Botanical macro-remains and insects from the Eemian and Weichselian site of Oerel (northwest Germany) and their evidence for the history of climate

The late Pleistocene site of Oerel which represents the Eemian and the Weichselian interstadials Brörup, Odderade, Oerel and Glinde as well as parts of the stadials Herning and Rederstall was investigated for botanical remains such as fruits, seeds, wood, leaves and mosses, as well as insect remains. A large number of taxa were identified. They show the different environmental conditions, in particular several changes of water level leading to the formation of lakes and diverse forms of mires up to raised bogs. The trophic conditions, too, changed several times. The macrofossil record supports the pollen evidence of dense forests during the two early Weichselian interstadials and tundra vegetation during the later ones. Several indicator species show comparably warm summers but very cold winters during the Brörup and Odderade while the climate during Oerel and Glinde was generally cool. Climatic reconstructions using the MCR method were performed on the basis of the beetle finds.     

A contribution towards the reconstruction of Eemian vegetation and climate in central Europe: First results of pollen and oxygen-isotope investigations from Mondsee, Austria

In this paper, the results of pollen analysis and oxygen-isotope investigations of two new cores from Mondsee are discussed. The climatic progression from the end of the penultimate glaciation to the end of the Eemian interglacial is compared with reconstructions from Bispingen and Gräbern, northern Germany. The rise in temperature, between thePinus phase and the climate optimum in theCorylus phase, appears to have occurred in two steps. Evidence for climatic deterioration is first recorded during thePicea-Pinus phase, i.e. after theCarpinus phase. These reconstructions are in agreement with those based on the Gräbern pollen data, but contrast with recent reconstructions based on the Bispingen pollen profile and the GRIP ice core from Greenland.     

Eemian and Early Weichselian vegetation and climate history in Central Europe: A case study from the Klinge section (Lusatia, eastern Germany)

The paper presents vegetation and climate reconstructions for Eemian and Early Weichselian in Central Europe based on detailed pollen data of the Klinge section. The sediments exposed in this profile were accumulated from the Saalian termination up to the Early Weichselian glaciation. A succession of forest communities, typical for the Eemian interglacial has been recorded. Pollen data indicate some oscillations during the very end of the Eemian (biozone E7). The climatic reconstructions show the heat supply rising gradually from the beginning of the interglacial to its middle part. A long-term cooling trend in January temperature was reconstructed for the second half of the interglacial. The difference between the optimum (zone E4b) and Pinus-Picea-Abies zone (E6) amounts to 4 °C, during the Pinus zone (E7) the temperature further decreased by 8 °C. The changes in July temperature were not so dramatic (about 3 °C).     

Paleontological evidence of a brief global sea-level event during the last interglacial

A gently undulating to flat erosion surface with shallow-water borings and burrows is present in the midst of a Sangamonian (Eemian; marine oxygen isotope substage 5e) reefal facies on the islands of San Salvador and Great Inagua, Bahamas. Precise U/Th dating of corals above and below this surface show that it formed around 125-124 ka, and that the sea-level regressive-transgressive cycle which produced it lasted for 1500 years or less. The surface occurs on entirely carbonate rocks and has a low relief punctuated by erosional channels and karstic caves formed during the sea-level lowstand. A terra rossa paleosol, developed during that lowstand, partially fills a set of large lithophagid bivalve borings ( Gastrochaenolites torpedo ), showing that they were excavated during the regression. Rhizomorphs formed by plant roots occur on the erosion surface at Great Inagua. Extensive boring of the upward-facing surfaces occurred during the ensuing transgression, including a smaller G. torpedo and a clionid sponge boring ( Entobia ovula ). The bored surface is encrusted by a variety of shallow-water corals and, eventually, the re-established bank-barrier coral reefs. A sparse assemblage of serpulid worm and vermicularid gastropod tubes encrusted the channel and cave walls. Robust Ophiomorpha burrow systems occur within pockets of sediment in the coral facies both below and above the erosion surface. The channels and caves are filled with transgressive calcarenitic sediments in which occur numerous Ophiomorpha and Skolithos burrows. The ichnofossils on, below, and above this erosion surface are prominent indicators of a short-lived but significant global sea-level event.     

Identifying refugia from climate change

This article highlights how the loose definition of the term ‘refugia’ has led to discrepancies in methods used to assess the vulnerability of species to the current trend of rising global temperatures. The term ‘refugia’ is commonly used without distinguishing between macrorefugia and microrefugia, ex situ refugia and in situ refugia, glacial and interglacial refugia or refugia based on habitat stability and refugia based on climatic stability. It is not always clear which definition is being used, and this makes it difficult to assess the appropriateness of the methods employed. For example, it is crucial to develop accurate fine‐scale climate grids when identifying microrefugia, but coarse‐scale macroclimate might be adequate for determining macrorefugia. Similarly, identifying in situ refugia might be more appropriate for species with poor dispersal ability but this may overestimate the extinction risk for good dispersers. More care needs to be taken to properly define the context when referring to refugia from climate change so that the validity of methods and the conservation significance of refugia can be assessed.