On the other hand, the rapid spread of built-up areas, roads and gardens allowed the growth of ruderal vegetation there. Natural wetland communities and semi-natural wet meadows and pastures were still common within the settled area until the 14th century.
The gradual expansion of the town caused a diversification of the local flora. They provide evidence of the earliest changes to the natural environment, starting in the Stare Miasto (“Old Town”) in the 11th–12th centuries, in the Główne Miasto (“Main Town”) in the 12th–13th centuries, and on Wyspa Spichrzów (“Granary Island”) during the 13th–14th centuries. Archaeobotanical results are consistent with archaeological data on the periods at which particular town districts were settled. An important factor making settlement possible was probably the lowering of the water table around the 9th–10th centuries ad, causing a reduction of wetland. Before the settlement was established, the landscape was dominated by alder woods and shallow water bodies of the extensive wetlands in the Wisła estuary.
This paper reviews the results of the many years of investigations on the ecological aspects of settlement development in the oldest districts of the city of Gdańsk, the impacts of the changing climate and growing human pressure on the local environment, as well as the question of plant use by the inhabitants during the Middle Ages.
