Vegetation, climate, and sea level in the past 55,000 years, Hanjiang Delta, Southeastern China

Abstract

<jats:title>Abstract</jats:title><jats:p>Pollen in Quaternary deposits from the subtropical Hanjiang Delta records three major phases in the local vegetation and climate history during the last 55,000 yr: (1) a prevalent cool-to-temperate and humid climate at ca. 24,000 <jats:sup>14</jats:sup>C yr B.P. is indicated by abundant pollen of temperate trees including conifers; (2) between 20,000 and 15,000 <jats:sup>14</jats:sup>C yr B.P., a cold, dry environment was associated with low sea level during the last glaciation, leading to subaerial exposure, weathering, and interruption of sedimentation, as well as departure from the region of <jats:italic>Dacrydium</jats:italic> and <jats:italic>Sonneratia;</jats:italic> (3) a short-term expansion of grassland at ca. 10,300 <jats:sup>14</jats:sup>C yr B.P. reduced the predominant Lauraceae-Fagaceae evergreen forest, possibly corresponding to the Younger Dryas cooling. The combined data indicate a maximum sea-level rise in the mid-Holocene (7500–4000 <jats:sup>14</jats:sup>C yr B.P.) and a marine influence in the late Pleistocene at 45,000–20,000 <jats:sup>14</jats:sup>C yr B.P. The Holocene warming, however, did not bring back moisture-sensitive taxa, indicating high seasonal aridity probably caused by renewed monsoon conditions.</jats:p>