58. Ammer River Valley (south-western Germany)

Abstract

The pollen profile was obtained from the floodplain of Ammer River Valley, west of Tübingen in southwestern Germany. Underground water from a Triassic limestone aquifer feeds the small modern-day Ammer River, which is a tributary of the Neckar River (Schwientek et al. 2013). The climate is humid-temperate with highest air temperatures from June to August (mean 21–24 °C) and lowest temperatures during December to February (mean −1 to 0 °C). The nature reserve Schönbuch north of the Ammer River Valley is characterised by thermophilous and drought-adapted vegetation on south-facing slopes (Arnold 1986). Pleistocene and Holocene sediments cover the Ammer River Valley consisting of brown alluvial clays, Tufa, grey clays, and fluvial and colluvial gravels on top of the Middle Triassic dolostones and mudstones (Geyer et al. 1995; Heidgen et al. 2020; Martin et al. 2020). In addition, the Ammer River Valley is partly covered by nutrient-rich loess deposits. Agriculture dominates today 71% of the land cover and oak, beech, and pine trees are covering hillslopes by ∼12% (Schwientek et al. 2013). Nearby, several archaeological sites have been investigated, such as Neolithic settlements of the Lineare Bandkeramik period (6.3–6.0 cal ka BP), excavated by Krauß et al. (2020), and the Mesolithic archaeological site ‘Rottenburg-Siebenlinden’ (c. 6 km away), which revealed human occupation from 10.1–7.8 cal ka BP (Kind 2010). Sediment description and dating Two sediment cores, X039A and X039B, (48° 31′ 44.11′′ N, 08° 57′ 47.73′′ E) were taken in continuous 2 m intervals with no overlap, with core recovery of about 82% (Heidgen et al. 2020). The palynological studies concentrated on the upper 8 m from core X039B (Table I), from which 46 samples, with pollen sums between 150 and 500 arboreal pollen grains, were analysed. Pollen taxonomy follows Beug (2004). In addition to dispersed spores and pollen grains, microcharcoals > 10 μm and non-pollen palynomorphs (NPPs) were registered as well. The software TILIA (incl. CONISS) was used for constructing the pollen diagram and to determine the local pollen assemblage zones (LPAZs) (Grimm 1992a, 1992b). The chronology of core X039B is based on 14 accelerator mass spectrometry (AMS) carbon-14 (C) dates (Table II).