Sprecher
Beschreibung
The Paleocene–Eocene Thermal Maximum (PETM; ~56 Ma) represents one of the most rapid global warming events of the Cenozoic, yet terrestrial ecosystem responses in Central Asia remain poorly constrained. Here, we present a quantitative palynological record from the Xining Basin (northeastern Tibetan Plateau), spanning the late Paleocene to early Eocene, to reconstruct vegetation and climate dynamics across the PETM. Late Paleocene assemblages are dominated by xerophytic steppe-desert taxa, indicating arid conditions within the basin, while the signal from surrounding highlands suggests the presence of relatively warmer and more humid vegetation. At the onset of the PETM, these arid-adapted taxa rapidly decline and are replaced by temperate broadleaved species, accompanied by increases in pteridophytes and other angiosperms. This shift indicates a transition to markedly warmer and more humid conditions, likely driven by intensified monsoonal precipitation. During the early Eocene, vegetation partially returns to more mixed assemblages, with some areas showing signs of renewed drying while others remain relatively humid. Our results point to a pronounced regional increase in humidity during the PETM and early Eocene, contrasting with model simulations that predict drier conditions in subtropical regions. This discrepancy highlights the importance of regional controls on hydrological responses to global warming and underscores the value of terrestrial proxy records from Central Asia for improving paleoclimate reconstructions.