Scale of mast-seeding and tree-ring growth [5]

Synchrony in growth and reproduction was detected both within and among genera of Northern Hemisphere boreal trees, across geographical areas almost the size of a continent. A significant negative correlation was found between seed production and tree-ring growth at sites up to 1,000 km apart, implying that there are trade-offs between them. This discovery suggests that mast-seeding is an evolved strategy that occurs on a geographic scale far larger than previously expected.