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  • 201. Brunet, Manola
    et al.
    Sigró, Javier
    Jones, Philip D.
    Saladié, Oscar
    Aguilar, Enric
    Moberg, Anders
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi.
    Lister, David
    Walther, Alexander
    Long-term changes in extreme temperatures and precipitation in Spain2007Inngår i: Contributions to Science: The International Journal of the Institute for Catalan Studies (IEC), ISSN 1575-6343, Vol. 3, nr 3, s. 331-342Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The development of the Spanish daily adjusted temperature

    series (SDATS) and the Spanish daily adjusted precipitation series

    (SDAPS) datasets in the framework of the European Community

    (EC)-funded project EMULATE (European and North Atlantic

    daily to MULtidecadal climATE variability) enabled the

    assessment of long-term annual changes of extreme temperature

    and precipitation indices over peninsular Spain for the period

    1901–2005. Within this framework, a set of procedures

    was developed to generate long-term (1850–2005) daily adjusted

    temperature and precipitation series and to use them to

    assess changes in climatic extremes. The present report describes

    details of the data employed to analyze the behavior of

    Spanish climate extremes and discusses the results of investigations

    into the annual changes in selected indices that occurred

    during the 20th century: exceedances of upper and lower

    percentiles of daily maximum (Tmax) and minimum (Tmin)

    temperatures, cold-spell duration index (CSDI), warm-spell duration

    index (WSDI), daily rainfall (R) exceeding the 95th and 99th

    percentiles, simple daily intensity index (SDII), and greatest 1–

    and 5-day total precipitation. Upper and lower temperature

    percentiles increased during the 20th century over mainland

    Spain, but changes in daytime extreme temperatures were

    larger than the changes in night-time extreme temperatures.

    This pattern, however, shifted slightly in the recent period of

    strong warming, with more similar rates of change among daytime

    and night-time extreme temperatures. Changes in extreme

    precipitation indices were not as evident as those in extreme-

    temperature indices, but there was a tendency towards

    heavier precipitation.

  • 202. Brázdil, Rudolf
    et al.
    Dobrovolný, Petr
    Luterbacher, Jürg
    Moberg, Anders
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Pfister, Christian
    Wheeler, Dennis
    Zorita, Eduardo
    European climate of the past 500 years: new challenges for historical climatology2010Inngår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 101, nr 1-2, s. 7-40Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Temperature reconstructions from Europe for the past 500 years basedon documentary and instrumental data are analysed. First, the basic documentarydata sources, including information about climate and weather-related extremes, aredescribed. Then, the standard palaeoclimatological reconstruction method adoptedhere is discussed with a particular application to temperature reconstructions fromdocumentary-based proxy data. The focus is on two new reconstructions; January–April mean temperatures for Stockholm (1502–2008), based on a combination ofdata for the sailing season in the Stockholm harbour and instrumental temperaturemeasurements, and monthly Central European temperature (CEuT) series (1500–2007) based on documentary-derived temperature indices of the Czech Republic,Germany and Switzerland combined with instrumental records from the samecountries. The two series, both of which are individually discussed in greater detail in subsequent papers in this special edition, are here compared and analysed usingrunning correlations and wavelet analysis. While the Stockholm series shows apronounced low-frequency component, the CEuT series indicates much weaker lowfrequencyvariations. Both series are analysed with respect to three different longperiodreconstructions of the North Atlantic Oscillation (NAO) and are comparedwith other European temperature reconstructions based on tree-rings, wine-harvestdata and various climate multiproxies. Correlation coefficients between individualproxy-based series show weaker correlations compared to the instrumental data.There are also indications of temporally varying temperature cross-correlationsbetween different areas of Europe. The two temperature reconstructions have alsobeen compared to geographically corresponding temperature output from simulationswith global and regional climate models for the past few centuries. The findingsare twofold: on the one hand, the analysis reinforces the hypothesis that the indexdatabased CEuT reconstruction may not appropriately reflect the centennial scalevariations. On the other hand, it is possible that climate models may underestimateregional decadal variability. By way of a conclusion, the results are discussed froma broader point of view and attention is drawn to some new challenges for futureinvestigations in the historical climatology in Europe.

  • 203. Bunce, R.G.H.
    et al.
    Metzger, M.J.
    Jongman, R.H.G.
    Brandt, J
    de Blust, G
    Elena-Rossello, R
    Groom, G.B.
    Halada, L
    Hofer, G
    Howard, D.C.
    Kovář, P.
    Mücher, C.A.
    Padoa-Schioppa, E
    Paelinx, D.
    Palo, A.
    Perez-Soba, M
    Ramos, I.L.
    Roche, P.
    Skånes, Helle
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi. Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi. Landskapsanalys och geomatik.
    Wrbka, T.
    A standardized procedure for surveillance and monitoring European habitats and provision of spatial data2007Inngår i: Landscape Ecology, ISSN 0921-2973 (Print) 1572-9761 (Online)Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Both science and policy require a practical, transmissible, and reproducible procedure for surveillance and monitoring of European habitats, which can produce statistics integrated at the landscape level. Over the last 30 years, landscape ecology has developed rapidly, and many studies now require spatial data on habitats. Without rigorous rules, changes from baseline records cannot be separated reliably from background noise. A procedure is described that satisfies these requirements and can provide consistent data for Europe, to support a range of policy initiatives and scientific projects. The methodology is based on classical plant life forms, used in biogeography since the nineteenth century, and on their statistical correlation with the primary environmental gradient. Further categories can therefore be identified for other continents to assist large scale comparisons and modelling. The model has been validated statistically and the recording procedure tested in the field throughout Europe. A total of 130 General Habitat Categories (GHCs) is defined. These are enhanced by recording environmental, site and management qualifiers to enable flexible database interrogation. The same categories are applied to areal, linear and point features to assist recording and subsequent interpretation at the landscape level. The distribution and change of landscape ecological parameters, such as connectivity and fragmentation, can then be derived and their significance interpreted.

  • 204.
    Burke, Jakob
    et al.
    Food and Agriculture Organization (FAO), Rome, Italy.
    Kuylenstierna, Johan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Paper 5: The Water Variable - Producing enough food in a climate insecure world2009Inngår i: Perspective papers on Water and Climate Change Adaptation, 5th World Water Forum , 2009Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    This paper serves as an input for the thematic, regional and political processes of the 5th WorldWater Forum and focuses on the challenges related to water, climate change and food security.Recent publications related to the anticipated impacts of climate change on water and agricultureare comprehensive, but a global analysis of specific impacts remains limited. The papersummarizes recent food production and food security trends and provides an overview of howclimate change, through impacts on global hydrology, could impact food production, and consequentlyfood security, in some key farming systems. However, as climate change is but oneof many drivers of agriculture, climate change impacts need to be appreciated in relation tospecific farming systems in order to identify appropriate adaptation measures. The paper highlightskey drivers and presents possible responses, emphasizing that the scope of policyresponse will need to be broad if water institutions are to be effective in coping with climatechange.

  • 205.
    Burström, Annika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Trends in mass balance indexes connected to spatial location and precipitation: Remote sensing of 111 glaciers in the Everest region2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Studies of Himalayan glacial response to climatic forcing are few and a more comprehensive understanding of the relationship between the two is needed. This has been highlighted by recent controversies over future glacier change in this area. This study has therefore reviewed if there is a connection between glacier mass balance indexes and precipitation pattern in the Everest region. 111 glaciers were mapped in ArcGIS through remote sensing. Glacial total area, accumulation area as well as snowline altitudes and aspect were mapped. From this, the two mass balance indexes Accumulation Area Ratio, AAR and Area-Altitude Balance Ratios, AABR were derived. The intention was to search for patterns.

    In addition to this, an expedition to parts of the study area was conducted in March to April 2011. Hundreds of photographs of snow stratigraphy, debris cover ice snouts, accumulation etc were taken. The expedition also led to an understanding of the environment and of the glaciers which was helpful for the assessment of the remote sensing results.

    No pattern in glacier size, ELA, AAR or AABR was found that suggests a connection between mass balance and local precipitation pattern. The glaciers instead appear to be more sensitive to elevation. The largest glaciers and highest AAR and AABR are found at high - although not the highest - elevations.

  • 206. Buylaert, J. -P
    et al.
    Murray, A. S.
    Gebhardt, A. C.
    Sohbati, R.
    Ohlendorf, C.
    Thiel, C.
    Wastegård, Stefan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Zolitschka, B.
    Luminescence dating of the PASADO core 5022-1D from Laguna Potrok Aike (Argentina) using IRSL signals from feldspar2013Inngår i: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 71, s. 70-80Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have measured and tested a luminescence chronology for the PASADO core 5022-1D from the maar lake of Laguna Potrok Aike. Because of unsuitable quartz OSL characteristics, sand-sized K-feldspar extracts were chosen as a dosimeter and the dose was measured using a post-IR IRSL (pIRIR(290)) measurement protocol. Using this approach we were able to access a stable signal and thus avoid the ubiquitous problem of feldspar signal instability. Extensive laboratory tests show that the chosen pIRIR(290) protocol is applicable to these samples. We also developed a new criterion based on known relative bleaching rates of the conventional IRSL signal (IR50) and the pIRIR(290) signal and the relationship between resulting equivalent doses; this is used to identify and reject poorly bleached samples. Eighteen samples out of 47 were rejected based on this criterion, without reference to absolute doses or stratigraphy; the resulting age-depth profile is self-consistent, increases smoothly with depth and is in agreement with independent age control based on volcanic ash layers (Reclus, Mt Burney and Hudson tephras) at the top and middle of the core. Our new luminescence chronology suggests that the 5022-1D core reaches back to similar to 65 ka at similar to 96 m below lake floor.

  • 207. Büntgen, U
    et al.
    Frank, DC.
    Grudd, H
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi.
    Esper, J
    Eight centuries of Pyrenees summer temperatures from tree-ring density2008Inngår i: Climate Dynamics, ISSN 0930-7575, Vol. 31, s. 615-631Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two hundred and sixty one newly measured tree-ring width and density series from living and dry-dead conifers from two timberline sites in the Spanish Pyrenees were compiled. Application of the regional curve standardization method for tree-ring detrending allowed the preservation of inter-annual to multi-centennial scale variability. The new density record correlates at 0.53 (0.68 in the higher frequency domain) with May–September maximum temperatures over the 1944–2005 period. Reconstructed warmth in the fourteenth to fifteenth and twentieth century is separated by a prolonged cooling from ∼1450 to 1850. Six of the ten warmest decades fall into the twentieth century, whereas the remaining four are reconstructed for the 1360–1440 interval. Comparison with novel density-based summer temperature reconstructions from the Swiss Alps and northern Sweden indicates decadal to longer-term similarity between the Pyrenees and Alps, but disagreement with northern Sweden. Spatial field correlations with instrumental data support the regional differentiation of the proxy records. While twentieth century warmth is evident in the Alps and Pyrenees, recent temperatures in Scandinavia are relatively cold in comparison to earlier warmth centered around medieval times, ∼1450, and the late eighteenth century. While coldest summers in the Alps and Pyrenees were in-phase with the Maunder and Dalton solar minima, lowest temperatures in Scandinavia occurred later at the onset of the twentieth century. However, fairly cold summers at the end of the fifteenth century, between ∼1600–1700, and ∼1820 were synchronized over Europe, and larger areas of the Northern Hemisphere.

  • 208. Cage, Alix G.
    et al.
    Davies, Siwan M.
    Wastegård, Stefan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Austin, William E. N.
    Identification of the Icelandic Landnam tephra (AD 871 +/- 2) in Scottish fjordic sediment2011Inngår i: Quaternary International, ISSN 1040-6182, E-ISSN 1873-4553, Vol. 246, s. 168-176Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Certain marginal marine environments, such as the Scottish fjord systems, contain high-resolution records of palaeoclimatic change in which decadal to centennial climatic events can be resolved. This paper explores the possibilities of using tephrochronology to stratigraphically constrain the timing of such events in the Loch Sunart record (MD04-2831) on the NW coast of Scotland (UK). One tephra horizon (containing both silicic and basaltic shards) is identified within Late Holocene sediment with geochemical analyses of the basaltic shards suggesting an origin in the Veidiviitn-Baroarbunga volcanic system. Radiocarbon age estimates and stratigraphic information suggests that the AD 871 Landnam tephra is the most likely candidate. The shards identified within this horizon appear hydrated and indicate the operation of post-depositional weathering processes possibly influenced by the saline conditions of the fjord environment.

  • 209. Callaghan, Terry
    et al.
    Tweedie, Craig
    Ņkerman, Jonas
    Andrews, Christopher
    Bergstedt, Johan
    Butler, Malcolm G.
    Christensen, Torben R
    Cooley, Dorothy
    Dahlberg, Ulrika
    Danby, Ryan K.
    Daniels, Fred J. A.
    Molenaar, Johannes G.
    Dick, Jan
    Mortensen, Christian Ebbe
    Ebert-May, Diane
    Emanuelsson, Urban
    Eriksson, Håkan
    Hedenås, Henrik
    Henry, Greg. H. R.
    Hik, David S.
    Hobbie, John E.
    Jantze, Elin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Jaspers, Cornelia
    Johansson, Cecilia
    Johansson, Margareta
    Johnson, David R.
    Johnstone, Jill F.
    Jonasson, Christer
    Kennedy, Catherine
    Kenney, Alice J.
    Keuper, Frida
    Koh, Saewan
    Krebs, Charles J.
    Lantuit, Hugues
    Lara, Mark J.
    Lin, David
    Lougheed, Vanessa L.
    Madsen, Jesper
    Matveyeva, Nadya
    McEwen, Daniel C.
    Myers-Smith, Isla H.
    Narozhniy, Yuriy K.
    Olsson, Håkan
    Pohjola, Veijo A.
    Price, Larry W.
    Rigét, Frank
    Rundqvist, Sara
    Sandström, Anneli
    Tamstorf, Mikkel
    Bogaert, Rik
    Villarreal, Sandra
    Webber, Patrick J.
    Zemtsov, Valeriy A.
    Multi-Decadal Changes in Tundra Environments and Ecosystems: Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)2011Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, nr 6, s. 705-716Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.

  • 210. Campbell, R
    et al.
    McCarroll, D
    Loader, NJ
    Grudd, H
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi.
    Robertson, I
    Jalkanen, R
    Blue intensity in Pinus sylvestris tree-rings: developing a new palaeoclimate proxy2007Inngår i: The Holocene, Vol. 17, nr 6, s. 821-828Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Minimum blue intensity measurements of resin-extracted Pinus sylvestris (L.) samples, conducted using a flat-bed scanner and commercially available software, are shown to provide a robust and reliable surrogate for maximum latewood density. Blue intensity data from 15 trees, from three stands, are reported relative to a standard blue-scale in a manner similar to grey-scale calibration in x-ray densitometry. The resulting time series are highly correlated with x-ray densitometry data generated from the same samples and preserve the same high level of signal strength. Sensitivity to summer climate variables is similar to that identified in the relative density record, demonstrating that minimum blue intensity can also be used for the study of climate change. While not a replacement for the powerful range of x-ray densitometry techniques, blue intensity provides an inexpensive and accessible alternative for accessing palaeoclimatic information.

  • 211. Campbell, Rochelle
    et al.
    McCarroll, Danny
    Robertson, Iain
    Loader, Neil J.
    Grudd, Håkan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Gunnarson, Björn
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    BLUE INTENSITY IN PINUS SYLVESTRIS TREE RINGS: A MANUAL FOR A NEW PALAEOCLIMATE PROXY2011Inngår i: TREE-RING RESEARCH, ISSN 1536-1098, Vol. 67, nr 2, s. 127-134Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Minimum blue intensity is a reflected light imaging technique that provides an inexpensive, robust and reliable surrogate for maximum latewood density. In this application it was found that temperature reconstructions from resin-extracted samples of Pious sylvestris (L.) from Fennoscandia provide results equivalent to conventional x-ray densitometry. This paper describes the implementation of the blue intensity method using commercially available software and a flat-bed scanner. A calibration procedure is presented that permits results obtained by different laboratories, or using different scanners, to be compared. In addition, the use of carefully prepared and chemically treated 10-mm-diameter cores are explored; suggesting that it may not be necessary to produce thin laths with the rings aligned exactly perpendicular to the measurement surface.

  • 212. Campell, R
    et al.
    Robertson, I
    McCarrol, D
    Loader, NJ
    Grudd, H
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Gunnarson, B
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Calibration proxy-climate relationshis in central Sweden using stable isotopes in tree rings.2008Konferansepaper (Annet vitenskapelig)
  • 213.
    Caretta, Martina Angela
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Kulturgeografiska institutionen.
    Westerberg, Lars-Owe
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Börjeson, Lowe
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Kulturgeografiska institutionen.
    Östberg, Wilhelm
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Kulturgeografiska institutionen.
    Labour, climate perceptions and soils in the irrigation systems in Sibou, Kenya & Engaruka, Tanzania2014Rapport (Annet vitenskapelig)
    Abstract [en]

    This booklet presents the results of a 4 years project (2011-2015) by four geographers from the university of Stockholm. This research took place in two small villages: Sibou, Kenya and Engaruka, Tanzania. The overall project looks at three variables: soil, climate and labor. These aspects can give an indication of the type of changes that happened in these irrigation systems and what have been the triggers behind them. In this booklet results are presented according to location and focus on: agricultural practices, women´s and men´s labor tasks, soil and water characteristics, adaptation weather variability and how all of these aspects have changed over time.

  • 214. Carey, Sean K.
    et al.
    Tetzlaff, Doerthe
    Seibert, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Soulsby, Chris
    Buttle, Jim
    Laudon, Hjalmar
    McDonnell, Jeff
    McGuire, Kevin
    Caissie, Daniel
    Shanley, Jamie
    Kennedy, Mike
    Devito, Kevin
    Pomeroy, John W.
    Inter-comparison of hydro-climatic regimes across northern catchments: synchronicity, resistance and resilience2010Inngår i: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 24, nr 24, s. 3591-3602Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The higher mid-latitudes of the Northern Hemisphere are particularly sensitive to climate change as small differences in temperature determine frozen ground status, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, seeks to improve our understanding of the sensitivity of northern catchments to climate change by examining their hydrological and biogeochemical responses. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). This briefing presents the initial stage of the North-Watch program, which focuses on how these catchments collect, store and release water and identify 'types' of hydro-climatic catchment response. At most sites, a 10-year data of daily precipitation, discharge and temperature were compiled and evaporation and storage were calculated. Inter-annual and seasonal patterns of hydrological processes were assessed via normalized fluxes and standard flow metrics. At the annual-scale, relations between temperature, precipitation and discharge were compared, highlighting the role of seasonality, wetness and snow/frozen ground. The seasonal pattern and synchronicity of fluxes at the monthly scale provided insight into system memory and the role of storage. We identified types of catchments that rapidly translate precipitation into runoff and others that more readily store water for delayed release. Synchronicity and variance of rainfall-runoff patterns were characterized by the coefficient of variation (cv) of monthly fluxes and correlation coefficients. Principal component analysis (PCA) revealed clustering among like catchments in terms of functioning, largely controlled by two components that (i) reflect temperature and precipitation gradients and the correlation of monthly precipitation and discharge and (ii) the seasonality of precipitation and storage. By advancing the ecological concepts of resistance and resilience for catchment functioning, results provided a conceptual framework for understanding susceptibility to hydrological change across northern catchments.

  • 215. Carlie, Anne
    et al.
    Arcini, Caroline
    Druid, Henrik
    Risberg, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Archaeology, forensics and the death of a child in Late Neolithic Sweden2014Inngår i: Antiquity, ISSN 0003-598X, E-ISSN 1745-1744, Vol. 88, nr 342, s. 1148-1163Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The discovery of a child's skeleton in a Late Neolithic well in Sweden raises again the issue of watery rituals and human sacrifice in prehistoric societies. Analysis of diatoms from the right humerus and from the surrounding sediment indicated that the child died by drowning and had not simply been disposed of in the well after death. The scenarios of accidental drowning and murder are examined to account for this discovery. The preferred hypothesis, based on a comparative study of similar finds from north-western Europe, interprets this instead as a ritual sacrifice. The use of diatom analysis to establish drowning as the cause of death adds a new weapon into the armoury of forensic archaeology.

  • 216. Carling, Paul
    et al.
    Jansen, John D.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Meshkova, Lyubov
    Multichannel rivers: their definition and classification2014Inngår i: Earth Surface Processes and Landforms, ISSN 0197-9337, E-ISSN 1096-9837, Vol. 39, nr 1, s. 26-37Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The etymology and historic usage of such terms as anabranch', anastamose' and braided' within river science are reviewed. Despite several decades of modern research to define river channel typologies inclusive of single channels and multiple channel networks, typologies remain ill-conditioned and consequently ill-defined. Conventionally employed quantitative planform characteristics of river networks possibly cannot be used alone to define channel types, yet the planform remains a central part of all modern classification schemes, supplemented by sedimentological and other qualitative channel characteristics. Planform characteristics largely have been defined using non-standardized metrics describing individual network components, such as link lengths, braiding intensity and bifurcation angles, which often fail to separate visually-different networks of channels. We find that existing typologies remain pragmatically utilitarian rather than fundamentally physics-based and too often fail to discriminate between two distinctive and important processes integral to new channel initiation and flow-splitting: (i) in-channel bar accretion, and (ii) channel avulsion and floodplain excision. It is suggested that, first, if channel planform is to remain central to river typologies, then more rigorous quantitative approaches to the analysis of extended integral channel networks at extended reach scales (rather than network components) are required to correctly determine whether visually-different' channel patterns can be discriminated consistently; and, second, if such visually-different styles do in fact differ in their governing processes of formation and maintenance. A significant question is why do so many seemingly equilibrium network geometries possess a large number of anabranches in excess of predictions from theoretical considerations? The key research frontier with respect to initiating and maintaining multichannel networks remains the understanding and discrimination of accretionary-bar flow splitting versus avulsive processes. Existing and new knowledge on flow splitting processes needs to be better integrated into channel typologies.

  • 217. Caron, M. M.
    et al.
    De Frenne, P.
    Brunet, J.
    Chabrerie, O.
    Cousins, Sara A. O.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    De Backer, L.
    Decocq, G.
    Diekmann, M.
    Heinken, T.
    Kolb, A.
    Naaf, T.
    Plue, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Selvi, F.
    Strimbeck, G. R.
    Wulf, M.
    Verheyen, K.
    Interacting effects of warming and drought on regeneration and early growth of Acer pseudoplatanus and A. platanoides2015Inngår i: Plant Biology, ISSN 1435-8603, E-ISSN 1438-8677, Vol. 17, nr 1, s. 52-62Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change is acting on several aspects of plant life cycles, including the sexual reproductive stage, which is considered amongst the most sensitive life-cycle phases. In temperate forests, it is expected that climate change will lead to a compositional change in community structure due to changes in the dominance of currently more abundant forest tree species. Increasing our understanding of the effects of climate change on currently secondary tree species recruitment is therefore important to better understand and forecast population and community dynamics in forests. Here, we analyse the interactive effects of rising temperatures and soil moisture reduction on germination, seedling survival and early growth of two important secondary European tree species, Acer pseudoplatanus and A.platanoides. Additionally, we analyse the effect of the temperature experienced by the mother tree during seed production by collecting seeds of both species along a 2200-km long latitudinal gradient. For most of the responses, A.platanoides showed higher sensitivity to the treatments applied, and especially to its joint manipulation, which for some variables resulted in additive effects while for others only partial compensation. In both species, germination and survival decreased with rising temperatures and/or soil moisture reduction while early growth decreased with declining soil moisture content. We conclude that although A.platanoides germination and survival were more affected after the applied treatments, its initial higher germination and larger seedlings might allow this species to be relatively more successful than A.pseudoplatanus in the face of climate change.

  • 218. Caron, M. M.
    et al.
    De Frenne, P.
    Brunet, J.
    Chabrerie, O.
    Cousins, Sara A. O.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    De Backer, L.
    Diekmann, M.
    Graae, B. J.
    Heinken, T.
    Kolb, A.
    Naaf, T.
    Plue, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Selvi, F.
    Strimbeck, G. R.
    Wulf, M.
    Verheyen, K.
    Latitudinal variation in seeds characteristics of Acer platanoides and A. pseudoplatanus2014Inngår i: Plant Ecology, ISSN 1385-0237, E-ISSN 1573-5052, Vol. 215, nr 8, s. 911-925Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change will likely affect population dynamics of numerous plant species by modifying several aspects of the life cycle. Because plant regeneration from seeds may be particularly vulnerable, here we assess the possible effects of climate change on seed characteristics and present an integrated analysis of seven seed traits (nutrient concentrations, samara mass, seed mass, wing length, seed viability, germination percentage, and seedling biomass) of Acer platanoides and A. pseudoplatanus seeds collected along a wide latitudinal gradient from Italy to Norway. Seed traits were analyzed in relation to the environmental conditions experienced by the mother trees along the latitudinal gradient. We found that seed traits of A. platanoides were more influenced by the climatic conditions than those of A. pseudoplatanus. Additionally, seed viability, germination percentage, and seedling biomass of A. platanoides were strongly related to the seed mass and nutrient concentration. While A. platanoides seeds were more influenced by the environmental conditions (generally negatively affected by rising temperatures), compared to A. pseudoplatanus, A. platanoides still showed higher germination percentage and seedling biomass than A. pseudoplatanus. Thus, further research on subsequent life-history stages of both species is needed. The variation in seed quality observed along the climatic gradient highlights the importance of studying the possible impact of climate change on seed production and species demography.

  • 219. Caron, M. M.
    et al.
    De Frenne, P.
    Brunet, J.
    Chabrerie, O.
    Cousins, Sara A. O.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Decocq, G.
    Diekmann, M.
    Graae, B. J.
    Heinken, T.
    Kolb, A.
    Lenoir, J.
    Naaf, T.
    Plue, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Selvi, F.
    Wulf, M.
    Verheyen, K.
    Divergent regeneration responses of two closely related tree species to direct abiotic and indirect biotic effects of climate change2015Inngår i: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 342, s. 21-29Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Changing temperature and precipitation can strongly influence plant reproduction. However, also biotic interactions might indirectly affect the reproduction and recruitment success of plants in the context of climate change. Information about the interactive effects of changes in abiotic and biotic factors is essential, but still largely lacking, to better understand the potential effects of a changing climate on plant populations. Here we analyze the regeneration from seeds of Acer platanoides and Acer pseudoplatanus, two currently secondary forest tree species from seven regions along a 2200 km-wide latitudinal gradient in Europe. We assessed the germination, seedling survival and growth during two years in a common garden experiment where temperature, precipitation and competition with the understory vegetation were manipulated. A. platanoides was more sensitive to changes in biotic conditions while A. pseudoplatanus was affected by both abiotic and biotic changes. In general, competition reduced (in A. platanoides) and warming enhanced (in A. pseudoplatanus) germination and survival, respectively. Reduced competition strongly increased the growth of A. platanoides seedlings. Seedling responses were independent of the conditions experienced by the mother tree during seed production and maturation. Our results indicate that, due to the negative effects of competition on the regeneration of A. platanoides, it is likely that under stronger competition (projected under future climatic conditions) this species will be negatively affected in terms of germination, survival and seedling biomass. Climate-change experiments including both abiotic and biotic factors constitute a key step forward to better understand the response of tree species' regeneration to climate change.

  • 220. Caron, M. M.
    et al.
    De Frenne, P.
    Chabrerie, O.
    Cousins, Sara A. O.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    De Backer, L.
    Decocq, G.
    Diekmann, M.
    Heinken, T.
    Kolb, A.
    Naaf, T.
    Plue, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Selvi, F.
    Strimbeck, G. R.
    Wulf, M.
    Verheyen, K.
    Impacts of warming and changes in precipitation frequency on the regeneration of two Acer species2015Inngår i: Flora: Morphologie, Geobotanik, Oekophysiologie, ISSN 0367-2530, E-ISSN 1618-0585, Vol. 214, s. 24-33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate projections indicate that temperatures will increase by up to 4.5 degrees C in Europe by the end of this century, and that more extreme rainfall events and longer intervening dry periods will take place. Climate change will likely affect all phases of the life cycle of plants, but plant reproduction has been suggested to be especially sensitive. Here, using a combination of approaches (soil heaters and different provenances along a latitudinal gradient), we analyzed the regeneration from seeds of Acer platanoides and A. pseudoplatanus, two tree species considered, from a management point of view, of secondary relevance. We studied germination, seedling survival and growth in a full-factorial experiment including warming and changes in watering frequency. Both species responded to warming, watering frequency and seed provenance, with stronger (negative) effects of warming and provenance than of watering frequency. In general, the central provenances performed better than the northernmost and southern-most provenances. We also detected interactive effects between warming, watering frequency and/or seed provenance. Based on these results, both species are expected to show dissimilar responses to the changes in the studied climatic factors, but also the impacts of climate change on the different phases of plant regeneration may differ in direction and magnitude. In general increases in the precipitation, frequency will stimulate germination while warming will reduce survival and growth. Moreover, the frequent divergent responses of seedlings along the latitudinal gradient suggest that climate change will likely have heterogeneous impacts across Europe, with stronger impacts in the northern and southern parts of the species' distribution ranges.

  • 221. Carstens, C.
    et al.
    Cvetkovic, V.
    Destouni, G.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Groundwater flow partitioning in near-coastal catchments of central Scandinavia2011Inngår i: Geophysical Research Abstracts,  Vol. 13, EGU2011-7880, 2011Konferansepaper (Fagfellevurdert)
  • 222. Castillo, Miguel
    et al.
    Bishop, Paul
    Fabel, Derek
    Jansen, John
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Estimating erosion rates on active bedrock channels using in situ produced 10Be: implications for landscape evolution in small transient rivers.2010Inngår i: Geological Society of America Abstract with Programs, 178678. Denver, USA, Oct-Nov 2010., 2010Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We measured concentrations of 10Be in two small bedrock rivers catchments on the Isle of Jura (western Scotland) in order to obtain erosion rates to test models of the responses of small bedrock rivers to base-level fall. The rivers of Jura experienced an abrupt, glacioisostatic base-level fall ca. 13.5ka, triggering upstream-propagating knickpoints. 10Be concentrations were obtained in the channel bed upstream and downstream of the main knickpoint triggered by that base-level fall. The preliminary results indicate that erosion rates are slightly higher downstream of the knickpoints, reflecting incomplete accommodation of the base-level fall by knickpoint retreat, ongoing glacioisostatic uplift and/or knickpoint rotation.

  • 223. Castillo, Miguel
    et al.
    Bishop, Paul
    Jansen, John D.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Knickpoint retreat and transient bedrock channel morphology triggered by base-level fall in small bedrock river catchments: The case of the Isle of Jura, Scotland2013Inngår i: Geomorphology, ISSN 0169-555X, E-ISSN 1872-695X, Vol. 180, s. 1-9Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A sudden drop in river base-level can trigger a knickpoint that propagates throughout the fluvial network causing a transient state in the landscape. Knickpoint retreat has been confirmed in large fluvial settings (drainage areas > 100 km(2)) and field data suggest that the same applies to the case of small bedrock river catchments (drainage areas < 100 km(2)). Nevertheless, knickpoint recession on resistant lithologies with structure that potentially affects the retreat rate needs to be confirmed with field-based data. Moreover, it remains unclear whether small bedrock rivers can absorb base-level fall via knickpoint retreat. Here we evaluate the response of small bedrock rivers to base-level fall on the isle of Jura in western Scotland (UK), where rivers incise into dipping quartzite. The mapping of raised beach deposits and strath terraces, and the analysis of stream long profiles, were used to identify knickpoints that had been triggered by base-level fall. Our results indicate that the distance of knickpoint retreat scales to the drainage area in a power law function irrespective of structural setting. On the other hand, local channel slope and basin size influence the vertical distribution of knickpoints. As well, at low drainage areas (similar to 4 km(2)) rivers are unable to absorb the full amount of base-level fall and channel reach morphology downstream of the knickpoint tends towards convexity. The results obtained here confirm that knickpoint retreat is mostly controlled by stream discharge, as has been observed for other transient landscapes. Local controls, reflecting basin size and channel slope, have an effect on the vertical distribution of knickpoints; such controls are also related to the ability of rivers to absorb the base-level fall.

  • 224.
    Cedergren, Boel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Havsnivåhöjningens påverkan på Gotlands kust och strandängar år 21002013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den globala havsnivåhöjningen är en direkt följd av den globala uppvärmningen och

    kommer i framtiden påverka stora områden i kustregionen. Syftet med detta arbete är

    att öka förståelsen samt se hur Gotlands strandängar samt kustområden kan påverkas av

    havsnivåhöjningen år 2100 och se vilka eventuella följder detta kan leda till. Metoderna

    som har använts är GIS-analys och litteraturstudier. Höjdmodeller med olika upplösning

    jämfördes även för att undersöka vilka som lämpar sig till en liknande analys inför

    framtida studier. Resultatet visar att vid en havsnivåhöjning på 1 m kommer 97 % av

    strandängarna försvinna och vid en havsnivåhöjning på 2 m försvinner 99 % av de

    gotländska strandängarna. För att nybildande av strandängar kring kusten ska vara

    möjligt så krävs en markanvändning som stödjer detta i form av bete och slåtter.

    Jämförelsen mellan de olika höjdmodellerna visar att en upplösning på 50 m inte lämpar

    sig för en studie av detta slag men en upplösning på 10 m kan användas om en

    höjdmodell med bättre upplösning inte är tillgänglig. Kring kusten finns många bostäder

    och samhällen som kommer drabbas till stor del vid en havsnivåhöjning på 2 m och

    detta bör tas på stort allvar. Planering samt åtgärder kring denna problematik i framtiden

    bör prioriteras av Region Gotland.

  • 225. Ceulemans, Tobias
    et al.
    Van Geel, Maarten
    Jacquemyn, Hans
    Boeraeve, Margaux
    Plue, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Saar, Liina
    Kasari, Liis
    Peeters, Gerrit
    van Acker, Kasper
    Crauwels, Sam
    Lievens, Bart
    Honnay, Olivier
    Arbuscular mycorrhizal fungi in European grasslands under nutrient pollution2019Inngår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 28, nr 12, s. 1796-1805Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Our aim was to quantify the extent to which nutrient pollution explains arbuscular mycorrhizal fungal community richness and composition.

    Location: Europe.

    Time period: 2014-2016.

    Major taxa studied: Arbuscular mycorrhizal fungi.

    Methods: We sampled soils of calcareous and acidic grasslands and roots of 34 host plant species across a large geographical gradient of atmospheric nitrogen deposition and soil phosphorus availability. Furthermore, we performed an independent pairwise comparison between fertilized and unfertilized grasslands in Belgium and Iceland to compare results.

    Results: We found that nitrogen deposition had a significant negative relationship to arbuscular mycorrhizal fungal richness, with a negative community threshold of 7.7 kg N/ha/year corresponding to the greatest reduction in operational taxonomic units. Additionally, we found that soil phosphorus had a significant negative relationship to mycorrhizal fungal richness.

    Main conclusions: Our results highlight the necessity to revisit the critical loads of atmospheric nitrogen deposition used in European environmental policy, currently set at 10-15 kg N/ha/year. Importantly, our observed threshold of 7.7 kg N/ha/year does not correspond to a critical load below which there is no environmental harm, because the least negative changes in arbuscular mycorrhizal fungal communities were observed at < 5 kg N/ha/year. Therefore, to avoid compromising the policy tenet of no environmental harm with respect to grassland mycorrhizal fungi, areas of zero tolerance to nitrogen pollution should be delimited. Our results also indicate that environmental policy biased towards reducing nitrogen pollution alone will fail to preserve mycorrhizal biodiversity in European grasslands. We advocate increased policy attention to avoid phosphorus enrichment, particularly through agricultural fertilization. Here too, areas of zero phosphorus input, ideally set in the currently unpolluted (or least polluted) areas, seem key for effective environmental policy, because elevated levels of soil phosphorus after phosphorus fertilization are known to be extremely persistent.

  • 226. Chalov, Sergey R.
    et al.
    Jarsjö, Jerker
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Kasimov, Nikolay S.
    Romanchenko, Anna O.
    Pietroń, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Thorslund, Josefin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Promakhova, Ekaterina V.
    Spatio-temporal variation of sediment transport in the Selenga River Basin, Mongolia and Russia2015Inngår i: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 73, nr 2, s. 663-680Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many Asian rivers have been intensively used to boost economic growth, resulting in sudden and drastic changes in sediment transport patterns. However, a few rivers are still undisturbed. The present paper considers the unregulated Selenga River and its basin, located in Russia and Mongolia. The river contributes to 50 % of the total inflow to Lake Baikal. Pending scientific challenges include the quantification of sediment loads and erosion-deposition patterns along the Selenga River system, the understanding of suspended particulate matter composition and the importance of peak flow events for total sediment discharge and heavy metal transport. Field data and hydraulic modeling converge on showing that peak flow events during spring and summer contribute to the main part (70-80 %) of the annual sediment and pollution loads in upstream parts of the basin. The Selenga River carries mostly silt and sand. The average particle size differs by a factor of four between summer floods and base flow periods. The low amount of particulate organic matter (ranging between 1 and 16 % in the studied rivers) is consistent with the significant role of sediments originating from mining areas and in-channel sources. The bed load transport in the downstream part of the river basin is high (up to 50 % of the total transport), and channel storage plays an important role in the total sediment transport to Lake Baikal. Reported statistically significant multi-decadal declines in sediment fluxes in the downstream Selenga River can be attributed to the abandonment of cultivated lands and (most likely) to changing hydroclimatic factors.

  • 227.
    Charpentier Ljungqvist, Fredrik
    et al.
    Stockholms universitet, Humanistiska fakulteten, Historiska institutionen.
    Grudd, Håkan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Arctic summer temperature variability since AD 8002009Inngår i: European climate of the last millennium: Millennium milestone meeting 3: Book of abstract, 2009, s. 8-9Konferansepaper (Annet vitenskapelig)
  • 228.
    Charpentier Ljungqvist, Fredrik
    et al.
    Stockholms universitet, Humanistiska fakulteten, Historiska institutionen.
    Krusic, Paul J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Brattström, Gudrun
    Stockholms universitet, Naturvetenskapliga fakulteten, Matematiska institutionen.
    Sundqvist, Hanna S.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Northern Hemisphere temperature patterns in the last 12 centuries2012Inngår i: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 8, s. 227-249Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We analyse the spatio-temporal patterns of temperature variability over Northern Hemisphere land areas, on centennial time-scales, for the last 12 centuries using an unprecedentedly large network of temperature-sensitive proxy records. Geographically widespread positive temperature anomalies are observed from the 9th to 11th centuries, similar in extent and magnitude to the 20th century mean. A dominance of widespread negative anomalies is observed from the 16th to 18th centuries. Though we find the amplitude and spatial extent of the 20th century warming is within the range of natural variability over the last 12 centuries, we also find that the rate of warming from the 19th to the 20th century is unprecedented in the context of the last 1200 yr. The positive Northern Hemisphere temperature change from the 19th to the 20th century is clearly the largest between any two consecutive centuries in the past 12 centuries. These results remain robust even after removing a significant number of proxies in various tests of robustness showing that the choice of proxies has no particular influence on the overall conclusions of this study.

  • 229.
    Chasset, Coralie
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Jarsjö, Jerker
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Erlström, Mikael
    Cvetkovic, Vladimir
    Destouni, Georgia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Scenario simulations of CO(2) injection feasibility, plume migration and storage in a saline aquifer, Scania, Sweden2011Inngår i: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 5, nr 5, s. 1303-1318Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Deep saline aquifers have large capacity for geological CO(2) storage, but are generally not as well characterized as petroleum reservoirs. We here aim at quantifying effects of uncertain hydraulic parameters and uncertain stratigraphy on CO(2) injectivity and migration, and provide a first feasibility study of pilot-scale CO(2) injection into a multilayered saline aquifer system in southwest Scania, Sweden. Four main scenarios are developed, corresponding to different possible interpretations of available site data. Simulation results show that, on the one hand, stratigraphic uncertainty (presence/absence of a thin mudstone/claystone layer above the target storage formation) leads to large differences in predicted CO(2) storage in the target formation at the end of the test (ranging between 11% and 98% of injected CO(2) remaining), whereas other parameter uncertainty (in formation and cap rock permeabilities) has small impact. On the other hand, the latter has large impact on predicted injectivity, on which stratigraphic uncertainty has small impact. Salt precipitation at the border of the target storage formation affects CO(2) injectivity for all considered scenarios and injection rates. At low injection rates, salt is deposited also within the formation, considerably reducing its availability for CO(2) storage.

  • 230.
    Chawchai, Sakonvan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper. Chulalongkorn University, Thailand.
    Chabangborn, Akkaneewut
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper. Chulalongkorn University, Thailand.
    Fritz, Sherilyn
    Valiranta, Minna
    Mörth, Carl-Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Blaauw, Maarten
    Reimer, Paula J.
    Krusic, Paul J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Lowemark, Ludvig
    Wohlfarth, Barbara
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Hydroclimatic shifts in northeast Thailand during the last two millennia - the record of Lake Pa Kho2015Inngår i: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 111, s. 62-71Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The Southeast Asian mainland is located in the central path of the Asian summer monsoon, a region where paleoclimatic data are still sparse. Here we present a multi-proxy (TOC, C/N, delta C-13, biogenic silica, and XRF elemental data) study of a 1.5 m sediment/peat sequence from Lake Pa Kho, northeast Thailand, which is supported by 20 AMS C-14 ages. Hydroclimatic reconstructions for Pa Kho suggest a strengthened summer monsoon between BC 170-AD 370, AD 800-960, and after AD 1450; and a weakening of the summer monsoon between AD 370-800, and AD 1300-1450. Increased run-off and a higher nutrient supply after AD 1700 can be linked to agricultural intensification and land-use changes in the region. This study fills an important gap in data coverage with respect to summer monsoon variability over Southeast Asia during the past 2000 years and enables the mean position of the Intertropical Convergence Zone (ITCZ) to be inferred based on comparisons with other regional studies. Intervals of strengthened/weaker summer monsoon rainfall suggest that the mean position of the ITCZ was located as far north as 35 degrees N between BC 170-AD 370 and AD 800-960, whereas it likely did not reach above 17 degrees N during the drought intervals of AD 370-800 and AD 1300-1450. The spatial pattern of rainfall variation seems to have changed after AD 1450, when the inferred moisture history for Pa Kho indicates a more southerly location of the mean position of the summer ITCZ.

  • 231. Chen, Deliang
    et al.
    Walther, Alexander
    Moberg, Anders
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Jones, Phil
    Jacobeit, Jucundus
    Lister, David
    European Trend Atlas of Extreme Temperature and Precipitation Records2015Bok (Fagfellevurdert)
  • 232.
    Chen, Hans W.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU). Penn State University .
    Zhang, Qiong
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Körnich, Heiner
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU). Swedish Meteorological and Hydrological Institute.
    Chen, Deliang
    A robust mode of climate variability in the Arctic: The Barents Oscillation2013Inngår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 40, nr 11, s. 2856-2861Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Barents Oscillation (BO) is an anomalous wintertime atmospheric circulation pattern in the Northern Hemisphere that has been linked to the meridional flow over the Nordic Seas. There are speculations that the BO has important implications for the Arctic climate; however, it has also been suggested that the pattern is an artifact of Empirical Orthogonal Function (EOF) analysis due to an eastward shift of the Arctic Oscillation/North Atlantic Oscillation (AO/NAO). In this study, EOF analyses are performed to show that a robust pattern resembling the BO can be found during different time periods, even when the AO/NAO is relatively stationary. This BO has a high and stable temporal correlation with the geostrophic zonal wind over the Barents Sea, while the contribution from the AO/NAO is small. The surface air temperature anomalies over the Barents Sea are closely associated with this mode of climate variability.

  • 233.
    Christiansen, Hanne H.
    et al.
    Geology Department, The University Centre in Svalbard, UNIS, Norway.
    Etzelmüller, Bernd
    Department of Geosciences, The University of Oslo, Norway.
    Isaksen, Ketil
    Norwegian Meteorological Institute, Norway.
    Juliussen, Håvard
    Geology Department, The University Centre in Svalbard, UNIS, Norway.
    Farbrot, Herman
    Department of Geosciences, The University of Oslo, Norway.
    Humlum, Ole
    Geology Department, The University Centre in Svalbard, UNIS, Norway.
    Johansson, Margareta
    GeoBiosphere Science Centre, Department of Physical Geography and Ecosystem Analyses, Lund University, Sweden.
    Ingeman-Nielsen, T.
    Department of Civil Engineering, The Technical University of Denmark, Denmark.
    Kristensen, Lene
    Geology Department, The University Centre in Svalbard, UNIS, Norway.
    Hjort, Jan
    Department of Geography, University of Helsinki, Finland.
    Holmlund, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Sannel, A. Britta K.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Sigsgaard, Charlotte
    Department of Geography and Geology, University of Copenhagen, Denmark.
    Åkerman, H. Jonas
    GeoBiosphere Science Centre, Department of Physical Geography and Ecosystem Analyses, Lund University, Sweden.
    Foged, Nils
    Department of Civil Engineering, The Technical University of Denmark, Denmark.
    Blikra, Lars H.
    International Centre for Geohazards, Åknes/Tafjord Early Warning Centre, Norway.
    Pernosky, M. A.
    Asiaq, Greenland Survey, Nuuk, Greenland.
    Ødegård, Rune S.
    Gjøvik University College, Norway.
    The thermal state of permafrost in the Nordic area during the International Polar Year 2007-20092010Inngår i: Permafrost and Periglacial Processes, ISSN 1045-6740, E-ISSN 1099-1530, Vol. 21, nr 2, s. 156-181Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper provides a snapshot of the permafrost thermal state in the Nordic area obtained during the International Polar Year (IPY) 2007–2009. Several intensive research campaigns were undertaken within a variety of projects in the Nordic countries to obtain this snapshot. We demonstrate for Scandinavia that both lowland permafrost in palsas and peat plateaus, and large areas of permafrost in the mountains are at temperatures close to 0°C, which makes them sensitive to climatic changes. In Svalbard and northeast Greenland, and also in the highest parts of the mountains in the rest of the Nordic area, the permafrost is somewhat colder, but still only a few degrees below the freezing point. The observations presented from the network of boreholes, more than half of which were established during the IPY, provide an important baseline to assess how future predicted climatic changes may affect the permafrost thermal state in the Nordic area. Time series of active-layer thickness and permafrost temperature conditions in the Nordic area, which are generally only 10 years in length, show generally increasing active-layer depths and rising permafrost temperatures.

  • 234.
    Clason, Caroline C.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Applegate, Patrick
    Holmlund, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Modelling Late Weichselian evolution of the Eurasian ice sheets forced by surface meltwater-enhanced basal sliding2014Inngår i: Journal of Glaciology, ISSN 0022-1430, E-ISSN 1727-5652, Vol. 60, nr 219, s. 29-40Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We simulated the Late Weichselian extent and dynamics of the Eurasian ice sheets using theshallow-ice approximation ice-sheet model SICOPOLIS. Our simulated Last Glacial Maximum ice-sheetextents closely resemble geomorphological reconstructions, and areas of modelled fast flow areconsistent with the known locations of palaeo-ice streams. Motivated by documented velocity responseto increased meltwater inputs on Greenland, we tested the sensitivity of the simulated ice sheet to thesurface meltwater effect (SME) through a simple parameterization relating basal sliding to local surfacemelt rate and ice thickness. Model runs including the SME produce significantly reduced ice volumeduring deglaciation, with maximum ice surface velocities much greater than in similar runs that neglectthe SME. We find that the simple treatment of the SME is not applicable across the whole ice sheet;however, our results highlight the importance of the SME for dynamic response to increased melting.The southwest sector of the Scandinavian ice sheet is most sensitive to the SME, with fast flow in theBaltic ice stream region shutting off by 15 kaBP when the SME is turned on, coincident with a retreat ofthe ice-margin position into the Gulf of Bothnia.

  • 235.
    Clason, Caroline C.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Mair, D. W. F.
    Nienow, P. W.
    Bartholomew, I. D.
    Sole, A.
    Palmer, S.
    Schwanghart, W.
    Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland2015Inngår i: The Cryosphere, ISSN 1994-0416, E-ISSN 1994-0424, Vol. 9, nr 1, s. 123-138Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment (< 1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.

  • 236.
    Clason, Caroline
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Mair, Douglas
    School of Geosciences, University of Aberdeen.
    Burgess, David
    Northern Canada Division, Geological Survey of Canada.
    Nienow, Peter
    School of GeoSciences, University of Edinburgh.
    Modelling the delivery of supraglacial meltwater to theice/bed interface: application to southwest Devon Ice Cap,Nunavut, Canada2012Inngår i: Journal of Glaciology, ISSN 0022-1430, E-ISSN 1727-5652, Vol. 58, nr 208, s. 361-374Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The transfer of surface-generated meltwater to the subglacial drainage system through fullice thickness crevassing may lead to accelerated glacier velocities, with implications for ice motionunder future climatic scenarios. Accurate predictions of where surface meltwater accesses the ice/bedinterface are therefore needed in fully coupled hydrodynamic ice-sheet models. We present a spatiallydistributed modelling routine for predicting the location and timing of delivery of surface-derivedmeltwater to the ice/bed interface through moulins and supraglacial lake drainage. The model isexplained as it is applied to the Croker Bay glacial catchment of Devon Ice Cap, Canada. The formationof moulins, drainage of lakes, and the transfer of meltwater through the full ice thickness are modelledfor the 2004 and 2006 ablation seasons. Through this case study we assess the model’s sensitivity todegree-day factors, fracture toughness, tensile strength and crevasse width, and confirm that parametersinfluencing the rate at which water fills a crevasse are the most significant controls on the ability of acrevasse to reach the bed. Increased surface melt production, therefore, has the potential to significantlyinfluence the spatial and temporal transfer of meltwater through surface-to-bed connections in awarmer climate.

  • 237. Clough, Yann
    et al.
    Ekroos, Johan
    Báldi, András
    Batáry, Péter
    Bommarco, Riccardo
    Gross, Nicolas
    Holzschuh, Andrea
    Hopfenmüller, Sebastian
    Knop, Eva
    Kuussaari, Mikko
    Lindborg, Regina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Marini, Lorenzo
    Öckinger, Erik
    Potts, Simon G.
    Pöyry, Juha
    Roberts, Stuart P. M.
    Steffan-Dewenter, Ingolf
    Smith, Henrik G.
    Density of insect-pollinated grassland plants decreases with increasing surrounding land-use intensity2014Inngår i: Ecology Letters, ISSN 1461-023X, E-ISSN 1461-0248, Vol. 17, nr 9, s. 1168-1177Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pollinator declines have raised concerns about the persistence of plant species that depend on insect pollination, in particular by bees, for their reproduction. The impact of pollinator declines remains unknown for species-rich plant communities found in temperate seminatural grasslands. We investigated effects of land-use intensity in the surrounding landscape on the distribution of plant traits related to insect pollination in 239 European seminatural grasslands. Increasing arable land use in the surrounding landscape consistently reduced the density of plants depending on bee and insect pollination. Similarly, the relative abundance of bee-pollination-dependent plants increased with higher proportions of non-arable agricultural land (e.g. permanent grassland). This was paralleled by an overall increase in bee abundance and diversity. By isolating the impact of the surrounding landscape from effects of local habitat quality, we show for the first time that grassland plants dependent on insect pollination are particularly susceptible to increasing land-use intensity in the landscape.

  • 238. Cohen, T. J.
    et al.
    Nanson, G. C.
    Jansen, John D.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Gliganic, L. A.
    May, J. -H.
    Larsen, J. R.
    Goodwin, I. D.
    Browning, S.
    Price, D. M.
    A pluvial episode identified in arid Australia during the Medieval Climatic Anomaly2012Inngår i: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 56, s. 167-171Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optically stimulated luminescence (OSL) ages from a relict shoreline on Lake Callabonna record a major pluvial episode in southern central Australia between 1050  70 and 1100  60 Common Era (CE), within the Medieval Climatic Anomaly (MCA). During this pluvial interval Lake Callabonna filled to 10e12 times the volume of the largest historical filling (1974) and reached maximum depths of 4e5 m, compared to the 0.5e1.0 m achieved today. Until now there has been no direct evidence for the MCA in the arid interior of Australia. A multi-proxy, analogue-based atmospheric circulation reconstruction indicates that the pluvial episode was associated with an anomalous meridional atmospheric circulation pattern over the Southern extratropics, with high sea-level pressure ridges in the central Indian Ocean and Tasman Sea, and a trough extending from the Southern Ocean into central Australia. A major decline in the mobility of the Australian aboriginal hunter-gatherer coincides with this MCA period, in southern central Australia.

  • 239. Cohen, Tim J.
    et al.
    Jansen, John D.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK). University of Wollongong, Australia.
    Gliganic, Luke A.
    Larsen, Joshua R.
    Nanson, Gerald C.
    May, Jan-Hendrik
    Jones, Brian G.
    Price, David M.
    Hydrological transformation coincided with megafaunal extinction in central Australia2015Inngår i: Geology, ISSN 0091-7613, E-ISSN 1943-2682, Vol. 43, nr 3, s. 195-198Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Central to the debate over the extinction of many of Australia's last surviving megafauna is the question: Was climate changing significantly when humans arrived and megafauna went extinct? Here we present a new perspective on variations in climate and water resources over the last glacial cycle in arid Australia based on the study of the continent's largest lake basin and its tributaries. By dating paleoshorelines and river deposits in the Lake Eyre basin, we show that major hydrological change caused previously overflowing megalakes to enter a final and catastrophic drying phase at 48 +/- 2 ka just as the giant bird, Genyornis newtoni, went extinct (50-45 ka). The disappearance of Genyornis and other megafauna has been previously attributed to ecosystem collapse coincident with the spread of fire-wielding humans. Our findings suggest a climate-driven hydrological transformation in the critical window of human arrival and megafaunal extinction, and the results call for a re-evaluation of a human-mediated cause for such extinctions in arid Australia.

  • 240. Cohen, Timothy
    et al.
    Nanson, Gerald
    Jansen, John
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Jones, Brian
    Jacobs, Zenobia
    Larsen, Joshua
    May, Jan-Hendrick
    Treble, Pauline
    Price, David
    Smith, Andrew
    Late Quaternary mega-lakes fed by the northern and southern river systems of central Australia: varying moisture sources and increased continental aridity2012Inngår i: Palaeogeography, Palaeoclimatology, Palaeoecology, ISSN 0031-0182, E-ISSN 1872-616X, Vol. 356, nr Special Issue, s. 89-108Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optically stimulated and thermoluminescence ages from relict shorelines, along with accelerator mass spectrometer 14C ages from freshwater molluscs reveal a record of variable moisture sources supplied by northern and southern river systems to Lake Mega-Frome in southern central Australia during the late Quaternary. Additional lacustrine, palynological and terrestrial proxies are used to reconstruct a record that extends back to 105 ka, confirming that Lakes Mega-Frome and Mega-Eyre were joined to create the largest system of palaeolakes on the Australian continent as recently as 50–47 ka. The palaeohydrological record indicates a progressive shift to more arid conditions, with marked drying after 45 ka. Subsequently, Lake Mega-Frome has filled independently at 33–31 ka and at the termination of the Last Glacial Maximum to volumes some 40 times those of today. Further sequentially declining filling episodes (to volumes 25–10 those of today) occurred immediately prior to the Younger Dryas stadial, in the mid Holocene and during the medieval climatic anomaly. Southern hemisphere summer insolation maxima are a poor predictor of palaeolake-filling episodes. An examination of multiple active moisture sources suggests that palaeolake phases were driven independently of insolation and at times by some combination of enhanced Southern Ocean circulation and strengthened tropical moisture sources.

  • 241. Cohen, Timothy
    et al.
    Nanson, Gerald
    Jansen, John
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Jones, Brian
    Jacobs, Zenobia
    May, Jan-Hendrick
    Larsen, Josh
    Treble, Pauline
    Smith, Andrew
    Late Quaternary mega-lakes of central Australia: varying moisture sources and increased continental aridity.2010Inngår i: EOS Transactions, American Geophysical Union, PP31B-1624. San Francisco, USA, Dec. 2010., Washington DC: American Geophysical Union , 2010Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Optically stimulated (OSL) and thermoluminescence (TL) ages from relict shorelines, along with accelerator mass spectrometer (AMS) 14C ages from freshwater molluscs reveal a record of mega-lake phases over the late Quaternary for Lake Mega-Frome, situated in the arid zone of South Australia. Additional lacustrine, palynological and terrestrial proxies are used to reconstruct a record that extends as far back as 105 ka and demonstrates that Mega-Frome was last joined to the adjacent mega-Eyre at 50 - 47 ka forming the largest palaeolake on the Australian continent. This time interval for hydrological decline coincides with the arrival of humans on the Australian continent and the demise of the mega-fauna. Since then, Mega-Frome has filled independently at 33 - 31 ka (Heinrich event 3) and at the termination of the Last Glacial Maximum (LGM) to depths far in excess of those seen today (up to 15 - 20 times modern lake volumes). Further evidence of subsequent lake-filling episodes is recorded immediately prior to the Younger Dryas, the mid Holocene and during the medieval climatic anomaly. We present evidence for multiple moisture sources over this time period with lake phases being driven by either an enhanced Southern Ocean circulation or an enhanced tropical moisture source or a combination of both. We show however, that southern hemisphere summer insolation maxima (monsoon proxy) is a poor predictor for past palaeo-lake filling episodes. This is the first palaeohydrological record for a large area of southern semi-arid Australia indicating a progressive shift to more arid conditions throughout the last glacial cycle

  • 242. Cohen, Timothy
    et al.
    Nanson, Gerald
    Jones, Brian
    Jansen, John
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Jacobs, Zenobia
    Treble, Pauline
    Price, David
    May, Jan-Hendrick
    Smith, Andrew
    Late Quaternary mega-lakes of central Australia: evidence of varying moisture sources.2010Inngår i: Geophysical Research Abstracts, 12, 6160, European Geosciences Union General Assembly, Vienna, Austria, May 2010., 2010Konferansepaper (Annet vitenskapelig)
  • 243. Cohen, Timothy
    et al.
    Nanson, Gerald
    Jones, Brian
    Price, David
    Larsen, Josh
    May, Jan-Hendrick
    Smith, Andrew
    Jansen, John
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Codilean, Alexandru
    Mega-lakes of central Australia: evidence of varying moisture sources and increased continental aridity.2010Inngår i: 4th Southern Connections Congress. Bariloche, Argentina, Feb 2010., 2010Konferansepaper (Annet vitenskapelig)
  • 244. Conley, Daniel J.
    et al.
    Björck, Svante
    Bonsdorff, Erik
    Carstensen, Jacob
    Destouni, Georgia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Gustafsson, Bo G.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Hietanen, Susanna
    Kortekaas, Marloes
    Kuosa, Harri
    Meier, H. E. Markus
    Muller-Karulis, Baerbel
    Nordberg, Kjell
    Norkko, Alf
    Nurnberg, Gertrud
    Pitkänen, Heikki
    Rabalais, Nancy N.
    Rosenberg, Rutger
    Savchuk, Oleg P.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Slomp, Caroline P.
    Voss, Maren
    Wulff, Fredrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Zillén, Lovisa
    Hypoxia-Related Processes in the Baltic Sea2009Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, nr 10, s. 3412-3420Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hypoxia, a growing worldwide problem, has been intermittently present in the modern Baltic Sea since its formation ca. 8000 cal. yr BP. However, both the spatial extent and intensity of hypoxia have increased with anthropogenic eutrophication due to nutrient inputs. Physical processes, which control stratification and the renewal of oxygen in bottom waters, are important constraints on the formation and maintenance of hypoxia. Climate controlled inflows of saline water from the North Sea through the Danish Straits is a critical controlling factor governing the spatial extent and duration of hypoxia. Hypoxia regulates the biogeochemical cycles of both phosphorus (P) and nitrogen (N) in the water column and sediments. Significant amounts of P are currently released from sediments, an order of magnitude larger than anthropogenic inputs. The Baltic Sea is unique for coastal marine ecosystems experiencing N losses in hypoxic waters below the halocline. Although benthic communities in the Baltic Sea are naturally constrained by salinity gradients, hypoxia has resulted in habitat loss over vast areas and the elimination of benthic fauna, and has severely disrupted benthic food webs. Nutrient load reductions are needed to reduce the extent, severity, and effects of hypoxia.

  • 245. Conley, Daniel J.
    et al.
    Bonsdorff, Erik
    Carstensen, Jacob
    Destouni, Georgia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Gustafsson, Bo G.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Hansson, Lars-Anders
    Rabalais, Nancy N.
    Voss, Maren
    Zillén, Lovisa
    Tackling hypoxia in the Baltic Sea: Is engineering a solution?2009Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, nr 10, s. 3407-3411Artikkel i tidsskrift (Fagfellevurdert)
  • 246. Cook, Edward R.
    et al.
    Krusic, Paul J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Anchukaitis, Kevin J.
    Buckley, Brendan M.
    Nakatsuka, Takeshi
    Sano, Masaki
    Tree-ring reconstructed summer temperature anomalies for temperate East Asia since 800 CE2013Inngår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 41, nr 11-12, s. 2957-2972Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We develop a summer temperature reconstruction for temperate East Asia based on a network of annual tree-ring chronologies covering the period 800-1989 C.E. The East Asia reconstruction is the regional average of 585 individual grid point summer temperature reconstructions produced using an ensemble version of point-by-point regression. Statistical calibration and validation tests indicate that the regional average possesses sufficient overall skill to allow it to be used to study the causes of temperature variability and change over the region. The reconstruction suggests a moderately warm early medieval epoch (ca. 850-1050 C.E.), followed by generally cooler 'Little Ice Age' conditions (ca. 1350-1880 C.E.) and 20th century warming up to the present time. Since 1990, average temperature has exceeded past warm epochs of comparable duration, but it is not statistically unprecedented. Superposed epoch analysis reveals a volcanic forcing signal in the East Asia summer temperature reconstruction, resulting in pulses of cooler summer conditions that may persist for several years. Substantial uncertainties remain, however, particularly at lower frequencies, thus requiring caution and scientific prudence in the interpretation of this record.

  • 247. Cory, Neil
    et al.
    Laudon, Hjalmar
    Köhler, Stephan
    Seibert, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi.
    Bishop, Kevin
    Evolution of soil solution aluminum during transport along a forested boreal hillslope2007Inngår i: J. Geophys. Res., Vol. 112, s. G03014-Artikkel i tidsskrift (Fagfellevurdert)
  • 248.
    Cottman, Petter
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Cykelolyckor, orsaksfaktorer och samband: Ett metodtest i GIS för att hitta ett eventuellt samband mellan cykelolyckor och platsen där de sker2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 249.
    Cousins, Sara
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Extinction debt in fragmented grasslands: paid or not?2009Inngår i: Journal of Vegetation Science, ISSN 1100-9233, E-ISSN 1654-1103, Vol. 20, nr 1, s. 3-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fragmentation of grasslands and forests is considered amajor threat to biodiversity. In the case of plants, theeffect of fragmentation or landscape context is still unclearand published results are divergent. One explanation forthis divergence is the slow response of long-lived plants,creating an extinction debt. However, this has not beenempirically confirmed. In this study, data were compiledfrom broad-scale studies of grasslands from throughoutthe world that relate plant diversity to fragmentationeffects. Only seven studies from northern Europe, out ofa total 61, gave any information on actual habitat fragmentationin time and space. In landscapes with 410%grassland remaining, present-day species richness wasrelated to past landscape or habitat pattern. In landscapeswith o10% grassland remaining, in contrast, plant speciesrichness was more related to contemporary landscapeor habitat pattern. Studies from landscapes with 410%grassland remaining supported the concept of an extinctiondebt, while studies from more fragmented landscapesdid not provide any evidence of an extinction debt. Inorder to make generalisations about historical legacies onspecies diversity in grasslands it is important to consider arange of highly transformed landscapes, and not onlylandscapes with a high amount of grassland remaining.

  • 250.
    Cousins, Sara A. O.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Analysis of land-cover transitions based on 17th and 18th century cadastral maps and aerial photographs2001Inngår i: Landscape Ecology, ISSN 0921-2973, E-ISSN 1572-9761, Vol. 16, nr 1, s. 41-54Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper explores the possibility of using non-geometric cadastral maps from the 17th and 18th century together with aerial photographs from 1945 and 1981 to analyse land-cover change in south-east Sweden. Habitats rich in plant species in the European rural landscape seem to be correlated with a long continuity of management. Accurate spatial data from historical data sources are fundamental to understand patterns of vegetation and biodiversity in the present-day landscape. However, traditional methods for rectification of non-geometric maps using corresponding points from orthophotos or modern maps are not satisfying, as internal inaccuracies will remain in the maps. This study presents a method to rectify the maps by local warping, thereby eliminating geometrical irregularities. Further, the land-cover changes were calculated and presented as transition matrices. The extent of arable fields and grasslands were analysed in relation to soil characteristics and continuity of management. The results show a dynamic relation between grassland and arable field, albeit the overall proportions remained almost the same between 17th and 18th centuries: 60% grassland to 32% arable field. The most substantial changes in land-cover were prior to 1945. Today there is 18% grasslands left in the study area, while 56% of the land-cover is arable field. Approximately 8% of present-day land-cover is semi-natural grassland 300 years of age or more. Compared to 300 years ago there is only 1% grassland left on peat and 2% on clay. In contrast, grassland covers associated with bare bedrock have been fairly stable in size. All semi-natural grasslands with a long continuity of management were situated on shallow soils, less than 50 cm depth. The major conclusions from this study are that (i) correctly rectified, old maps are very useful to address questions of land-cover changes in historical time, (ii) general trends in land use over 300 years in this hemi-boreal landscape seem to underestimate the full dynamics of land use change, and (iii) only a small proportion of the semi-natural grassland area had a 300 year continuity of management.

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