Submerged Mesolithic plant remains reveal lush thermophilous woodland on remote isle off the SW-Norwegian coast

Abstract

A palaeoecological multidisciplinary study from a well-preserved bark dominated structure and other organic sediments are presented. The study provides new data about Mesolithic coastal environments and includes a reconstruction of concurrent vegetation units, concluding that thermophilous woodland was established at the outer SW-Norwegian coast as early as 9000-8500 cal. BP. A pine bark dominated, possibly human made, structure was recovered from the former seabed at the Kvitsøy archipelago. The study involves various palaeoecological proxies, and synthesises results from soils, pollen, macro botanical remains, insect and mite analyses. The organic deposits are beach-derived, possibly trampled in sediments and includes abundant well-preserved waterlogged plant remains and arthropods. Species from the tidal zone are well represented, and upland taxa from fen and swamp communities, coastal heath and open woodland including Pinus sylvestris L., Betula pubescens L., and more warm demanding species such as Malus sylvestris (L.) Mill, Crataegus L., Prunus padus L., Quercus L., Betula pendula Roth, Corylus avellana L., Alnus glutinosa (L.) Gaertn and possibly Ulmus glabra Huds. and Tilia cordata Mill. Wild apples and hazelnuts were infested by the moth Cydia pomonella (L.) and the weevil Curculio nucum (L.) respectively. The beetle and mite fauna provides evidence of taxa associated with open coastal woodland and the tidal zone and driftwood. A large variety of edible plants are documented, of which seeds, fruits, roots, a.o., indicate the possibility of their seasonal collection from spring until late autumn. The plant and insect data provide additional evidence which could be associated with human impact. These results highlight the importance of integrated palaeoecological studies for establishing facts about past local environments and detecting slight human impact from this and similar contexts.