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  • 1.
    Cui, Qiao-Yu
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lemdahl, Geoffrey
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsson, Fredrik
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sugita, Shinya
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Holocene local forest history at two sites in Småland, southern Sweden: Insights from quantitative reconstruction using the Landscape Reconstruction Algorithm2010Conference paper (Refereed)
  • 2.
    Drake, Henrik
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Ivarsson, Magnus
    University of Southern Denmark, Denmark.
    Tillberg, Mikael
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Whitehouse, Martin
    Swedish Museum of Natural History.
    Kooijman, Ellen
    Swedish Museum of Natural History.
    Ancient Microbial Activity in Deep Hydraulically Conductive Fracture Zones within the Forsmark Target Area for Geological Nuclear Waste Disposal, Sweden2018In: Geosciences, E-ISSN 2076-3263, Vol. 8, no 6, article id 211Article in journal (Refereed)
    Abstract [en]

    Recent studies reveal that organisms from all three domains of life—Archaea, Bacteria, and even Eukarya—can thrive under energy-poor, dark, and anoxic conditions at large depths in the fractured crystalline continental crust. There is a need for an increased understanding of the processes and lifeforms in this vast realm, for example, regarding the spatiotemporal extent and variability of the different processes in the crust. Here, we present a study that set out to detect signs of ancient microbial life in the Forsmark area—the target area for deep geological nuclear waste disposal in Sweden. Stable isotope compositions were determined with high spatial resolution analyses within mineral coatings, and mineralized remains of putative microorganisms were studied in several deep water-conducting fracture zones (down to 663 m depth), from which hydrochemical and gas data exist. Large isotopic variabilities of δ13Ccalcite (−36.2 to +20.2‰ V-PDB) and δ34Spyrite (−11.7 to +37.8‰ V-CDT) disclose discrete periods of methanogenesis, and potentially, anaerobic oxidation of methane and related microbial sulfate reduction at several depth intervals. Dominant calcite–water disequilibrium of δ18O and 87Sr/86Sr precludes abundant recent precipitation. Instead, the mineral coatings largely reflect an ancient archive of episodic microbial processes in the fracture system, which, according to our microscale Rb–Sr dating of co-genetic adularia and calcite, date back to the mid-Paleozoic. Potential Quaternary precipitation exists mainly at ~400 m depth in one of the boreholes, where mineral–water compositions corresponded

  • 3. F. Stallard, Robert
    et al.
    Lindell, Lina
    Geology, hydrology, and soils2014In: Perú: Cordillera Escalera-Loreto / [ed] Nigel Pitman, Corine Vriesendorp, Diana Alvira, Jonathan A. Markel, Mark Johnston, Ernesto Ruelas Inzunza, Agustín Lancha Pizango, Gloria Sarmiento Valenzuela, Patricia Álvarez-Loayza, Joshua Homan, Tyana Wachter, Álvaro del Campo, Douglas F. Stotz, Sebastian Heilpern, Chicago: The Field Museum , 2014, p. 280-292Chapter in book (Other academic)
    Abstract [en]

    The Cordillera Escalera mountain range on the Loreto-San Martín border in Amazonian Peru was barely known to scientists until the September 2013 expedition described in this report. Richly illustrated with twenty four color plates featuring more than one hundred photographs, this volume contains the full results of the expedition’s rapid inventories of the geology, plants, fishes, amphibians, reptiles, birds, and mammals in the Cordillera Escalera, as well as in-depth descriptions of the history, daily life, and natural resource use of local Shawi communities. Contributors also discuss threats to and opportunities for the landscape and its people and offer recommendations for sustaining biodiversity and human well-being in this megadiverse region of Peru. This volume contains the expedition team’s full report in both Spanish and English, as well as an overview in Shawi.

  • 4. Gaillard, Marie-José
    et al.
    Cui, Qiao-Yu
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Chinese Academy of Sciences, China.
    Lemdahl, Geoffrey
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Trondman, Anna-Kari
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    The potential of pollen-based quantitative vegetation reconstructions in studies of past human settlements and use of resources – examples from Europe2015In: Geophysical Research Abstracts, 2015, Vol. 17Conference paper (Refereed)
    Abstract [en]

    There is a long tradition of collaboration between palaeoecologists and archaeologists in many parts of the world with the purpose of reconstructing the environment of humans through time and the study of the interactions between humans and their environment. Vegetation (i.e. vegetated landscapes and plants) has long been one of the most important parts of the environment for humans’ resources. Thanks to the interpretation of palaeoecological data such as pollen and plant macrofossils, it is well known that humans have used plants for their subsistence and formed many landscapes of the Earth through their activities over many millennia. Pollen analysis in particular has been used to reconstruct the landscapes of humans in order i) to learn something on their use of the landscape for building material, grazing and food (e.g. woods, grazed land, cultivated fields), and ii) to understand their influence on the landscape through deforestation in particular. Pollen data as proxy records of vegetation have been very useful to provide qualitative descriptions of cultural landscapes through time in terms of the presence of major tree, shrub and herb species, and the character of the landscape, wooded, “half-wooded” (or partly wooded), and primarily open (poorly wooded) (1). Efforts to calibrate pollen onto land-use in the 1990ies has made possible to provide more precise and detailed interpretation of pollen records in terms of land-use type (2). However, when it came to questions related to the size of cultivated land or grazed land in relation to wooded land, interpretation of pollen records has been problematic until recently. The non-linear relationship between pollen and vegetation due to inter-taxonomic differences in pollen productivity and pollen dispersion and deposition characteristics of plant taxa has long hampered estimation of the percentage cover of plant taxa or landscape units in the past. Thanks torecent developments in pollen-vegetation modelling, a new approach - the Landscape Reconstruction Algorithm (LRA) (3, 4) - makes it possible to estimate the cover of plant taxa or landscape units at both regional and local spatial scales using pollen records. The LRA has been tested and applied in various types of studies in Europe in particular. Examples from Europe and Scandinavia show that pollen-based quantitative reconstructions of vegetation cover, in combination with other palaeoecological records such as insect and plant macroremains, show the great potential of such studies to provide new insights on the use of landscapes and vegetation by humans in the past and its environmental consequences at both regional and local spatial scales (5, 6). These results provide a new environmental framework for the discussion and testing of hypotheses based on archaeological data.

  • 5.
    Gaillard, Marie-José
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Greisman, Annica
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lemdahl, Geoffrey
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsson, Fredrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Skoglund, Peter
    The role of climate, human impact and fire on forestdynamics, landscape development and biodiversity during the last 10,500 calendar years in southern Sweden: a synthesis ofthe multiproxy study of Stavsåkra bogManuscript (Other academic)
    Abstract [en]

    In this paper, we discuss the contribution of a multi-proxy approach to the study of long-term forest dynamics and biodiversity (at the species to landscape levels), using the records from a palaeoecological investigation at Stavsåkra, province of Småland, southern Sweden. The results from all the proxies, i.e. beetles, pollen, plant macrofossils, charred plant remains, andmicroscopical and macroscopical charcoal, are compared. The study of all charred material has the advantage of providing valuable information on the local plants that burnt (charred plant remains) and a more robust reconstruction of the local fire history and its regional representativeness. The plant macrofossil analysis allows specifying the origin of pollen from plants that may grow either on the coring site (fen or bog) or in the surrounding vegetation on dry land. This is particularly crucial for the interpretation of pollen types such as Gramineae, Cyperaceae, and Ericaceae (Calluna, Empetrum and Vaccinium species). The origin of Calluna pollen (bog, forest floor or open heaths) is often difficult to establish with certainty. In this study, the total absence of Calluna remains in the plant macrofossil record, and theoccurrence of beetle species dependant on Calluna heath ecosystems from the Late Neolithic (ca. 2000 BC) suggest that Calluna pollen originated from the surrounding vegetation, probably from the under-storey of the pine forests in early Holocene, and from the Calluna heaths during late Holocene. The beetle record further strengthens the inferred fire history by providing findings of species dependant on fire and, therefore, confirms the existence ofrelatively large burnt areas. Moreover, the insect analysis provides information on vegetation characteristics that cannot be inferred from pollen and plant macrofossil with certainty - or cannot be inferred at all - such as the forest structure in terms of openness, sun exposure, occurrence of dead wood and old trees. The results at Stavsåkra demonstrate that disturbances such as fire, forest clearance, and grazing can have both positive and negative impacts onbiodiversity, depending on the character and intensity of the disturbance in both time and space, and on the type of biota concerned, in this case plants and beetles.

  • 6.
    Gaillard, Marie-José
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sugita, Shinya
    Tallinn University, Estonia.
    Mazier, Florence
    University of Toulouse, France ; Lund University.
    Trondman, Anna-Kari
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Broström, A
    Lund University.
    Hickler, T
    Lund University.
    Kaplan, J.O.
    Ecole Polytechnique Fédérale de Lausanne, Switzerland.
    Kjellström, E
    Swedish Meteorological and Hydrological Institute.
    Kokfelt, U
    Lund University.
    Kunes, P
    Aarhus University, Denmark.
    Lemmen, C
    Miller, P
    Olofsson, J
    Poska, A
    Rundgren, M
    Smith, B
    Strandberg, G
    Fyfe, R
    Nielsen, A.B.
    Alenius, T
    Balakauskas, L
    Barnekov, L
    Birks, H.J.B.
    Bjune, A
    Bjorkman, L
    Giesecke, T
    Hjelle, K
    Kalnina, L
    Kangur, M
    van der Knaap, W.O.
    Koff, T
    Lageras, P
    Latalowa, M
    Leydet, M
    Lechterbeck, J
    Lindbladh, M
    Odgaard, B
    Peglar, S
    Segerstrom, U
    von Stedingk, H
    Seppa, H
    Holocene land-cover reconstructions for studies on land cover-climate feedbacks2010In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 6, p. 483-499Article in journal (Refereed)
    Abstract [en]

    The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cover from pollen data, (3) to present a new project (LANDCLIM: LAND cover – CLIMate interactions in NW Europe during the Holocene) currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene, and (4) to discuss the implications and future directions in climate and vegetation/land-cover modeling, and in the assessment of the effects of human-induced changes in land-cover on the regional climate through altered feedbacks. The existing ALCC scenarios show large discrepancies between them, and few cover time periods older than AD 800. When these scenarios are used to assess the impact of human land-use on climate, contrasting results are obtained. It emphasizes the need for methods such as the REVEALS model-based land-cover reconstructions. They might help to fine-tune descriptions of past land-cover and lead to a better understanding of how long-term changes in ALCC might have influenced climate. The REVEALS model is demonstrated to provide better estimates of the regional vegetation/landcover changes than the traditional use of pollen percentages. This will achieve a robust assessment of land cover at regional- to continental-spatial scale throughout the Holocene. We present maps of REVEALS estimates for the percentage cover of 10 plant functional types (PFTs) at 200 BP and 6000 BP, and of the two open-land PFTs “grassland” and “agricultural land” at five time-windows from 6000 BP to recent time. The LANDCLIM results are expected to provide crucial data to reassess ALCC estimates for a better understanding of the land suface-atmosphere interactions.

  • 7.
    Gaillard, Marie-José
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sugita, Shinya
    Rundgren, Mats
    Smith, Benjamin
    Mazier, Florence
    Trondman, Anna-Kari
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Fyfe, Ralph
    Kokfelt, Ulla
    Nielsen, Anne-Birgitte
    Strandberg, Gustav
    Team, LANDCLIM members
    Pollen-inferred quantitative reconstructions of Holocene land-cover in NW Europe for the evaluation of past climate-vegetation feedbacks: The Swedish LANDCLIM project and the NordForsk LANDCLIM network2010Conference paper (Refereed)
  • 8.
    Gaillard-Lemdahl, Marie-Jose
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Berglund, B E
    Quantification of land surfaces cleared of forest during the Holocene1998Collection (editor) (Other academic)
  • 9.
    Gaillard-Lemdahl, Marie-Jose
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hicks, SheilaRitchie, J C
    Modern pollen rain and fossil pollen spectra: the use of modern pollen/vegetation/environment relationships in the interpretation of fossil pollen spectra: PAPERS FROM THE 8TH INTERNATIONAL PALYNOLOGICAL CONGRESS, SESSION E2, MODERN POLLEN RAIN AND FOSSIL POLLEN SPECTRA, AIX-EN-PROVENCE, FRANCE, SEPTEMBER 11, 1992 - Abstracts1994Collection (editor) (Other academic)
  • 10.
    Guenthner, William R.
    et al.
    Univ Illinois, USA.
    Reiners, Peter W.
    Univ Arizona, USA.
    Drake, Henrik
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Tillberg, Mikael
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Zircon, titanite, and apatite (U-Th)/He ages and age-eU correlations from the Fennoscandian Shield, southern Sweden2017In: Tectonics, ISSN 0278-7407, E-ISSN 1944-9194, Vol. 36, no 7, p. 1254-1274Article in journal (Refereed)
    Abstract [en]

    Craton cores far from plate boundaries have traditionally been viewed as stable features that experience minimal vertical motion over 100-1000Ma time scales. Here we show that the Fennoscandian Shield in southeastern Sweden experienced several episodes of burial and exhumation from similar to 1800Ma to the present. Apatite, titanite, and zircon (U-Th)/He ages from surface samples and drill cores constrain the long-term, low-temperature history of the Laxemar region. Single grain titanite and zircon (U-Th)/He ages are negatively correlated (104-838Ma for zircon and 160-945Ma for titanite) with effective uranium (eU=U+0.235xTh), a measurement proportional to radiation damage. Apatite ages are 102-258Ma and are positively correlated with eU. These correlations are interpreted with damage-diffusivity models, and the modeled zircon He age-eU correlations constrain multiple episodes of heating and cooling from 1800Ma to the present, which we interpret in the context of foreland basin systems related to the Neoproterozoic Sveconorwegian and Paleozoic Caledonian orogens. Inverse time-temperature models constrain an average burial temperature of similar to 217 degrees C during the Sveconorwegian, achieved between 944Ma and 851Ma, and similar to 154 degrees C during the Caledonian, achieved between 366Ma and 224Ma. Subsequent cooling to near-surface temperatures in both cases could be related to long-term exhumation caused by either postorogenic collapse or mantle dynamics related to the final assembly of Rodinia and Pangaea. Our titanite He age-eU correlations cannot currently be interpreted in the same fashion; however, this study represents one of the first examples of a damage-diffusivity relationship in this system, which deserves further research attention.

  • 11. Mazier, Florence
    et al.
    Kunes, Petr
    Sugita, Shinya
    Trondman, Anna-Kari
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Broström, Anna
    Gaillard, Marie-José
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Pollen-inferred quantitative reconstructions of Holocene land-cover in NW Europe for the evaluation of past climate-vegetation feedbacks III: Evaluation of the REVEALS-based reconstructions using the Czech Republic pollen database2010Conference paper (Refereed)
  • 12.
    Müller Bicca, Marcos
    et al.
    Universidade Federal do Rio Grande do Sul, Brazil.
    Philipp, Ruy Paulo
    Universidade Federal do Rio Grande do Sul, Brazil.
    Jelinek, Andrea Ritter
    Universidade Federal do Rio Grande do Sul, Brazil.
    Ketzer, João Marcelo
    Pontifícia Universidade Catolica do Rio Grande do Sul, Brazil.
    dos Santos Scherer, Claiton Marlon
    Universidade Federal do Rio Grande do Sul, Brazil.
    Jamal, Daúd Liace
    Universidade Eduardo Mondlane, Mozambique.
    Domingos dos Reis, Adriano
    Universidade Federal do Rio Grande do Sul, Brazil.
    Permian-Early Triassic tectonics and stratigraphy of the Karoo Supergroup in northwestern Mozambique2017In: Journal of African Earth Sciences, ISSN 1464-343X, E-ISSN 1879-1956, Vol. 130, p. 8-27Article in journal (Refereed)
    Abstract [en]

    The Gondwana continent was the base of great basin inception, sedimentation and magmatism throughout the Cambrian to Middle Jurassic periods. The northwestern Mozambique igneous and metamorphic basement assemblages host the NW-trending Moatize Minjova Basin, which has great economic potential for coal and gas mining. This rift basin was activated by an S-SW stress field during the Early Permian period, as constrained by regional and field scale structural data. Tectonically induced subsidence in the basin, from the reactivation of NW-SE and NNE-SSW regional structures is well recorded by faults, folds and synsedimentary fractures within the Early Late Permian Moatize Formation. NW-SE, N-S and NE-SW field structures consist of post-Karoo reactivation patterns related to a NNE-SSW extension produced by the Pangea breakup and early inception stages of the Great East African Rift System. The Early Late Permian sequences of the Moatize-Minjova Basin are composed of fluvial meandering, coal-bearing beds of the Moatize Formation, which comprises mostly floodplain, crevasse splay and fluvial channel lithofacies associations, deposited in a cyclic pattern. This sequence was overlapped by a multiple-story, braided fluvial plain sequence of the Matinde Formation (Late Permian – Early Triassic). Lithofacies associations in the Matinde Formation and its internal relationships suggest deposition of poorly channelized braided alluvial plain in which downstream and probably lateral accretion macroforms alternate with gravity flow deposits. NW paleoflow measurements suggest that Permian fluvial headwaters were located somewhere southeast of the study area, possibly between the African and Antarctic Precambrian highlands.

  • 13.
    Olsson, Fredrik
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Gaillard, Marie-José
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lemdahl, Geoffrey
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Greisman, Annica
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lanos, Philippe
    Holocene forest fires in the hemiboreal zone of southern Sweden10500 calendar years BP to modern time: the role of climateand human activitiesManuscript (Other academic)
    Abstract [en]

    A high-resolution, continuous macroscopic charcoal record from Storasjö (hemiboreal vegetation zone, southern Sweden), covering the last 10500 calendar years, is presented. This record was compared with the microscopic charcoal record from the same core, and tentatively correlated with the macroscopic and microscopic charcoal records from Stavsåkra, situated 30 km West of Storasjö, in order to disentangle regional from local fire episodes. The charcoal records are also compared with regional climate proxy records with the aim to separate climate- from human induced fire activity. The results suggest that the major signal of both microscopic and macroscopic charcoal records represents local fire history. The clearest record of local fire history was obtained from the macroscopic charcoal analysis performed using image analysis. A tentative correlation of the charcoal records between the sites indicates that most fire episodes of the early and mid Holocene are probably of regional character. Both sites exhibit three major phases of high fire activity, around 8500 BC, 7500-7000 BC to ca. 4000 BC, and 1000-500 BC to the 19th century. These phases are separated by longer periods with lower or very low fire activity. This general trend is in good agreement with the pattern emerging for Europe from the analysis of the recently developed global charcoal database. These results demonstrate that fire was an important disturbance factor in the past in the hemiboreal vegetation zone of Sweden. It was controlled by climate during early and mid Holocene, and primarily by human activities until the 19th century. Warmer and drier climate during early and mid Holocene caused frequent and intensive fires, which suggests that natural fire activity might increase under global warming conditions.

  • 14.
    Olsson, Fredrik
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lemdahl, Geoffrey
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Greisman, Annica
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lanos, Philippe
    Marguerie, Dominique
    Marcoux, Nancy
    Skoglund, Peter
    Wäglind, Jonas
    A continuous record of fire covering the last 10500 calendar years from souther Sweden: The role of climate and human activities2010In: Palaeogeography, Palaeoclimatology, Palaeoecology, ISSN 0031-0182, E-ISSN 1872-616X, Vol. 291, p. 128-141Article in journal (Refereed)
    Abstract [en]

    A high-resolution, continuous 10,500 cal. yrs-long macroscopic charcoal record from a peat and lake sediment deposit at Storasjö, in the hemiboreal vegetation zone of southern Sweden, is presented. This record was compared with the microscopic charcoal record from the same core, and tentatively correlated with the macroscopic and microscopic charcoal records from another site (Stavsåkra), situated 30 km West of Storasjö. The charcoal records are also compared with regional climate proxy records with the aim to separate climate microscopic and macroscopic charcoal records represents local history was obtained from the continuous macroscopic charcoal analysis. A tentative correlation of the charcoal records between the sites indicates that most probably of regional character. Both sites exhibit three major phases of high 7250 BC to ca. 4000 BC, and 3) 750 BC to the 19th century. These three phases are separated by periods with lower or very low from the analysis of the recently developed global charcoal database. Fire appears to have been controlled by climate during the early and middle Holocene and by humans during the late Holocene. Warmer and drier climate during the early and middle Holocene caused frequent and intensive natural was an important disturbance factor in the hemiboreal vegetation zone of Sweden and played an important role in the forest dynamics and characteristics of the — from human-induced fire activity. The results suggest that the major signal of bothfire history. The best record of local firefire episodes of the early and middle Holocene arefire activity 1) 8700–8300 BC, 2)fire activity. This general trend is in good agreement with the pattern emerging for Europefires, which suggests thatfire activity might increase under predicted future climate scenarios. The results also suggest that fireflora and fauna of the region.

  • 15.
    Olsson, Fredrik
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lemdahl, Geoffrey
    University of Kalmar, School of Pure and Applied Natural Sciences.
    A continuous Holocene beetle record from the site Stavsåkra, southern Sweden: implications for the last 10 600 years of forest and land use history2009In: Journal of Quaternary Science, ISSN 0267-8179, E-ISSN 1099-1417, Vol. 24, no 6, p. 612-626Article in journal (Refereed)
    Abstract [en]

    Beetle remains from a small bog in southern Sweden contribute information concerning the forest history of the study area. The study shows that beetles are valuable indicators of woodland structures such as openness, field vegetation, presence of dead wood and disturbance factors such as climate change, fire regimes, grazing and land use. The early Holocene, ca. 8600-6450 cal. BC, was characterised by open, pine-dominated woodlands maintained by fire and grazing disturbances. The changes in the wetland fauna, between 8600 and 7500 cal. BC, correlate well with low lake levels in southern Sweden. During the mid Holocene, ca. 6450-2400 cal. BC, the woodlands were relatively dense, with few openings in the canopy. Around 4200 cal. BC, there was a shift to a dominance of deciduous trees. Fire and grazing pressures were particularly low. Numbers of aquatic and hygrophilic beetles indicate dry conditions between ca. 5000 and 3000 cal. BC. During the late Holocene, ca. 2400 cal. BC to present, the woodlands opened up mainly through increased land use. The main disturbance factors were fire and grazing. The beetles indicate the formation of heather-dominated heathland around 800 cal. BC.

  • 16.
    Olsson, Fredrik
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lemdahl, Geoffrey
    University of Kalmar, School of Pure and Applied Natural Sciences.
    A forest history for the last 10,900 years at the site Storasjö, southern Sweden: implications from beetle assemblagesManuscript (preprint) (Other academic)
    Abstract [en]

    A continues Holocene beetle record from a small bog in southern Sweden is presented and compared with results from a similar study that was previously presented. The comparison reveals both regional trends in the development of the woodlands and local differences, particularly during the late Holocene. The early Holocene, ca. 8900 – 7500 cal. BC, was characterised by open, pine dominated woodlands at both sites. Fire and probably grazing maintained the openness of the woodlands and favoured a certain vegetation and fauna. During the mid Holocene, ca. 7500 – 900 cal. BC, the woodlands grew denser with elements of broadleaved trees. However, there were local differences in vegetation composition at the two sites. Grazing impacts were probably low at both sites, whereas fires were more frequent at the presented site. The late Holocene, ca. 900 cal. BC to the present, was characterised by a progressive opening up of the woodlands, mainly by land use such as grazing and clearance by fire. This process started ca. 2400 cal. BC at the formerly studied site, where there were settlements already during the late Neolithic. At the presented site, which was mainly used as outland until Medieval Time, the woodlands gradually opened up about 1500 years later. Heather-dominated heathland formed ca. between 900 and 800 cal. BC at both sites. The twostudies show that insect data may contribute with valuable information on long term changes in woodland structures and disturbances.

  • 17.
    Trondman, Anna-Kari
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Sugita, Shinya
    Tallinn University, Estonia .
    Björkman, Leif
    Viscum pollenanalys & miljöhistoria.
    Greisman, Annica
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Tove, Hultberg
    Swedish University of Agricultural Sciences.
    Lagerås, Per
    Swedish National Heritage Board.
    Lindbladh, Matts
    Swedish University of Agricultural Sciences.
    Mazier, Florence
    Toulouse University Le Mirail, France.
    Are pollen records from small sites appropriate for REVEALS model-based quantitative reconstructions of past regional vegetation?: An empirical test in southern Sweden2016In: Vegetation History and Archaeobotany, ISSN 0939-6314, E-ISSN 1617-6278, Vol. 25, no 2, p. 131-151Article in journal (Refereed)
    Abstract [en]

    In this paper we test the performance of the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model using pollen records from multiple small sites. We use Holocene pollen records from large and small sites in southern Sweden to identify what is/are the most significant variable(s) affecting the REVEALS-based reconstructions, i.e. type of site (lakes and/or bogs), number of sites, site size, site location in relation to vegetation zones, and/or distance between small sites and large sites. To achieve this objective we grouped the small sites according to (i) the two major modern vegetation zones of the study region, and (ii) the distance between the small sites and large lakes, i.e. small sites within 50, 100, 150, or 200 km of the large lakes. The REVEALS-based reconstructions were performed using 24 pollen taxa. Redundancy analysis was performed on the results from all REVEALS-model runs using the groups within (i) and (ii) separately, and on the results from all runs using the groups within (ii) together. The explanatory power and significance of the variables were identified using forward selection and Monte Carlo permutation tests. The results show that (a) although the REVEALS model was designed for pollen data from large lakes, it also performs well with pollen data from multiple small sites in reconstructing the percentage cover of groups of plant taxa (e.g. open land taxa, summer-green trees, evergreen trees) or individual plant taxa; however, in the case of this study area, the reconstruction of the percentage cover of Calluna vulgaris, Cyperaceae, and Betula may be problematic when using small bogs; (b) standard errors of multiple small-site REVEALS estimates will generally be larger than those obtained using pollen records from large lakes, and they will decrease with increasing size of pollen counts and increasing number of small sites; (c) small lakes are better to use than small bogs if the total number of small sites is low; and (d) the size of small sites and the distance between them do not play a major role, but the distance between the small sites and landscape/vegetation boundaries is a determinant factor for the accuracy of the vegetation reconstructions.

  • 18.
    Trondman, Anna-Kari
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sugita, Shinya
    Institute of Ecology, Tallinn University, Tallinn, Estonia .
    Mazier, Florence
    Fyfe, Ralph
    Nielsen, Anne-Brigitte
    Leydet, Michelle
    Team, LANDCLIM members
    Pollen-inferred quantitative reconstructions of Holocene land-cover in NW Europe for the evaluation of past climate-vegetation feedbacks: methods and first maps of the cover of plant functional types at 6000, 3000, 600, 200 and 0 BP2010Conference paper (Refereed)
  • 19.
    Xu, Qinghai
    et al.
    Hebei Normal University, China.
    Zhang, Shengrui
    Chinese Academy of Sciences, China.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Li, Manyue
    Hebei Normal University, China.
    Cao, Xianyong
    Hebei Normal University, China ; Alfred Wegener Institute, Germany.
    Tian, Fang
    Hebei Normal University, China ; Alfred Wegener Institute, Germany.
    Li, Furong
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Studies of modern pollen assemblages for pollen dispersal- deposition- preservation process understanding and for pollen-based reconstructions of past vegetation, climate, and human impact: A review based on case studies in China2016In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 149, p. 151-166Article in journal (Refereed)
    Abstract [en]

    Fossil pollen, as a direct proxy record of past vegetation, and indirect proxy record of past climate, plays an essential role in revealing and reconstructing past vegetation and climate. However, relationships between pollen, vegetation and climate are not linear, hence quantitative reconstructions of past vegetation and climate based on pollen records are not straightforward, and results may be highly contradictory and difficult to interpret. One of the main causes of discrepancies between results has been the lack of comprehensive and systematical studies on modern pollen dispersal and deposition processes, particularly on the quantification of these processes. Based on empirical studies performed in China over the last 30 years, this paper provides the state-of-the-art of the understanding of pollen dispersal and deposition processes in China and the remaining questions to be investigated. We show that major progress has been achieved in the study of modern pollen dispersal and deposition processes, and in the application of models of the pollen-vegetation-climate relationships for quantitative reconstruction of past vegetation and climate. However, several issues are not entirely solved or understood yet, such as how to quantify the reworking and re-deposition of pollen grains in quaternary alluvial sediments, the influence of pollen preservation on pollen assemblages, and human impact on vegetation. Even so, the progress made during the last decades makes it possible to achieve significantly more precise and informative reconstructions of past vegetation, land-use and climate in China than was possible earlier.

  • 20.
    Zhang, Shengrui
    et al.
    Hebei Normal University, China.
    Xu, Qinghai
    Hebei Normal University, China.
    Gaillard, Marie-José
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Cao, Xianyong
    Hebei Normal University, China ; Research Unit Potsdam, Germany ; University of Potsdam, Germany.
    Li, Jianyong
    University of Helsinki, Finland.
    Zhang, Liyan
    Shijiazhuang University of Economics, China.
    Li, Yuecong
    Hebei Normal University, China.
    Tian, Fang
    Research Unit Potsdam, Germany ; University of Potsdam, Germany.
    Zhou, Liping
    Peking University, China.
    Lin, Fengyou
    Chinese Academy of Sciences, China.
    Yang, Xiaolan
    Hebei Institute of Geography Science, China.
    Characteristic pollen source area and vertical pollen dispersal and deposition in a mixed coniferous and deciduous broad-leaved woodland in the Changbai mountains, northeast China.2016In: Vegetation History and Archaeobotany, ISSN 0939-6314, E-ISSN 1617-6278, Vol. 25, no 1, p. 29-43Article in journal (Refereed)
    Abstract [en]

    Pollen influx (number of pollen grains cm−2 year−1) can objectively reflect the dispersal and deposition features of pollen within a certain time and space, and is often used as a basis for the quantitative reconstruction of palaeovegetation; however, little is known about the features and mechanisms of vertical dispersal of pollen. Here we present the results from a 5 year (2006–2010) monitoring program using pollen traps placed at different heights from ground level up to 60 m and surface soil samples in a mixed coniferous and deciduous broad-leaved woodland in the Changbai mountains, northeastern China. The pollen percentages and pollen influx from the traps have very similar characteristics to the highest values for Betula,FraxinusQuercus and Pinus, among the tree taxa and Artemisia, Chenopodiaceae and Asteraceae among the herb taxa. Pollen influx values vary significantly with height and show major differences between three distinct layers, above-canopy (≥32 m), within the trunk layer (8 ≤ 32 m) and on the ground (0 m). These differences in pollen influx are explained by differences in (i) the air flows in each of these layers and (ii) the fall speed of pollen of the various taxa. We found that the pollen recorded on the ground surface is a good representation of the major part of the pollen transported in the trunk space of the woodland. Comparison of the pollen influx values with the theoretical, calculated “characteristic pollen source area” (CPSA) of 12 selected taxa indicates that the pollen deposited on the ground surface of the woodland is a fair representation with 85–90 % of the total pollen deposited at a wind speed of 2.4 m s−1 coming from within ca. 1–5 km for Pinus and Quercus, ca. 5–10 km for UlmusTilia, Oleaceae and Betula, ca. 20–40 km for Fraxinus, Poaceae, Chenopodiaceae, Populus andSalix, and ca. 30–60 km for Artemisia; it is also a good representation with 90–98 % of the total pollen deposited coming from within 60 km at a wind speed of 2.4 m s−1, or 100 km at a wind speed: 6 m s−1, for the 12 selected taxa used in the CPSA calculation. Furthermore, comparison with the vegetation map of the area around the sampling site shows that the pollen deposited on the ground represents all plant communities which grow in the study area within 70 km radius of the sampling site. In this study, the pollen percentages obtained from the soil surface samples are significantly biased towards pollen taxa with good preservation due to thick and robust pollen walls. Therefore, if mosses are available instead, soil samples should be avoided for pollen studies, in particular for the study of pollen-vegetation relationships, the estimation of pollen productivities and quantitative reconstruction of past vegetation. The results also indicate that the existing model of pollen dispersal and deposition, Prentice’s model, provides a fair description of the actual pollen dispersal and deposition in this kind of woodland, which suggests that the application of the landscape reconstruction algorithm would be relevant for reconstruction of this type of woodland in the past.

  • 21.
    Zhao, Yan
    et al.
    Chinese Acad Sci, Peoples Republic of China.
    Tang, Yu
    Lanzhou Univ, Peoples Republic of China.
    Yu, Zicheng
    Lehigh Univ, USA.
    Li, Huan
    Lanzhou Univ, Peoples Republic of China.
    Yang, Bao
    Chinese Acad Sci, Peoples Republic of China.
    Zhao, Wenwei
    Lanzhou Univ, Peoples Republic of China;Univ Cologne, Germany.
    Li, Furong
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Lanzhou Univ, Peoples Republic of China.
    Li, Quan
    Chinese Acad Sci, Peoples Republic of China.
    Holocene peatland initiation, lateral expansion, and carbon dynamics in the Zoige Basin of the eastern Tibetan Plateau2014In: The Holocene, ISSN 0959-6836, E-ISSN 1477-0911, Vol. 24, no 9, p. 1137-1145Article in journal (Refereed)
    Abstract [en]

    The Zoige Basin on the eastern Tibetan Plateau has the largest area of highland peatlands in China. However, the development history of these peatlands is still poorly understood. Understanding how these carbon-rich ecosystems responded to change in the Asian summer monsoons during the Holocene will provide insight into the peatland carbon accumulation processes under different climate boundary conditions. Here, we document the timing of initiation and expansion histories of these peatlands using 59 new basal peat ages across the Zoige Basin, with 29 ages for initiation analysis and 30 additional ages for lateral expansion analysis. Also, we synthesized basal ages from 26 sites and carbon accumulation records at four sites from previous studies in this region. The results show that the peatland initiation is widespread at 11.5-10 and 7-6 kyr (1 kyr = 1000 cal. yr BP) and the minimum initiation periods occurred after 5 kyr. Our multiple basal ages along eight transects show that slopes are a dominant control on peatland lateral expansion rates, with very slow and less variable rates at slopes >0.4 degrees. Furthermore, we found a significant relationship between peatland basal ages and peat depths from 85 sites, suggesting relatively uniform peat properties. Carbon accumulation rates from detailed downcore analysis at four sites and on the basis of peat depth-basal age relationship show similar patterns with a peak carbon accumulation at 10-8 kyr. On the basis of estimated mean values of bulk density and carbon content from the region, the Holocene average C accumulation for the Zoige Basin is 31.1 g C/m(2)/yr. The widespread peatland initiation and rapid accumulation in the early Holocene were likely in response to higher temperature and stronger summer monsoon intensity, while the slowdown of peatland development during the late Holocene might have been caused by climate cooling and drying.

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