CANHAM, C.D. (Institute of Ecosystem Studies, Cary Arboretum, Box AB, Millbrook, New York 12545). Suppression and release during canopy recruitment in Acer saccharum. Bull. Torrey Bot. Club. 112: 134-145. 1985.-Patterns of radial growth were used to reconstruct the history of suppression and release during canopy recruitment of Acer saccharum Marsh. in old-growth northern hardwood forests of the Adirondack Mountains of New York. In a stand that had been selectively logged 60-80 years ago, only 20 per cent of canopy trees between 20-40 cm DBH had undergone periods of suppression prior to canopy recruitment. However, in 2 unlogged stands, all of the sampled trees had undergone from 1 to 5 definable episodes of suppression prior to eventual recruitment at an average age of 110-126 years. The mean lengths of periods of suppression (22-28 years in the two unlogged stands), combined with the mean numbers of periods of suppression in each core (2.9-3.1 per tree) indicate that saplings of Acer saccharum responded to canopy openings cr'eated by the death of neighboring trees before eventually replacing an individual directly overhead. The ability to withstand suppression appears to be an essential trait for a life history that allows Acer saccharum to exploit the relatively short-lived pulses of resources created by small canopy openings.