Talk: Tracking prehistoric pastoralism in subalpine and alpine soils - preliminary results of the Montafon and the Silvretta Alps (Austria/Switzerland)

• Katja Kothieringer
• Astrid Röpke, Universität zu Köln
• Thomas Reitmaier, Archäologischer Dienst Graubünden, Schweiz
• Rüdiger Krause, Goethe Universität Frankfurt

Subalpine and alpine soils in high mountainous regions of the Alps have been influenced by pastoral activity for thousands of years. Building on previous palaeoecological, geoarchaeological and archaeological investigations in the Montafon (Austria) and the adjacent Silvretta Alps (Austria, Switzerland), we assume increasing pastoral activity during the Bronze Age. Total phosphate content was measured in subalpine (~ 1300 - 2300 m a.s.l) soils in order to receive more knowledge about past grazing intensity at different altitudes. We mostly selected soils which have been radiocarbon dated by charcoal, if possible charcoal layers. So far, our results suggest that the uppermost topsoil clearly reflects recent pasture activity. Abandoned or less-used pasture areas have lower phosphate values. In the subalpine region of Val Urschai (Silvretta), a mesolithic soil profile at the steep left flank of the valley, which nowadays is barely used for grazing, shows rather low phosphate concentrations; however, the values indicate past grazing of wild animals or livestock. According to our radiocarbon dates, we also have evidence of increased phosphate concentrations in Bronze Age colluvial layers at Bartholomäberg, and maximum phosphate values have been measured in a Bronze Age enclosure in Las Gondas (Silvretta). Additionally, high phosphate concentrations in different colluvial layers at Schafberg, Gargellen (Montafon) can be interpreted as long-term grazing pressure. Beside tracking former pastoral activity, phosphate concentrations seem to be a suitable parameter to identify palaeosurfaces (fossil A-horizons) and thus help to reconstruct past and present soil formation processes. Measurements of phosphate in alpine soils above 2300 m a.s.l are still pending, first results of which will be presented at the conference.