A deep-sea sediment core from the western Portuguese margin has provided a continuous, high-resolution record of millennial-scale climatic oscillations during the interval 9000–65,000 yr B.P. Pollen analysis of the same sequence allows direct, in situ assessment of the phase relationship between the North Atlantic climate system and vegetation changes on the adjacent landmass. This demonstrates for the first time that variability in NW Iberian tree population size closely tracked millennial-scale climate variability.
