Abstract
The southern Levant is a Mediterranean climate zone of complex variability in which uncertainty remains in regional palaeoclimate reconstruction. In spite of the proven value of diatoms in circum-Mediterranean palaeoenvironmental research, their potential remains largely unexplored in the southern Levant region. In this study, we generate a new, high-resolution multi-proxy record for the last ca. 9000 cal. yr BP, supported by diatom data and key biological, mineralogical and geochemical indicators preserved in a 17.8-m-long sediment sequence recovered from Lake Kinneret (the Sea of Galilee), Israel. During the Holocene, well-correlated shifts in the diatom, minero-geochemical and palynological data indicate marked lake-level variation over time as well as changes in the trophic state of Lake Kinneret. Our results are particularly important in improving the reconstruction of Holocene lake-level variation, and thus past moisture availability. Diatom-inferred lake-level oscillations correlate well with the output from climatic models from the Levantine region and clarify previous uncertainty concerning regional variation in moisture availability. The Early Holocene (from ca. 9000 to 7400 cal. yr BP) was characterized by lake-level shifts due to fluctuating dry-wet climate conditions. During the mid-Holocene (from 7400 to 2200 cal. yr BP), a stable, deep lake-level phase persisted due to high humidity. The lake level of modern Lake Kinneret not only fluctuates seasonally with available moisture, but has also been influenced for ca. 2000 years by the impacts of water abstraction for human consumption and agriculture. Over the last 9000 cal. yr BP, the trophic state of Lake Kinneret has changed from an oligotrophic to a meso- to eutrophic environment, mainly triggered by increased human impact from around 2200 cal. yr BP onwards. The lake’s ecosystem status was not strongly affected by the documented major changes in human occupation patterns during the mid-Holocene, when a relatively stable environment persisted.
Highlights
The Eastern Mediterranean is a key region for palaeoclimate research due to its considerable sensitivity to climate change because of its location between the North Atlantic pressure systems, the monsoons of East Africa and India and the continental climate of Europe (Lionello et al, 2006)
We present the results of high-resolution diatom analysis combined with minerogeochemical analysis of a 17.8 m long Holocene sediment sequence from Lake Kinneret
Diatom analysis A total of 143 diatom taxa were identified within the subfossil sediment sequence of Lake Kinneret, most of which can be classified as oligohalobous-indifferent, requiring alkaline water for optimal growth (Krammer and Lange-Bertalot, 1986, 1988, 1991a, 1991b, Ehrlich, 1995, Lange-Bertalot, 2013)
Summary
The Eastern Mediterranean is a key region for palaeoclimate research due to its considerable sensitivity to climate change because of its location between the North Atlantic pressure systems, the monsoons of East Africa and India and the continental climate of Europe (Lionello et al, 2006). Establishing a coherent linkage between different sources of data in the southern Levant (e.g. lacustrine and marine sediment records, speleothem data) can be challenging, e.g. due to distinctive gradients in topography and moisture availability It is not understood whether apparent discrepancies are a result of real spatial variability in climate response (Rambeau, 2010), that of differences in response thresholds between palaeoenvironmental archives, or are a function of data quality. Palaeolimnological reconstructions based on diatoms (single-celled siliceous algae; Bacillariophyceae) have been limited in the southern Levant, in spite of their high sensitivity to a wide range of limnological variables (van Dam et al, 1994) and proven potential in palaeoclimate research in Mediterranean climate zones (Battarbee et al, 2001, Cvetkoska et al, 2014, Zhang et al, 2014). Our results are set in the context of known regional records, considering short-term climate events, to test whether there is coherency in regional patterns of climate change during the Holocene
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
