Postglacial evolution of vegetation and environment in the Scheldt Basin (northern Belgium)

Abstract

The infill of abandoned river channels is the main information source on postglacial vegetation and landscape evolution in inland northern Belgium. Palynological studies of these deposits also contribute to a better understanding of the environmental context of the numerous archaeological sites in this area. The results are presented of palynological analyses, including pollen, spores, non-pollen palynomorphs and microcharcoal from the palaeochannel infill at seven sites in the Scheldt and Durme valleys in northern Belgium. Based on the regional vegetation evolution and radiocarbon dating, a biozonation for the Scheldt Basin is constructed encompassing the final Late-glacial and Holocene period. The local taxa show a hydroseral succession from open-water environment, through reed or sedge fen to carr forest. Salix and Viburnum opulus were important elements in the Early Holocene riparian and carr vegetation, but are often underrepresented in pollen diagrams from larger valleys. There are indications for human disturbance and agriculture between 7,000 and 6,400 cal bp. The simultaneous decline of elm and lime in the study area around 4,000 cal bp can be linked to human impact

Ecology and fluvial dynamics of an Early Holocene medium‐sized European lowland river valley (Upper Scheldt, northern Belgium)

“…Peat deposits in palaeochannels along the middle reach of the Scheldt (Kerkhove, Roose ; Oudenaarde Donk, Depredomme and Ename Castrum, Storme et al . ), close to the study site of this paper, document a very similar vegetation evolution to the one described for the Boreal in the Lower Scheldt. The wetlands of the upper Scheldt valley consisted of fen vegetation including ponds with bur‐reed and other aquatics and did not show a clear succession to carr vegetation before the appearance of alder (Pont‐à‐Chin, de Heinzelin et al .…”

“…The comparison of the pollen assemblages of the study site to those of contemporaneous peaty deposits (biozone SB4) in the nearby residual channel at Ename Castrum (Storme et al . ) reveals some differences between the respective environments: a flood‐plain with clastic point bar accretion and a channel‐fill with carr vegetation. Hedera helix , Humulus lupulus and Sambucus nigra are more important on the point bar, and reflect rather open and light‐penetrating conditions, typical of alluvial forests (Schnitzler ).…”

“…This peat was formed in an environment of first fens, succeeded by carr vegetation (Storme et al . ). From the Middle Holocene ( sensu Walker et al .…”

“…; Deforce ; Storme et al . ). In these locations, the Boreal biozone corresponds to peat accumulation in a fen vegetation with ferns, horsetails, sedges and reeds, which was gradually succeeded by carr vegetation with willow and, from the Atlantic onward, alder as a dominant vegetation component (Storme et al .…”

“…Due to increasing afforestation and low discharge, depositional processes were largely limited to peat accumulation, without significant channel formation or lateral erosion (De Smedt 1973;Kiden 1991;Verbruggen et al 1991;Huybrechts & Verbruggen 1994;Huybrechts 1999;Bogemans et al 2012;Meylemans et al 2013;D'Haese 2015). This peat was formed in an environment of first fens, succeeded by carr vegetation (Storme et al 2017). From the Middle Holocene (sensu Walker et al 2012) onwards, peat also accumu-lated outside the Lateglacial palaeochannels, and eventually covered the entire flood-plain.…”