Abstract ID: 3.21205 | Accepted as Poster | Poster | TBA | TBA

Subfossil remains in lake sediments help us to understand past ecological events. In the case of the Salzbodensee, a shallow alpine lake in East-Tyrol fed exclusively by groundwater, the sediment core likely covers a time span of approximately 145 years. The age of the lake itself is estimated to predate the end of the Little Ice-Age. The lake plankton is currently dominated by two large cladoceran and copepod species, Daphnia longispina and Hetercope saliens.

As part of a long-term biodiversity study in the Hohe Tauern region, this work aims to help to answer the questions of when these species first appeared after the glacier retreated, how the species composition changed over time, whether the lake has always been dominated by the two species currently found or whether there has been species replacements over time.

For identification, mainly cladoceran remains were used, especially postabdomens and postabdominal claws. The analysis was carried out as a part of a bachelor´s thesis project and is still in progress, but first observations suggest a continuous presence of cladocerans and an increasing number of individuals in the upper (younger) layers, but with a different species composition than is currently found in the plankton.

These findings offer a basis for further analysis, such as the identification of species by reactivating resting eggs (if present in the sediment) or through genetic analysis of the sediment core.