Pollen from Lake Sedmo Rilsko reveals southeast European postglacial vegetation in the highest mountain area of the Balkans

Abstract

A lacustrine sequence from Lake Sedmo Rilsko (altitude 2095 m) in the northwest of Rila Mountain, Bulgaria, was analysed on the basis of 84 pollen spectra and three "%C accelerator mass spectrometry dates. The lower part of the sequence (413-530 cm) corresponds to the Late-glacial. Three phases, two stadial and one interstadial, are characterized by the dominance of mountain-steppe herb vegetation composed of Artemisia, Chenopodiaceae and Poaceae, with single trees of Pinus and shrub land of Juniperus and Ephedra. The identification of pollen grains of Abies, Quercus robur-type, Corylus, Acer, Fagus and other mesophilous trees suggests that they survived the harsh Late-glacial conditions in refuges below an altitude of 1000 m, where moisture was sufficient for their growth. In the early Holocene period, Betula forests at high altitudes and, below them, closed deciduous forests with Quercus, Tilia, Ulmus and Corylus, occurred from 11800 until approx. 6700 cal. BP. The formation of the coniferous belt dominated by Pinus sylvestris, Pinus peuce and Abies alba lasted from between 6700 and 5000 cal. BP. The forest dynamics in the Subboreal and the Subatlantic ended with the invasion of Fagus sylvatica and Picea abies after approx. 4500 and 3300 cal. BP, respectively. Indications of anthropogenic activities, expansion of agriculture in the lowland foothills, and livestock grazing in the mountain meadows and pastures, are clearly evident from the pollen diagram from 2400 cal. BP onwards.

Negative responses of highland pines to anthropogenic activities in inland Spain: a palaeoecological perspective

“…Moreover, the expansion of the pines does not seem to have been severely impacted by human land use or by fire (e.g. Bozilova and Tonkov 2000;Tonkov 2003;Tonkov and Marinova 2005;Lazarova et al 2009). …”

Interactions between climate and vegetation during the Lateglacial period as recorded by lake and mire sediment archives in Northern Italy and Southern Switzerland

“…The development of a P. mugo (ssp. mugo)-belt above the treeline is a characteristic shared in the Eastern Alps, the Carpathians, and the Balkanic ranges during the last 15,000 years (Bozilova & Tonkov, 2000;Schmidt et al, 2000;Bjo¨rkman et al, 2002). However, the role of P. mugo in the early stages of the Lateglacial colonization of mountain belts is probably underestimated in pollen studies due to the difficulty distinguishing its pollen from P. sylvestris.…”

Postglacial vegetation history as recorded from the subalpine Lake Ribno (NW Rila Mts), Bulgaria

“…During the last decade, intensive palaeoecological research was conducted in the northwestern part of the Rila Mountains -an area that became a key element in resolving important issues, such as the origin and evolution of glacial lakes and peat-bogs after the retreat of the glaciers, the patterns of vegetation and climate dynamics, the location of tree refugia and migration routes, and anthropogenic impact [11,12,[17][18][19][20]. This paper presents the results of pollen analysis and radiocarbon dating of a core obtained from the glacial Lake Ribno (2184 m).…”

“…In this context, the geographical position of Bulgaria in the middle of the Balkans offers prospective opportunities for exploring and understanding the mechanisms of postglacial vegetation development in Southeastern Europe. An important prerequisite for such studies is the availability of long pollen and plant macrofossil records supplemented by reliable chronologies.Regarding the vegetation history of the highest Bulgarian mountains, Rila and Pirin, which had been glaciated during the late Quaternary, the main afforestation stages after the last deglaciation are comparatively well defined [9][10][11][12][13][14][15][16], although consistent radiocarbon chronologies and local/regional correlations remain indispensable for more precise conclusions.During the last decade, intensive palaeoecological research was conducted in the northwestern part of the Rila Mountains -an area that became a key element in resolving important issues, such as the origin and evolution of glacial lakes and peat-bogs after the retreat of the glaciers, the patterns of vegetation and climate dynamics, the location of tree refugia and migration routes, and anthropogenic impact [11,12,[17][18][19][20]. This paper presents the results of pollen analysis and radiocarbon dating of a core obtained from the glacial Lake Ribno (2184 m).…”