Soils of external islands of the Gulf of Finland: Soil pollution status and dynamics in abandoned agricultural ecosystems

External islands of the Gulf of Finland are an archipelago of relatively small islands located in central-eastern parts of the gulf. These islands are unique natural environments that represent an informative model for the evaluation of former agricultural soil dynamics in abandoned agricultural landscapes. Soils of these islands have been in a fallow state for about 70 years, although before that, they were arable vegetable soils of Finnish settlements for a long time. The morphological pedodiversity of external islands of the Gulf of Finland was studied during a complex expedition that took place within the framework of the program “My Region” in 2019 and was supported by Nord Stream 2 AG. The determination of main soil characteristics was carried out using standard analysis procedures. The unique soils of these areas could be used for the evaluation of the long-term evolution of anthropogenically developed soils after being in an abandoned (fallow) state. Data on soil morphology, taxonomy state and agrochemical soil characteristics are discussed, as are current soil pollution processes of these remote areas based on trace elements. Lands of external islands of the Gulf of Finland are characterised by a wide diversity of soil patterns at different stages of development.