Living organisms and sedimentary remains from high mountain lakes in the Alps

We publish a data set of environmental and biological data collected in 2000 during the ice-free period in high mountain lakes located above the local timberline in the Alps, in Italy, Switzerland and Austria. Environmental data include coordinates, geographical attributes and detailed information on vegetation, bedrock and land use in lake catchments. Chemical analyses of a sample for each lake collected at the lake surface in Summer 2000 are also reported. Biological data include phytoplankton (floating algae and cyanobacteria), zooplankton (floating animals), macroinvertebrates (aquatic organisms visible to the naked eye living in contact with sediments on lake bottom), benthic diatoms. Diatoms, cladocera and chironomids remains and algal and bacterial pigments were also analysed in lake sediments

Klimawandel in Österreich – Die letzten 20.000 Jahre ... und ein Blick voraus.

The changes in climate affected especially the Alps during the past 20,000 years. In this book more than 20 experts from different fields present the current state of climate research in Austria, starting from the last ice age until the current climate warming. In the early Holocene human activities were driven by the climate while in modern societies climate change is driven to an increasing amount by human activities. Undoubtedly the Alps where much more affected by climate change than many other regions of the world, but still the authors dare to look ahead into the future

The Water Balance of the Alps – What do we need to protect the water resources of the Alps? Proceedings of the Conference held at Innsbruck University, 28-29 September 2006

This book contains the proceedings of the conference “The Water Balance of the Alps. What do we need to protect the water resources of the Alps?” held in Innsbruck in September 2006. The aim of the conference was to present the view of researchers as well as of administrators, and to discuss the best way to protect sensitive waters, including ice and snow, of the Alps. Intensive discussions about the best way to protect sensitive water bodies in the Alps – either by implementing specific and hitherto neglected aspects peculiar to mountain regions into the EU Water Framework Directive or by creating a new Water Protocol for the Alpine Convention – went along with the presentation of fresh views on known water problems

Impact of late glacial climate variations on stratification and trophic state of the meromictic lake Längsee (Austria): validation of a conceptual model by multi proxy studies

Selected pigments, diatoms and diatom-inferred phosphorus (Di-TP) concentrations of a late glacial sediment core section of the meromictic Längsee, Austria, were compared with tephra- and varve-dated pollen stratigraphic and geochemical results. A conceptual model was adopted for Längsee and evaluated using multi proxy data. During the unforested late Pleniglacial, a holomictic lake stage with low primary productivity prevailed. Subsequent to the Lateglacial Betula expansion, at about 14,300 cal. y BP, okenone and isorenieratene, pigments from purple and green sulphur bacteria, indicate the onset of anoxic conditions in the hypolimnion. The formation of laminae coincides with this anoxic, meromictic period with high, though fluctuating, amounts of okenone that persisted throughout the Lateglacial interstadial. The occurrence of unlaminated sediment sections of allochthonous origin, and concurrent low concentrations of okenone, were related to cool and wet climate fluctuations during this period, probably coupled with a complete mixing of the water column. Two of these oscillations of the Lateglacial interstadial have been correlated tentatively with the Aegelsee and Gerzensee oscillations in the Alps. The latter climate fluctuation divides a period of enhanced anoxia and primary productivity, correlated with the Alleröd chronozone. Continental climate conditions were assumed to be the main driving forces for meromictic stability during Alleröd times. In addition, calcite dissolution due to severe hypolimnetic anoxia, appear to have supported meromictic stability. Increased pigment concentrations, which are in contrast to low diatom-inferred total phosphorus (Di- TP), indicate the formation of a productive metalimnion during this period, probably due to a clear-water phase (low catchment erosion), increased temperatures, and a steep gradient between the phosphorus enriched hypolimnion and the oligotrophic epilimnion. Meltwater impacts from an extended snow-cover and a summer temperature decline, together with climate instability, are assumed to be the main reasons for the lowering of the anoxic level during the following, climatically heterogeneous, Younger Dryas. Meromictic stability was re-established with the termination of the Younger Dryas. The sequence of key pigments, Di-TP, calcite, siliciclastics, and organic carbon, seem to be in accordance with the assumptions of the conceptual model