From wetland to commercial centre: the natural history of Wyspa Spichrzów (“Granary Island”) in medieval Gdańsk, northern Poland

Abstract

This paper describes the analyses of pollen, nonpollen palynomorphs, macroremains and geochemistry in sediments from archaeological excavations at Wyspa Spichrzów (''Granary Island'') in Gdańsk, northern Poland. The aim of this study was to reconstruct the environmental conditions in this part of the town in the period preceding its occupation and during its transformation with the establishment of a trade centre and an increasing number of granaries, warehouses and workshops. The results show that this area was originally covered by wetlands typical of river oxbows, with a landscape formed by alder woods, shallow pools of water, fens and patches of wet meadows. Around the 9th-10th centuries, a distinct lowering of the groundwater table reduced the pools, and the alder stands also reduced. These changes coincided with the Medieval Climatic Anomaly. Drying of the ground could have been an important factor enabling expansion of settlement in the Gdańsk area. Between the 10th and 13th-14th centuries, the area around the investigated sites was probably used as pasture, as shown by high frequencies of coprophilous fungal spores. A large representation of cereal pollen and pollen and macroremains of field weeds reflects crop transport and storage on the island from ca. the 13th/14th centuries in the northern part of the area and the 15th/16th centuries in its southern part. The increasing human impact caused development of a rich flora associated with human activities, habitat enrichment by nitrogen and phosphorus, and heavy metal pollution from the beginning of the 13th century. Keywords Archaeobotany Á Multi-proxy palaeoenvironmental reconstruction Á Wetland occupation Á Urban development Á Medieval climatic anomaly Communicated by K.-E. Behre.

Abrupt Alnus population decline at the end of the first millennium CE in Europe – The event ecology, possible causes and implications

“…Historical sources reviewed by Stothers (1998) reported excessive flooding in France and Germany in the period following the Eldgjá eruption. In fact, our data from Gdańsk confirm the presence of floods prior to the Alnus decline (Święta-Musznicka and Latałowa, 2016; Święta-Musznicka et al, 2011), which is in agreement with other studies showing that in Poland, floods were particularly frequent around the 10th century (Gębica and Wojtal, 2011; Macklin et al, 2006). Thus, one or a series of floods could have initiated the Alnus decline.…”

“…Its leaves have no mechanism for controlling transpiration, and its roots, when exposed to air, are extremely vulnerable to cavitation (Claessens et al, 2010; Hacke and Sauter, 1996); thus, water deficits during dry and warm summers may affect the tree. Drought as the possible agent for the Alnus decline has already been suggested by Noryśkiewicz (2013) and Święta-Musznicka and Latałowa (2016). In fact, the occurrence of a dry period reflected in several sites analysed in this study agrees with the data from many regions of northern and central Europe.…”

Environmental changes and plant use during the 5th-14th centuries in medieval Gdańsk, northern Poland

“…The IntCal13 age calibration curve was used for calculating the calendar age ranges and the medians used in the present paper (Reimer et al 2013). The radiocarbon dates for particular sites have been published (Latałowa et al 2009b;Święta-Musznicka et al 2011Święta-Musznicka et al , 2013Święta-Musznicka and Latałowa 2016). The new chronology based on recent dendrochronological research (Kościński and Paner 2005) has been used for the data originally published in the 1950s and 60s from site 2.…”

“…Sampling of sediment profiles including both natural and cultural layers and application of different methods (pollen analysis including NPPs, macrofossil analysis, geochemistry and radiocarbon dating), have enabled a comprehensive reconstruction of the natural history of Gdańsk. The data have allowed us to describe the natural and human environmental changes in the period preceding the foundation of the earliest medieval settlement and then during the early stages of the development of the town (Latałowa et al 2009b;Święta-Musznicka et al 2011;Święta-Musznicka and Latałowa 2016). Information on environmental changes around the town has been obtained from the Gołębiewo pollen site, Wysoczyzna Gdańska ("Gdańsk Upland") ( Fig.…”

“…In Gdańsk, abundance of dung is confirmed by the many remains of coprophilous fungi (including Sordaria-type, Sporormiella and Chaetomium sp.) and intestinal parasite eggs of Trichuris and Ascaris in the sediments dated to the 11th century and later (Święta-Musznicka et al 2013;Święta-Musznicka and Latałowa 2016;Figs. 2b, 3).…”