Book ID: 102196
Edited by Andrzej Witkowski: Volume 15: Cvetkoska, Aleksandra, Jane M. Reed and Zlatko Levkov: Diatoms as indicators of environmental change in ancient Lake Ohrid during the last glacial - interglacial cycle (ca. 140 ka). 2012. 49 plates (SEM). 224 p. gr8vo. Hardcover. (ISBN 978-3-87429-428-7)
Contents (chapter headings): Introduction (Previous research on Lake Ohrid); Materials and Methods (Site description, Core recovery and chronology, Diatom analysis); Observations (Observations of dominant Cyclotella species complexes, Cyclotella ocellata complex, Cyclotella fottii complex, Description of the most abundant diatom taxa in core Co1202); Diatom response to climate change and tephra impact (Ordination of C. fottii and C. ocellata morphotype data, Dissolution, Correlation with tephra impact); Discussion (Species-level diatom response to climate, Biodiversity and evolution, Diatom dissolution, Correlating morphological variability with climate changes, Strategies for future taxonomic analysis); Conclusions. Lake Ohrid (Macedonia/Albania) is probably the oldest lake in Europe, with an estimated age of 2 - 10 Ma. It is widely recognized that the palaeolimnological records preserved in the sediments of ancient lakes such as Ohrid are important archives of Quaternarycclimate change, providing long-term, high-resolution, continuous sequences which are terrestrial equivalents of the marine and ice-core records. These lakes are also hotspots of biodiversity,habouring exceptional diversity of endemic taxa. As part of multi-proxy palaeolimnological research in advance of an International Continental Deep Drilling Programme coring campaign in 2012, this study focuses on taxonomy in presenting the results of a diatom-based study of a 14.5 m long sequence (core Co1202), which spans the last ca. 135 ka of lacustrine history. The authors aimed at testing diatom response to major climate events and the impact of tephra from Italian volcanic eruptions across two glacial-interglacial transitions. Pursuing the taxonomic theme, this extended to analysis of sub-species level morphological variability. The results indicate that in Ohrid the diatoms are extremely sensitive palaeoclimate indicators, tracking glacial-interglacial shifts and more subtle global events including MIS3. We have also identified a sub-species level response in planktonic diatom taxa which is likely to contribute additional proxy data in future palaeoclimate studies. They are theonly biotic organisms to be preserved throughout glacial-interglacial cycles, suggesting their value extends also to testing theories of evolution and biodiversity over the Quaternary as a whole.