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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]

A pollen analysis conducted on a 600 cm core from Lake Ribno (2184 m) in the Northwestern Rila Mountains, supplemented by 13 radiocarbon dates, has revealed the basic stages in its postglacial vegetation dynamics. The lateglacial vegetation, composed of Artemisia, Chenopodiaceae and Poaceae, with stands of Pinus and Juniperus-Ephedra shrubland, dominated in the stadials and partly retreated during the Bølling/Allerød interstadial (14700-12900 cal. yrs. BP). The afforestation in the early Holocene (11600-7800 cal. yrs. BP) started with pioneer Betula forests, with groups of Pinus and Juniperus at mid-high altitudes, and Quercus forests with Tilia, Ulmus, Fraxinus, Corylus below the birch zone. A coniferous belt composed of Pinus sylvestris, P. peuce and Abies was shaped under the conditions of a more humid climate (7800-5800 cal. yrs. BP). The last trees that invaded the study area were Fagus after 4300 cal. yrs. BP and Picea abies after 3400 cal. yrs. BP. Evidence for destructive changes in the vegetation and indications of agricultural and stock-breeding activities (pollen of Triticum, Secale, Plantago lanceolata, Rumex, Juglans) was continuously recorded since the Late Bronze Age (3400-3200 cal. yrs. BP). The postglacial vegetation history in the Northwestern Rila Mountains demonstrated close similarities with that of the Northern Pirin Mountains. [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]

A palynological study was performed on a 2 m thick sediment sequence recovered from Mire Kupena (1356 m), a former lake in the Western Rhodopes Mountains (south Bulgaria) and supported by radiocarbon dating. The record extends back to ca. 30,000 cal. yrs. BP (Middle Pleniglacial) when the study area was occupied by wooded steppe composed of Pinus sp., Pinus peuce, some Betula, Juniperus, and cold-tolerant herb vegetation dominated by Artemisia and Chenopodiaceae. In addition, the almost continuous presence of deciduous Quercus, Tilia, Corylus, Abies, Picea, Fagus, Alnus, and Carpinus betulus pollen suggests interstadial conditions and this area could be recognized as a montane refugial place. A reconstruction of the interval between ca. 24,000 and 15,000 cal. yrs. BP was not possible due to an extremely low sediment accumulation rates or, more likely, a hiatus. The lateglacial landscape was dominated by mountain-herb steppe vegetation with isolated stands of Pinus, Betula and shrubland of Juniperus. The afforestation in the Early Holocene started with broad-leaved forests composed of Quercus with C. betulus, Carpinus orientalis/Ostrya, Ulmus, Tilia and Corylus and minor amounts of Pinus, Betula and Abies. In the Late Holocene (< ca. 4700 cal. yrs. BP) Fagus began to gain importance chiefly at the expense of the mixed oak forests, while after ca. 2000 cal. yrs. BP forests of Pinus sylvestris with some P. peuce quickly expanded around the mire. A comparison with other long palynological records from the mountains and lowlands of Bulgaria and in northern Greece reveals not only common trends in the vegetation development that are a reflection of the climate changes, but also site-specific features related to the location and topography of each site. [ABSTRACT FROM AUTHOR]