Middle Bronze Age land use practices in the north-western Alpine foreland – A multi-proxy study of colluvial deposits, archaeological features and peat bogs

35 This paper aims to reconstruct Middle Bronze Age (MBA, 1600 – 1250 BCE) land use practices in the north-western Alpine foreland (SW Germany, Hegau). We used a multi-proxy approach including the analysis of biogeochemical proxies from colluvial deposits and buried topsoils in the surrounding of the well-documented settlement site of Anselfingen and offsite pollen data from two peat bogs. This approach allowed in-depth insights into the MBA subsistence economy and shows that

archaeopedological and archaeobotanical evidence is available so far for MBA settlements in the north-western Alpine foreland. Additionally, the information from offsite (distance > 5 km to the site) proxies is more closely related to the vicinity of lakes and bogs than to settlements further inland (Rösch, 2013;Tinner et al., 2003).
One approach to overcome these drawbacks is the analysis of colluvial deposits and buried topsoils as archives for the 75 reconstruction of past land use practices, close to documented settlement sites (Kittel, 2015, Ponomarenko et al., 2020. With respect to the diverse definitions of colluvial deposits as hillslope sediments transported by either mass-gravity transport or slopewash type processes (Miller and Juilleret, 2020), we refer to the German term 'Kolluvium', which defines colluvial deposits as the correlate sediments of human-induced soil erosion (e.g. Kadereit et al., 2010). In Central Europe, human impact on the terrestrial ecosystem has distinctly increased since the Late Holocene (Winiwarter and Bork, 2019) and land use 80 practices such as deforestation and soil tillage have left land use traces (e.g. charcoal, archaeobotanical and biogeochemical proxies) that are archived in colluvial deposits by impeding degradation processes through continuous sedimentation . Therefore, colluvial deposits can be considered one of the key archives for human-land interactions (Pietsch and Kühn, 2017;Zádorová, and Penížek, 2018) as they store not only the history of climate and sedimentation, but also proxies for past land use change and associated practices (Dreibrodt et al., 2010a;Scherer et al., 2021). These land use proxies can be 85 spatially and temporally related to nearby settlement sites, which allows for a more detailed understanding of local phases of land use. For example, the determination of charcoal assemblages from different colluvial horizons can help to identify changes in woody vegetation that could be the result of anthropogenic efforts to promote a certain type of landscape (Dreibrodt et al., 2009;Schroedter et al., 2013). The vegetation changes could be accompanied by the use of fire, which is reflected in the accumulation of polycyclic aromatic hydrocarbons (PAHs) (Tan et al., 2020). An increased occurrence of open landscapes, as 90 indicated by a higher abundance of grass phytoliths and the determination of charred archaeobotanical remains, provides information on past arable farming and on the nutritional basis of past societies (Ball et al., 1999;Rösch, 2013;Weißkopf et al., 2014). The application of manure and/or the keeping of livestock can be considered an integral part of prehistoric land use practices (Bogaard, 2004). The analysis of extracellular urease and faecal biomarker in colluvial horizons helps to identify these land use practices (Borisov and Peters, 2017;Lauer et al., 2014). The distinction between the geogenic background and 95 the additional atmospheric or direct input by anthropogenic contamination in colluvial horizons can be investigated by heavy metal analyses of all horizons, including part of the buried soil profiles, which have no or minor anthropogenic influences (Dreibrodt et al., 2009;Henkner et al., 2018b).
Within the north-western Alpine foreland, the Hegau (SW Germany) is a suitable study area for the investigation of MBA land use due to the widely distributed occurrence of colluvial deposits and the density of known archaeological sites (Dieckmann, 100 1998;Höpfer, 2014). Studies on colluvial deposits in the Hegau have shown that local land use activities can be dated back to the Neolithic and still occur in the modern period (Höpfer et al., 2016;Schulte and Stumböck, 2000;Vogt, 2014). Regarding the Bronze Age, Vogt (2014) has documented a regional deposition phase close to Lake Constance, that occurred mainly in the Early Bronze Age (EBA, 2200 -1600 BCE). Further inland, Schulte and Stumböck (2000) found only Late Bronze Age (LBA, 1050 -800 BCE) to Early Iron Age (EIA, 800 -450 BCE) colluvial deposits. However, archaeological remains from 105 the inner Hegau reflect phases of human occupation during the MBA, but corresponding phases of colluvial deposition are far less frequent. Hence, biogeochemical proxies of MBA colluvial deposits for the reconstruction of related land use practices have not been analysed in this region so far.
To address the question of which land use practices were typical for the MBA in the north-western Alpine foreland, we applied a multi-proxy approach to colluvial deposits, buried topsoils and archaeological features at the well-documented settlement 110 site of Anselfingen, ca. 20 km west of Lake Constance. Colluvial deposits, buried topsoils and archaeological features were associated by deciphering the local stratigraphy. Numerical dating, such as the optically stimulated luminescence (OSL) dating of single colluvial horizons and the AMS radiocarbon ( 14 C) measurements of charcoal fragments, were applied to establish a temporal framework that could be related to local archaeological records. The analysis of the soil micromorphology, phytoliths, charred archaeobotanical remains, urease activity, faecal biomarker, animal bones, PAHs, charcoal assemblages, and heavy 115 metals were used to reconstruct past land use practices. The sum of all proxies, which were applied within the settlement (onsite) and at the presumable land use areas (near-site), is used for a better understanding of land use practices related to the human occupation at the Anselfingen site. The investigation of two offsite pollen profiles in this study allowed for a comparison between the local information of land use and vegetation change with vegetation and land use pattern visible on a regional scale. 120 Our study focuses on the: archaeopedological reconstruction of phases of colluvial depositions and onsite and near-site land use practices (e.g. crop cultivation, livestock husbandry, and manuring as well as the use of fire, wood and metal) at the settlement site of Anselfingen through combining the biogeochemical analyses of colluvial deposits and buried topsoils with the analysis of archaeological features, 125 (ii) identification of spatial patterns of on-and near-site land use practices within the Anselfingen settlement and its surrounding area, (iii) characterization of differences and similarities between the onsite and near-site vegetation patterns resulting from land use practices in Anselfingen and the offsite vegetation signals derived from two pollen profiles.

Physical geographical setting
The study area is in the north-west of the Hegau (SW Germany), which is part of the north-western Alpine foreland (Fig. 1).
In the north, the study area borders the southern decline of the Swabian Jura, from where the tertiary sediments of the Younger Juranagelfluh were transported into the Hegau. The Hegau is characterized by filled volcanic vents (with phonolite, basalt, and porphyry) as remains of the tertiary volcanism and is mainly covered by tertiary porphyry (Deckentuff), Würmian glacial and 135 glacio-fluvial deposits such as (terminal) moraines and gravel (Schreiner, 2008;Geyer et al., 2011).
Soil substrates in and around the excavation near Anselfingen (ABR) are redeposited sediments and weathered bedrock from the Younger Juranagelfluh and the Würmian glaciofluvial deposits (mainly gravel, sand and silt). Volcanic material comes from the Hohenhewen (mainly basalt) in the west of the excavation area. The ABR site lies on glaciofluvial deposits next to the outer young terminal moraine of the Würmian (Äußere Jungendmoräne). Cambisols, Luvisols, Phaeozems and Calcaric 140 Regosols, which developed on different substrates and with different stagnic and vertic features, dominate the Reference Soil Groups according to WRB (IUSS Working Group WRB, 2015). The climate is moderately warm with annual average air temperatures between 7.5 and 8.5 °C, whereas the hilltops are between 6 and 7 °C. The annual precipitation is between 700 and 825 mm. The potentially natural vegetation is dominated by Central European thermophilous calciphilous beech forests (Fagus sylvatica) with white wood-rush (Luzula luzuloides) and by Central European sessile oak (Quercus petraea)-beech 145 forests; both are characterized by a rich and diverse shrub and herb layer (Bohn et al, 2003). The modern vegetation is strongly shaped by agricultural and forestry activities.

Archaeological setting
The Hegau is rich in archaeological sites and is particularly important for the Bronze Age research in the north-western Alpine 155 foreland (Hald and Kramer, 2011). Among the most prominent sites are the large Early Bronze Age (EBA) cemetery of Singen (Krause et al., 1988) and several well-preserved lakeside settlements such as Bodman 'Schachen' (Köninger, 2006). However, EBA sites are comparatively scarce further inland, whereas, during the Middle Bronze Age (MBA), there was an increase in settlement activity concentrated mainly on the areas further inland, while the lakeshore sites were almost completely excluded (Höpfer, 2014;Menotti, 2003). From the Late Bronze Age (LBA) numerous burial sites are known, such as the necropolis in 160 Singen (Brestrich, 1988). Additionally, numerous LBA settlements have been documented in the inland, on the lakesides and on the hilltops (Schöbel, 1996;Hopert et al., 1998).
The Anselfingen (Anselfingen-Breite, ABR) settlement (Fig. 2) lies further inland of the Hegau and had occupation phases in the Younger and Final Neolithic, the EBA, MBA and LBA, the Hallstatt and Latène period of the Celtic Iron Age, and the Roman period (Ehrle et al., 2018). The adjacent area was densely settled during the MBA, with up to three additional villages, 165 Mühlhausen-Ehingen (Dieckmann, 1998;, Engen-Welschingen  and Hilzingen-Binningen (Wissert, 1985), within a distance of 5 km. Since the beginning of the 20 th century, the gravel pit has been active and many archaeological finds have been reported. Until recently, these finds mainly included the remains of a Celtic settlement (Kellner-Depner, 2016). Along with a scattering of Final Neolithic finds, there were also stray finds, which indicated the existence of an MBA burial site (Kraft, 1928;Garscha, 1936). The actual MBA settlement was discovered during rescue excavations, which 170 have been performed by the Cultural Heritage Authorities of Baden-Württemberg and the Archaeological Service of the District of Constance since 2008 and continue with the expansion of the gravel pit. To date, almost nine hectares have been excavated and another four hectares to the north have been explored by trench-prospection.

Vegetation history
Compared to the Lake Constance area, with its lake, peat bogs and wetland depositional environments, the inner Hegau was 175 hardly investigated palynologically until the end of the 20 th century (Eusterhues et al., 2002;Hölzer and Hölzer, 1990). Lake Steißlingen remained the most north-western pollen archive investigated so far, which left the interpretation of vegetation history vague further inland. Despite the scarceness of potential archives in the inner Hegau, the profiles of Grassee and Hartsee presented here (Fig. 1) are two recently studied pollen profiles that provided nearly complete Late Würmian and Holocene sequences with sufficient pollen preservation. 180 Around Lake Steißlingen the vegetation was dominated by mixed birch and pine forests in the early Holocene (Preboreal, 9600-8700 BCE) before the spread of hazel in the Boreal (8700-7200 BCE). During the Atlanticum (7200-3700 BCE) the land was mainly covered by thermophilus deciduous vegetation, with mixed oak forests restricted to drier soil conditions (Lechterbeck, 2001;Rösch, 1987). Before the arrival of the settlers of the Linear Pottery Culture (5500-5000 BCE), those forests, consisting of Quercus, Alnus, Fraxinus, Ulmus and Corylus, were probably dense. Evidence for agricultural activity 185 profiles from the shores of Lake Constance (Rösch, 1987). From the EBA to the beginning of the MBA, indicators for open landscapes, such as herbs and sweet grasses, are more abundant in the pollen spectra of Lake Steißlingen and lakes in the area surrounding Lake Constance. A lower density of mixed oak forests, an increase in micro-charcoal (as proxy for paleo-fire) and non-arboreal pollen (as proxy for open vegetation) seem to further underline human influence on the landscape. During the 190 MBA and LBA, natural succession indicates a weakening of anthropogenic disturbance (Lechterbeck, 2001;Rösch, 1987).
Thereafter, phases of natural succession alternate with phases of human-land interaction during the early Latène period (ca. 450 BCE), the Roman period (ca. 50 BCE -260 CE) and since 550 CE (Lechterbeck, 2001). Age; LBA: Late Bronze Age) and their topographic situation in Anselfingen "Breite" (ABR). Coloured area shows the boundary A after Edgeworth et al. (2015), i.e. the paleosurface on which the colluvial deposits accumulated. (B) The excavation area (red frame) and the anscent to the Hohenhewen to the west. Coordinates are shown in UTM 32N reference system; EPSG 25832. LIDAR credits: © LGL Baden-Württemberg, www.lgl-bw. de (2002), resolution 1x1 m.
Soil samples were collected in 2017 and 2018. Soil description followed the German guidelines for soil description (Ad-hoc- AG Boden, 2005) and were classified according to the World Reference Base for Soil Resources (IUSS Working Group WRB, 2015) by using the translation software of Eberhardt et al. (2014). Soil horizons that appeared blackish-brown, were homogeneous and mostly rich in organic matter and charcoal fragments and were without other characteristics of soil formation, were designated as colluvial horizons (M horizon, lat. migrare, to migrate). In the area surrounding the ABR 205 settlement, colluvial deposits are widely distributed due to the slopes of the Hohenhewen and the heterogeneous paleo-relief which remained after glacier retreat. After a soil survey, eight locations were chosen for colluvial profiles. Along the profiles, every colluvial horizon was sampled in a continuous column with 5 cm depth increments. Different samples were collected for the analysis of faecal biomarkers as well as for the investigation of charcoal, microbiological proxies, soil micromorphological features and further pedogenic and soil-biogeochemical proxies. The microbiological samples were 210 cooled during field work and stored at -18 °C.
Two samples for micromorphology were taken in Profile ABR SA2 from 187-197 cm and 190-200 cm, which refers to the buried plough horizon 2Apb. Samples for luminescence dating were taken from newly cleaned profile walls with light-proof steel cylinders that were hammered horizontally into the profiles. Bulk samples for dose-rate determination and water content measurements were taken in plastic bags around the sample holes of the cylinders. 215 During the rescue excavation, the colluvial deposits were removed mechanically until the in-situ soil was exposed (Fig. 3).
Subsequently, a main planum was made and documented. Archaeological features observed in colluvial horizons were documented in additional plana. All features were further examined in at least one cross section. Documentation comprised analogue and digital photography, standardized text descriptions and digital mapping via theodolite and/or photogrammetry. Spatial data were processed using ArchaeoCAD (ArcTron GmbH) during the excavation and transferred to Quantum GIS (long 220 term release 3.10.8 "A Coruña") for analysis. From a series of documented finds, charcoal samples for further AMS-14 C measurements were collected, in addition to those already published (Höpfer et al., accepted).
The two cores for the pollen analysis were taken with a modified Livingstone sampler (Merkt and Streif, 1970) from the almost dry surface of Grassee and from a raft at Hartsee. The Grassee mire is divided into two sections by a forest and two forest tracks. The eastern section is dominated by an alder carr and the western section, from which the core was taken, represents 225 an open fen. The Hartsee mire consists of several small and shallow lakes which are surrounded by wetland. The core was taken from the eastern part. Both profiles were subsampled in close distances; samples for pollen analysis were taken at 2 cm intervals. The Grassee and Hartsee profile had a length of 700 and 635 cm, respectively.

Laboratory analyses
X-ray granulometry (SediGraph 5120, Micromeritics GmbH, Germany) was used for the determination of grain sizes < 20 230 µm, while grain sizes between 20 µm and 2 mm were measured by weighing the sieved soil material. Soil pH (CaCl2) value was analysed by using a soil:solution ratio of 1:2.5 (Sentix 81, WTW, pH 340). Carbonate content (CaCO3) was volumetrically determined using a calcimeter (Eijkelkamp, Giesbeek). An element analyzer ("vario EL III", Elementar Analysesysteme GmbH, Germany, in CNS mode) with helium atmosphere and oxidative heat combustion at 1150 °C was used for the measurement of total carbon (TC) and nitrogen (TN). The difference of total inorganic carbon (TIC) and TC was used for the 235 calculation of the soil organic carbon (SOC) content (Don et al., 2009).
After air-drying, the oriented samples for soil micromorphology were impregnated with Viscovoss N50S resin and MEKP505F hardener. After the resin had cured, the blocks were first formatted into 60 × 90 mm blocks and then cut in half with a saw (Woco Top 250 A1, Uniprec). One half was ground with an encapsulated precision grinding machine (LDQ 6100,Huayid) and mounted on a glass. After three days the mounted samples were cut into about 100 μm thick slices and then ground to 30 240 μm. Thin sections were described under a polarizing microscope (Zeiss Axio Imager.A2m; Software AxioVision 4.7.2) mainly using the terminology of Stoops (2003).
All samples for OSL dating were analysed using the coarse grain quartz fraction with a grain size range of 90-200 µm. The paleodose (De) determination was conducted using a standard SAR protocol following Murray and Wintle (2000;. Radionuclide concentrations were determined either via a combination of thick source alpha-counting (for U and Th) and ICP-245 OES (for K), or via a combination of alpha-and beta-counting in a µdose system (Tudyka et al., 2020).
Charcoal fragments from the colluvial profiles and archaeological features were dated with AMS-14 C dating at the Klaus-Tschira-Lab at the Curt-Engelhorn-Centre of Archaeometry in Mannheim. The Acid-Base-Acid method was conducted for sample pre-treatment (Steinhof et al., 2017). The 14 C ages were normed to δ 13 C = -25 ‰ (Stuiver and Polach, 1977). The calibration of 14 C ages to calendar years was performed with SwissCal 1.0 using the IntCal13 calibration curve (Ramsey, 2009;250 Reimer et al., 2013).
For the determination of charcoals, 529 fragments from three colluvial profiles (ABR W2: 267, ABR SA1: 120, ABR SA2: 162) were retrieved by flotation. The transversal, tangential and radial sections of charcoal were investigated for diagnostic features, using magnifications between 60x and 500x. Identification literature (Schweingruber, 1990a; was consulted as well as the charcoal reference collection of the Archaeobotany Laboratory at University of Tübingen. 255 The extraction of phytoliths was conducted at the Universities of Würzburg and Tübingen and followed the procedures outlined by Albert et al. (1999) and Katz et al. (2010), respectively. Morphological identification of the phytoliths followed the standard literature (Brown, 1984;Parr and Carter, 2003;Piperno, 2006;Twiss et al., 1969) and modern plant reference collections (Albert, 1999;Meister et al., 2017;Portillo et al., 2014;Tsartsidou et al., 2007). The International Code for Phytolith Nomenclature was followed where possible (Madella et al., 2005). Phytolith morphologies are grouped into three main 260 categories: herbaceous dicotyledonous plants, woody dicotyledonous plants and monocotyledonous plants (Piperno, 2006).
For the archaeobotanical investigation, a total of 20 samples from MBA structures (e.g. firepits with heat stones, fireplaces, deposited vessels, and post-holes from architectural remains) were analyzed. The sediment samples were washed over a multipart sieve set. The smaller fractions were floated to separate the organic components from the mineral ones. The 0.3 mm fractions of three charcoal-rich samples could only be examined for 10 to 30 %. All other samples and fractions were screened 265 completely under the binocular and botanical macro remains, excluding charcoal, were taken out. The determination was carried out following the current literature (Jacomet, 1987;Jacomet et al., 1989;Bekker and Cappers, 2006) and the reference collection of the Laboratory for Archaeobotany in Hemmenhofen.
For the analysis of polycyclic aromatic hydrocarbons (PAHs), a modified protocol of Bläsing et al. (2016) was followed. A Speed Extractor (E-916, Büchi Labortechnik GmbH, Germany) was used for sample extraction; samples were concentrated 270 using Rotavapor (Büchi, Switzerland). Solid Phase Extraction (SPE) was used for sample purification according to Lehndorff and Schwark (2009). The quantification of PAHs was performed using gas chromatography (GC, Agilent Technologies 7890B, Germany) coupled with mass spectrometry (MS/MS, EVO 3, Chromtech, Germany).
The extracellular enzyme urease is responsible for the cleavage of urea to ammonia and CO2 and its microbial production is stimulated by the presence of eutrophic soil conditions (e.g. faeces of animals) (Kandeler and Gerber 1988). Its specific feature 275 is that urease-organo-mineral complexes are stable for long time periods (Skujiņs and McLaren, 1968). Extracellular urease activity derived from soil organisms was determined colorimetrically according to Kandeler and Gerber (1988). Synergy HTX multi-mode reader (BioTek) was used for colorimetric measurements at 690 nm.
Microbial biomass carbon (Cmic) was determined by the substrate-induced respiration method (SIR) (Anderson and Domsch, 1978). Measurements were taken using an automated respirometer system based on electrolytic O2 microcompensation (Scheu, 280 1992). A detailed description of sample preparation and data analysis is given in see Scherer et al. (2020). In this study, the urease activity was related to the microbial biomass carbon to differentiate between past and present input of urea, since extracellular urease is considered to be very stable and Cmic as proxy for current microbial activity. Increased urease activities to microbial biomass ratios are therefore an indicator for ancient soil eutrophication by animal faeces.
Faecal biomarkers (sterols, stanols, stanones) were analysed using a modified protocol according to Prost et al. (2017) and 285 Birk et al. (2012). A Speed Extractor (E-916, Büchi Labortechnik GmbH, Germany) was used for accelerated sample extraction. For the analysis of sterols, stanols and stanones, the total lipid extracts (TLE) were analysed by using gas chromatography (GC, Agilent Technologies 7890B, Germany) coupled with mass spectrometry (MS/MS, EVO 3, Chromtech, Germany). For detailed information about sample preparation, equipment and hardware settings, see Scherer et al. (2020).
A reverse aqua regia solution (HNO3 to HCl ratio 1:3, DIN ISO 11466: 1997-06) in a microwave (MLS GmbH, Germany) 290 was used for the dissolutions of the heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn). ICP-OES (Optima 5300DV, Perkin Elmer Inc.) equipped with a Miramist nebulizer using the element-specific wavelengths according to Nölte (2002), was used for the measurements of heavy metal contents.
The taxonomic and taphonomic analysis of bone material was carried out in the zooarchaeological comparative collection of the University of Tübingen. The faunal age was assessed and classified according to Lyman (1994). The taphonomic analysis 295 comprised natural and anthropogenic impacts on the bones such as burning, animal bites, human cutmarks and traces of natural environmental influences as root etching, changes due to sunlight or weathering. Burned bones were categorized in six categories following Stiner (1995). A detailed description of the methodological approach is given in see Scherer et al. (2020).
The investigation of the pollen profiles was focused on the Bronze Age period (2200 -800 BCE), and was composed of 17 pollen samples at the Grassee and 59 pollen samples from the Hartsee mire. The time resolution was 70 years for the Grassee 300 and 20 years for the Hartsee mire. The chemical preparation for pollen analyses was carried out using hot HCl, HF, Chloration, and Acetolysis (Berglund, 1986). The material was stored in Glycerol. For the analysis, permanent unstained Glycerol-slides were used.
Detailed information on sample preparation, equipment, and data presentation for each method can be found in Scherer et al. (2020). 305  increasing trend with depth, was determined. The maximum clay contents (> 60 %) were measured in the buried subsoil horizons (2Bwig) of ABR W1 and ABR W2. The sand fraction decreased with depth (up to 17 % difference) for profiles ABR 325 W1 and ABR W2, whereas for ABR SA2 differences of only 7 % were determined. The silt proportions were the highest at the present topsoil horizons and ranged between 25 and 48 %. The soil pH of all soil profiles showed a neutral soil milieu and no tendency in depth, with values between 7.1 and 7.8 (mean: 7.4, sd: 0.1, n: 75). The content of CaCO3 ranged between 1 and 32 % (mean: 11.1, sd: 9.6, n: 75) for all profiles, with decreasing values in greater soil depth. The less weathered or unweathered glacial and glacio-fluvial sediments (all 2C horizons) showed less evidence of decalcification. The SOC contents were between 330 0.1 and 3.1 % (mean: 0.9, sd: 0.5, n: 75) and for all profiles the maximum values were found in the present and buried topsoil and in the deepest colluvial horizons. The carbon to nitrogen ratio (C/N) mimicked the depth gradients of SOC, showing narrower ratios at lower carbon states. In total the ratio varied between 5 and 12 (mean: 7.8, sd: 3.0, n: 75) (Tab. 1).

Dating
All measurements revealed bright and fast decaying luminescence signals indicative of quartz with a dominant fast component.
At least 19 aliquots were measured per sample, and the resulting De distributions were analysed with respect to their overdispersion, kurtosis and skewness (Bailey and Arnold, 2006). The samples GI520-GI531 (ABR W1 and ABR W2), GI743 (ABR SA2), GI 786 and GI788 (both ABR M) showed narrow and symmetric De distributions, typical for complete bleaching, 340 whereas all other samples (mainly from ABR SA1 and ABR M) displayed strong indications for incomplete bleaching through positively skewed and overdispersed De distributions (see Fig. S1). For well bleached samples, the mean De was calculated using the Central Age Model (Galbraith et al., 1999) and for incompletely bleached samples, a bootstrap Minimum Age Model (Galbraith et al., 1999;Cunningham and Wallinga, 2012) was applied. A sigma b-value of 0.12-0.15 was used in this model, according to the lowest overdispersion of a well bleached sample from the same profile. Resulting ages are in correct 345 chronostratigraphic order and are summarised in Fig. 4 (see also see Scherer et al., 2020), along with De values and the underlying age model.
The AMS 14 C ages showed a correct chronological trend, and only a few minor age reversals occurred on a 2-sigma significance level ( Fig. 4; see also see Scherer et al., 2020). The comparison of OSL and 14 C ages at the same sampling depth mostly showed older radiocarbon ages in younger dated sediments (especially ABR W1 and ABR W2). The overall range of 14 C and OSL 350 ages was narrower at the profile ABR SA2.

Archaeology
The majority of MBA finds was observed in the central part of the excavation (Fig. 2, Höpfer et al., accepted). Most MBA 355 features were from wooden architecture, especially in the form of several hundred post-holes. At least 20 buildings, of mostly rectangular shapes but varying sizes and layouts, could be reconstructed (Fig. 5). Ten buildings were reconstructed with smaller areas (ca. 3-7 m 2 ) and square or short-rectangular shapes (Fig. 5, J-T). These were grouped around the presumed MBA settlement centre. A small kiln was observed, while a small pit to the north contained a 2 kg fragment of a copper ingot. Several shallow pits and stone clusters filled with heat stones were grouped around the presumed settlement centre. Up to ca. 50 m 360 southeast of these domestic structures, several ceramic pots and larger firepits with heat stones were found. The ceramic pots were apparently set into the ground and sometimes contained heat stones. Several wagon tracks and linear discolorations or stone clusters were documented, albeit of mostly uncertain age. North of the settlement, a small kettle hole with a stone plaster was described. The pottery from these features has its biggest similarities with inventories from the later MBA (ca. 1450-1300 BCE). Among the characteristic elements are thick flattened rims on short and steep vessel mouths, raw slurried surfaces, lobes 365 on the body and rim of larger pots and the occasional notched decoration on finer pottery (Krumland, 1998;Rigert et al., 2001;Honig, 2008).

Archaeobotanical proxies
In total 555 charcoal fragments were collected from the colluvial profiles ABR W2, ABR SA1and ABR SA2. Although ca.
1.5 m of ABR W2 were not sampled for charcoal determination, the more than 1 mm charcoal output was the highest compared 370 to the other two profiles (50 %). Of the charcoal fragments, 29 % were collected from the ABR SA2 profile, and 21 % from ABR SA1. Amongst the charcoal proportions from ABR W2, between a depth of 141 and 262 cm was only dicotyledonous woods. Quercus sp. were strongly represented throughout this depth. Fagus sp. could be identified in the horizons M4 to M6 (165-200 cm). Additionally, a few Fraxinus sp. fragments were found in the horizon M6 (200-215 cm) (Fig. 6, a). The charcoal spectra of ABR SA1 showed the following trend: From horizon M7 onwards (110 cm), only dicotyledons were present, 375 amongst which Quercus sp. were strongly represented. Charcoal fragments of Quercus sp. were not found in a soil depth lower than 73 cm, whereas Fagus sp. occurred in the horizons Ap to M4 (0-73 cm) only. From the modern surface to 85 cm (Ap-M5) conifers appear, some of which could be identified as Pinus sp. (Fig. 6, b). A considerable number of charcoal fragments from ABR SA2 could not be determined in detail, because they were too small, but are attributed as dicotyledonous. In horizon M6 (133-138 cm), Quercus and Fagus sp. dominated the charcoal spectra. In horizons M3 to M5 single fragments were 380 allocated to Pinus sp., Quercus sp., Prunus sp. and conifer wood in general, whereas the majority were determined as dicotyledonous only. In horizons Ap, M1 and M2 similar amounts of conifer (Pinus sp., Abies sp.) and deciduous species (Quercus sp., Fagus sp., Populus/Salix sp.) were identified (Fig. 6, c).  concentrations of profile ABR W1 were not comparable with those of ABR W2 and ABR SA2 due to different analytical 390 approaches. However, a relative comparison of the phytolith concentrations and different morphotypes and their anatomical origin was possible.
The phytolith concentrations showed an increasing trend with depth for all investigated profiles. The highest values were found in the buried topsoil horizons (2Bwig/2Ahb; 2Apb) and the lowest values in the present topsoil and buried subsoil horizons.
The morphological analysis revealed that all profiles were similar in their morphotype assemblages. Monocotyledonous 395 morphotypes were the most common group identified. At all profiles 68 % (sd: 14.0 %, n: 24) of the phytoliths were assigned to grasses, whereas 16 % (sd: 10.0 %, n: 24) were determined as dicotyledonous morphotypes. On average, 15 % (sd: 10.8, n: 24) of the phytoliths appeared to be weathered, so that a morphological or anatomical identification was not possible.
In total, 163 charred archaeobotanical remains were found in different archaeological features of the ABR site (Fig. 7). They were recovered through wash-over flotation from ca. 150 liters of sediment and reached a concentration of ca. one plant macro remain per liter. The majority of these finds comprises chaff and grains of cereals like barley (Hordeum distichon/vulgare), emmer (Triticum dicoccum), einkorn (Triticum monococcum), spelt (Triticum spelta) and free threshing wheat (Triticum 410 aestivum/turgidum) and occur mostly in fire pits and architectural remains. The chaff originates exclusively from hulled wheats, namely einkorn, emmer and spelt. Figure 7 (b) shows the grain equivalents for the chaff, i.e. how many grains were developed in the glumes and spikelets of the respective species. A fragment of hazelnut (Corylus avellana) shell and a nutlet that probably derived from a raspberry, blackberry or dewberry (cf. Rubus) indicate the use of nuts and fruits from the surrounding vegetation. The number of wild plant finds was also low since only a few seed remains from weeds and footpath 415 vegetation occur in the studied material (Fig. 7, a).

Micromorphology
Two thin sections from the 2Apb horizon at the ABR SA2 profile were analyzed to further support MBA ploughing activity.
The thin section from the upper part of the 2Apb horizon (ABR SA2, 183-193 cm) had a channel to a weakly developed angular blocky microstructure with few partially accommodating planes. A dark brown limpidity, with an undifferentiated b-fabric, was pronounced for most parts of the micromass, with the exception of rounded peds within the groundmass, which showed a 430 light brown limpidity and stipple speckled to mosaic-speckled b-fabric. Despite the non-calcareous micromass, fragments of limestone and oval pellets of micritic calcium carbonate occurred. Throughout the thin section there were small fragments of charcoal and fragments of basaltic, metamorphic and magmatic rocks (Fig. 8, a). Partially laminated, very dusty thick (up to 1600 µm) dark brown clay coatings with embedded coarse material (quartz and feldspars) with a size of up to 700 µm were particularly common in the macrochannels (Fig. 8, b). 435 blocky microstructure with well to partially accommodating planes (Fig. 8, c). A dark brown limpidity of the micromass with a predominantly undifferentiated b-fabric, was pronounced for about two thirds of the thin section, with the exception of rounded and angular peds within the groundmass, which showed a light brown limpidity and stipple speckled to mosaicspeckled b-fabric. The last third is covered by an almost rectangular area with sharp boundaries and a light brown limpidity of 440 the micromass (Fig. 8, d), which had a stipple-speckled, mosaic speckled and striated b-fabric. In many parts, granostriated bfabric was present. Within this area, bands, inclined at about 45°, alternate with coarse material "floating" in fine material with bands consisting mainly of clay and silt -micromass with mosaic to striated b-fabric (Fig. 8, e). Additionally, large (up to 2000 µm) rounded to subrounded peds were frequently occurring (Fig. 8, f)

Biogeochemical proxies 460
Relative changes in polycyclic aromatic hydrocarbon (PAH) input were indicated by PAH to SOC normalization. The suite of individual PAHs was dominated by phenanthrene, fluoranthene and pyrene for all horizons of the analysed profiles ABR M, ABR W1 and ABR SA2 (Fig. 9, a- The ratio of fluoranthene to fluoranthene plus pyrene (Flu/Flu+Py) was higher than 0.5 in 77 % of the values. The ratio was 470 lower in ABR W1 (M6, 206-211 cm: 0.41) and in ABR SA2 (Ap, 0-27 cm: 0.46; M7, 150-155 cm: 0.24). The phenanthrene to phenanthrene plus the sum of methylated phenanthrenes ranged between 0.76 and 1 (Fig. 9, d). The pattern for both ratios was similar and with a distribution of the ratios independent of the sum of PAH concentrations. The urease activity to microbial biomass (Cmic) ratio was determined for colluvial profiles ABR W1, ABR W2, ABR WA1, ABR WA2, ABR SA1 and ABR SA2 and varied between 0 and 2.1 µgN µgCmic -1 (Fig. 10). All profiles showed a comparable trend with increasing values with greater soil depth. A peak in the urease activity/Cmic ratio was either reached in the buried 480 topsoil horizon (ABR W1, 2Bwig/Ahb, 216-235 cm; ABR WA1, 2Bwig/Ahb, 220-260 cm; ABR SA1, 2Bw, 128-145 cm) or in the deepest colluvial horizon (ABR W2, M6, 185-215 cm; ABR WA2, M7, 205-225 cm) and was in all cases considerably higher than the ratios of the modern topsoil horizon. Only for ABR SA2, the peak in urease activity/Cmic ratio occurred in the The peak value at ABR SA1 was remarkable that it far exceeded other values from the same profile. A positive correlation of 485 urease [µgN gTS -1 *2h] and SOC was observed within 0 and 130 ± 20 cm for most of the analysed profiles (R 2 : 0.82). Below this depth, the correlation of urease and SOC was weaker (R 2 : 0.44). Clay and urease activity were not (ABR W1, ABR W2) or only weakly positively correlated (R 2 : 0.37, ABR SA2) (Tab. S3).  Steroid compositions were analysed for selected horizons of profiles ABR W1 and ABR SA1 (Fig. 11, a-b). In total, eleven different compounds were identified comprising the molecular groups of stanols (coprostanol, epicoprostanol, 5ß-stigmastanol, epi-5ß-stigmastanol), stanones (cholestanone, coprostanone, cholestenone) and Δ 5 -sterols (cholesterol, ß-sitosterol, ergosterol, ß-stigmasterol). At ABR W1 coprostanol, epicoprostanol, cholestanone and cholesterol were dominating the molecular assemblages, whereas the relative amount of coprostanol and epicoprostanol was decreasing from horizon M6 (206-211 cm) 495 to 2Bwig (235-240 cm) and an opposite trend was observed for cholestanone and cholesterol. At ABR SA1, cholestanone also increased with depth, while the relative proportions of coprostanol and epicoprostanol were less distinct compared to ABR W1. Further, at ABR SA1 considerable proportions of ß-sitosterol and 5ß-stigmastanol and epi-5ß-stigmastanol were observed.
At ABR W1, the ratio of coprostanol/(coprostanol+epi-5ß-stigmastanol)*100 was mainly greater than 73 % for the colluvial horizon M6 (206-211 cm) and the buried topsoil 2Bwig/Ahb (216-221 cm, 226-231 cm). In the buried subsoil horizon 2Bwig 500 (235-240 cm), a single value below 38 % was calculated. The profile ABR SA1 showed ratios below 38 % which mainly occurred in the buried subsoil horizon 2Bw (133-138 cm, 138-145 cm) and above 73 % in the colluvial horizon M7 (110-115 cm) and buried subsoil horizon 2Bw (133-138 cm) (Fig. 11, c). The heavy metal contents showed two main patterns (Fig. 12). First, the Pb, Cu and As contents were significantly lower than the Zn, Ni and Cr contents for all colluvial profiles. Secondly, different values were observed for the different soil substrates, with the highest heavy metal contents in the (b) basaltic sediments of the Hohenhewen volcano and the lowest in the (a) sediments of the Younger Juranagelfluh. In most cases, the 25 th and 75 th quartile ± 1.5 Interquartile range mimicked the natural 510 variation of the heavy metal contents, depending on the substrate, according to the data of the geological state office of Baden-Württemberg (LGRB, 2020). Positive outliers, which indicate human influence, were detected at the colluvial profiles ABR S30 (Cu, M4 horizon, 110-115 cm, sediments of the Younger Jurannagelfluh), ABR WA2 (As, M7, 220-225 cm; Pb, Ap, 0-20 cm, sediments of the Hohenhewen volcano) and ABR SA1 (Zn, M6-M7, 100-128 cm, sediments of the Hohenhewen volcano). Heavy metals analysed from sediment samples from the Younger Juranagefluh and the glacial and fluvio-glacial 515 sediments of the Würm glaciation correlated mostly with CaCO3. No correlation was observed between heavy metals and SOC, pH-value as well as heavy metals from samples of the sediments of the Hohenhewen volcano with CaCO3, SOC and pH-value (Tab. S4).

Animal bones
In total 415 animal bones from different MBA features (onsite) with a total weight of 1076 g were investigated at the ABR 520 site (Tab. 3). In total, 21 % of the animal bones could be assigned to their species while 79 % had to stay unidentified due to their high level of fragmentation. Considering only those bones that were assigned to species, most of them belonged to sheep/goat (30 %; 95 g), cattle (30 %; 290 g) and pig (14 %; 47 g). Wild animal species (e.g. roe deer, deer, boar, wolf, wild cattle) made up 17 % (187 g) of the elements identified to species.
The taphonomic analysis revealed natural and human modifications of animal bones. Most of the assemblages were affected 525 by insect damage or by root damage in different stages. The burning of bones could be identified with a low rate of 0.7 %, and occurred mainly in the fillings of pits and deposited vessels. Anthropogenic traces such as cutmarks were documented on only 0.3 % of the animal bones. Another human modification was observed in a piece of antler (most likely red deer) from an MBA house, which had been worked into a point (tool or hunting object). Another specimen from an MBA fire pit showed slight polishing of one of the edges. Carnivore marks could only be identified on one specimen from the MBA sample. 530 Table 3: Absolute (n) and relative number (n-%) of animal bones, absolute (g) and relative weight (mass-%) of species-specific animal bones, which were assigned to their species.

Offsite pollen profiles
For the Grassee profile (Fig. 13), which consisted mainly of fen peat, six local pollen assemblages' zones (LPAZ) could be For the Hartsee mire (Fig. 14), where peat and lake sediments alternate, seven LPAZ could be distinguished during the Bronze During the Bronze Age, the anthropogenic indicators Plantago lanceolata and Artemisia were continuously present. The cereal pollen (especially Triticum-type and Hordeum-type) showed almost continuous occurrence with their curves following the same trend as that of the NAP sum. After a minimum during the 18 th /17 th century BCE, Betula was increasing, with some fluctuations, and gained a maximum of 15.5 % in the 12 th century BCE. Another peak (20.4%) occurred in the late 11 th century 575 BCE. From 930 BCE onwards, the overall occurrence of Betula was continuous (11-15 %). After a maximum in the 18 th century BCE, Corylus decreased continuously, apart from minor peaks. Quercus showed a peak in the 17 th /16 th century BCE and retained a strong significance afterwards. A more distinct increase was not observed as earlier as the pre-Roman Iron Age.
Fagus, the dominating tree at the beginning of the Bronze Age, decreased from the 17 th century BCE onwards. After a recovery phase in the 13 th /11 th century BCE, it decreased again. The micro-charcoal record shows a first peak at ca. 2250 BCE and two 580 more pronounced at ca. 1650-1600 BCE and 1150-1100 BCE.

Phases of colluvial deposition and land use 585
The stratigraphic and chronostratigraphic deciphering of colluvial deposits and buried topsoils based on 14 C and OSL dating is fundamental for the reconstruction of land use phases of nearby settlements (Kittel, 2015;Scherer et al., 2021). In the northwestern Alpine foreland, phases of colluvial deposition during the MBA have been reported much less frequently (Schulte and Stumböck, 2000;Vogt, 2014), while related archaeological remains provide evidence of simultaneous human occupation (Dieckmann, 1998;Ehrle et al., 2018;Wissert, 1985). 590 The summed probability density (SPD) of OSL ages (Fig. 15, a) indicate main phases of colluvial deposition during the Middle Bronze Age (MBA), the Iron Age, the Medieval period and modern times. During the Late Neolithic, weak colluviation is observed (M6 in ABR W2, 2700 ± 400 BCE; cf. Tab. S1), while soil tillage (e.g. hoe-farming) of the paleo-surface may have also been responsible for Younger Neolithic OSL signals (2Bwig/Ahb in ABR W1, 3300 ± 400 BCE; 2Bw in ABR SA2, 4400 ± 700 BCE; 2Bwg/Ahb in ABR M, 2500 ± 300 BCE). Neolithic soil deposition was also reported by Poręba et al. (2019) and 595 Zádorová et al. (2013) in loess-covered upland sites in Poland and the Czech Republic, where the sedimentation rates were higher, which could be the result of a high erodibility of loess. At the ABR site, the main colluvial deposition began during the MBA, as indicated by the OSL ages from ABR W1 (M6, 1500 ± 300 BCE; M5, 1200 ± 200 BCE) and ABR W2 (GI529, M6, 1300 ± 300 BCE) and the formation of about 30 cm of colluvial deposit. These phases of colluvial deposition are in line with MBA settlement remains but are restricted to the northern surrounding areas of the ABR site (ABR W1, ABR W2), while 600 during the MBA no colluvial deposition occurred within the settlement area (ABR M) or south of it (ABR SA1, ABR SA2).
However, the OSL signal from the 2Apb in profile ABR SA2 (1500 ± 300 BCE) indicates MBA soil tillage of the paleosurface and the presence of an agricultural field associated with the MBA settlement. Pedofeatures indicating prehistoric ploughing are scarce (Twardy, 2011), while to our knowledge an MBA ploughing horizon is not yet documented (see sect. 4.2.2). Regarding the profile ABR M, colluvial deposition was not expected during the MBA due to its location within the 605 settlement area. Since the Iron Age, colluvial deposition occurred across the ABR site as reflected in the higher sedimentation rate compared to the MBA (Fig. 15, b). This is in line with the sedimentation history from other study sites, and is mostly interpreted as the consequence of increased human impact (e.g. Dotterweich, 2008;Dreibrodt et al., 2010b;Henkner et al., 2017;Lang, 2003). However, the low sedimentation rate during the Roman period is remarkable and contradicts the archaeological finds at the ABR site (Ehrle et al., 2018). Possible explanations are that Roman land use did not contribute to 610 higher soil erosion rates, or Roman land use areas were located elsewhere at the ABR site. It should be noted that the SPDs could also be biased in this respect, as no charcoal was found and no OSL samples could be taken from the M5 horizon in ABR SA2, which according to the ages of the over-and underlying horizons M4 and M6, could be dated to the Roman period ( Fig. 4).
Higher SPDs of 14 C ages often precede phases of colluvial deposition, indicating that landscape opening by local deforestation 615 was responsible for colluvial deposition at the ABR site. During the Neolithic at least three phases of land use are reflected in the 14 C ages (Fig. 15, a). They can be related to the Early (Linear Pottery Culture, 5500-5000 BCE), Younger (Hornstaader Culture, 4100-3800 BCE) and Late Neolithic (Horgener Culture, 3700-2800 BCE), all of which are documented through burials or architectural remains from the ABR site or its close proximity (Ehrle et al., 2018;Hald, 2020, Fig. 14, c). During

Use of fire, deforestation, and forest management
Prehistoric deforestation and landscape maintenance could have been accompanied by fire practices (Rösch, 2013), which led 635 to the accumulation of charcoal and PAHs in respective colluvial horizons (Tan et al., 2020). The PAH sum of the examined profiles was slightly related to SOC (R 2 : 0.30), indicating that SOM partially explains the PAH abundances, but other processes might have also contributed to their accumulation. In the north-western Alpine foreland, thermophilus deciduous vegetation comprising the species Quercus, Alnus, Fraxinus, Ulmus and Corylus were naturally growing before the beginning of anthropogenic disturbances. Since the forests were assumed to be rather dense before human arrival, large-scale deforestation 640 with the help of fire was likely afterwards (Lechterbeck, 2001). In the 2Bwg/2Ahb and 2CBg horizons (ABR M) PAH distribution points to natural vegetation fires during the early Holocene with Pinus, Betula and Poaceae as the natural vegetation and possible fuel source. The higher concentrations of phenanthrene in greater soil depths, compared to all other PAHs, indicates contribution not only of in-situ combustion residue inputs but also of atmospherically transported fire condensates (Lehndorff and Schwark, 2004;Kappenberg et al., 2019). This is also indicated by the phenanthrene to 645 phenanthrene plus the sum of methylated phenanthrenes ratio (Phe/Phe+ΣMP), which suggests a predominance of complete combustion processes with lower concentrations of methylated phenanthrenes and an excess of fire condensates. In the horizons related to the MBA (2Bwg/Ahb in ABR M; M6 in 2Bwig/Ahb in ABR W1; 2Apb in ABR SA2) we found indications for relatively low combustion temperatures as might have been the case for controlled burning of biomass to maintain land use areas. This is supported by the fluoranthene to fluoranthene plus pyrene ratio (Fl/Fl+Py) with values mostly > 0.5, indicating 650 that the combustion of grass, wood and charcoal (Budzinski et al., 1997;Yunker et al., 2002) was predominant at the ABR site. Moreover, we would expect different combustion processes within the settlement area compared to its surroundings as indicated by several MBA fire places, fire pits and the secondary deposition of heat stones. Indeed, the suites of PAHs were more complete at the ABR M profile (onsite), which is located within the MBA settlement area, compared to the profiles ABR W1 and ABR SA2 (near-site). There, various combustion processes, such as cooking practices, heating of houses, and technical 655 application (e.g. metal processing and burning of ceramics), and different fire temperatures may have contributed to the PAH pattern.
In relation to MBA fire-use practices, the determination of onsite and near-site charcoal assemblages provide information on natural and human-modified vegetation patterns and thus, on past land use practices such as deforestation, wood procurement, promotion of individual tree species and forest ecosystems (Jansen and Nelle, 2014;Schroedter et al., 2013). Moreover, 660 different fuel sources can be estimated from the investigation of charcoal assemblages from fireplaces and fire pits (Höpfer et al., accepted). The generally very small size of charcoal fragments in the M horizons may be the consequence of erosional transport, while longer-distance aerial transport can be neglected due to fragment sizes > 1 mm (Whitlock and Larsen, 2002).
Hence, an anthracological determination further than dicotyledons was not always achievable. However, the higher abundance of Quercus compared to Fagus in the buried soils and colluvial horizons related to the MBA (2Bwig/Ahb, M6 in ABR W2; 665 2Bw, M7 in ABR SA1) indicates a shift from thermophilous calciphilous forests consisting of sessile oak and beech, to a forest ecosystem dominated by oak. These findings are supported by charcoal assemblages from MBA fire pits at the settlement site of Anselfingen (Höpfer et al., accepted). The MBA fire pits contained about 85 % Quercus charcoal, while 98 % of the total charcoal spectra consisted of Quercus and Fagus (Rösch, 1996). Whether Quercus and Fagus were collected intentionally or unintentionally during the MBA cannot be conclusively assessed. However, the very good fuel quality of both taxa along with 670 the occasionally observed insect holes within the charcoal fragments and the smaller branch diameters, strongly indicate an opportunistic collection of deadwoods following the "principle of least effort" (Höpfer et al., accepted). Naturally, oak mixed forests develop into beech forests, since oak is more light demanding, and therefore restricted to drier or alluvial sites and beeches are faster growing, even in shady areas (Mosandl and Abt, 2016). The potential occurrence of Quercus was probably limited to alluvial areas or drier sites close to the ABR site. Therefore, a human-induced promotion, for different purposes, of 675 Quercus appears likely during the MBA, which is also suggested by the off-site palynological record from the pollen archives of Hartsee and Grassee (see sect. 4.3), where more or less pronounced microcharcoal peaks occur from ca. 1750-1600 BCE onwards. At Hartsee, the increase of Quercus and decrease of Fagus are accompanied by relative high values of micro-charcoal and several palynological indicators for human impact on the vegetation in the time span between ca. 1650 -1150 BCE. The fern Pteridium aquilinum, typical in pasture and marginal areas, which is favoured by fire activities also shows a continuous 680 curve for the same period. In Grassee those tendencies are less pronounced, therefore the two charcoal peaks at 1650 BCE and 1400 BCE are more difficult to interpret, but also seem related to subsequent increases in oak and anthropogenic indicators.
Particularly since the Final Neolithic, forest pastures in anthropogenically modified forest ecosystems were likely; these pastures likely resulted from the combined effects of wood procurement (construction, burning) and maintenance of areas for livestock husbandry (Rösch, 2013). Considering the weaker evidence for Neolithic settlements at the ABR site, such land use 685 practices seem to have commenced at the beginning of the Bronze Age, especially considering the archaeological record of the MBA. Similar observations were made for pollen profiles from Lake Biber (close to an MBA settlement in Switzerland), where increased abundances of Quercus pollen were interpreted as the result of human promotion of oak species to maintain areas for livestock husbandry (e.g. acorn for pigs) as well as for timber and firewood procurement (Achour-Uster et al., 2001;Knaap and Leeuwen, 2001). The higher diversity of taxa in the upper part of ABR SA1 and ABR SA2 with increasing amounts 690 of conifers and Fagus, indicates human impact until the modern period (Vrška et al., 2009).
During the MBA, the use of fire at the ABR site for landscape opening, maintenance and domestic purposes, associated with the combustion of grass as well as wood and charcoals is indicated by the PAH patterns in the corresponding colluvial horizons and by the local archaeological record. The forest ecosystems were anthropogenically modified and Quercus was promoted, which can be linked to land use practices, such as forest pastures (see sect. 4.2.3) and wood procurement. The offsite pollen 695 data support the occurrence of oak dominated forest ecosystems on a regional scale (see sect. 4.3).

Arable farming
Past land use practices in the context of arable farming can be interpreted from different proxies preserved in archaeological remains, colluvial deposits and buried topsoils. These proxies provide information on the presence and spatial distribution of potential arable land (open landscapes), the occurrence of different crop species and related archaeological and pedological 700 structures such as storage facilities and plough marks (e.g. Pietsch and Machado, 2014;Rösch et al., 2014a).
With this, phytoliths from buried soils and colluvial deposits are frequently used to decipher past arable farming (e.g. Meister et al., 2017;Weisskopf et al., 2014). At the ABR site, the high proportion of weathered phytoliths together with the absence of multicellular phytoliths are an indication of the poor preservation of the assemblages, likely due to a variety of depositional 705 and post-depositional processes (Cabanes et al., 2009;Madella and Lancelotti, 2012). However, some general trends can be noted in the phytolith assemblages: Monocotyledonous plants produce more phytoliths than dicotyledons in most cases (Piperno 2006), but the relatively higher abundance of monocotyledonous morphotypes in combination with the other proxies is likely the result of an open landscape in the area immediately surrounding of the ABR site. It is interesting to note that the lowest phytolith concentrations were found in the modern topsoils (Ap) and the highest concentrations in the buried horizons, 710 as the phytolith concentrations usually decrease with soil depth (Meister et al. 2017). The phytolith assemblages from all samples were predominantly composed of phytoliths originating in the leaves and stems of monocotyledonous plants, which includes many of the regionally important crop species. As the result of harvesting activities, the inflorescences of these plants were likely removed from the agricultural field leading to a lower abundance of inflorescence phytoliths in these samples (Dietrich et al. 2019). Particularly in the buried plough horizons (2Apb) of the ABR SA2 profile, a relatively high 715 concentrations of phytoliths with a simultaneous low abundances of inflorescence compartments indicate an arable field south of the MBA settlement that may have been quickly buried, thus leading to better phytolith preservation and higher concentrations in these horizons (Cabanes et al., 2009). Micromorphology also confirmed a buried plough horizon (2Apb) in profile ABR SA2. So far, MBA plow marks and soil-structural features indicating tillage have not been published for the northwestern Alpine foreland at inland sites. Therefore, the micromorphological analysis of thin section from a buried plough 720 horizon offers an unique opportunity of identifying prehistoric tillage practices. Evidence of arable farming derived from phytolith analysis is further supported by micromorphological analysis of two thin sections at the 2Apb horizon (ABR SA2), which indicates the use of ards that were widely spread since the Late Neolithic (see Tegtmeier, 1987). Very dusty clay coatings with embedded coarse material (clay-silt-sand coatings) can be related to soil cultivation (Macphail et al., 1990, Usai, 2001, while the occurrence of compacted large (sub)rounded peds may indicate ploughing with an ard (cf., Fig. 6 in Gebhardt 1999). 725 The occurrence of a nearly rectangular area with inclined bands of alternating coarse and fine material can be caused by the disturbance of ards or ploughs as described by Lewis (2012); with this, the material is relocated in clods and inclined around 45° to one side. All found relocation features such as inclined bands, large partially rounded peds and the very dusty clay-sand coatings indicate mixing and slaking and can be interpreted as a result of cultivation (Macphail 1990). In addition, the frequently occurring charcoal fragments, coprolites and phytoliths can be related to cultivation. Based on the phytolith and 730 micromorphological data, the agricultural activity at the ABR site is verified; however, the question of which staple crops were used by MBA farmers in the Hegau remains open.
This gap can be filled by the onsite archaeobotanical remains at the ABR site. These remains hold special value, as on-and near-site evidence on MBA crop production in the north-western Alpine foreland is still scarce (Rösch et al., 2014a,b;Rösch et al., 2015). The cereals typical for the Early and Middle Bronze Age like Hordeum distichon/vulgare, Triticum dicoccum, 735 Triticum monococcum, Triticum aestivum/turgidum, Triticum spelta also occur at the ABR site. A similar spectrum of cereals was found in fire pits at the MBA settlement in Cham-Oberwil (Switzerland) (Gnepf-Horisberger and Hämmerle, 2001), however these fire pits also contained pulses (e.g. broad bean), which were missing at the ABR site. From the observed cereal crop diversity, a sophisticated cropping system, with utilized different soil types, different sowing and harvesting times and a the summer periods, while spelt, which is resistant to low temperatures, is typically sown in winter. Einkorn and barley are known to be viable as both summer and winter crops. Einkorn, emmer and spelt can easily be stored, all of them require further time-consuming processing (e.g. husking) before consumption in contrast to free-threshing wheat, which however is more vulnerable to storage infestation. The MBA crop diversity allows a distribution of the agricultural activities throughout the year, which leads to a potentially larger territory being available for crop growing and improves food security. However, the 745 cultivation of various cereals crops requires knowledge and capacities for post-harvest processing of the cereal crops (e.g. drying, roasting, husking) and storing, which are both indicated by the archaeological record. The secondary deposition of heat stones at the ABR site can also be related to MBA food processing. Even though the function of the heat stones is widely discussed, with interpretations including technical applications such as stone breweries and metal processing (Beigel, 2019;Honeck, 2009), they are most commonly considered to be cooking pits for the roasting of cereals and other agrarian products 750 (Lindemann, 2008). Furthermore, post-holes from ten very small constructions with square or short-rectangular shapes at the ABR site are most likely remnants from storage buildings. There is a broad consensus that such constructions are related to arable farming and represent stilted pantries for the storage of food, especially of cereals . In general, stilted pantries are frequently observed from MBA sites in the north-western Alpine foreland, whereas similar structures are significantly in excavations from neighboring regions, such as Bavaria (Höpfer et al., accepted). 755 Statements on the importance of individual cereal species cannot yet be made, since the number of records is still too low and the hulled wheat species with their very robust glumes are often overrepresented in archaeobotanical records. Leguminous (lens, broad bean and pea) as well as oil and fiber (flax and poppy) crops were also important elements of the Early and Middle Bronze Age agricultural economy of the Alpine foreland (Stika and Heiss 2013), but they are rarely preserved in charred form and are therefore mostly underrepresented at sites with aerobic soil conditions (Rösch et al., 2014a;Rösch et al., 2015). During 760 the Middle Bronze Age sporadic finds of millet are also known from the study area but did not occur in the record of botanical macro remains of the ABR site. However, the fact that all those crops are missing from the archaeobotanical assemblages of the ABR site cannot be interpreted as their definitive absence in the region's MBA economy. Nevertheless, the occurrence of open landscapes and an MBA arable field, which was cultivated for cereal crop production, are verified, and are also supported by the identification of the common MBA crop species. Furthermore, post-harvest processing and storage facilities for cereal 765 crops appeared to be an integral part of the MBA agriculture.

Livestock husbandry
The reconstruction of livestock husbandry from sedimentary archives is commonly achieved through the analysis of urease activity or faecal biomarker resulting from past exposure to urea or animal faeces (e.g. Chernysheva et al., 2015;Prost et al., 2017). Both proxies are a suitable marker for the past as they are resistant against weathering (urease-organo-mineral 770 complexes and aromatic molecule structure) and rather immobile in the soil environment and therefore persist in soils over millennia (Bull et al., 1999;Burns et al., 2013;Skujiņs and McLaren, 1968). The comparison of these proxies with the zooarchaeological record of animal bones derived from archaeological features could provide detailed information about past livestock farming practices.
Eutrophication always leads to an input of urea into the soil, and urea may originate from past and recent animal faeces or 775 from the degradation of nucleic acids as part of the soil necromass. However, in greater soil depths, lower levels of currently active microorganisms and urease enzyme activity are expected. Therefore, a higher urease to microbial biomass C quotient in greater soil depths indicates formerly eutrophicated areas that could be associated with areas of livestock husbandry, such as pastures or livestock shelters. In contrast to other studies, increased levels of urease enzyme activities in soils of the ABR site cannot be solely explained by a relationship to SOC or clay (Roscoe et al., 2000;Taylor et al., 2002). Particularly below 780 130 ± 20 cm, other factors must have been responsible for increased urease activities. The past anthropogenic input of urea in relation to livestock husbandry or manuring has been shown in several archaeological studies (e.g. Borisov and Peters, 2017;Chernysheva et al., 2015). Hence, elevated urease/Cmic ratios in soil horizons, associated with the MBA land surface or concurrent colluvial horizons, can be interpreted as an anthropogenic input of urea due to land use activities at the ABR site.
However, no spatial differences in urease/Cmic ratios could be observed that would indicate a separation of different land use 785 practices and intensities. Only the lower part of the 2Bw horizon in profile ABR SA1 had considerably higher values of urease/Cmic, ratio, suggesting formerly eutrophicated areas and high urease levels in the past. Although the OSL age from the 2Bw horizon showed a last bleaching of mineral grains during the Roman period (300 ± 200 CE), soil tillage prior to the Roman period is likely for two reasons: First at ABR SA1, the first phase of sedimentation is dated to the Early Medieval period (800 ± 100 CE, M7), which means the in-situ land surface could have been used during the MBA. Second, ABR SA1 790 is located less than 40 m north of ABR SA2, which has a buried plough horizon (2Apb) that is dated to the MBA and indicates related land use activities. At the ABR site, the increased urease/Cmic ratios in MBA soil horizons indicate past input of urea into the soils, which could be associated with land use practices such as livestock husbandry (on fallow land and in forests) and the application of manure to arable fields. However, there is weak evidence of intentional manure application during MBA, and agricultural practices such as livestock farming on long-standing fallow land have more likely contributed to increased 795 urea concentrations (Tserendorj et al., accepted). Whether urea originated from omnivorous or herbivorous livestock cannot be assessed by the analysis of urease enzyme activity.
The analysis of faecal biomarker enables a differentiation between herbivorous and omnivorous animal faeces, which enter the soil via the faeces of past livestock. In previous studies steroid analyses helped to identify organic manuring in Neolithic soil relicts (Lauer et al., 2014) and in soils surrounding a Roman settlement . Hence, the steroid 800 composition of human-influenced soil horizons (buried topsoils, colluvial horizons) should be different from the adjacent subsoils, if such land use was practiced. In the northern surrounding area of the ABR site (ABR W1), 5ß-stanols (e.g. coprostanol, epicoprostanol) were enriched in the M6 horizon and support the interpretation of the MBA deposition of faeces, as indicated by higher levels of past urease enzyme activities. These 5ß-stanols originate mainly from the microbial reduction of Δ 5 -sterols during omnivorous digestion processes and are related to pig or human faeces in the context of past land use (Birk 805 et al., 2011). The higher levels of 5ß-stanols are further supported by the coprostanol/(coprostanol+epi-5ß-stigmastanol)*100 ratio, which was introduced by Leeming et al. (1997) to differentiate between herbivorous and omnivorous faeces. In profile ABR W1, the ratio clearly indicates an input of steroids from omnivorous digestion processes (> 73 %). With increasing soil depth, cholestanone and cholesterol were most abundant at both profiles. Cholesterol is the dominating Δ 5 -sterol occurring in nearly all eukaryotic cells (Mouritsen and Zuckermann, 2004), while cholestanone is produced by microbial transformation 810 from its sterol precursors. We interpret the higher abundance of source-unspecific sterols and lipids formed during microbial metabolization as the given background composition of steroids of the soil environment with low human influence. In profile ABR SA1, 5ß-stanols were not as dominant as in profile ABR W1, indicating a reduced input of omnivorous faeces.
Nevertheless, faecal input by wildlife species, organic manuring and/or occasional pasture on fallow land could have contributed to the occurrence of 5ß-stanols. The latter may have also contributed to increased levels of epi-5ß-stigmastanol, 815 which mainly originates from herbivorous digestion processes (Derrien et al., 2011). This is in line with the coprostanol/(coprostanol+epi-5ß-stigmastanol)*100 ratio, pointing to mainly faecal input by herbivores (< 38 %) at the ABR SA1 profile. There, phytosterols, such as ß-sitosterol and stigmastanol, were also more abundant. In the buried subsoil of ABR SA1 (2Bw), source-unspecific steroids, e.g. cholestanone, were dominating the steroidal assemblage, indicating lower anthropogenic influence. The faecal biomarkers show past input of animal faeces in the area surrounding the MBA settlement, 820 which can be associated with the occurrence of omnivorous and herbivorous livestock. North of the settlement site, we identified a dominance of 5ß-stanols, which, together with the results from the charcoal determination, suggests a forest ecosystem dominated by oaks, where mainly pig farming was practiced (see sect. 4.2.1). Higher levels of plant lipids and herbivorous biomarker in the area south of the settlement site supports the presence of arable fields, which could have also been subject to an input of animal faeces during fallow practices or intentional manuring. 825 Information on different animal species, which were part of the farming practices at the ABR site, can be provided by the determination of animal bones, which were deposited at the MBA settlement. With 79 % of unidentified animal bones from various archaeological pit fillings, the degree of fragmentation is high, which is further indicated by post-depositional bone damage from insects and roots. Acidic weathering of animal bones can be mostly ruled out at the ABR site since the soil milieu is neutral. Hochuli et al. (2001) reported a similar degree of fragmentation of animal bones at an MBA settlement in 830 Switzerland. The taxonomic determination of animal bones, with four to five domestic and five wild species at the ABR site, supports the results of the urease enzymatic activity and faecal biomarker investigations insofar as domestication and livestock husbandry were important at the ABR site during the MBA. The dominance of sheep/goat, pig and cattle species are also observed at MBA settlements sites in southwest Germany (Kokabi, 1990;Köninger, 2006;Stephan, 2016). Nevertheless, the wide range of wildlife species and their share in the total number and weight illustrate that hunting was still important during 835 the MBA. The high percentage of sheep/goat and cattle bones partially contradicts the low evidence of herbivorous faeces by steroid analysis. It is likely that the colluvial profiles were not always congruent with MBA grazing areas. Areas within the MBA settlement and in the east, where the Hepbach river might have formed floodplain forests, could have been suitable for grazing. However, the subdominant abundance of pig bone is consistent with higher concentrations of 5ß-stanols especially in the north of the ABR site (ABR W1). In combination the results from the charcoal and animal bone determination, urease 840 enzyme activity and faecal biomarker are complementary and suggest a diverse landscape management model with a spatial distribution of livestock practices. North of the MBA settlement, the occurrence of oak dominated forest ecosystems and the high concentrations of 5ß-stanols are in line with a considerable amount of pig bone from MBA pit fillings and indicate a forest pasture mainly for pig farming and wood procurement. In the south of the ABR site, the higher concentrations of phytoliths with minor amounts of grass phytoliths derived from the floral parts, as well as the occurrence of an MBA plough 845 horizon and the increased input of herbivorous faeces indicate an open landscape for crop cultivation (arable fields) and livestock husbandry on fallow land and/or manuring with animal faeces.

Metal processing
The distribution of heavy metals in soils is influenced by the substrate, pH-value, content of lime and SOC, sedimentation processes and past and modern anthropogenic impact (Young, 2013). These factors must be considered when assessing the 850 natural and anthropogenic accumulations of heavy metals (Henkner et al., 2018b). Cu and Zn are major elements of bronze that gained importance during the Metal Ages but had to be traded over long distances due to their limited natural occurrences in the area (Jennings, 2017;Knopf, 2017). Cr and Ni, as secondary components, can also be associated with the production of bronze. Pb has been used metallurgically since the Roman period, while Cd and As are tracers for more recent land use (around 1900 CE) (Smolders and Mertens, 2013;Völkel, 2003). 855 The percolation of heavy metals through the soil can be neglected in all profiles of the ABR site since the pH is always > 7.
The variations in CaCO3 mostly explain the heavy metals patterns for the sediments of the Younger Juranagelfuh and Würm glaciation, but not for the basaltic sediments of the Hohenhewen volcano. The natural variation of heavy metals, as indicated by the range between the 25 th and 75 th quartile ± 1.5 Interquartile range, is supported by the analysis of geological background values by the geological state office of Baden-Württemberg (LGRB, 2020). However, a few positive outliers were identified 860 for the different soil substrates. At ABR WA2 and ABR S30, the outliers cannot be further assessed for prehistoric humanland interactions due to lacking age determinations, while the maximum tin values at ABR SA1 are detected at the colluvial horizon M7, dated to the Roman period. Based on heavy metal contents, which are mostly in the range of natural variation, and their correlation with CaCO3, an intensive MBA metal processing, which also affects the adjacent sediments, cannot be deduced at the ABR site. The deposited copper ingot, most likely from the Eastern Alps (Lutz and Pernicka, 2013), however, 865 indicates that metals were traded over long distances and that the processing and maintaining of tools may have been carried out at the ABR site, but with no detectable effect of heavy metals in the investigated buried and colluvial horizons.

Offsite vegetation signals in relation to land use practices at the ABR site
The two new pollen profiles ( Fig. 13 and 14) show close similarities regarding the Bronze Age (2200-800 BCE) human-land interactions in the Hegau. At Grassee and Hartsee, human impact is very weak between 2000 and 1800 BCE. At Grassee, a 870 short period of human impact on the vegetation can be noticed in the 18 th century BCE, which subsequently decreases between 1600-1500 BCE. At Hartsee, human influence was high between the 17 th and 15 th century BCE without any intermediate decrease. Both profiles show a very strong human influence between 1500-1400 BCE, which after that slightly decreases. At Hartsee, human influence is clearly pronounced between 1000 and 800 BCE, whereas this influence is absent in the Grassee pollen profile. 875 The NAP percentages at Grassee and Hartsee, which are a robust indication of human-land interaction, are analogous to other profiles near Lake Constance (Rösch et al., accepted). Especially during the MBA, anthropogenic deforestation appears to be rather similar in the Hegau. In Oberschwaben, the Allgäu (southern Germany) and in the Black Forest (south-west Germany) deforestation is generally weaker, while at Lake Aalkisten in the Kraichgau (south-west Germany) a pronounced deforestation is observed in the EBA and LBA (Rösch et al., accepted). 880 The comparison of the pollen archives of Grassee and Hartsee with the local records of the ABR site helps to assess the supraregional character of onsite and near-site land use and vegetation changes at MBA settlements in the north-western Alpine foreland. In both profiles, the percentage of NAP increases from the EBA to the MBA with a distinct peak between 1500 and 1400 BCE. This peak is accompanied by low percentages of Betula, Corylus and Fagus, suggesting that human-land interactions gradually shifted from the lakeshores of Lake Constance (EBA) to areas further inland (MBA). This cannot be 885 interpreted as an abrupt shift in the land use pattern, but rather a refined form of agropastoralism, which had its roots in the EBA and continued throughout the MBA in the Hegau. This is also supported by the offsite pollen record with several microcharcoal peaks, which indicate palaeo-fire activities shaping the land cover since 2450 BCE, as well as the high concentrations of phytoliths in MBA soil horizons as the result of advanced landscape opening related to local agricultural practices. The pollen curves of Quercus and Fagus clearly alternate corresponding to increasing and decreasing human occupation. 890 Considering the different input pathways of charred archaeobotanical remains, pollen and charcoal, with respect to their catchment area, the pollen spectrum comprises the regional vegetation record of human occupation and adjacent successional phases. Even the use of cereals is distinct from onsite archaeobotanical data, 'closed' forested landscapes may have hindered the distribution of the offsite pollen of cultivated cereals by the filtering effect. Due to their size (ca. 40-55 µm), the spread of the Cerealia-type pollen is hindered if they are not in the immediate surrounding of the depositional environment. Moreover, 895 the pollination of several cereal crops (Triticum, Hordeum) is cleistogamic -this means the flower is closed -which also contributes to a limited pollen spread if no threshing or further crop processing took place near the peat bog.The anthracological data indicate local vegetation and deforestation patterns (colluvial deposits) and human decision-making (fuel procurement).
The human impact on vegetation, as recorded in those palaeoecological archives, seems to clearly promote the increase of Quercus in the MBA landscape of Hegau. This is in line with the charcoal record of MBA colluvial deposits and fireplaces at 900 the ABR site, which exhibited a strong dominance of Quercus. In the pollen diagram of Hartsee the Fagus usually decreases after the occurrence of microcharcoal peaks and is then followed by an increase in Quercus and pollen indicators of agriculture (Triticum-type) and pasture (Plantago lanceolata). Forest pastures for pig farming are indicated at the ABR site, when considering the high occurrence of Quercus in the colluvial deposits and MBA fireplaces as well as the identification of 5ßstanols and pig bone (see sect.s 4.2.1, 4.2.3). Agricultural indicators are present in both the onsite and near-site colluvial and 905 archaeological archives at the ABR site and in the offsite pollen records. These indicators, as well as indicators from another practices during the MBA.

Conclusion
The multi-proxy analysis of archaeological features (onsite), colluvial deposits, buried topsoils (near-site), and peat bogs 910 (offsite) of the Middle Bronze Age in the Hegau (SW Germany) shows how helpful such multi-proxy approaches can be for a refined understanding of past human-land interactions. (i) From the archaeopedological reconstruction of phases of colluvial deposition and onsite and near-site land use practices, we can infer sophisticated land use practices at the Middle Bronze Age settlement site in Anselfingen, which undoubtedly marked the beginning of major colluvial deposition. The land use practices promoted Quercus at the expense of Fagus, the arable farming relied on cultivation of five cereal crops and involved ploughing 915 Livestock husbandry was based on pasture on fallow land and forest pasture for pig farming , while hunting was also part of the MBA economy. (ii) The spatial patterns of the onsite and near-site land use practices revealed that a forest management (incl. pig farming) mostly occurred in the surrounding area north of the ABR settlement site, while arable farming was practiced in the south. Based on the differentiation of combustion processes between the settlement and the close by land use areas, we conclude a wide range of fire application such as domestic fires for cooking, technical applications and ritual practices as well 920 as fires to open and maintain the land use areas, that differed on the spatial scale. (iii) From the comparison of onsite and nearsite vegetation patterns from colluvial deposits and archaeological remains and the offsite vegetation signals from two pollen profiles, we conclude similar patterns of human-induced vegetation change, which characterized the anthropogenic impact in the Hegau on a local and regional scale. The pollen records show that during the Early and Middle Bronze Age fire played a role in shaping the landscape and that also on regional scale anthropogenic activities favoured Quercus dominated forest 925 ecosystems.
In summary, the interdisciplinary approach between soil science, archaeology, archaeobotany and archaeozoology allowed indepth insights into the Middle Bronze Age subsistence economy in the Hegau. From the similar patterns of human-induced vegetation change and land use on a local and regional scale, one can infer a characteristic appearance of landscapes in the north-western Alpine foreland during the Middle Bronze Age. The study also supports the assumption that the Middle Bronze 930 Age in the north-western Alpine foreland was a period of mainly spatial changes at a regional scale with a shift of settlements from the lakeshore to sites further inland, which was accompanied by corresponding landscape transformations.

Authors Contribution
PK, TK and TS acquired the funding to carry out the study. SaS, BH, TK, TS and PK conceptualized the research experiment and the hypothesis. SaS carried out the soil scientific field work and sampling, and most of the data collection, including the 935 analysis of urease activity, microbial biomass carbon and faecal biomarker. JL and MF performed the OSL dating, BH contributed with data of the local archaeological record, JM and KW analyzed the phytolith assemblages, KD performed the anthracological determination of charcoals, EF investigated the charred archaeobotanical remains, HR analyzed the polycyclic aromatic hydrocarbons, JZ performed the zooarchaeological investigations, MR, JL and EM contributed with the pollen analysis. SaS and PK prepared the manuscript and all authors contributed to the interpretation of the results, to the discussion 940 and the manuscript in general.