Faecal biomarkers as tools to reconstruct land‐use history in maar sediments in the Westeifel Volcanic Field, Germany

Abstract

The analysis of faecal biomarkers in lake sediments has been used to reconstruct human population densities and animal husbandry practices in an increasing number of studies in recent years. However, terrigenous biomarkers can decompose in soils, can be stored and redeposited in colluvium and on flood-plains prior to their ultimate deposition in lakes. These and other effects can blur and distort biomarker signals. Therefore, we analysed sediments from two maars in Westeifel to evaluate whether signals of the faecal biomarkers (5b-stanols, bile acids) demonstrate statistically significant differences between contrasting periods in land-use intensity. In Holzmaar, palaeoenvironmental data showed evidence for agriculture including cereal cultivation and grassland during the pre-Roman Iron Age and Middle Ages compared with those from periods that were less influenced by land use and showed a higher abundance of broadleaf forest. However, the specific domesticated taxa of livestock in the locale from these periods remain speculative. We found statistically significantly different faecal biomarker signals, which we interpret to be related to an enhanced deposition of faeces of horses, pigs and ruminants in the core sections that represented periods of amplified land use. The analyses of grass-and broadleaf-tree characteristic n-alkanes supported the applicability of biomarkers for land-use reconstruction. Stanol data from a core section dating to the Mesolithic showed no clear results. Analyses of two core sections from Ulmener Maar, which covered periods before and after the decline of elm in the Neolithic, indicated input of pig faeces in the younger section. This study provides important evidence that faecal biomarkers can be used for land-use reconstruction in central European lakes with small catchment areas for time periods from the Neolithic onwards. The results underscore the importance of bile acid analyses in addition to stanol analyses for an identification of faeces inputs from different animals.

ASSESSING 14C BLANKS IN THE SMALL-SCALE ANALYSIS OF N-ALKANE COMPOUND-SPECIFIC-RADIOCARBON-ANALYSIS

“…The Holzmaar is one of the best-studied maar lakes in the Eifel (Germany) (Kienel et al 2013;Mollidor et al 2013;Musa Bandowe et al 2014;Prasad and Baier 2014;Lehndorff et al 2015;Brunck et al 2016;Sirocko et al 2016;Birk et al 2021). Since, CSRA samples require considerable amounts of carbon, enough core material is necessary (typically 15-25 g), so we decided to sample a 10 cm long section of the core (between 3.80 to 3.90 m).…”

Biomarker proxies for reconstructing Quaternary climate and environmental change

“…White et al ., 2018; Vachula et al ., 2019; McWethy et al, 2020; Elliott Arnold et al, 2021; Keenan et al ., 2021; Ortiz et al, 2022), characterized long‐term animal husbandry practices and land use (e.g. Mackay et al ., 2020; Schroeter et al ., 2020; Birk et al ., 2021), and the diets of extinct species (e.g. van Geel et al ., 2008; Sistiaga et al ., 2014).…”

“…Current uncertainties associated with within‐species variability of steroid distributions, contributions from environmentally transformed 5β‐stanols, and steroid transportation, storage, secondary deposition and degradation processes (e.g. Birk et al ., 2021; Keenan et al ., 2021; Davies et al ., 2022; Lawson et al, 2022) present a range of opportunities for further analysis to refine steroid identification of faecal sources and enhance their applications as anthropogenic and mammalian tracers in Quaternary science.…”

It's been a long time coming

“…However, in areas where the preservation is poor, or there is a low density of faecal matter, chemical methods need to be employed (Bethell et al 1994:619). Different archaeological studies in Europe have showcased the potential of faecal biomarkers as tracers to identify the past presence of either humans or other animals (e.g., Harrault et al 2019;Mackay et al 2020, Birk et al 2021. For this article, paleoenvironmental studies will be highlighted, though this method has also been used to identify activity patterns in houses and contextualise burials where preservation has been poor (Mackay et al 2020;Sulas et al 2022).…”