Chronological and ecological information on Late-glacial and early Holocene reindeer from northwest Europe using radiocarbon (14C) and stable isotope (13C, 15N) analysis of bone collagen: Case study in southwestern Germany

摘要

The Late-glacial and early Holocene periods are characterized by significant climatic and environmental changes that result in a global warming. In this context, typical glacial species such as reindeer {Rangifer tarandus) were extirpated from the southern regions of western Europe following different timing according to the geographical location. A new direct radiocarbon date was performed on a reindeer metatarsus from the Mesolithic site of Rottenburg-Siebenlinden in the Swabian Jura. The result (9225 ± 35 BP; 10,270-10,500 cal BP) confirmed the survival of this species during the early Holocene in southwestern (SW) Germany. Collagen 13C and 15N abundances (613Ccoll and δ15Ncoll) were measured on this Holocene reindeer and on Late-glacial reindeer from Magdalenian sites — Petersfels, Schussenquelle, Felsstalle and Kesslerloch - of the same region to investigate their diet and environment. During the first part of the Late-glacial (ca. 16.6-14 ka cal BP), the δ13Ccoll values of the SW Germany reindeer were slightly lower than those found in reindeer from Stellmoor and Meiendorf sites in northern Germany, probably as a result of lower lichen consumption and higher humidity. Lower δ15Ncoll values in SW Germany reindeer compared to southwestern France could be linked to less advanced soil maturation as the inheritance of higher permafrost intensity linked to harsher climatic conditions during the Late-Glacial Maximum. In SW Germany, the early Holocene reindeer had a higher δ15Ncoll value (4%,,) than those of its Late-glacial counterparts (1.2-3.3‰), which would reflect the expected increase in 15N abundances of soils and plants with higher temperature. However, relatively high δ15N values (ca. 4—5‰) were also found in the reindeer of southwestern England as early as during the Younger Dryas, the last cold stadial preceding the early Holocene. In contrast, northern and western Germany reindeer exhibited increasing δ13Ncoll values but stable δ15Ncoll values during the Younger Dryas compared to the previous Bolling/Allerod interstadial. This could indicate a slower response in δ15Ncoll than in 13Ncoll abundances of ancient reindeer to climatic changes. Finally, the reindeer of southern England and SW Germany survived the Younger Dryas/early Holocene transition in a relatively open landscape as confirmed by the δ13Ncoll values measured on coeval deer.