The Holocene vegetation history of Northern Pirin Mountain,southwestern Bulgaria: pollen analysis and radiocarbon dating of a core from Lake Ribno Ban derishko

Abstract

Pollen analysis was performed on a 343 cm long core recovered from Lake Ribno Banderishko (2190 m) on Northern Pirin Mountain (southwestern Bulgaria), supplemented by six '⁴C AMS dates. The lower part of the sequence (343-290 cm) was deposited during the Lateglacial when mountain-steppe vegetation with Artemnisia, Poaceae, Chenopodiaceae and other herbs, and with stands of Pinus and Juniperus, dominated at high altitudes. The identification of pollen of mesophilous trees suggests that local populations may have survived in refuges below 1000 m where environmental conditions were favourable for their growth. The reforestation dynamics in early-Holocene times (11200-8400 cal. BP) started with Betula forests at high altitudes and deciduous forests with Quercus, Ulmus, Tilia and Fraxinus excelsior at lower altitudes. The time of the maximal spread of Corylus at c. 8000 cal. BP coincided with the establishment of Abies alba in the forests, and the beginning of the formation of a coniferous belt, dominated by pines (Pinus sylvestris, P. peuce, P. nigra and P. heldreichii). The late immigrants Fagus sylvatica and Picea abies invaded the mountain slopes at c. 4400 cal. BP and 3300 cal. BP, respectively. Palynological traces of anthropogenic activity and landscape management began after c. 2200 cal. BP.