NBS – Palaeoecological Studies within the Prehistorical Pile-dwelling and Settlement Hot-Spot at Lake Nussbaumersee, Thurgovia (Switzerland

The Seebachtal Valley located southwest of Lake Constance in the Swiss province of Thurgovia was settled by prehistoric people since the Neolithic period. Archaeological research has revealed three major lake-shore and pile-dwelling villages at Lake Nussbaumersee from the Neolithic (3840-3700 BC), Early Bronze Age (1580-1538 BC) and Late Bronze Age (850-800 BC). Lake sediment cores are studied for pollen, non-pollen palynomorphs and macrofossils in order to reconstruct general landscape and vegetation dynamics related to anthropogenically induced landscape alterations. Both pollen and macrofossils show human impact on the surrounding vegetation and on the hydrophyte vegetation during several periods since the Neolithic. Additional evidence for human and livestock activities in and around the settlements (e.g. through findings of higher numbers of Sordariales or parasitic animal remains) is revealed by the analysis of non-pollen-palynomorphs. Various phases of sharp increases in numbers of Cyanobacteria and Chlorophyceae, indicating lake eutrophication, may be linked with human settlement phases. The best example for this human-induced eutrophication was found during the time of the Neolithic village, where a succession from Cyanobacteria to green algae is revealed within a time frame of less than 200 years. This succession is very similar to the human influence period found for Early Bronze Age and Medieval settlements at lakes in Poland. After the end of according settlement periods on the shore of Lake Nussbaumersee the abundance of both green algae and Cyanobacteria decreased rapidly, suggesting a high level of resilience to eutrophication of the lake ecosystem. High-resolution analyses of the cultural layers of the Neolithic, Pfyner Culture (after 3582 BC) village settlement Nussbaumersee-"Inseli" will allow correlation of palynological and palaeoethnobotanical results in terms of anthropogenic pressure on prehistorical ecosystems.

Selected Publications
Haas, J.N. & Hadorn, P. (1998): Die Vegetations- und Kulturlandschaftsgeschichte des Seebachtals von der Mittelsteinzeit bis zum Frühmittelalter anhand von Pollenanalysen.In: A. Hasenfratz & M. Schnyder: Das Seebachtal - Eine archäologische und paläoökologische Bestandesaufnahme. Forschungen im Seebachtal 1. Archäologie im Thurgau 4: 221-255.

Hillbrand, M., Hadorn, Ph., Hasenfratz, A. & Haas, J.N. (2010): Neolithic and Bronze Age Human Impact and Landscape Development in the Seebachtal, Thurgau, Switzerland. Terra Nostra 2010/2: 137.