Multi-proxy analyses of subatlantic peat bog sediments from the Western Tatra Mts. (Poland)

The main aim of our study was to analyse local slope processes, vegetation changes and human impact during the last millennium in the Pyszniańska Valley (Western Tatra Mts.) on the basis of palynological and lithological analyses combined with radiocarbon datings from a small peat bog in the Pyszniańska Valley. These data were supplemented by a lithological analysis of cirque bottom-slope deposits from a depression within the Pyszniański cirque. Sedimentation at the site probably began in the 14^th-15^th century, which is suggested by pollen analysis. The sediments are dominated by fine grain material (sands and silts) transported by surface and linear slope washing with the interbedding of distinctive layers of coarse clastic material, which are indicators of high-energy geomorphic processes. The first phases of vegetation development (TZNP-1,2 zones) are characterized by visible deforestation caused by fire clearances and/or development of mining and metallurgical centers. The high number of hazel (Corylus avellana) pollen grains is probably the effect of the redeposition of sediments originating in the Boreal or Atlantic period from the higher elevation of the valley. In the TZNP-3 zone the Pyszniańska Valley was affected by a most catastrophic high-energy geomorphic event, recorded as a continuous layer of coarse material. The upper phase (TZNP-4a subzone) signifies pasture development based on animal husbandry. Regular determination of Ambrosia artemisifolia type pollen combined with radiocarbon data points to the 19^th-20^th century. The TZNP-4b subzone reflects the succession of Carex rostrata on the peat bog and reforestation in the vicinity of the site caused by the establishment of the Tatra National Park in 1954. The cirque floor sediments consist of massive, 1.65 m thick, very coarse layers of gravels and boulders, which represent dynamic sedimentation caused by the activity of high magnitude slope processes (debris flows).