Vegetation transition from the terminal Pleistocene to early Holocene reconstructed from phytolith records in the southernmost part of mainland Japan

Phytolith records in paleosols provide valuable information on past vegetation in situ, especially for herbaceous plants. Although vegetation transition between the terminal Pleistocene and early Holocene in the southernmost parts of mainland Japan has been examined, detailed information on herbaceous plants during the period is scarce. Therefore, this study examined phytolith records in paleosols in the region to reconstruct the vegetation transition from the terminal Pleistocene to the early Holocene, focusing on herbaceous vegetation. Additionally, the combination of our phytolith and previous palynological records enable us to reconstruct vegetation transition in detail. Before ~30,000 cal BP, Andropogoneae species flourished under forest, comprising temperate pinaceous conifers, deciduous broad-leaved trees, and/or their adjacent area. In the Last Glacial Maximum (LGM), grasslands comprising Panicoideae, Chloridoideae, and Pooideae species were widely distributed under the influence of cool climate conditions and/or Aira caldera eruption. Furthermore, between ~18,000 and ~17,000 cal BP, Sasa flourished as a component of grassland or on forest floors, and then was gradually replaced by Andropogoneae species. Evergreen broad-leaved forests had developed at least by 7,300 cal BP in the study region.