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Die Ursachen rezenten Auftretens von Massensterben und die Bedingungen für die Erhaltung von Weichteilen von Tieren und Pflanzen werden untersucht. Dabei können die Umstände definiert werden, unter denen im lakustrinen Bereich fossile Ablagerungen mit artikulierten Fischskeletten entstanden. Wichtigste Bedingung scheint das Vorhandensein von Stillwasserkörpern gewesen zu sein. Es ist für die Entwicklung von Schichtung im Wasser notwendig und damit verantwortlich für die Bildung dauerhafter, stagnierender Tiefwasserschichten mit Sauerstoffentzug, in denen eine anaerobe Zersetzung organischen Materials stattfand. Drei Haupttypen lakustriner fossilführender Sedimente werden unterschieden und durch konkrete Beispiele veranschaulicht., The causes of Recent mass-mortality events and the conditions needed for fossilization of soft parts of animals and plants are examined. So, can be defined the circumstances in which have been sedimented the strata yielding lacustrine articulated fossil fish skeletons. The occurrence of a quiet water-body seems to have been the more important condition. It is necessary for the development of water stratification and for the appearance of a permanent, stagnant deep-water layer, deprived of oxygen, in which took place the anaerobic decay of organic matter. Three main types of lacustrine fossiliferous sediments are distinguished and illustrated with concrete examples., Les causes des hécatombes actuelles et les conditions nécessaires à la fossilisation des tissus mous des organismes animaux et végétaux sont passées en revue. Cela permet de préciser les circonstances dans lesquelles se sont formés les gisements de squelettes de poissons dulçaquicoles. L'existence d'un milieu calme semble avoir été le facteur primordial. Elle favorise en effet la stratification des eaux et la formation d'une couche d'eau profonde dépourvue d'oxygène, dans laquelle peut se produire une décomposition anaérobie de la matière organique. Trois grandes catégories de sédiments lacustres fossilifères sont définies à l'aide d'exemples précis., Gaudant Jean. L'ichthyofaune des milieux confinés : intérêt pour l'étude paléolimnologique. In: Sciences Géologiques. Bulletin, tome 36, n°4, 1983. La vie dans les milieux confinés actuels et anciens. pp. 231-238.

During late - and post-glacial times lakes played a leading role in the development of the landscape of the North-west European part of USSR. A variety of geographic circumstances created great variegation of natural conditions in lakes and determined the composition of their diatoms. The basic stages of the development of the diatom flora of lakes are linked with general climatic changes. The deepwater regions of large periglacial lakes of the North-west USSR are inhabited by plankton diatoms of the genera Melosira and Cyclotella. Diatom analysis is further applied for the study of the history of the lakes of north-west USSR. Translated from German into English

Multi-proxy studies are becoming increasingly common in palaeolimnology. Eight basic requirements and challenges for a multi-proxy study are outlined in this essay – definition of research questions, leadership, site selection and coring, data storage, chronology, presentation of results, numerical tools, and data interpretation. The nature of proxy data is discussed in terms of physical proxies and biotic proxies. Loss-on-ignition changes and the use of transfer functions are reviewed as examples of problems in the interpretation of data from multi-proxy studies. The importance of pollen analysis and plant macrofossil analysis in multi-proxy studies is emphasised as lake history cannot be interpreted without knowledge of catchment history. Future directions are outlined about how multi-proxy studies can contribute to understanding biotic responses to environmental change.

In this study, Holocene mean July temperatures were reconstructed quantitatively based on subfossil chironomid remains. The specific goal was to evaluate whether lakes located below the modern tree line are appropriate sites for the chironomid-based reconstruction of small-scale temperature variations. On this account, the main questions were whether the water chemistry and physical conditions of the chosen lakes can be regarded as stable during the Holocene and whether the chironomid assemblages react sensitively to Holocene temperature fluctuations. To answer these questions, the sediments of the lakes Reiarsdalsvatnet and Isbenttjà ¸nn situated in Setesdal in southern Norway were studied in a multi-proxy approach, including age-depth modelling based on radiocarbon dating, chironomid and pollen analyses, and the analyses of carbon, nitrogen, sulphur and biogenic silica.The results show that subfossil chironomids from the studied non-alpine lakes do react sensitive to small-scale summer temperature fluctuations but they also point to the importance of a cautious selection of study sites. A thorough knowledge about the catchment-lake system and a thorough evaluation of the reconstructed temperatures is crucial to obtain reliable results. The results suggest that non-alpine lakes are high potential sites for the reconstruction of small-scale temperature variations based on chironomids.

This is the eighth in a series of nine papers published in this special issue dedicated to recent environmental change on Svalbard. H.J.B. Birks, Vivienne J. Jones, and Neil L. Rose were guest editors of this special issue. As part of a broader investigation into recent environmental change on Svalbard, the inorganic geochemical record of six lake-sediment cores was analysed. The major temporal trends in sediment elemental composition are driven by variations in two contrasting sediment components, both derived from catchment soils: (1) mineral matter, and (2) soil organic matter (SOM), enriched in Fe and Mn oxides and heavy metals. Two environmental impacts are recorded in most or all of the lake sediment sequences. An up-core increase in organic matter can be partly attributed to diagenetic effects, but also requires an enhanced supply of SOM relative to mineral matter. In addition, the central and southern sites all show a ca. 1970 event characterised by an enhanced mineral matter accumulation rate. This requires either an enhanced allochthonous supply or an enhanced mobilisation of littoral sediments. In either case a regional-scale driving force, such as a shift in climate, is required. At five of the lakes the sediment heavy metal concentration profiles can be explained entirely by natural factors. However, at Tenndammen (U), situated close to the Svalbard’s largest settlement at Longyearbyen, possible anthropogenic Pb enrichment is found. Comparison of observed and expected heavy metal profiles (based on Greenland ice-core data) shows that the lakes are generally too insensitive to have recorded a long-transported heavy metal pollution signal.

The first sediment core analyses were carried out in 1958, but it is only from 1985 onward that a modern palaeolimnological approach was applied to the study of Lake Orta, a large and deep lake in North Italy, heavily polluted by ammonia and copper for about 50 and 30 years, respectively. Thus, we summarise those studies from a variety of sediment cores, collected in different years and sites, using both published and unpublished data. Changes in algal pigments (mainly chlorophyll derivatives, total and single carotenoids), inorganic geochemistry, especially heavy metals (e.g. Cu), diatoms, Cladocera, and thecamoebians were studied and related to the stressed environment. The whole picture reveals a close relationship between modifications in algal biomass, density, taxonomic composition and organisms size on the one hand, and water chemistry changes on the other hand. Long-term history of this lake over 7-8 centuries, including invertebrate and terrestrial vegetation dynamics (pollen stratigraphy), reveals close relationship with natural (climate) and anthropogenic forces.