TY - JOUR A1 - Wischnewski, Juliane A1 - Kramer, Annette A1 - Kong, Zhaochen A1 - Mackay, Anson W. A1 - Simpson, Gavin L. A1 - Mischke, Steffen A1 - Herzschuh, Ulrike T1 - Terrestrial and aquatic responses to climate change and human impact on the southeastern Tibetan Plateau during the past two centuries JF - Global change biology N2 - Rapid population growth and economic development have led to increased anthropogenic pressures on the Tibetan Plateau, causing significant land cover changes with potentially severe ecological consequences. To assess whether or not these pressures are also affecting the remote montane-boreal lakes on the SE Tibetan Plateau, fossil pollen and diatom data from two lakes were synthesized. The interplay of aquatic and terrestrial ecosystem response was explored in respect to climate variability and human activity over the past 200 years. Nonmetric multidimensional scaling and Procrustes rotation analysis were undertaken to determine whether pollen and diatom responses in each lake were similar and synchronous. Detrended canonical correspondence analysis was used to develop quantitative estimates of compositional species turnover. Despite instrumental evidence of significant climatic warming on the southeastern Plateau, the pollen and diatom records indicate very stable species composition throughout their profiles and show only very subtle responses to environmental changes over the past 200 years. The compositional species turnover (0.36-0.94 SD) is relatively low in comparison to the species reorganizations known from the periods during the mid-and early-Holocene (0.64-1.61 SD) on the SE Plateau, and also in comparison to turnover rates of sediment records from climate-sensitive regions in the circum arctic. Our results indicate that climatically induced ecological thresholds are not yet crossed, but that human activity has an increasing influence, particularly on the terrestrial ecosystem in our study area. Synergistic processes of post-Little Ice Age warming, 20th century climate warming and extensive reforestations since the 19th century have initiated a change from natural oak-pine forests to seminatural, likely less resilient pine-oak forests. Further warming and anthropogenic disturbances would possibly exceed the ecological threshold of these ecosystems and lead to severe ecological consequences. KW - climate change KW - compositional species turnover KW - diatoms KW - human impact KW - pollen KW - Procrustes rotation KW - Tibetan Plateau Y1 - 2011 U6 - https://doi.org/10.1111/j.1365-2486.2011.02474.x SN - 1354-1013 VL - 17 IS - 11 SP - 3376 EP - 3391 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Herzschuh, Ulrike A1 - Kramer, Annette A1 - Mischke, Steffen A1 - Zhang, Chengjun T1 - Quantitative climate and vegetation trends since the late glacial on the northeastern Tibetan Plateau deduced from Koucha Lake pollen spectra N2 - Quantitative information on vegetation and climate history from the late glacial-Holocene on the Tibetan Plateau is extremely rare. Here, we present palynological results of a 4.30-m-long sediment record collected from Koucha Lake in the Bayan Har Mountains, northeastern Tibetan Plateau. Vegetation change has been traced by biomisation, ordination of pollen data, and calculation of pollen ratios. The application of a pollen-climate calibration set from the eastern Tibetan Plateau to Koucha Lake pollen spectra yielded quantitative climate information. The area was covered by alpine desert/steppe, characteristic of a cold and dry climate (with 50% less precipitation than today) between 16,700 and 14,600 cal yr BP. Steppe vegetation, warm (similar to 1 degrees C higher than today) and wet conditions prevailed between 14,600 and 6600 cal yr BR These findings contradict evidence from other monsoon-influenced areas of Asia, where the early Holocene is thought to have been moist. Low effective moisture on the northeastern Tibetan Plateau was likely due to high temperature and evaporation, even though precipitation levels may have been similar to present- day values. The vegetation changed to tundra around 6600 cal yr BP, indicating that wet and cool climate conditions occurred on the northeastern Tibetan Plateau during the second half of the Holocene. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00335894 U6 - https://doi.org/10.1016/j.yqres.2008.09.003 SN - 0033-5894 ER - TY - JOUR A1 - Hellmann, Uwe A1 - Rettweiler, Udo A1 - Kramer, Annette A1 - Zehe, Erwin A1 - Jacob, Andreas A1 - Hafner, Johann Evangelist A1 - Tronicke, Jens A1 - Mühle, Ralf-Udo A1 - Klauss, Susanne A1 - Dietrich, Larissa A1 - Richter, Norbert A1 - Schweigl, Kerstin T1 - Portal = Ressource Wasser: Mehr als ein Elixier des Lebens BT - Die Potsdamer Universitätszeitung N2 - Aus dem Inhalt: - Ressource Wasser: Mehr als ein Elixier des Lebens - Dorniges hinter Glas - Die Profstars 2007 - Technik gegen unerwünschte Mithörer entwickelt T3 - Portal: Das Potsdamer Universitätsmagazin - 04-05/2007 Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-440051 SN - 1618-6893 IS - 04-05/2007 ER - TY - THES A1 - Kramer, Annette T1 - Late quaternary environment of the south-eastern Tibetan Plateau-ecosystem and climate dynamic inferred from pollen and non-pollen palynomorphs Y1 - 2008 CY - Potsdam ER -