The first reconstruction of the late glacial plant communities on the Yamal Peninsula based on plant macrofossils.

Abstract

Strong climatic fluctuations during the Late Glacial stages of the Late Pleistocene, which resulted intransformation of vegetation in northern Eurasia, havebeen characterized in detail on the basis of numerouspaleobotanic data [1–3]. At this time, there were twointerstadial periods of warming—Bolling (12400–12000 radiocarbon years ago) and Allerod (11800–10900 radiocarbon years ago)—when the most pronounced climatic changes occurred, accompanied byexpansion of woody vegetation to the subarctic areas ofEurasia [4–6]. The time interval from 12400 to10900 years ago was often regarded as an interstadialBolling–Allerod complex interrupted by a minorshortterm cooling of the Older Dryas (12000–11800 radiocarbon years ago), which preceded a significant and strong cooling of the Younger Dryas(10900–10200 radiocarbon years ago) [2, 7, 8].Despite the extensive paleobotanic material thatcharacterizes the Late Glacial stages of the vegetationgrowth in the subarctic areas of Russian Arctic [4, 5, 9],only separate reports [10, 11] concerning the reconstructions of the Late Glacial paleovegetation in theareas north of Western Siberia are available. In thispaper, we describe the first dated complexes of plantmacrofossils from the alluvial deposits of the YuribeyRiver valley. They served as the basis for reconstructionof the plant community of the Yamal Peninsula duringinterstadial Bolling–Allerod warming.The Ngoyun crosssection lies on the west bank ofan unnamed lake 0.5 km northeast of Lake Ngoyun,on the left bank of the Yuribey River, upstream themeridional flow on the Yamal Peninsula (68°32′ N,72°06′ E) [12]. According to geobotanical zoning, theYuribey River valley lies currently in a subzone ofsouthern shrub tundra [13]. This territory is mostlyrepresented by ledum–small shrub–lichen–moss(moss–lichen) grumous, spotted grumous, and sometimes polygonal tundras. On the convex relief, there isthe shrubspotted grumous and polygonal tundras.The following plants form the basis of the herb–shrublayer of tundra: