Level regime of the lake Bayn-Tsagan in the Holocene according to the results of palynological research (South-Eastern Transbaikalia)

¹ Vinogradov Institute of Geochemistry, Siberian Branch of RAS, 1А, Irkutsk Favorsky Street, 664033, Russia
² Institute of Natural Resources, Ecology and Cryology Siberian Branch of RAS, 16A, Chita Nedorezova Street, 672014, Russia

^* Corresponding author: srescht@mail.ru

Abstract

According to pollen of terrestrial vegetation and micro remains of algae in the bottom sediments of the Lake Bayn-Tsagan reconstructed the vegetation of southeastern Transbaikalia in the Late Holocene. The palynological record showed a change in the lake level against the background of the absence of a dramatic change in vegetation and significant climate changes. During the accumulation of a 30 cm layer of bottom sediments, a threefold shallowing of this reservoir was recorded. In dry years, the level of the first aquifer below the surface decreased, the lake became shallow, and the abundance of higher macrophyte vegetation was overgrown with Staurastrum algae. In wet years, when the groundwater level rose, significant watering occurred. Due to increased surface runoff, the turbidity of the water in the lake increased. This contributed to an increase in the density of phytoplankton with Botryococcus.