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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]

Palaeoecological reconstructions from the region of southwestern Bulgaria were used for inferring the human impact on the vegetation and landscape during the last 8 millennia. They are based on data from pollen analyses of lakes and peat-bogs, plant macrofossils, archaeobotanical finds and radiocarbon dating. During the early Holocene, after 7900 cal. b.p. (5950 cal. b. c.) the climate changed to cooler summers, milder winters and higher precipitation resulting in the formation of a coniferous belt dominated by Pinus sp. and Abies alba. These favorable environmental pre-conditions had a positive influence on the Neolithisation of the Balkans after the 8200 cal. b. p. (6250 cal. b. c.) cold event, which caused drought in the Eastern Mediterranean. Direct evidence from wood charcoal records from the Neolithic settlement layers in the study area shows a slight modification of the surrounding woodlands and an increase of the light-demanding components, probably expressed through larger forest border zones and thinning out of the wood stands. The increase in the number of settlements in the valleys of southwestern Bulgaria intensified the human activity visible in the palaeobotanical record from 6950 cal. b. p. (5000 cal. b. c.) onwards. Between ca. 5700-5100 cal. b. p. (3800-3200 cal. b. c.) signs of anthropogenic influence on the vegetation are virtually absent. The intensity of human impact increased notably after 3200 cal. b. p. (1400-1250 cal. b. c., approx. Late Bronze Age), documented by a rise of pollen anthropogenic indicators. The final transformations in the natural forest cover after 2750 cal. b. p. (800 cal. b. c. onset of the Iron Age) marked the reduction of the coniferous forests dominated by Abies alba and Pinus sp. and the expansion of Fagus sylvatica and Picea abies. These vegetation changes are contemporaneous with increase of the palaeofire activities and the next peak of anthropogenic indicators. The changes in the landscape during the Roman period and the medieval period reflect regional environmental features and were forced by the diversification of anthropogenic activity. [ABSTRACT FROM AUTHOR]

Abstract: Pollen analysis of sediments from the glacial Lake Trilistnika (2216m) in the Northwestern Rila Mountains (Bulgaria), supplemented by 13 radiocarbon dates, allowed the reconstruction of the palaeoenvironment and vegetation history in postglacial time. The exact time of the cirque glacier retreat is still under discussion but the lake was free of ice before 15,000cal.BP, when sedimentation of gray silt began. The lateglacial vegetation, composed of Artemisia, Chenopodiaceae and Poaceae, with isolated stands of Pinus and Juniperus–Ephedra shrubland, dominated during the stadials and partly retreated during the Bølling/Allerød interstadial complex. The afforestation in the early Holocene (11,500–7800cal.BP) started with the distribution of pioneer Betula forests with groups of Pinus (P. mugo, P. sylvestris and P. peuce) at mid-high altitudes, and Quercus forests with Tilia, Ulmus, Fraxinus, Corylus below the birch zone. The change to more humid and cooler climate ca. 7800–7500cal.BP favored the vertical migration of Abies, P. sylvestris and P. peuce. The establishment of Fagus sylvatica took place after 5200cal.BP, when pure or mixed beech communities were formed. The last tree which invaded the coniferous belt between 4300 and 3400cal.BP was Picea abies. The first expansion maximum of spruce was recorded after ca. 2700cal.BP. The vegetation development in historical times was also influenced by human interference, indicated by the continuous presence of pollen anthropogenic indicators such as Triticum, Secale, Hordeum, Plantago lanceolata, Rumex, Scleranthus, Juniperus. [Copyright &y& Elsevier]

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]

The article offers information on the Lateglacial vegetation at the Lake Sedmo Rilsko in Bulgaria. It mentions that in September 1994, the lateglacial core RD7B was collected from the center of the lake and at the depth of 8.25 meters, but lack with radiocarbon control. It adds that it sampled 100% of the pollen grains at the core except for aquatic plants, spores of pteridophytes, and Cyperaceae.

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]

Abstract: Pollen analysis and AMS radiocarbon dating were conducted on the lateglacial sediments (175cm in thickness) of a core obtained from the glacial Lake Ribno (2184m) in the northwestern Rila Mountains. The vegetation dynamics at high-mid altitudes based on important changes in palynostratigraphy as a response to the lateglacial climate fluctuations for the time interval 16000–11600cal.yrsBP is bound to an interstadial/stadial cycle, analogous with the Bölling/Alleröd–Younger Dryas. The established local chronology demonstrates also good correlation with the isotopic signal from Greenland ice-cores. The reconstruction of the lateglacial vegetation shows common features with other sites from the Bulgarian mountains (Rila, Pirin, Western Rhodopes) and the glacial lakes in the southern Romanian Carpathians (Retezat Mountains). [Copyright &y& Elsevier]