New and previously collected ostracod specimen will be used to test the relationship between microhabitat characteristics and morphological variability (Fürstenberg et al., 2015) in order to improve the taxonomy and further redefine the existing water depth-related transfer function. This will provide a high-resolution lake level reconstruction and check the effects of environmental changes on morphological character traits. In cooperation with project P1, living specimen and fossil remains of ostracods and chironomid larvae will be used for stable isotope analysis to detect past changes in food webs and especially the aquatic C cycle. This hitherto untested combination of stable isotope proxies is especially promising as we will combine two benthic organism groups, with the isotope signature of the chitinous chironomid fossils closely resembling the one of living larvae (Frossard et al., 2013), whereas isotope values of calcarous ostracod shells may be influenced by selection during shell calcite production and / or diagenetic modification. The comparison of both stable isotope signatures may thus show potential to infer further information about lacustrine conditions during / after time of fossil deposition.
Our Chinese cooperation partners will focus on detection of physico-chemical cycles in water and sedimentary parameters within the Nam Co catchment (e.g. Wang et al., 2015). Research on season and interannual variation in stable isotope signatures of water and sediment (from sediment traps) will largely contribute to understand present and past variations in the isotope signature of invertebrates and their fossil remains, and allow to calibrate the organism stable isotope proxy. Long-time monitoring of lake volume changes from SRTM data and Landsat images will be available to control invertebrate-based reconstructions for recent decades.
Prof. Dr. Antje Schwalb, TU Braunschweig
PD Dr. Peter Frenzel, FSU Jena
Prof. Dr. Zhu Liping, ITP