Holocene vegetation history in the Northern Vosges Mountains (NE France): Palynological, geochemical and sedimentological data

Abstract

Palynological data from the Northern Vosges Mountains (NVM) are very rare, unlike for the Southern and Central Vosges Mountains, where the past vegetation history is relatively well known. As a consequence, the beginning of human activities has never been clearly identified and dated in the NVM. In order to reconstruct the evolution of vegetation in this region, multiproxy studies (pollen, non-pollen palynomorphs, sedimentological and geochemical analyses) were conducted in two peatlands. Overall, the results, extending from about 9500 cal. BP to recent times, show a classical vegetation succession with local particularities resulting from human activities. In the La Horn peatland, a strong human impact related to pastoralism is attested from the late Bronze Age onwards. The second phase of human occupation, mainly characterized by crop cultures, begins during the Hallstatt period. The geochemical results (x-ray fluorescence) also highlight the presence of metallic elements, which, combined with significant quantities of carbonized particles, point to potential metal working. In the Kobert-Haut peatland, human occupation began much later (1500 cal. BP), but lasted from the Gallo-Roman period to the beginning of the Modern Period. Unlike for the vegetation history of the rest of the Vosges, Pinus remains a prevailing taxon throughout the Holocene in the NVM. Another particularity is the early establishment of Picea, long before the 18th to 19th century plantations.

From the Neolithic to the present day: The impact of human presence on floristic diversity in the sandstone Northern Vosges (France)

“…In the area under consideration here, pine (Pinus) and hazelnut (Corylus) forests dominate (reaching 50 and 30% respectively) and this certainly explains why the mixed oak (Quercus) forest is reduced around the peat bog (WAL 1-2). The predominance of pine during the mixed oak phase is observed in all the sequences analysed in the Northern Vosges (Hatt, 1937, Gouriveau et al, 2020. The omnipresence of pine, which is not observed in neighbouring regions, such as the Lorraine Plateau, the Central and Southern Vosges and the Black Forest (Janssen et al, 1975, Ruffaldi, 1999, Rösch, 2000, De Klerk, 2014, is due to the competitiveness of this species compared to hardwoods, such as oak (Quercus) or beech (Fagus), on the very poor and dry…”

“…Vosges sandstone soils (Guillet et al, 1976, Sudhaus and Friedmann, 2015, Gouriveau et al, 2020. Therefore, the presence of numerous sandstone landforms close to the peat bog (within 400 m) can explain the high percentages of pine ( Fig.…”

“…BP) in two other sites in the Pays de Bitche, where it spreads in the mixed oak forest and develops to the detriment of other hardwoods, mainly oak (Gouriveau et al, 2020). Around Waldeck peat bog, beech grows mainly at the expense of pine, competing with it on richer soils and on northern slopes favourable to its development, at the end of the Holocene Climate Optimum and when temperatures decreased during the Neoglaciation (Dahl-Jensen et al, 1998, Bradley and Bakke, 2019, Geirsdóttir et al, 2019.…”

“…BP onwards, with the appearance of crops pollen. The opening of dense forests then promotes the spread of the hornbeam (Huntley et al, 1989, Küster, 1997, Gouriveau et al, 2020.…”

“…In addition, there are no radiocarbon dates in these studies. In the Pays de Bitche (which is currently the subject of a Man-Environment Observatory), only two recent studies have investigated the impact of societies on the dense forests of these regions, through anthracological and palynological analyses (Gocel-Chalté et al, 2020, Gouriveau et al, 2020.…”