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The vegetation history of the Central Rila Mountains for the last 14,000 years was reconstructed by means of pollen analysis and radiocarbon chronology of a core retrieved from Lake Manastirsko-2 (2326 m). The Lateglacial landscape was dominated by open herb vegetation composed of Artemisia, Chenopodiaceae, Poaceae, and other cold-resistant herbs (14,000–11,700 cal. yr BP). Stands of Pinus, Betula, and Juniperus–Ephedra shrubland partly enlarged during the Lateglacial interstadial. Pioneer forests of Betula with Pinus and Juniperus occupied barren soils in the early Holocene (11,700–7900 cal. yr BP), while mixed oak forests with Tilia, Ulmus, Acer, and later on Corylus spread at lower elevations. A coniferous forest belt with Pinus sylvestris, Pinus peuce, and Abies developed after 7900 cal. yr BP in the conditions of milder winters, cooler summers, and increase in precipitation. The late Holocene dynamic vegetation changes were associated with the invasion of Picea abies after 3400 cal. yr BP, while Fagus communities slightly enlarged in the river valleys. Indications of human activities are visible in the pollen diagram since the ‘Late Bronze Age’ (3400–3200 cal. yr BP). The vegetation development in the study area followed a similar pattern when compared with palynological and macrofossil records from other parts of the Rila and the adjacent Northern Pirin Mountains. On a larger geographical scale, the postglacial vegetation history of the Rila Mountains displays common features with sites in the Romanian Carpathians, whereas the differences observed are result of the location of tree refugia, competing abilities, climate changes, and human activities. [ABSTRACT FROM AUTHOR]

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 [sup 14]C AMS dates. The lower part of the sequence (343-290 cm) was deposited during the Lateglacial when mountain-steppe vegetation with Artemisia, 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. [ABSTRACT FROM AUTHOR]

Information on the Holocene vegetation history of the Central Rila Mountains for the last 10,000 years was obtained by means of pollen and fossil stomata analyses of a 500 cm core retrieved from peat bog Vodniza (2113 m a.s.l.), and supported by radiocarbon chronology. The early Holocene afforestation started with an initial Betula phase with stands of Juniperus and Pinus which occupied barren soils (10,000–8300 cal. yrs. BP) while deciduous oak forests with abundant Tilia , Ulmus , Acer , and later on Corylus , spread at lower elevations. During the Holocene climatic optimum (8300–6000 cal. yrs. BP) the conifers Pinus ( Pinus sylvestris , Pinus mugo , Pinus peuce ) and Abies expanded at the expense of the birch and oak forests. The tree line was running above 2100 m comparable to the present-day situation and started to descend after ca. 3200 cal. yrs. BP mostly due to human impact. The last tree which penetrated into the coniferous belt after 3400 cal. yrs. BP and reached altitudes of 2000–2100 m, confirmed by the find of fossil stomata, was Picea abies . Its maximal distribution was achieved between 2250 and 1100 cal. yrs. BP, alongside with some enlargement of beech communities. The first indications of stock-breeding and other human activities in the Central Rila Mountains were recorded since 3400–3200 cal. yrs. BP (Late Bronze Age). The vegetation reconstruction during the Holocene followed a pattern coherent with the information from the Northern Pirin and partly from the Western Rhodopes Mountains. The palaeoecological evidence from the Rila Mountains could be compared in broad lines with the high quality data obtained from the Romanian Carpathians by the application of multi-proxy research approach. [ABSTRACT FROM AUTHOR]