ISSN 2072-4292, Vol. 14, no 13, article id 3227Article in journal (Refereed)
    Abstract [en]

    One of the main problems in developing countries is unplanned urban growth and land use change. Timely identification of new constructions can be a good solution to mitigate some environmental and social problems. This study examined the possibility of identifying new constructions in urban areas using images from unmanned aerial vehicles (UAV), Google Earth and Sentinel-2. The accuracy of the land cover map obtained using these images was investigated using pixel-based processing methods (maximum likelihood, minimum distance, Mahalanobis, spectral angle mapping (SAM)) and object-based methods (Bayes, support vector machine (SVM), K-nearest-neighbor (KNN), decision tree, random forest). The use of DSM to increase the accuracy of classification of UAV images and the use of NDVI to identify vegetation in Sentinel-2 images were also investigated. The object-based KNN method was found to have the greatest accuracy in classifying UAV images (kappa coefficient = 0.93), and the use of DSM increased the classification accuracy by 4%. Evaluations of the accuracy of Google Earth images showed that KNN was also the best method for preparing a land cover map using these images (kappa coefficient = 0.83). The KNN and SVM methods showed the highest accuracy in preparing land cover maps using Sentinel-2 images (kappa coefficient = 0.87 and 0.85, respectively). The accuracy of classification was not increased when using NDVI due to the small percentage of vegetation cover in the study area. On examining the advantages and disadvantages of the different methods, a novel method for identifying new rural constructions was devised. This method uses only one UAV imaging per year to determine the exact position of urban areas with no constructions and then examines spectral changes in related Sentinel-2 pixels that might indicate new constructions in these areas. On-site observations confirmed the accuracy of this method.

  • 36. Aliabad, Fahime Arabi
    et al.
    Shojaei, Saeed
    Mortaz, Morad
    Santos Ferreira, Carla Sofia
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI). Polytechnic Institute of Coimbra, Portugal.
    Kalantari, Zahra
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI). KTH Royal Institute of Technology, Sweden.
    Use of Landsat 8 and UAV Images to Assess Changes in Temperature and Evapotranspiration by Economic Trees following Foliar Spraying with Light-Reflecting Compounds2022In: Remote Sensing, E-ISSN 2072-4292, Vol. 14, no 23, article id 6153Article in journal (Refereed)
    Abstract [en]

    Pistachio is an important economic crop in arid and semi-arid regions of Iran. A major problem leading to a reduction in crop quality and reduced marketability is extreme air temperature in summer, which causes sunburn of pistachio leaves and fruit. A solution proposed to deal with the negative effects of high temperatures and increase water consumption efficiency in pistachio orchards is use of light-reflecting compounds. This study investigated the effect of foliar application of gypsum, sulfur, and NAX-95 (calcium-based suspension coating) to trees in a pistachio orchard (150 ha) in central Iran. The effect of these foliar products is assessed at plot scale, using control plots sprayed with calcium sulfate, based on temperature and evapotranspiration changes analyzed through remote sensing. Landsat 8 sensor images and RGB images collected by UAVs (spatial resolution of 30 m and 20 cm, respectively), on the same dates, before and after foliar spray application, were merged using the PCA method and bilinear interpolation re-sampling. Land surface temperature (LST) was then estimated using the split-window algorithm, and daily evapotranspiration using the surface energy balance algorithm for land (SEBAL) algorithm. A land use map was prepared and used to isolate pistachio trees in the field and assess weed cover, whose effect was not accounted. The results showed that temperature remained constant in the control plot between the spraying dates, indicating no environmental changes. In the main plots, gypsum had the greatest effect in reducing the temperature of pistachio trees. The plots with foliar spraying with gypsum displayed a mean tree temperature (47–48 °C) decrease of 3.3 °C in comparison with the control plots (>49 °C), leading to an average decline in evapotranspiration of 0.18 mm/day. NAX-95 and sulfur reduced tree temperature by on average 1.3 °C and 0.6 °C, respectively. Thus, gypsum is the most suitable foliar-spraying compound to lower the temperature of pistachio trees, reduce the water requirement, and increase crop productivity.

  • 37.
    Allègre, Xavier
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Different generation of controlled moraines in the glacier foreland of Midtdalsbreen, Norway2018Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    A series of small mounds (< 3m) were sampled in the foreland of Midtdalsbreen outlet glacier, southern Norway. These landforms were interesting, especially at site number 1 because they were located very close to a higher Little Ice Age (LIA) moraine (> 5 m), thereby informing the dynamic of the glacier after the LIA at this location. It was yet to determine if these specific mounds are controlled moraines. If they are controlled moraines, then this would have implication for the glacier dynamics and the geometry of the snout after the LIA. It could be determined, based on the landform record evidence, whether the ice at the snout of Midtdalsbreen was thin and cold shortly after the LIA. Furthermore, whether the landscape was deglaciated by downwasting and then by backwasting was the main question addressed in relation to the nature of the mound and the thickness of ice at the snout during and after the LIA. In order to better understand the nature of the landform record and the mounds near the LIA moraine, satellite imagery coupled with careful field investigations were used in the foreland of the Midtdalsbreen outlet glacier. A geomorphological map was produced, and it was useful to put the mounds in a geographical context. Further sedimentological investigation; including clast-shape analyze, produced more evidence about the inner nature of these landforms. Both few controlled moraines and other landforms throughout the glacier foreland indicate that the ice geometry for Midtdalsbreen, shortly after the LIA was such that the snout of the glacier was a thin sheet of ice flowing against the previously deposited LIA moraine. The sedimentology of the controlled moraine is such that the sediments are deposited in steeply dipping layers, and they could even be misinterpreted as permafrost terrains at first glimpse. However, other sedimentological evidences such as the presence of sorted sand and sometimes dipping beds of gravels in addition to the geomorphological mapping make it meaningful to interpret few of the mounds as controlled moraines. A modern analogue to these controlled moraines is dirt cones present on top of the glacier snout as well as controlled moraines a few hundred of meter from the snout. Observations both on the glacier snout and on the foreland involve that dirt-cones later evolve into these sedimentological hummocky units with steeply dipping layers within the paleo-landscape. These observations constrain the thickness of ice at the snout of Midtdalsbreen after the LIA as well as the glacier dynamic during its melt: for controlled moraines to be generated by glaciers, these accumulations of sediments would have to thaw by downwasting and then by backwasting, directly at the glacier snout. This process -comprising of different stages- allows enough time to deposit controlled moraine. It is then a thin, cold-based sheet of ice which is by the end responsible for the deposition of such a landform record. There was even dead-ice present on the landscape at that point. After deposition of dirt cones on top of the ice, important meltwater action is contributing to the glacifluvial origin of these hummocks which evolve from dirt-cones onto the glacier, to ice-cored moraines, and then to controlled moraines onto the foreland. Details about the multistage processes leading to the formation of controlled moraines is also at the center of the investigations.

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  • 38.
    Alm, Klara
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Inventering av skred genom jämförelse av två generationer LiDAR-genererad höjddata2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Landslides are a natural hazard that is expected to increase in the future, due to climate change. In order to keep risk management plans up to date, an efficient inventory method is needed. In previous studies, multi-temporal high-resolution digital elevation models (DEM) produced with LiDAR technology have been used successfully for landslide inventory and monitoring in different parts of the world. The aim of this study has been to discover an inventory method for landslides in Sweden, using two generations of elevation data produced with LiDAR. The analysis was performed in GIS with the creation of a DEM of difference (DoD) and visual comparison as key components. The sites were also verified using Google Earth satellite imagery and aerial photos. The result of the study shows that a functional, efficient method was developed and several potential landslides were found in the three different study areas. The soil characteristics, slope gradient and distance to areas affected by forestry were recorded for all potential landslide sites. Using multi-temporal DEM for landslide inventory is time- and cost efficient, and the results are more accurate compared to traditional inventory techniques. Hopefully the method developed in this study can be used on a larger scale and lead to updated risk management and prevention plans throughout all risk areas for landslides in Sweden. In future studies field work is recommended to verify the potential landslide sites.

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  • 39.
    Althoff, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    Global patterns in water flux partitioning: Irrigated and rainfed agriculture drives asymmetrical flux to vegetation over runoff2023In: One Earth, ISSN 2590-3330, E-ISSN 2590-3322, Vol. 6, no 9, p. 1246-1257Article in journal (Refereed)
    Abstract [en]

    The partitioning of precipitation water input on land between green (evapotranspiration) and blue (runoff) water fluxes distributes the annually renewable freshwater resource among sectors and ecosystems. The patterns and main drivers of this partitioning are not fully understood around the global land area. We decipher the worldwide patterns and key determinants of this water flux partitioning and investigate its predictability based on a global machine learning model. Available data for 3,614 hydrological catchments and model application to the global land area agree in showing mostly larger green than blue water flux. Possible expansion/intensification of irrigated and/or rainfed agriculture to feed a growing human population, along with climate warming, will tend to increase this flux partitioning asymmetry, jeopardizing blue water security. The developed machine learning model presents a promising predictive tool for future blue and green water availability under various forthcoming climate and land-use change scenarios around the world.

  • 40. Ameli, Ali A.
    et al.
    Beven, Keith
    Erlandsson, Martin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Creed, Irena F.
    McDonnell, Jeffrey J.
    Bishop, Kevin
    Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone2017In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 53, no 1, p. 942-960Article in journal (Refereed)
    Abstract [en]

    The permeability architecture of the critical zone exerts a major influence on the hydrogeochemistry of the critical zone. Water flow path dynamics drive the spatiotemporal pattern of geochemical evolution and resulting streamflow concentration-discharge (C-Q) relation, but these flow paths are complex and difficult to map quantitatively. Here we couple a new integrated flow and particle tracking transport model with a general reversible Transition State Theory style dissolution rate law to explore theoretically how C-Q relations and concentration in the critical zone respond to decline in saturated hydraulic conductivity (K-s) with soil depth. We do this for a range of flow rates and mineral reaction kinetics. Our results show that for minerals with a high ratio of equilibrium concentration ( Ceq) to intrinsic weathering rate ( Rmax), vertical heterogeneity in K-s enhances the gradient of weathering-derived solute concentration in the critical zone and strengthens the inverse stream C-Q relation. As <mml:mfrac>CeqRmax</mml:mfrac> decreases, the spatial distribution of concentration in the critical zone becomes more uniform for a wide range of flow rates, and stream C-Q relation approaches chemostatic behavior, regardless of the degree of vertical heterogeneity in K-s. These findings suggest that the transport-controlled mechanisms in the hillslope can lead to chemostatic C-Q relations in the stream while the hillslope surface reaction-controlled mechanisms are associated with an inverse stream C-Q relation. In addition, as <mml:mfrac>CeqRmax</mml:mfrac> decreases, the concentration in the critical zone and stream become less dependent on groundwater age (or transit time).

  • 41.
    Aminjafari, Saeid
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Monitoring Water Availability in Northern Inland Waters from Space2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    River deltas and lakes support biodiversity and offer crucial ecosystem services such as freshwater provision, flood control, and fishing. However, climate change and human activities have affected deltas and lakes globally, altering the services they provide. Since delta and lake surface water occurrence and water levels respond to climate change and anthropogenic activities, we need to monitor their variations to understand the potential drivers for effective water management strategies. However, important deltas like the Selenga River Delta (SRD) in Russia lack a detailed analysis of water occurrence. Regarding lake water level, there has been a decline in the number of gauging stations globally, due to installation and maintenance costs. For example, Sweden has ~100,000 lakes which are sources of freshwater and hydro-power, but only 38 lakes have long and continuous in-situ records of water level.

    As satellite data are reliable alternatives for conventional methods to monitor deltas and lakes, I employed Earth Observations (EO) to quantify changes in surface water occurrence in the SRD and water levels in Swedish lakes and identify their main drivers. I also developed and explored a novel methodology for lake water level estimation based on Differential Interferometric Synthetic Aperture Radar (D-InSAR) by calculating the six-day phase differences in 30 Swedish lakes.

    To achieve these objectives, I trained and applied a Maximum Likelihood classification to Landsat images from 1987 to 2020 and quantified surface water occurrence and its changes in the SRD. I found that surface water occurrence in 51% of the delta experienced a decrease. As the Selenga River is the only river flowing into the SRD, the change in surface water occurrence in the SRD correlated with river discharge, but not with the river suspended sediment concentration, the lake water level in the outlet of the SRD, or evapotranspiration over the delta.

    In Sweden, I used satellite altimetry data from ERS-2, ENVISAT, JASON-1,2,3, SARAL, and Sentinel-3A/B to quantify water levels in 144 lakes from 1995-2022. I found that 52% of the lakes showed increasing trends (mostly in the north) and 43% decreasing trends (mostly in the south). Water level trends and variabilities did not correlate strongly with hydroclimatic changes (precipitation and temperature) but differed in regulated lakes compared to unregulated ones, both in the north and in the south of Sweden.

    The results of the D-InSAR method for water level estimation in two Swedish lakes (Hjälmaren and Solnen) showed that with water level changes smaller than a complete SAR phase, the phase changes correlate with in-situ water level changes with a minimum Root Mean Square Error of 0.43 cm in some pixels. In all 30 lakes, I accumulated the phase changes of each pixel throughout the whole number of interferograms to construct water levels. This method replicated the direction of water level changes shown by high Pearson’s correlations in at least one pixel in each lake.

    This thesis highlights the importance of EO for estimating surface water occurrence and lake water levels and brings focus to the future of EO through advanced space missions such as Surface Water and Ocean Topography (SWOT) and NASA-ISRO Synthetic Aperture Radar (NISAR). The findings underscore the need to continuously monitor lake water level and occurrence to adapt to climate change and understand the effects of water-regulatory schemes.

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  • 42.
    Aminjafari, Saeid
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Brown, Ian
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Chalov, Sergey
    Simard, Marc
    Lane, Charles R.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Darvishi, Mehdi
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre. Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Drivers and extent of surface water occurrence in the Selenga River Delta, Russia2021In: Journal of Hydrology: Regional Studies, E-ISSN 2214-5818, Vol. 38, article id 100945Article in journal (Refereed)
    Abstract [en]

    Study region: Selenga River Delta (SRD), Russia.

    Study focus: How is water occurrence changing in the SRD, and what are the hydroclimatic drivers behind these changes? The presence of water on the surface in river deltas is governed by land use, geomorphology, and the flux of water to and from the Delta. We trained an accurate image classification of the Landsat satellite imagery during the last 33 years to quantify surface water occurrence and its changes in the SRD. After comparing our estimations with global-scale data sets, we determined the hydrological drivers of these changes.

    New hydrological insights for the region: We find mild decreases in water occurrence in 51% of the SRD's surface area from 1987-2002 to 2003-2020. Water occurrence in the most affected areas decreased by 20% and in the most water-gaining areas increased by 10%. We find a significant relationship between water occurrence and runoff (R-2 = 0.56) that does not exist between water occurrence and suspended sediment concentration (SSC), Lake Baikal's water level, and potential evapotranspiration. The time series of water occurrence follows the peaks in the runoff but not its long-term trend. However, the extremes in SSC do not influence surface water occurrence (R-2 < 0.1), although their long-term trends are similar. Contrary to expected, we find that the Delta has a relatively stable long-term water availability for the time being.

  • 43.
    Aminjafari, Saeid
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Brown, Ian
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Frappart, Frédéric
    ISPA, INRAE/Bordeaux Sciences Agro.
    Papa, Fabrice
    LEGOS, Université de Toulouse.
    Blarel, Fabien
    LEGOS, Université de Toulouse.
    Farzad, Vahidi Mayamey
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre. Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    Assessing the Effects of Regulation on Swedish Lake Water Levels with Satellite AltimetryManuscript (preprint) (Other academic)
    Abstract [en]

    Lakes are important sources of freshwater for human activities and provide critical ecosystem services. However, despite having approximately 100,000 lakes, Sweden has limited continuous gauged water level data. Although satellite radar altimetry has emerged as a popular alternative to measure water levels in inland water bodies, it is yet to be exploited to understand large-scale changes in inland water bodies in Sweden. Here, we quantify the changes in water levels of 144 lakes using satellite altimetry data and in-situ gauged measurements and examine the effects of flow regulation and hydroclimatic variability. Data from multiple altimetry missions, including ERS-2, ENVISAT, JASON-1,2,3, SARAL, and Sentinel-3A/B, are employed to estimate the variability and yearly and seasonal trends of water levels in two periods, 1995-2022 and 2013-2022. Our study finds that water levels significantly increased in 52% of the lakes during 1995-2022. The increasing trends primarily occurred in northern Sweden and are potentially attributed to earlier snowmelt. On the other hand, 43% of the lakes exhibited a significant decreasing trend, which was mostly concentrated in Southern Sweden. Dividing the set of lakes into regulated and unregulated groups shows how lake regulation in Sweden can partly explain the spatial patterns of water levels and their variability. This study highlights the need to continuously monitor lake water levels for adaptation strategies in the face of climate change and understand the downstream effects of water regulatory schemes.

  • 44.
    Aminjafari, Saeid
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Brown, Ian
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre. Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    Evaluating D-InSAR Performance to Detect Small Water Level Fluctuations in LakesManuscript (preprint) (Other academic)
    Abstract [en]

    It is essential to track lake water level fluctuations, however, the number of conventional gauging stations is declining worldwide due to impractical installation and maintenance procedures. Satellite altimetry is a substitute for traditional gauges. Nevertheless, altimetry sensors cannot identify small lakes owing to poor spatial coverage. Their application is limited to lakes falling exactly below the path of the altimeter. Differential Interferometric Synthetic Aperture Radar (D-InSAR) is commonly used to track land deformation and water surface changes, with the latter being comparatively limited and focused mainly on wetlands. We here explore the potential of D-InSAR to track water level changes in two Swedish lakes, focusing on the shoreline in search of potential double-bounce backscattering and analyzing pixel phase changes and coherence. We use Sentinel-1A and Sentinel-1B data from 2019, generate six-day interferograms, and exclude those when corresponding to in-situ water level changes exceeding one phase cycle. We find that D-InSAR is sensitive to minor water level changes, obtaining Lin's correlations of up to 0.63 and 0.89 (RMSE = 9 & 4 mm, respectively). These results evidence the potential of future L-band SAR missions with larger wavelengths, such as NISAR, to track water level changes in lakes and aid water tracking missions such as the SWOT.

  • 45.
    Aminjafari, Saeid
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Brown, Ian
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Vahidi Mayamey, Farzad
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography. Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre. Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    The Potential of D-InSAR for Water Level Estimation in Swedish LakesManuscript (preprint) (Other academic)
    Abstract [en]

    Lakes are valuable water resources that support aquatic and terrestrial ecosystems and supply fresh water for the agricultural, industrial, and urban sectors worldwide. Although water levels should be tracked to monitor these services, conventional gauging is unfeasible in most lakes. This study explores the potential, advantages, and limitations of using Differential Interferometric Synthetic Aperture Radar (D-InSAR) to estimate small water level changes in lakes (i.e., less than the full cycle of the SAR signal) and overall long-term direction of change. We validated the method across the shores of 30 Swedish lakes with gauged observations during 2019. We used Sentinel-1A/B images with a six-day temporal separation to construct consecutive interferograms and accumulated the phase changes in pixels of high coherence to build time series of water levels. We find that the accumulated phase change replicates the magnitude of water levels in seven lakes in Southern Sweden, where water level changes seldom exceed a complete SAR phase (i.e., 1.8 cm in the vertical direction), evident from the Concordance Correlation Coefficients (0.30 < CCC < 0.55). Furthermore, D-InSAR can estimate the long-term direction of water level change (i.e., increase or decrease) in all 30 lakes. We elaborate on the possible explanation for this last finding. The novel methodology could be used to validate future altimetry missions such as SWOT in lakes worldwide and can be improved with upcoming SAR missions with longer wavelengths.

  • 46. An, Wenling
    et al.
    Hou, Shugui
    Zhang, Qiong
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Zhang, Wangbin
    Wu, Shuangye
    Xu, Hao
    Pang, Hongxi
    Wang, Yetang
    Liu, Yaping
    Enhanced Recent Local Moisture Recycling on the Northwestern Tibetan Plateau Deduced From Ice Core Deuterium Excess Records2017In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 122, no 23, p. 12541-12556Article in journal (Refereed)
    Abstract [en]

    Local moisture recycling plays an essential role in maintaining an active hydrological cycle of the Tibetan Plateau (TP). Previous studies were largely limited to the seasonal time scale due to short and sparse observations, especially for the northwestern TP. In this study, we used a two-component mixing model to estimate local moisture recycling over the past decades from the deuterium excess records of two ice cores (i.e., Chongce and Zangser Kangri) from the northwestern TP. The results show that on average almost half of the precipitation on the northwestern TP is provided by local moisture recycling. In addition, the local moisture recycling ratio has increased evidently on the northwestern TP, suggesting an enhanced hydrological cycle. This recent increase could be due to the climatic and environmental changes on the TP in the past decades. Rapid increases in temperature and precipitation have enhanced evaporation. Changes of land surface of plateau have significantly increased evapotranspiration. All of these have intensified local moisture recycling. However, the mixing model used in this study only includes a limited number of climate factors. Some of the extreme values of moisture recycling ratio could be caused by large-scale atmospheric circulation and other climatic and weather events. Moreover, the potential mechanisms for the increase in local recycling need to be further examined, since the numeric simulations from climate models did not reproduce the increased contribution of local moisture recycling in precipitation.

  • 47. An, Yiming
    et al.
    Zhao, Wenwu
    Li, Changjia
    Santos Ferreira, Carla Sofia
    Stockholm University, Faculty of Science, Department of Physical Geography. Navarino Environmental Observatory, Greece.
    Temporal changes on soil conservation services in large basins across the world2022In: Catena (Cremlingen. Print), ISSN 0341-8162, E-ISSN 1872-6887, Vol. 209, article id 105793Article in journal (Refereed)
    Abstract [en]

    Soil erosion is one of the main drivers of land degradation across the world, thus soil conservation service has received increasing attention. Limited studies have focused on it, hence this study investigates spatial and temporal patterns on soil conservation service in four large representative basins globally (i.e., Amazon, Mississippi, Yangtze, and Yellow River Basins), between 2001 and 2018. Annual soil conservation service and soil erosion rate are estimated under RUSLE framework, and temporal trends are analyzed using Mann-Kendall test. Additionally, impacts of soil erosion factors on spatial distribution of soil conservation service are assessed through fitting stepwise regressions annually and calculating the factors' contributions. Furthermore, driving factors of temporal changes are identified as climate or land cover dominated, and combined effect of both, according to Z scores from Mann-Kendall test for soil conservation service, R and C factors. Results show the Yangtze River Basin produces the highest average annual erosion rate (mean values of 133.28 Mg ha(-1) yr(-1) in 2001 and 143.21 Mg ha(-1) yr(-1) in 2018) and average soil conservation service (mean values of 2663.57 Mg ha(-1) yr(-1) in 2001 and 3126.43 Mg ha(-1) yr(-1) in 2018). Amazon River Basin yields the lowest average annual soil erosion rate (15.96 Mg ha(-1) yr(-1) in 2001 and 21.30 Mg ha(-1) yr(-1) in 2018), whereas the Mississippi River Basin produces the lowest average soil conservation service (388.48 Mg ha(-1) yr(-1) in 2001 and 730.70 Mg ha(-1) yr(-1) in 2018). Over the study period, soil conservation service shows an increasing trend in the Yangtze and Yellow River Basins, with average changing rates of 27.23 Mg ha(-1) yr(-1) and 16.60 Mg ha(-1) yr(-1), respectively. Increasing soil conservation service is mainly driven by climate change (i.e., rainfall) and the combined effect of climate and land cover changes, but terrain conditions are the main spatial drivers.

  • 48. Anchukaitis, Kevin J.
    et al.
    Wilson, Rob
    Briffa, Keith R.
    Buntgen, Ulf
    Cook, Edward R.
    D'Arrigo, Rosanne
    Davi, Nicole
    Esper, Jan
    Frank, David
    Gunnarson, Björn E.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Hegerl, Gabi
    Helama, Samuli
    Klesse, Stefan
    Krusic, Paul J.
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden.
    Linderholm, Hans W.
    Myglan, Vladimir
    Osborn, Timothy J.
    Zhang, Peng
    Rydval, Milos
    Schneider, Lea
    Schurer, Andrew
    Wiles, Greg
    Zorita, Eduardo
    Last millennium Northern Hemisphere summer temperatures from tree rings: Part II, spatially resolved reconstructions2017In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 163, p. 1-22Article, review/survey (Refereed)
    Abstract [en]

    Climate field reconstructions from networks of tree-ring proxy data can be used to characterize regional scale climate changes, reveal spatial anomaly patterns associated with atmospheric circulation changes, radiative forcing, and large-scale modes of ocean-atmosphere variability, and provide spatiotemporal targets for climate model comparison and evaluation. Here we use a multiproxy network of tree-ring chronologies to reconstruct spatially resolved warm season (May August) mean temperatures across the extratropical Northern Hemisphere (40-90 degrees N) using Point-by-Point Regression (PPR). The resulting annual maps of temperature anomalies (750-1988 CE) reveal a consistent imprint of volcanism, with 96% of reconstructed grid points experiencing colder conditions following eruptions. Solar influences are detected at the bicentennial (de Vries) frequency, although at other time scales the influence of insolation variability is weak. Approximately 90% of reconstructed grid points show warmer temperatures during the Medieval Climate Anomaly when compared to the Little Ice Age, although the magnitude varies spatially across the hemisphere. Estimates of field reconstruction skill through time and over space can guide future temporal extension and spatial expansion of the proxy network.

  • 49.
    Anderberg, Niklas
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Betesmarker i Mjölkkrisens Sverige: Mjölkbönder och betesmarken, landskapet och framtiden2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The situation for Swedish dairy farmers has been difficult since 2014. Many are choosing to close down their businesses. At the same time, Sweden has experienced a reduction of important habitats consisting of grazing lands, a trend that is still ongoing. This study explores how dairy farmers look at grasslands, their values, management, and future. Through interviews with dairy farmers it investigates how farmers look at the systems of environmental compensation awarded for the management of pastures and grassland habitats. The study concludes that is primarily an aesthetic landscape value that is the main reason behind the desire to preserve pastures amongst farmers. This can be linked to a personal relationship between the farmers and the landscape he/she grew up in and help create through with their work. Any reduction in grasslands has not been observed by a majority of the interviewed farmers, despite the fact that such a reduction is occurring in their counties as a whole. This suggests that the situation can vary widely at a local level. The opinions concerning the environmental compensations vary among the interviewees, but overall there is a wish for a less bureaucratic system that provides more flexibility for the farmer. This wish for less bureaucracy is also found concerning the system around the law demanding that all cows should be allowed to graze during a period of the year. In the end, it seems important for the future of grazinglands and the habitats they create that profitability returns to the dairy farmers, since without farmers grazing will be further reduced. Today’s difficult situation for the farmers increases the risk of it being difficult to find the workforce of future farmers who are willing and able to perform the work that is done today.

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  • 50. Andersen, J. L.
    et al.
    Newall, Jennifer C.
    Stockholm University, Faculty of Science, Department of Physical Geography. Purdue University, USA.
    Blomdin, Robin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Sams, S. E.
    Fabel, D.
    Koester, A. J.
    Lifton, N. A.
    Fredin, O.
    Caffee, M. W.
    Glasser, Neil F.
    Rogozhina, I.
    Suganuma, Y.
    Harbor, Jonathan M.
    Stockholm University, Faculty of Science, Department of Physical Geography. Purdue University, USA; Purdue University Global, USA.
    Stroeven, Arjen P.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Ice surface changes during recent glacial cycles along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica2020In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 249, article id 106636Article in journal (Refereed)
    Abstract [en]

    Reconstructing past ice-sheet surface changes is key to testing and improving ice-sheet models. Data constraining the past behaviour of the East Antarctic Ice Sheet are sparse, limiting our understanding of its response to past, present and future climate change. Here, we report the first cosmogenic multinuclide (Be-10, Al-26, Cl-36) data from bedrock and erratics on nunataks along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica. Spanning elevations between 741 and 2394 m above sea level, the samples have apparent exposure ages between 2 ka and 5 Ma. The highest-elevation bedrock sample indicates (near-) continuous minimum exposure since the Pliocene, with a low apparent erosion rate of 0.15 +/- 0.03 m Ma(-1), which is similar to results from eastern Dronning Maud Land. In contrast to studies in eastern Dronning Maud Land, however, our data show clear indications of a thicker-than-present ice sheet within the last glacial cycle, with a thinning of similar to 35-120 m during the Holocene (similar to 2-11 ka). Difficulties in separating suitable amounts of quartz from the often quartz-poor rock-types in the area, and cosmogenic nuclides inherited from exposure prior to the last deglaciation, prevented robust thinning estimates from elevational profiles. Nevertheless, the results clearly demonstrate ice-surface fluctuations of several hundred meters between the current grounding line and the edge of the polar plateau for the last glacial cycle, a constraint that should be considered in future ice-sheet model simulations.

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