The survey of gaps at El Verde covers about 35 ha, including the 9 ha grid. We defined a treefall gap at El Verde as a hole in the forest canopy extending down to an average height of about 3 m or less above ground. The edge of a gap was delineated by the vertical projection of the edge of the canopy foliage. We measured the dimensions of all gaps present in the 35-ha study site in August 1989, one month before Hurricane Hugo. For each gap we measured L, the longest axis of the gap (distance between edges), and W, the longest axis perpendicular to L, and then approximated gap area as that of an ellipse: Area = p LW/4 (Runkle 1992). Only openings ³ 20 m2; were counted as gaps.