Local Environmental Conditions of Lake Balyktukel (Russian Altai) in the Holocene from Non-Pollen Palynomorphs

The local environmental conditions of Lake Balyktukel, located on the Ulagan Plateau of the Russian Altai, over the last ~7 cal. ka, are studied. The taxonomic and quantitative composition and the pattern of distribution of non-pollen palynomorphs (algal cells, invertebrate remains, fungal spores, and conifer stomata) are studied in a column of mid-upper Holocene bottom sediments of the lake. From the beginning of the paleorecord to 6.5 cal. ka, the phytoplankton of the lake was dominated by cyanobionts, which indicates a bloom at that time. The proportion of green algae and dinophytes increases after 6.5 cal. ka, possibly due to increased influx of nutrients from the shore. After 4.3 cal. ka, the amount of green algae (Botryococcus) sharply decreases in the lake, due to climate cooling at this boundary. Also, the shores of the water body gradually became swampy after 4.3 cal. ka: the proportion of charophytes increased in the phytoplankton community. The amount of cyanobionts and green algae has sharply increased over the last 500 years, indicating blooming in the water body.