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Record of environmental changes during the Holocene in the light of malacological studies of river sediments in the Łapszanka Stream valley (Spisz area, Carpathians, Southern Poland)

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Alexandrowicz W. P.

2024

tom Vol. 94, No. 2

187--204

The analysis included alluvial sediments in the Łapszanka Stream valley in the Spisz area (Carpathians, Southern Poland). Seven gravel levels were distinguished in the sedimentary sequence, which is a record of periods of intense fluvial activity correlated with wet climate phases. They fall in the Early Holocene (10 100–8900 y BP), the beginning of the Middle Holocene (7900–6600 y BP), the Middle Holocene (6100–5900 y BP), the beginning of the Late Holocene (5100–4000 y BP), the Iron Age Cold Epoch, the Dark Ages Cold Period and the Little Ice Age. The gravels are separated by layers of mud, containing an abundant mollusc fauna. It was possible to distinguish five types of fauna assemblages corresponding to the environmental changes in the Spisz area during the Holocene. The malacofauna indicates that forests covered this area to a large extent during almost the entire period analysed. During the Early Holocene, the area was dominated by coniferous forests, and the fauna contained numerous cold-tolerant taxa. The Middle Holocene saw the emergence of mixed forests inhabited by mollusc communities that included species with high ecological tolerance. A malacofauna containing moisture-loving forest assemblages is characteristic of the sediments of the Late Holocene. The occurrence of muds (agricultural muds) with open-country snails at the top of the sequence indicates increased anthropogenic impact and associated deforestation during the last 500 years.

Record of environmental changes and fluvial phases in the Late Holocene within the area of Podhale (the Carpathians, southern Poland) : studies in the Falsztyński valley

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Alexandrowicz W. P.

tom Vol. 63, No. 4

629--642

The Falsztyński valley, in the eastern part of Podhale, Poland includes a low terrace spanning the stream channel, the structure of which has been studied in nine profiles. Five gravel levels and five mud levels with plant and abundant mollusc remains are described, temporally constrained by ten radiocarbon dates. The terrace deposits represent the terminal part of the Atlantic Phase and all of the Late Holocene. The mollusc analysis helped identify phases of environmental change, notably one in the Middle Ages connected with intensive settlement activities in the area of Podhale. These include deforestation, affecting mollusc communities with replacement of forest assemblages by open-country species. The gravel levels records increased fluvial activity periods correlated with humid climate phases. It is possible to distinguish five such periods corresponding to the transition of the Atlantic and Subboreal phases, the middle part of the Subboreal Phase, the transition of the Subboreal and Subatlantic phases, the younger part of the Subatlantic Phase, and the last 200 years. These correspond to the periods of increased fluvial activity in the valleys of other Carpathian rivers.