Climate and vegetation in southeastern Australia respond to Southern Hemisphere insolation forcing in the late Pliocene - Early Pleistocene

Terrestrial climate responses to orbital forcing during the late Pliocene-early Pleistocene are poorly understood, particularly in the Southern Hemisphere, but are important for determination of the timing of regional climate evolution early in the history of the glaciated Quaternary world. We present a pollen record from southeastern Australia that shows marked cyclic change over some 280,000 yr straddling the Pliocene-Pleistocene boundary. Rainforest communities responded to climate forcing primarily within the precession and eccentricity bands, suggesting that major vegetation changes were driven directly by summer insolation, rather than by obliquity-dominated glacial cycles.