Ostracoda from inland waterbodies with saline influence in Central Germany: Implications for palaeoenvironmental reconstruction

As a necessary precursor to reconstructing the palaeoenvironmental conditions likely to be temporarily influenced by salt bearing ground waters, modern sites of Central Germany, known from the literature to be continental salt water localities, were investigated for their ostracod faunas. Analysing their associations enables the test of several methods in palaeoenvironmental analysis based on ostracods. In total, 54 ostracod taxa are documented. One species, Microdarwinula zimmeri, is new for the area. Interesting is the historical occurrence of Cyprideis torosa and Cytheromorpha fuscata, typically regarded as indicators of brackish water. The draining of wetlands has led to the disappearance of many former inland salt sites so that only a few of the sampled water bodies still show slightly elevated salinity (oligohaline range). The most important factors for the distribution of ostracod associations are groundwater influence, turbidity and ecological stability, whereas the type of dominating ions is of lesser importance because of time-averaging using taphocoenoses from surface sediments in our study. The relative proportion of ecological groups of ostracods appears to be the best tool for reconstructing past habitat types. The newly established Ostracod Permanence Index and Ostracod Turbulence Index allow the recognition of the influx of ground and surface waters, perennial habitats and flowing waters. A test of the Mutual Ostracod Temperature Range (MOTR) method demonstrates its capability to reconstruct, with a precision of +/-2 degrees C, the mean July and January air temperatures for the time interval 2002-2012. Additionally, the study contributes to the poorly known Recent distribution of ostracods in Central Germany. (C) 2014 Elsevier B.V. All rights reserved.