TY - JOUR A1 - Mischke, Steffen A1 - Almogi-Labin, Ahuva A1 - Al-Saqarat, Bety A1 - Rosenfeld, Arik A1 - Elyashiv, Hadar A1 - Boomer, Ian A1 - Stein, Mordechai A1 - Lev, Lilach A1 - Ito, Emi T1 - An expanded ostracod-based conductivity transfer function for climate reconstruction in the Levant JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - We present the first modern calibration dataset linking ostracod assemblage composition to water chemistry, and other site-specific variables, in the hydrologically and geopolitically sensitive southern Levant region. A total of 42 ostracod taxa were recorded from the 178 sampled sites in Israel and Jordan. Ilyocypris spp., Heterocypris salina and Cypridopsis vidua are the most abundant taxa. Species strictly confined to freshwater conditions are Prionocypris zenkeri, Gomphocythere ortali and Prionocypris olivaceus. In contrast, H. sauna, Bradleytriebella lineata and Cyprideis torosa show high frequencies in brackish waters (waters with higher conductivity). Humphcypris subterranea, G. ortali, P. olivaceus and Cypridopsis elongata apparently prefer flowing waters. Specific conductivity optima and tolerance ranges were calculated for the recorded ostracod species and may be used for the palaeoenvironmental assessment of fossil ostracod assemblages. In addition, a transfer-function for quantitative specific conductivity estimation based on 141 samples was established with weighted averaging partial least squares regression (WA-PLS). The resulting coefficient of determination r(2) between observed and predicted conductivity values (0.72) and the root-mean-square error of prediction (RMSEP) in % gradient length (13.1) indicate that conductivity may be reliably estimated from ostracod assemblage data. The transfer function was first applied to last glacial ostracod assemblage data from an archaeological trench in the Sea of Galilee (northern Israel). Relatively large conductivity fluctuations between ca 1 and 7 mS cm(-1) were inferred for the period 24-20 cal ka BP. In addition, four episodes of freshwater influx near the site of the trench were identified from the presence of shells of freshwater and stream-dwelling species intermingled with very abundant shells of Cyprideis torosa. The results of our study allow a better use of Quaternary ostracods from the Levant as palaeoenvironmental indicators of water-body types and past conductivity levels and will contribute to a better understanding of Quaternary environmental and climate change in the Levant. (C) 2014 Elsevier Ltd. All rights reserved. KW - Ostracoda KW - Transfer function KW - Conductivity KW - Salinity KW - Near East KW - Sea of Galilee KW - Ohalo Site Y1 - 2014 U6 - https://doi.org/10.1016/j.quascirev.2014.04.004 SN - 0277-3791 VL - 93 SP - 91 EP - 105 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Mischke, Steffen A1 - Ginat, Hanan A1 - Al-Saqarat, Bety A1 - Almogi-Labin, Ahuva T1 - Ostracods from water bodies in hyperarid Israel and Jordan as habitat and water chemistry indicators JF - Ecological indicators : integrating monitoring, assessment and management N2 - The hyperarid region of Israel and Jordan covers a large area where numerous sites of Pleistocene lake sediments suggest that climate conditions were significantly wetter during the Pleistocene. This region experienced a significant increase in aridity in recent decades and the number of existing surface waters is diminishing rapidly. We studied ostracod shells from 49 pond and stream sites to determine the species distribution and to infer ecological preferences especially with respect to general differences in water movement, conductivity and ion composition. Twenty-two ostracod species were identified in total of which 12 taxa occur at three or more sites. Among the rarer species. Cyprinotus scholiosus was identified for the first time after two records from Plio- and Pleistocene sites in Yemen and Saudi Arabia. Further, Paracypretta amati was recorded and its ecological preferences discussed for the first time following the description of the species from its type locality in Sudan. Cypridopsis elongata is the only typical inhabitant of lotic habitats, strictly preferring freshwater conditions and waters with an alkalinity/Ca ratio around 1 and cations dominated by Ca(2+) and anions by HCO(3)(-). In contrast, Cyprideis torosa, Limnocythere inopinata and Heterocypris incongruens apparently prefer waters dominated by Na(+) associated with cations and Cl(-) associated with anions. Heterocypris salina and C. torosa occur over a wide conductivity (or salinity) range and in waters with alkalinity/Ca ratios around 1 and with significant alkalinity depletion. Humphcypris subterranea, Ilyocypris spp. and H. sauna are the only taxa which do not show any preference with respect to both the cation and anion dominance of the waters. The ecological preferences of the ostracod species from water bodies in the study area are discussed in detail and can be used for a qualitative assessment of the hydrodynamical and hydrochemical conditions of former water bodies in the presently hyperarid environment based on ostracod species composition analysis of Pleistocene aquatic sediments. KW - Ostracoda KW - Non-marine KW - Water chemistry KW - Ecology KW - Near East Y1 - 2012 U6 - https://doi.org/10.1016/j.ecolind.2011.07.017 SN - 1470-160X VL - 14 IS - 1 SP - 87 EP - 99 PB - Elsevier CY - Amsterdam ER -